commit 2

.github/workflows/ci.yml

@@ -40,8 +40,10 @@ jobs:
         run: zig env
       - name: Build test executables
         run: zig build all_tests -Dci --verbose
-      - name: Run host tests
-        run: zig build test_host
+      - name: Set up QEMU
+        uses: davidgm94/setup-qemu@main
+      - name: Run all tests
+        run: zig build test_all -Dci --verbose
   # build_and_test:
   #   runs-on: [self-hosted, Linux, X64]
   #   steps:

build.zig

@@ -1,31 +1,45 @@
 const std = @import("std");
-const common = @import("src/common.zig");
-const os = common.os;
+const ArrayList = std.ArrayList;
+const assert = std.debug.assert;
+const concat = std.mem.concat;
+const cwd = std.fs.cwd;
+const Cpu = Target.Cpu;
+const CrossTarget = std.zig.CrossTarget;
+const EnumArray = std.EnumArray;
+const enumValues = std.enums.values;
+const fields = std.meta.fields;
+const json = std.json;
+const maxInt = std.math.maxInt;
+const OptimizeMode = std.builtin.OptimizeMode;
+const Target = std.Target;
 
 // Build types
 const Build = std.Build;
-const CompileStep = std.Build.CompileStep;
-const FileSource = std.Build.FileSource;
-const Module = std.Build.Module;
-const ModuleDependency = std.Build.ModuleDependency;
-const OptionsStep = std.Build.OptionsStep;
-const RunStep = std.Build.RunStep;
-const Step = std.Build.Step;
+const CompileStep = Build.CompileStep;
+const LazyPath = Build.LazyPath;
+const Module = Build.Module;
+const ModuleDependency = Build.ModuleDependency;
+const OptionsStep = Build.OptionsStep;
+const RunStep = Build.RunStep;
+const Step = Build.Step;
 
-const assert = std.debug.assert;
+const builtin = @import("builtin");
+const os = builtin.os.tag;
+const cpu = builtin.cpu;
+
+const common = @import("src/common.zig");
+const ArgumentParser = common.ArgumentParser;
 const Bootloader = common.Bootloader;
+const canVirtualizeWithQEMU = common.canVirtualizeWithQEMU;
 const Configuration = common.Configuration;
-const Cpu = common.Cpu;
-const CrossTarget = common.CrossTarget;
 const DiskType = common.DiskType;
 const ExecutionType = common.ExecutionType;
 const ExecutionEnvironment = common.ExecutionEnvironment;
 const FilesystemType = common.FilesystemType;
-const OptimizeMode = common.OptimizeMode;
+const ImageConfig = common.ImageConfig;
 const QEMUOptions = common.QEMUOptions;
-const BirthProgram = common.BirthProgram;
 const Suffix = common.Suffix;
-const Target = common.Target;
+const TraditionalExecutionMode = common.TraditionalExecutionMode;
 
 const Error = error{
     not_implemented,
@@ -44,9 +58,87 @@ var modules = Modules{};
 var b: *Build = undefined;
 var build_steps: *BuildSteps = undefined;
 var default_configuration: Configuration = undefined;
-var user_modules: []const common.Module = undefined;
+var user_modules: []const UserModule = undefined;
 var options = Options{};
 
+const supported_architectures = [_]Cpu.Arch{
+    .x86_64,
+    //.aarch64,
+    //.riscv64,
+};
+
+fn architectureIndex(comptime arch: Cpu.Arch) comptime_int {
+    inline for (supported_architectures, 0..) |architecture, index| {
+        if (arch == architecture) return index;
+    }
+
+    @compileError("Architecture not found");
+}
+
+const ArchitectureBootloader = struct {
+    id: Bootloader,
+    protocols: []const Bootloader.Protocol,
+};
+
+const architecture_bootloader_map = blk: {
+    var array: [supported_architectures.len][]const ArchitectureBootloader = undefined;
+
+    array[architectureIndex(.x86_64)] = &.{
+        .{
+            .id = .birth,
+            .protocols = &.{ .bios, .uefi },
+        },
+        .{
+            .id = .limine,
+            .protocols = &.{ .bios, .uefi },
+        },
+    };
+
+    // array[architectureIndex(.aarch64)] = &.{
+    //     .{
+    //         .id = .birth,
+    //         .protocols = &.{.uefi},
+    //     },
+    //     .{
+    //         .id = .limine,
+    //         .protocols = &.{.uefi},
+    //     },
+    // };
+
+    // array[architectureIndex(.riscv64)] = &.{
+    //     .{
+    //         .id = .birth,
+    //         .protocols = &.{.uefi},
+    //     },
+    // };
+
+    break :blk array;
+};
+
+pub const UserModule = struct {
+    package: UserPackage,
+    name: []const u8,
+};
+pub const UserPackage = struct {
+    kind: Kind,
+    dependencies: []const Dependency,
+
+    pub const Kind = enum {
+        zig_exe,
+    };
+
+    pub const Dependency = struct {
+        foo: u64 = 0,
+    };
+};
+
+pub const BirthProgram = enum {
+    bootloader,
+    cpu,
+    user,
+    host,
+};
+
 pub fn build(b_arg: *Build) !void {
     b = b_arg;
     ci = b.option(bool, "ci", "CI mode") orelse false;
@@ -56,9 +148,9 @@ pub fn build(b_arg: *Build) !void {
     const default_cfg_override = b.option([]const u8, "default", "Default configuration JSON file") orelse "config/default.json";
     modules = blk: {
         var mods = Modules{};
-        inline for (comptime common.enumValues(ModuleID)) |module_id| {
+        inline for (comptime enumValues(ModuleID)) |module_id| {
             mods.modules.set(module_id, b.createModule(.{
-                .source_file = FileSource.relative(switch (module_id) {
+                .source_file = LazyPath.relative(switch (module_id) {
                     .limine_installer => "src/bootloader/limine/installer.zig",
                     else => switch (module_id) {
                         .bios, .uefi, .limine => "src/bootloader",
@@ -93,12 +185,12 @@ pub fn build(b_arg: *Build) !void {
     };
 
     default_configuration = blk: {
-        const default_json_file = try std.fs.cwd().readFileAlloc(b.allocator, default_cfg_override, common.maxInt(usize));
-        const parsed_cfg = try std.json.parseFromSlice(Configuration, b.allocator, default_json_file, .{});
+        const default_json_file = try cwd().readFileAlloc(b.allocator, default_cfg_override, maxInt(usize));
+        const parsed_cfg = try json.parseFromSlice(Configuration, b.allocator, default_json_file, .{});
         const cfg = parsed_cfg.value;
 
         const optimize_mode = b.option(
-            std.builtin.Mode,
+            OptimizeMode,
             "optimize",
             "Prioritize performance, safety, or binary size (-O flag)",
         ) orelse cfg.optimize_mode;
@@ -162,13 +254,13 @@ pub fn build(b_arg: *Build) !void {
         run_native: bool = true,
 
         const C = struct {
-            include_paths: []const []const u8,
+            include_paths: []const LazyPath,
             source_files: []const SourceFile,
             link_libc: bool,
             link_libcpp: bool,
 
             const SourceFile = struct {
-                path: []const u8,
+                path: LazyPath,
                 flags: []const []const u8,
             };
         };
@@ -183,10 +275,10 @@ pub fn build(b_arg: *Build) !void {
             .root_project_path = disk_image_root_path,
             .modules = disk_image_builder_modules,
             .c = .{
-                .include_paths = &.{"src/bootloader/limine/installables"},
+                .include_paths = &.{LazyPath.relative("src/bootloader/limine/installables")},
                 .source_files = &.{
                     .{
-                        .path = "src/bootloader/limine/installables/limine-deploy.c",
+                        .path = LazyPath.relative("src/bootloader/limine/installables/limine-deploy.c"),
                         .flags = &.{},
                     },
                 },
@@ -200,7 +292,7 @@ pub fn build(b_arg: *Build) !void {
 
     const native_test_optimize_mode = .ReleaseFast;
     for (native_tests) |native_test| {
-        const test_name = try std.mem.concat(b.allocator, u8, &.{ native_test.name, "_", @tagName(native_test_optimize_mode) });
+        const test_name = try concat(b.allocator, u8, &.{ native_test.name, "_", @tagName(native_test_optimize_mode) });
         const test_exe = try addCompileStep(.{
             .name = test_name,
             .root_project_path = native_test.root_project_path,
@@ -215,7 +307,7 @@ pub fn build(b_arg: *Build) !void {
             }
 
             for (c.source_files) |source_file| {
-                test_exe.addCSourceFile(source_file.path, source_file.flags);
+                test_exe.addCSourceFile(.{ .file = source_file.path, .flags = source_file.flags });
             }
 
             if (c.link_libc) {
@@ -247,20 +339,20 @@ pub fn build(b_arg: *Build) !void {
     const ovmf_path = ovmf_downloader_run_step.addOutputFileArg("OVMF.fd");
 
     {
-        var user_module_list = std.ArrayList(common.Module).init(b.allocator);
-        var user_program_dir = try std.fs.cwd().openIterableDir(user_program_dir_path, .{ .access_sub_paths = true });
+        var user_module_list = ArrayList(UserModule).init(b.allocator);
+        var user_program_dir = try cwd().openIterableDir(user_program_dir_path, .{ .access_sub_paths = true });
         defer user_program_dir.close();
 
         var user_program_iterator = user_program_dir.iterate();
 
         while (try user_program_iterator.next()) |entry| {
             const dir_name = entry.name;
-            const file_path = try std.mem.concat(b.allocator, u8, &.{ dir_name, "/module.json" });
-            const file = try user_program_dir.dir.readFileAlloc(b.allocator, file_path, common.maxInt(usize));
-            const parsed_user_program = try std.json.parseFromSlice(common.UserProgram, b.allocator, file, .{});
-            const user_program = parsed_user_program.value;
+            const file_path = try concat(b.allocator, u8, &.{ dir_name, "/module.json" });
+            const file = try user_program_dir.dir.readFileAlloc(b.allocator, file_path, maxInt(usize));
+            const parsed_user_package = try json.parseFromSlice(UserPackage, b.allocator, file, .{});
+            const user_package = parsed_user_package.value;
             try user_module_list.append(.{
-                .program = user_program,
+                .package = user_package,
                 .name = b.dupe(dir_name), // we have to dupe here otherwise Windows CI fails
             });
         }
@@ -270,8 +362,8 @@ pub fn build(b_arg: *Build) !void {
 
     const executable_kinds = [2]CompileStep.Kind{ .exe, .@"test" };
 
-    for (common.enumValues(OptimizeMode)) |optimize_mode| {
-        for (common.supported_architectures, 0..) |architecture, architecture_index| {
+    for (enumValues(OptimizeMode)) |optimize_mode| {
+        for (supported_architectures, 0..) |architecture, architecture_index| {
             const user_target = try getTarget(architecture, .user);
 
             for (executable_kinds) |executable_kind| {
@@ -301,7 +393,7 @@ pub fn build(b_arg: *Build) !void {
                     else => return Error.architecture_not_supported,
                 };
 
-                const cpu_driver_linker_script_path = FileSource.relative(try std.mem.concat(b.allocator, u8, &.{ cpu_driver_path, "/arch/", switch (architecture) {
+                const cpu_driver_linker_script_path = LazyPath.relative(try concat(b.allocator, u8, &.{ cpu_driver_path, "/arch/", switch (architecture) {
                     .x86_64 => "x86/64",
                     .x86 => "x86/32",
                     else => @tagName(architecture),
@@ -309,14 +401,14 @@ pub fn build(b_arg: *Build) !void {
 
                 cpu_driver.setLinkerScriptPath(cpu_driver_linker_script_path);
 
-                var user_module_list = try std.ArrayList(*CompileStep).initCapacity(b.allocator, user_modules.len);
-                const user_architecture_source_path = try std.mem.concat(b.allocator, u8, &.{ "src/user/arch/", @tagName(architecture), "/" });
-                const user_linker_script_path = FileSource.relative(try std.mem.concat(b.allocator, u8, &.{ user_architecture_source_path, "linker_script.ld" }));
+                var user_module_list = try ArrayList(*CompileStep).initCapacity(b.allocator, user_modules.len);
+                const user_architecture_source_path = try concat(b.allocator, u8, &.{ "src/user/arch/", @tagName(architecture), "/" });
+                const user_linker_script_path = LazyPath.relative(try concat(b.allocator, u8, &.{ user_architecture_source_path, "linker_script.ld" }));
                 for (user_modules) |module| {
                     const user_module = try addCompileStep(.{
                         .kind = executable_kind,
                         .name = module.name,
-                        .root_project_path = try std.mem.concat(b.allocator, u8, &.{ user_program_dir_path, "/", module.name }),
+                        .root_project_path = try concat(b.allocator, u8, &.{ user_program_dir_path, "/", module.name }),
                         .target = user_target,
                         .optimize_mode = optimize_mode,
                         .modules = &.{ .lib, .user, .birth },
@@ -328,7 +420,7 @@ pub fn build(b_arg: *Build) !void {
                     user_module_list.appendAssumeCapacity(user_module);
                 }
 
-                const bootloaders = common.architecture_bootloader_map[architecture_index];
+                const bootloaders = architecture_bootloader_map[architecture_index];
                 for (bootloaders) |bootloader_struct| {
                     const bootloader = bootloader_struct.id;
                     for (bootloader_struct.protocols) |boot_protocol| {
@@ -353,9 +445,9 @@ pub fn build(b_arg: *Build) !void {
 
                                         executable.strip = true;
 
-                                        executable.addAssemblyFile("src/bootloader/arch/x86/64/smp_trampoline.S");
-                                        executable.addAssemblyFile(bootloader_path ++ "/unreal_mode.S");
-                                        executable.setLinkerScriptPath(FileSource.relative(bootloader_path ++ "/linker_script.ld"));
+                                        executable.addAssemblyFile(LazyPath.relative("src/bootloader/arch/x86/64/smp_trampoline.S"));
+                                        executable.addAssemblyFile(LazyPath.relative(bootloader_path ++ "/unreal_mode.S"));
+                                        executable.setLinkerScriptPath(LazyPath.relative(bootloader_path ++ "/linker_script.ld"));
                                         executable.code_model = .small;
 
                                         break :blk executable;
@@ -380,7 +472,7 @@ pub fn build(b_arg: *Build) !void {
                                     executable.strip = true;
 
                                     switch (architecture) {
-                                        .x86_64 => executable.addAssemblyFile("src/bootloader/arch/x86/64/smp_trampoline.S"),
+                                        .x86_64 => executable.addAssemblyFile(LazyPath.relative("src/bootloader/arch/x86/64/smp_trampoline.S")),
                                         else => {},
                                     }
 
@@ -405,7 +497,7 @@ pub fn build(b_arg: *Build) !void {
 
                                 executable.code_model = cpu_driver.code_model;
 
-                                executable.setLinkerScriptPath(FileSource.relative(try common.concat(b.allocator, u8, &.{ limine_loader_path ++ "arch/", @tagName(architecture), "/linker_script.ld" })));
+                                executable.setLinkerScriptPath(LazyPath.relative(try concat(b.allocator, u8, &.{ limine_loader_path ++ "arch/", @tagName(architecture), "/linker_script.ld" })));
 
                                 break :blk executable;
                             },
@@ -431,7 +523,7 @@ pub fn build(b_arg: *Build) !void {
                         };
 
                         const execution_types: []const ExecutionType =
-                            switch (common.canVirtualizeWithQEMU(architecture, ci)) {
+                            switch (canVirtualizeWithQEMU(architecture, ci)) {
                             true => &.{ .emulated, .accelerated },
                             false => &.{.emulated},
                         };
@@ -448,13 +540,13 @@ pub fn build(b_arg: *Build) !void {
                                     .executable_kind = executable_kind,
                                 };
 
-                                var disk_argument_parser = common.ArgumentParser.DiskImageBuilder{};
+                                var disk_argument_parser = ArgumentParser.DiskImageBuilder{};
                                 const disk_image_builder_run = b.addRunArtifact(disk_image_builder);
                                 const disk_image_path = disk_image_builder_run.addOutputFileArg("disk.hdd");
 
                                 while (disk_argument_parser.next()) |argument_type| switch (argument_type) {
-                                    .configuration => inline for (common.fields(Configuration)) |field| disk_image_builder_run.addArg(@tagName(@field(configuration, field.name))),
-                                    .image_configuration_path => disk_image_builder_run.addArg(common.ImageConfig.default_path),
+                                    .configuration => inline for (fields(Configuration)) |field| disk_image_builder_run.addArg(@tagName(@field(configuration, field.name))),
+                                    .image_configuration_path => disk_image_builder_run.addArg(ImageConfig.default_path),
                                     .disk_image_path => {
                                         // Must be first
                                         assert(@intFromEnum(argument_type) == 0);
@@ -540,7 +632,7 @@ pub fn build(b_arg: *Build) !void {
 }
 
 const Options = struct {
-    arr: std.EnumArray(BirthProgram, *OptionsStep) = std.EnumArray(BirthProgram, *OptionsStep).initUndefined(),
+    arr: EnumArray(BirthProgram, *OptionsStep) = EnumArray(BirthProgram, *OptionsStep).initUndefined(),
 
     pub fn createOption(options_struct: *Options, birth_program: BirthProgram) void {
         const new_options = b.addOptions();
@@ -591,31 +683,31 @@ fn addFileSize(artifact: *CompileStep, comptime name: []const u8) void {
 
 fn newRunnerRunArtifact(arguments: struct {
     configuration: Configuration,
-    disk_image_path: FileSource,
+    disk_image_path: LazyPath,
     loader: *CompileStep,
     runner: *CompileStep,
     cpu_driver: *CompileStep,
     user_init: *CompileStep,
     qemu_options: QEMUOptions,
-    ovmf_path: FileSource,
+    ovmf_path: LazyPath,
     is_default: bool,
 }) !*RunStep {
     const runner = b.addRunArtifact(arguments.runner);
 
-    var argument_parser = common.ArgumentParser.Runner{};
+    var argument_parser = ArgumentParser.Runner{};
 
     while (argument_parser.next()) |argument_type| switch (argument_type) {
-        .configuration => inline for (common.fields(Configuration)) |field| runner.addArg(@tagName(@field(arguments.configuration, field.name))),
-        .image_configuration_path => runner.addArg(common.ImageConfig.default_path),
+        .configuration => inline for (fields(Configuration)) |field| runner.addArg(@tagName(@field(arguments.configuration, field.name))),
+        .image_configuration_path => runner.addArg(ImageConfig.default_path),
         .cpu_driver => runner.addArtifactArg(arguments.cpu_driver),
         .loader_path => runner.addArtifactArg(arguments.loader),
         .init => runner.addArtifactArg(arguments.user_init),
-        .disk_image_path => runner.addFileSourceArg(arguments.disk_image_path),
-        .qemu_options => inline for (common.fields(QEMUOptions)) |field| runner.addArg(if (@field(arguments.qemu_options, field.name)) "true" else "false"),
+        .disk_image_path => runner.addFileArg(arguments.disk_image_path),
+        .qemu_options => inline for (fields(QEMUOptions)) |field| runner.addArg(if (@field(arguments.qemu_options, field.name)) "true" else "false"),
         .ci => runner.addArg(if (ci) "true" else "false"),
         .debug_user => runner.addArg(if (debug_user) "true" else "false"),
         .debug_loader => runner.addArg(if (debug_loader) "true" else "false"),
-        .ovmf_path => runner.addFileSourceArg(arguments.ovmf_path),
+        .ovmf_path => runner.addFileArg(arguments.ovmf_path),
         .is_default => runner.addArg(if (arguments.is_default) "true" else "false"),
     };
 
@@ -631,15 +723,17 @@ const ExecutableDescriptor = struct {
     modules: []const ModuleID,
 };
 
+const main_package_path = LazyPath.relative(source_root_dir);
 fn addCompileStep(executable_descriptor: ExecutableDescriptor) !*CompileStep {
-    const main_file = try std.mem.concat(b.allocator, u8, &.{ executable_descriptor.root_project_path, "/main.zig" });
+    const main_file = try concat(b.allocator, u8, &.{ executable_descriptor.root_project_path, "/main.zig" });
     const compile_step = switch (executable_descriptor.kind) {
         .exe => blk: {
             const executable = b.addExecutable(.{
                 .name = executable_descriptor.name,
-                .root_source_file = FileSource.relative(main_file),
+                .root_source_file = LazyPath.relative(main_file),
                 .target = executable_descriptor.target,
                 .optimize = executable_descriptor.optimize_mode,
+                .main_pkg_path = main_package_path,
             });
 
             build_steps.build_all.dependOn(&executable.step);
@@ -647,13 +741,14 @@ fn addCompileStep(executable_descriptor: ExecutableDescriptor) !*CompileStep {
             break :blk executable;
         },
         .@"test" => blk: {
-            const test_file = FileSource.relative(try std.mem.concat(b.allocator, u8, &.{ executable_descriptor.root_project_path, "/test.zig" }));
+            const test_file = LazyPath.relative(try concat(b.allocator, u8, &.{ executable_descriptor.root_project_path, "/test.zig" }));
             const test_exe = b.addTest(.{
                 .name = executable_descriptor.name,
                 .root_source_file = test_file,
                 .target = executable_descriptor.target,
                 .optimize = executable_descriptor.optimize_mode,
                 .test_runner = if (executable_descriptor.target.os_tag) |_| main_file else null,
+                .main_pkg_path = main_package_path,
             });
 
             build_steps.build_all_tests.dependOn(&test_exe.step);
@@ -669,8 +764,6 @@ fn addCompileStep(executable_descriptor: ExecutableDescriptor) !*CompileStep {
         compile_step.entry_symbol_name = "_start";
     }
 
-    compile_step.setMainPkgPath(source_root_dir);
-
     for (executable_descriptor.modules) |module| {
         modules.addModule(compile_step, module);
     }
@@ -700,8 +793,8 @@ const ModuleID = enum {
 };
 
 pub const Modules = struct {
-    modules: std.EnumArray(ModuleID, *Module) = std.EnumArray(ModuleID, *Module).initUndefined(),
-    dependencies: std.EnumArray(ModuleID, []const ModuleDependency) = std.EnumArray(ModuleID, []const ModuleDependency).initUndefined(),
+    modules: EnumArray(ModuleID, *Module) = EnumArray(ModuleID, *Module).initUndefined(),
+    dependencies: EnumArray(ModuleID, []const ModuleDependency) = EnumArray(ModuleID, []const ModuleDependency).initUndefined(),
 
     fn addModule(mods: Modules, compile_step: *CompileStep, module_id: ModuleID) void {
         compile_step.addModule(@tagName(module_id), mods.modules.get(module_id));
@@ -718,7 +811,7 @@ pub const Modules = struct {
     }
 };
 
-fn getTarget(asked_arch: Cpu.Arch, execution_mode: common.TraditionalExecutionMode) Error!CrossTarget {
+fn getTarget(asked_arch: Cpu.Arch, execution_mode: TraditionalExecutionMode) Error!CrossTarget {
     var enabled_features = Cpu.Feature.Set.empty;
     var disabled_features = Cpu.Feature.Set.empty;
 
@@ -743,14 +836,14 @@ fn getTarget(asked_arch: Cpu.Arch, execution_mode: common.TraditionalExecutionMo
 
     return CrossTarget{
         .cpu_arch = asked_arch,
-        .cpu_model = switch (common.cpu.arch) {
+        .cpu_model = switch (cpu.arch) {
             .x86 => .determined_by_cpu_arch,
             .x86_64 => if (execution_mode == .privileged) .determined_by_cpu_arch else
             // zig fmt off
             .determined_by_cpu_arch,
             // .determined_by_cpu_arch,
             // TODO: this causes some problems: https://github.com/ziglang/zig/issues/15524
-            //.{ .explicit = &common.Target.x86.cpu.x86_64_v3 },
+            //.{ .explicit = &Target.x86.cpu.x86_64_v3 },
             else => .determined_by_cpu_arch,
         },
         .os_tag = .freestanding,

config/default.json

@@ -1,6 +1,6 @@
 {
     "architecture": "x86_64",
-    "bootloader": "limine",
+    "bootloader": "birth",
     "boot_protocol": "uefi",
     "execution_environment": "qemu",
     "optimize_mode": "Debug",

src/birth.zig

@@ -1,23 +1,111 @@
 const lib = @import("lib");
+const Allocator = lib.Allocator;
+const assert = lib.assert;
 
 pub const arch = @import("birth/arch.zig");
-pub const capabilities = @import("birth/capabilities.zig");
-pub const syscall = @import("birth/syscall.zig");
+pub const interface = @import("birth/interface.zig");
 
 /// This struct is the shared part that the user and the cpu see
-pub const UserScheduler = extern struct {
-    self: *UserScheduler,
+pub const Scheduler = extern struct {
+    common: Common,
+    current_thread: *Thread,
+    thread_queue: ?*Thread = null,
+    time_slice: u32,
+    core_id: u32,
+    core_state: CoreState,
+    bootstrap_thread: Thread,
+    fast_allocator: Allocator,
+
+    pub fn initializeAllocator(scheduler: *Scheduler) void {
+        scheduler.fast_allocator = Allocator{
+            .callbacks = .{
+                .allocate = callbackAllocate,
+            },
+        };
+    }
+
+    fn callbackAllocate(allocator: *Allocator, size: u64, alignment: u64) Allocator.Allocate.Error!Allocator.Allocate.Result {
+        const scheduler = @fieldParentPtr(Scheduler, "fast_allocator", allocator);
+        assert(scheduler.common.heap.address.isAligned(alignment));
+        const result = scheduler.common.heap.takeSlice(size) catch return error.OutOfMemory;
+        return @bitCast(result);
+    }
+
+    pub const Common = extern struct {
+        self: *Common,
         disabled: bool,
         has_work: bool,
         core_id: u32,
-    setup_stack: [lib.arch.valid_page_sizes[0]]u8 align(lib.arch.stack_alignment),
+        heap: lib.VirtualMemoryRegion,
+        setup_stack: [lib.arch.valid_page_sizes[0] * 4]u8 align(lib.arch.stack_alignment),
         setup_stack_lock: lib.Atomic(bool),
+        disabled_save_area: arch.RegisterArena,
 
-    pub inline fn architectureSpecific(user_scheduler: *UserScheduler) *arch.UserScheduler {
-        return @fieldParentPtr(arch.UserScheduler, "generic", user_scheduler);
+        // pub fn heapAllocateFast(common: *Common, comptime T: type) !*T {
+        //     const size = @sizeOf(T);
+        //     const alignment = @alignOf(T);
+        //     lib.log.debug("Heap: {}. Size: {}. Alignment: {}", .{ common.heap, size, alignment });
+        //     const result = try common.heap.takeSlice(size);
+        //     const ptr = &result.access(T)[0];
+        //     assert(lib.isAligned(@intFromPtr(ptr), alignment));
+        //
+        //     return ptr;
+        // }
+    };
+
+    pub fn enqueueThread(scheduler: *Scheduler, thread_to_queue: *Thread) void {
+        // TODO: check queue
+        // TODO: defer check queue
+        if (scheduler.thread_queue) |thread_queue| {
+            _ = thread_queue;
+            @panic("TODO: enqueueThread");
+        } else {
+            scheduler.thread_queue = thread_to_queue;
+            thread_to_queue.previous = thread_to_queue;
+            thread_to_queue.next = thread_to_queue;
+        }
+    }
+
+    pub noinline fn restore(scheduler: *Scheduler, register_arena: *const arch.RegisterArena) noreturn {
+        assert(scheduler.common.generic.disabled);
+        assert(scheduler.common.generic.has_work);
+
+        assert(register_arena.registers.rip > lib.arch.valid_page_sizes[0]);
+        assert(register_arena.registers.rflags.IF and register_arena.registers.rflags.reserved0);
+
+        register_arena.contextSwitch();
     }
 };
 
-pub const CommandBuffer = struct {
-    foo: u32,
+pub const Thread = extern struct {
+    self: *Thread,
+    previous: ?*Thread = null,
+    next: ?*Thread = null,
+    stack: [*]u8,
+    stack_top: [*]align(lib.arch.stack_alignment) u8,
+    register_arena: arch.RegisterArena align(arch.RegisterArena.alignment),
+    core_id: u32,
+
+    pub fn init(thread: *Thread, scheduler: *Scheduler) void {
+        thread.* = Thread{
+            .self = thread,
+            .core_id = scheduler.generic.core_id,
+            .stack = thread.stack,
+            .stack_top = thread.stack_top,
+            .register_arena = thread.register_arena,
+        };
+    }
+};
+
+pub const CoreState = extern struct {
+    virtual_address_space: *VirtualAddressSpace,
+};
+pub const VirtualAddressSpace = extern struct {
+    // TODO: physical map
+    // TODO: layout
+    regions: ?*VirtualMemoryRegion = null,
+};
+
+pub const VirtualMemoryRegion = extern struct {
+    next: ?*VirtualMemoryRegion = null,
 };

src/birth/arch/x64_64.zig

@@ -2,18 +2,14 @@ const lib = @import("lib");
 const assert = lib.assert;
 const birth = @import("birth");
 
-pub const UserScheduler = extern struct {
-    generic: birth.UserScheduler,
-    disabled_save_area: RegisterArena,
-};
-
 pub const RegisterArena = extern struct {
     fpu: FPU align(lib.arch.stack_alignment),
     registers: birth.arch.Registers,
 
+    pub const alignment = lib.arch.stack_alignment;
+
     pub fn contextSwitch(register_arena: *align(lib.arch.stack_alignment) const RegisterArena) noreturn {
         assert(lib.isAligned(@intFromPtr(register_arena), lib.arch.stack_alignment));
-        //lib.log.debug("ASDASD: {}", .{register_arena});
         register_arena.fpu.load();
         register_arena.registers.restore();
     }
@@ -129,9 +125,9 @@ pub const FPU = extern struct {
 pub const user_code_selector = 0x43;
 pub const user_data_selector = 0x3b;
 
-pub inline fn syscall(options: birth.syscall.Options, arguments: birth.syscall.Arguments) birth.syscall.Result {
-    var first: birth.syscall.Result.Birth.First = undefined;
-    var second: birth.syscall.Result.Birth.Second = undefined;
+pub inline fn syscall(options: birth.interface.Raw.Options, arguments: birth.interface.Raw.Arguments) birth.interface.Raw.Result {
+    var first: birth.interface.Raw.Result.Birth.First = undefined;
+    var second: birth.interface.Raw.Result.Birth.Second = undefined;
     asm volatile (
         \\syscall
         : [rax] "={rax}" (first),
@@ -153,3 +149,28 @@ pub inline fn syscall(options: birth.syscall.Options, arguments: birth.syscall.A
         },
     };
 }
+
+pub const PageTable = extern struct {
+    /// The frame that holds the memory of this page table
+    frame: birth.interface.RAM,
+    flags: packed struct(u8) {
+        level: Level4, // TODO: move to other
+        granularity: Granularity,
+        reserved: u4 = 0,
+    },
+
+    pub const Granularity = enum(u2) {
+        @"4_kb",
+        @"2_mb",
+        @"1_gb",
+    };
+
+    pub const Level4 = enum(u2) {
+        PML4 = 0,
+        PDP = 1,
+        PD = 2,
+        PT = 3,
+
+        pub const count = lib.enumCount(@This());
+    };
+};

src/birth/capabilities.zig

@@ -1,381 +0,0 @@
-const lib = @import("lib");
-const assert = lib.assert;
-const PhysicalAddress = lib.PhysicalAddress;
-
-const birth = @import("birth");
-const syscall = birth.syscall;
-
-const Capabilities = @This();
-
-pub const Type = enum(u8) {
-    io, // primitive
-    cpu, // primitive
-    ram, // primitive
-    cpu_memory, // non-primitive Barrelfish: frame
-    boot,
-    process, // Temporarily available
-    page_table, // Barrelfish: vnode
-    // TODO: device_memory, // primitive
-    // scheduler,
-    // irq_table,
-
-    // _,
-
-    pub const Type = u8;
-
-    pub const Mappable = enum {
-        cpu_memory,
-        page_table,
-
-        pub inline fn toCapability(mappable: Mappable) Capabilities.Type {
-            return switch (mappable) {
-                inline else => |mappable_cap| @field(Capabilities.Type, @tagName(mappable_cap)),
-            };
-        }
-    };
-};
-
-pub const Subtype = u16;
-pub const AllTypes = Type;
-
-pub fn CommandBuilder(comptime list: []const []const u8) type {
-    const capability_base_command_list = .{
-        "copy",
-        "mint",
-        "retype",
-        "delete",
-        "revoke",
-        "create",
-    } ++ list;
-    const enum_fields = lib.enumAddNames(&.{}, capability_base_command_list);
-
-    // TODO: make this non-exhaustive enums
-    // PROBLEM: https://github.com/ziglang/zig/issues/12250
-    // Currently waiting on this since this will enable some comptime magic
-    const result = @Type(.{
-        .Enum = .{
-            .tag_type = Subtype,
-            .fields = enum_fields,
-            .decls = &.{},
-            .is_exhaustive = true,
-        },
-    });
-    return result;
-}
-
-/// Takes some names and integers. Then values are added to the Command enum for an specific capability
-/// The number is an offset of the fields with respect to the base command enum fields
-pub fn Command(comptime capability: Type) type {
-    const extra_command_list = switch (capability) {
-        .io => .{
-            "log",
-        },
-        .cpu => .{
-            "get_core_id",
-            "shutdown",
-            "get_command_buffer",
-        },
-        .ram => [_][]const u8{},
-        .cpu_memory => .{
-            "allocate",
-        },
-        .boot => .{
-            "get_bundle_size",
-            "get_bundle_file_list_size",
-        },
-        .process => .{
-            "exit",
-        },
-        .page_table => [_][]const u8{},
-    };
-
-    return CommandBuilder(&extra_command_list);
-}
-
-const success = 0;
-const first_valid_error = success + 1;
-
-pub fn ErrorSet(comptime error_names: []const []const u8) type {
-    return lib.ErrorSet(error_names, &.{
-        .{
-            .name = "forbidden",
-            .value = first_valid_error + 0,
-        },
-        .{
-            .name = "corrupted_input",
-            .value = first_valid_error + 1,
-        },
-        .{
-            .name = "invalid_input",
-            .value = first_valid_error + 2,
-        },
-    });
-}
-
-const raw_argument_count = @typeInfo(syscall.Arguments).Array.len;
-
-pub fn Syscall(comptime capability_type: Type, comptime command_type: Command(capability_type)) type {
-    const Types = switch (capability_type) {
-        .io => switch (command_type) {
-            .copy, .mint, .retype, .delete, .revoke, .create => struct {
-                pub const ErrorSet = Capabilities.ErrorSet(&.{});
-                pub const Result = void;
-                pub const Arguments = void;
-            },
-            .log => struct {
-                pub const ErrorSet = Capabilities.ErrorSet(&.{});
-                pub const Result = usize;
-                pub const Arguments = []const u8;
-
-                inline fn toResult(raw_result: syscall.Result.Birth) Result {
-                    return raw_result.second;
-                }
-
-                inline fn resultToRaw(result: Result) syscall.Result {
-                    return syscall.Result{
-                        .birth = .{
-                            .first = .{},
-                            .second = result,
-                        },
-                    };
-                }
-
-                inline fn argumentsToRaw(arguments: Arguments) syscall.Arguments {
-                    const result = [2]usize{ @intFromPtr(arguments.ptr), arguments.len };
-                    return result ++ .{0} ** (raw_argument_count - result.len);
-                }
-
-                inline fn toArguments(raw_arguments: syscall.Arguments) !Arguments {
-                    const message_ptr = @as(?[*]const u8, @ptrFromInt(raw_arguments[0])) orelse return error.invalid_input;
-                    const message_len = raw_arguments[1];
-                    if (message_len == 0) return error.invalid_input;
-                    const message = message_ptr[0..message_len];
-                    return message;
-                }
-            },
-        },
-        .cpu => switch (command_type) {
-            .copy, .mint, .retype, .delete, .revoke, .create => struct {
-                pub const ErrorSet = Capabilities.ErrorSet(&.{});
-                pub const Result = void;
-                pub const Arguments = void;
-            },
-            .get_core_id => struct {
-                pub const ErrorSet = Capabilities.ErrorSet(&.{});
-                pub const Result = u32;
-                pub const Arguments = void;
-
-                inline fn toResult(raw_result: syscall.Result.birth) Result {
-                    return @as(Result, @intCast(raw_result.second));
-                }
-
-                inline fn resultToRaw(result: Result) syscall.Result {
-                    return syscall.Result{
-                        .birth = .{
-                            .first = .{},
-                            .second = result,
-                        },
-                    };
-                }
-            },
-            .shutdown => struct {
-                pub const ErrorSet = Capabilities.ErrorSet(&.{});
-                pub const Result = noreturn;
-                pub const Arguments = void;
-
-                pub const toResult = @compileError("noreturn unexpectedly returned");
-            },
-            .get_command_buffer => struct {
-                pub const ErrorSet = Capabilities.ErrorSet(&.{});
-                pub const Result = noreturn;
-                pub const Arguments = *birth.CommandBuffer;
-
-                pub const toResult = @compileError("noreturn unexpectedly returned");
-
-                inline fn toArguments(raw_arguments: syscall.Arguments) !Arguments {
-                    const ptr = @as(?*birth.CommandBuffer, @ptrFromInt(raw_arguments[0])) orelse return error.invalid_input;
-                    return ptr;
-                }
-
-                inline fn argumentsToRaw(arguments: Arguments) syscall.Arguments {
-                    const result = [1]usize{@intFromPtr(arguments)};
-                    return result ++ .{0} ** (raw_argument_count - result.len);
-                }
-            },
-        },
-        .ram => struct {
-            pub const ErrorSet = Capabilities.ErrorSet(&.{});
-            pub const Result = void;
-            pub const Arguments = void;
-        },
-        .cpu_memory => struct {
-            pub const ErrorSet = Capabilities.ErrorSet(&.{
-                "OutOfMemory",
-            });
-            pub const Result = PhysicalAddress;
-            pub const Arguments = usize;
-
-            inline fn toResult(raw_result: syscall.Result.birth) Result {
-                return PhysicalAddress.new(raw_result.second);
-            }
-
-            inline fn resultToRaw(result: Result) syscall.Result {
-                return syscall.Result{
-                    .birth = .{
-                        .first = .{},
-                        .second = result.value(),
-                    },
-                };
-            }
-
-            inline fn toArguments(raw_arguments: syscall.Arguments) !Arguments {
-                const size = raw_arguments[0];
-                return size;
-            }
-
-            inline fn argumentsToRaw(arguments: Arguments) syscall.Arguments {
-                const result = [1]usize{arguments};
-                return result ++ .{0} ** (raw_argument_count - result.len);
-            }
-        },
-        .boot => switch (command_type) {
-            .get_bundle_file_list_size, .get_bundle_size => struct {
-                pub const ErrorSet = Capabilities.ErrorSet(&.{
-                    "buffer_too_small",
-                });
-                pub const Result = usize;
-                pub const Arguments = void;
-
-                inline fn resultToRaw(result: Result) syscall.Result {
-                    return syscall.Result{
-                        .birth = .{
-                            .first = .{},
-                            .second = result,
-                        },
-                    };
-                }
-
-                inline fn toResult(raw_result: syscall.Result.birth) Result {
-                    return raw_result.second;
-                }
-            },
-            else => struct {
-                pub const ErrorSet = Capabilities.ErrorSet(&.{
-                    "buffer_too_small",
-                });
-                pub const Result = void;
-                pub const Arguments = void;
-            },
-        },
-        .process => switch (command_type) {
-            .exit => struct {
-                pub const ErrorSet = Capabilities.ErrorSet(&.{});
-                pub const Result = noreturn;
-                pub const Arguments = bool;
-
-                inline fn toArguments(raw_arguments: syscall.Arguments) !Arguments {
-                    const result = raw_arguments[0] != 0;
-                    return result;
-                }
-                inline fn argumentsToRaw(arguments: Arguments) syscall.Arguments {
-                    const result = [1]usize{@intFromBool(arguments)};
-                    return result ++ .{0} ** (raw_argument_count - result.len);
-                }
-            },
-            else => struct {
-                pub const ErrorSet = Capabilities.ErrorSet(&.{});
-                pub const Result = void;
-                pub const Arguments = void;
-            },
-        },
-        .page_table => switch (command_type) {
-            else => struct {
-                pub const ErrorSet = Capabilities.ErrorSet(&.{});
-                pub const Result = void;
-                pub const Arguments = void;
-            },
-        },
-        // else => @compileError("TODO: " ++ @tagName(capability)),
-    };
-
-    return struct {
-        pub const ErrorSet = Types.ErrorSet;
-        pub const Result = Types.Result;
-        pub const Arguments = Types.Arguments;
-        pub const toResult = Types.toResult;
-        pub const toArguments = if (Arguments != void)
-            Types.toArguments
-        else
-            struct {
-                fn lambda(raw_arguments: syscall.Arguments) error{}!void {
-                    _ = raw_arguments;
-                    return {};
-                }
-            }.lambda;
-        pub const capability = capability_type;
-        pub const command = command_type;
-
-        pub inline fn resultToRaw(result: Result) syscall.Result {
-            return if (@hasDecl(Types, "resultToRaw")) blk: {
-                comptime assert(Result != void and Result != noreturn);
-                break :blk Types.resultToRaw(result);
-            } else blk: {
-                if (Result != void) {
-                    @compileError("expected void type, got " ++ @typeName(Result) ++ ". You forgot to implement a resultToRaw function" ++ " for (" ++ @tagName(capability) ++ ", " ++ @tagName(command) ++ ").");
-                }
-
-                break :blk syscall.Result{
-                    .birth = .{
-                        .first = .{},
-                        .second = 0,
-                    },
-                };
-            };
-        }
-
-        pub inline fn errorToRaw(err: @This().ErrorSet.Error) syscall.Result {
-            const error_enum = switch (err) {
-                inline else => |comptime_error| @field(@This().ErrorSet.Enum, @errorName(comptime_error)),
-            };
-            return syscall.Result{
-                .birth = .{
-                    .first = .{
-                        .@"error" = @intFromEnum(error_enum),
-                    },
-                    .second = 0,
-                },
-            };
-        }
-
-        /// This is not meant to be called in the CPU driver
-        pub fn blocking(arguments: Arguments) @This().ErrorSet.Error!Result {
-            const raw_arguments = if (Arguments != void) Types.argumentsToRaw(arguments) else [1]usize{0} ** raw_argument_count;
-            // TODO: make this more reliable and robust?
-            const options = birth.syscall.Options{
-                .birth = .{
-                    .type = capability,
-                    .command = @intFromEnum(command),
-                },
-            };
-
-            const raw_result = birth.arch.syscall(options, raw_arguments);
-
-            const raw_error_value = raw_result.birth.first.@"error";
-            comptime {
-                assert(!@hasField(@This().ErrorSet.Enum, "ok"));
-                assert(!@hasField(@This().ErrorSet.Enum, "success"));
-                assert(lib.enumFields(@This().ErrorSet.Enum)[0].value == first_valid_error);
-            }
-
-            return switch (raw_error_value) {
-                success => switch (Result) {
-                    noreturn => unreachable,
-                    else => toResult(raw_result.birth),
-                },
-                else => switch (@as(@This().ErrorSet.Enum, @enumFromInt(raw_error_value))) {
-                    inline else => |comptime_error_enum| @field(@This().ErrorSet.Error, @tagName(comptime_error_enum)),
-                },
-            };
-        }
-    };
-}

src/birth/syscall.zig

@@ -1,117 +0,0 @@
-const lib = @import("lib");
-const assert = lib.assert;
-const log = lib.log.scoped(.Syscall);
-
-const birth = @import("birth");
-const capabilities = birth.capabilities;
-
-pub const argument_count = 6;
-pub const Arguments = [argument_count]usize;
-
-pub const Convention = enum(u1) {
-    linux = 0,
-    birth = 1,
-};
-
-pub const Options = extern union {
-    general: General,
-    birth: Birth,
-    linux: Linux,
-
-    pub const General = packed struct(u64) {
-        number: Number,
-        convention: Convention,
-
-        pub const Number = lib.IntType(.unsigned, union_space_bits);
-
-        comptime {
-            assertSize(@This());
-        }
-
-        pub inline fn getNumberInteger(general: General, comptime convention: Convention) NumberIntegerType(convention) {
-            const options_integer = @as(u64, @bitCast(general));
-            return @as(NumberIntegerType(convention), @truncate(options_integer));
-        }
-
-        pub fn NumberIntegerType(comptime convention: Convention) type {
-            return switch (convention) {
-                .birth => birth.IDInteger,
-                .linux => u64,
-            };
-        }
-    };
-
-    pub const Birth = packed struct(u64) {
-        type: capabilities.Type,
-        command: capabilities.Subtype,
-        reserved: lib.IntType(.unsigned, @bitSizeOf(u64) - @bitSizeOf(capabilities.Type) - @bitSizeOf(capabilities.Subtype) - @bitSizeOf(Convention)) = 0,
-        convention: Convention = .birth,
-
-        comptime {
-            Options.assertSize(@This());
-        }
-
-        const IDInteger = u16;
-        pub const ID = enum(IDInteger) {
-            qemu_exit = 0,
-            print = 1,
-        };
-    };
-
-    pub const Linux = enum(u64) {
-        _,
-        comptime {
-            Options.assertSize(@This());
-        }
-    };
-
-    pub const union_space_bits = @bitSizeOf(u64) - @bitSizeOf(Convention);
-
-    fn assertSize(comptime T: type) void {
-        assert(@sizeOf(T) == @sizeOf(u64));
-        assert(@bitSizeOf(T) == @bitSizeOf(u64));
-    }
-
-    comptime {
-        assertSize(@This());
-    }
-};
-
-pub const Result = extern union {
-    general: General,
-    birth: Birth,
-    linux: Linux,
-
-    pub const General = extern struct {
-        first: packed struct(u64) {
-            argument: u63,
-            convention: Convention,
-        },
-        second: u64,
-    };
-
-    pub const Birth = extern struct {
-        first: First,
-        second: Second,
-
-        pub const First = packed struct(u64) {
-            padding1: u32 = 0,
-            @"error": u16 = 0,
-            padding2: u8 = 0,
-            padding3: u7 = 0,
-            convention: Convention = .birth,
-        };
-
-        pub const Second = u64;
-    };
-
-    pub const Linux = extern struct {
-        result: u64,
-        reserved: u64 = 0,
-    };
-
-    fn assertSize(comptime T: type) void {
-        assert(@sizeOf(T) == @sizeOf(u64));
-        assert(@bitSizeOf(T) == @bitSizeOf(u64));
-    }
-};

src/bootloader.zig

@@ -315,6 +315,13 @@ pub const Information = extern struct {
                 return Error.unexpected_memory_map_entry_count;
             }
             bootloader_information.configuration.memory_map_diff = @as(u8, @intCast(memory_map_entry_count - new_memory_map_entry_count));
+
+            const entries = bootloader_information.getMemoryMapEntries();
+            const entry = entries[total_allocation.index];
+            assert(entry.region.address.value() == total_allocation.region.address.value());
+            assert(entry.region.size == total_allocation.region.size);
+
+            page_counters[total_allocation.index] = bootloader_information.getAlignedTotalSize() >> lib.arch.page_shifter(lib.arch.valid_page_sizes[0]);
         }
 
         // Check if the host entry still corresponds to the same index
@@ -366,7 +373,9 @@ pub const Information = extern struct {
                     }
 
                     const aligned_size = lib.alignForward(u64, ph.size_in_memory, lib.arch.valid_page_sizes[0]);
-                    const physical_allocation = try bootloader_information.allocatePages(aligned_size, lib.arch.valid_page_sizes[0], .{});
+                    const physical_allocation = try bootloader_information.allocatePages(aligned_size, lib.arch.valid_page_sizes[0], .{
+                        .virtual_address = @bitCast(@as(u64, 0)),
+                    });
                     const physical_address = physical_allocation.address;
                     const virtual_address = VirtualAddress.new(ph.virtual_address);
                     const flags = Mapping.Flags{ .write = ph.flags.writable, .execute = ph.flags.executable };
@@ -469,7 +478,7 @@ pub const Information = extern struct {
     }
 
     pub inline fn getSlice(information: *const Information, comptime offset_name: Slice.Name) []Slice.TypeMap[@intFromEnum(offset_name)] {
-        const slice_offset = information.slices.array.values[@intFromEnum(offset_name)];
+        const slice_offset = &information.slices.array.values[@intFromEnum(offset_name)];
         return slice_offset.dereference(offset_name, information);
     }
 
@@ -684,6 +693,10 @@ pub const MemoryMapEntry = extern struct {
         bad_memory = 2,
     };
 
+    pub fn getUsedRegion(mmap_entry: MemoryMapEntry, page_counter: u32) PhysicalMemoryRegion {
+        return mmap_entry.region.slice(page_counter << lib.arch.page_shifter(lib.arch.valid_page_sizes[0]));
+    }
+
     pub fn getFreeRegion(mmap_entry: MemoryMapEntry, page_counter: u32) PhysicalMemoryRegion {
         return mmap_entry.region.offset(page_counter << lib.arch.page_shifter(lib.arch.valid_page_sizes[0]));
     }

src/bootloader/bios.zig

@@ -68,10 +68,8 @@ pub const Disk = extern struct {
                 .segment = 0,
                 .lba = lba,
             };
-            lib.log.debug("DAP: {}", .{dap});
 
             const dap_address = @intFromPtr(&dap);
-            lib.log.debug("DAP address: 0x{x}", .{dap_address});
             const dap_offset = offset(dap_address);
             const dap_segment = segment(dap_address);
             var registers = Registers{
@@ -81,9 +79,7 @@ pub const Disk = extern struct {
                 .ds = dap_segment,
             };
 
-            lib.log.debug("Start int", .{});
             interrupt(0x13, &registers, &registers);
-            lib.log.debug("End int", .{});
 
             if (registers.eflags.flags.carry_flag) return error.read_error;
 
@@ -92,7 +88,6 @@ pub const Disk = extern struct {
             const src_slice = buffer[0..bytes_to_copy];
 
             if (maybe_provided_buffer) |provided_buffer| {
-                lib.log.debug("A", .{});
                 const dst_slice = provided_buffer[@as(usize, @intCast(provided_buffer_offset))..][0..bytes_to_copy];
 
                 // TODO: report Zig that this codegen is so bad that we have to use rep movsb instead to make it go fast
@@ -102,19 +97,11 @@ pub const Disk = extern struct {
                 const use_rep_movsb = true;
                 if (use_rep_movsb) {
                     lib.memcpy(dst_slice, src_slice);
-                    const bytes_left = asm volatile (
-                        \\rep movsb
-                        : [ret] "={ecx}" (-> usize),
-                        : [dest] "{edi}" (dst_slice.ptr),
-                          [src] "{esi}" (src_slice.ptr),
-                          [len] "{ecx}" (src_slice.len),
-                    );
-                    assert(bytes_left == 0);
                 } else {
                     @memcpy(dst_slice, src_slice);
                 }
             } else {
-                lib.log.debug("B", .{});
+                //lib.log.debug("B", .{});
             }
         }
 

src/bootloader/birth/bios/main.zig

@@ -5,8 +5,7 @@ const log = lib.log;
 const privileged = @import("privileged");
 const ACPI = privileged.ACPI;
 const MemoryManager = privileged.MemoryManager;
-const PhysicalHeap = privileged.PhyicalHeap;
-const writer = privileged.writer;
+pub const writer = privileged.writer;
 
 const stopCPU = privileged.arch.stopCPU;
 const GDT = privileged.arch.x86_64.GDT;
@@ -54,10 +53,7 @@ pub const std_options = struct {
         _ = format;
         _ = scope;
         _ = level;
-        // _ = level;
-        // writer.writeByte('[') catch stopCPU();
-        // writer.writeAll(@tagName(scope)) catch stopCPU();
-        // writer.writeAll("] ") catch stopCPU();
+        _ = level;
         // lib.format(writer, format, args) catch stopCPU();
         // writer.writeByte('\n') catch stopCPU();
     }
@@ -83,17 +79,13 @@ const Filesystem = extern struct {
     }
 
     pub fn readFile(filesystem: *Filesystem, file_path: []const u8, file_buffer: []u8) ![]const u8 {
-        log.debug("File {s} read started", .{file_path});
         assert(filesystem.fat_allocator.allocated <= filesystem.fat_allocator.buffer.len);
         const file = try filesystem.fat_cache.readFileToBuffer(file_path, file_buffer);
-        log.debug("File read succeeded", .{});
         return file;
     }
 
     pub fn sneakFile(filesystem: *Filesystem, file_path: []const u8, size: usize) ![]const u8 {
-        log.debug("File {s} read started", .{file_path});
         const file = try filesystem.fat_cache.readFileToCache(file_path, size);
-        log.debug("File read succeeded", .{});
         return file;
     }
 

src/bootloader/birth/uefi/main.zig

@@ -14,16 +14,13 @@ const uefi = @import("uefi");
 const BootloaderInformation = uefi.BootloaderInformation;
 const BootServices = uefi.BootServices;
 const ConfigurationTable = uefi.ConfigurationTable;
-const FileProtocol = uefi.FileProtocol;
 const Handle = uefi.Handle;
-const LoadedImageProtocol = uefi.LoadedImageProtocol;
 const LoadKernelFunction = uefi.LoadKernelFunction;
 const MemoryCategory = uefi.MemoryCategory;
 const MemoryDescriptor = uefi.MemoryDescriptor;
 const ProgramSegment = uefi.ProgramSegment;
 const Protocol = uefi.Protocol;
 const page_table_estimated_size = uefi.page_table_estimated_size;
-const SimpleFilesystemProtocol = uefi.SimpleFilesystemProtocol;
 const SystemTable = uefi.SystemTable;
 
 const privileged = @import("privileged");
@@ -68,7 +65,7 @@ pub fn panic(message: []const u8, _: ?*lib.StackTrace, _: ?usize) noreturn {
 }
 
 const Filesystem = extern struct {
-    root: *FileProtocol,
+    root: *uefi.protocol.File,
     buffer: [0x200 * 10]u8 = undefined,
 
     pub fn deinitialize(filesystem: *Filesystem) !void {
@@ -91,7 +88,7 @@ const Filesystem = extern struct {
     }
 
     const FileDescriptor = struct {
-        handle: *FileProtocol,
+        handle: *uefi.protocol.File,
         path_size: u32,
     };
 
@@ -111,14 +108,14 @@ const Filesystem = extern struct {
             return Error.boot_services_exited;
         }
 
-        var file: *FileProtocol = undefined;
+        var file: *uefi.protocol.File = undefined;
         var path_buffer: [256:0]u16 = undefined;
         const length = try lib.unicode.utf8ToUtf16Le(&path_buffer, file_path);
         path_buffer[length] = 0;
         const path = path_buffer[0..length :0];
         const uefi_path = if (path[0] == '/') path[1..] else path;
 
-        try uefi.Try(filesystem.root.open(&file, uefi_path, FileProtocol.efi_file_mode_read, 0));
+        try uefi.Try(filesystem.root.open(&file, uefi_path, uefi.protocol.File.efi_file_mode_read, 0));
 
         const result = FileDescriptor{
             .handle = file,
@@ -236,16 +233,16 @@ const Initialization = struct {
             },
             .filesystem = .{
                 .root = blk: {
-                    const loaded_image = try Protocol.open(LoadedImageProtocol, boot_services, handle);
-                    const filesystem_protocol = try Protocol.open(SimpleFilesystemProtocol, boot_services, loaded_image.device_handle orelse @panic("No device handle"));
+                    const loaded_image = try Protocol.open(uefi.protocol.LoadedImage, boot_services, handle);
+                    const filesystem_protocol = try Protocol.open(uefi.protocol.SimpleFileSystem, boot_services, loaded_image.device_handle orelse @panic("No device handle"));
 
-                    var root: *FileProtocol = undefined;
+                    var root: *uefi.protocol.File = undefined;
                     try uefi.Try(filesystem_protocol.openVolume(&root));
                     break :blk root;
                 },
             },
             .framebuffer = blk: {
-                const gop = try Protocol.locate(uefi.GraphicsOutputProtocol, boot_services);
+                const gop = try Protocol.locate(uefi.protocol.GraphicsOutput, boot_services);
 
                 const pixel_format_info: struct {
                     red_color_mask: bootloader.Framebuffer.ColorMask,
@@ -253,20 +250,19 @@ const Initialization = struct {
                     green_color_mask: bootloader.Framebuffer.ColorMask,
                     bpp: u8,
                 } = switch (gop.mode.info.pixel_format) {
-                    .PixelRedGreenBlueReserved8BitPerColor => .{
+                    .RedGreenBlueReserved8BitPerColor => .{
                         .red_color_mask = .{ .size = 8, .shift = 0 },
                         .green_color_mask = .{ .size = 8, .shift = 8 },
                         .blue_color_mask = .{ .size = 8, .shift = 16 },
                         .bpp = 32,
                     },
-                    .PixelBlueGreenRedReserved8BitPerColor => .{
+                    .BlueGreenRedReserved8BitPerColor => .{
                         .red_color_mask = .{ .size = 8, .shift = 16 },
                         .green_color_mask = .{ .size = 8, .shift = 8 },
                         .blue_color_mask = .{ .size = 8, .shift = 0 },
                         .bpp = 32,
                     },
-                    .PixelBitMask, .PixelBltOnly => @panic("Unsupported pixel format"),
-                    .PixelFormatMax => @panic("Corrupted pixel format"),
+                    .BitMask, .BltOnly => @panic("Unsupported pixel format"),
                 };
 
                 break :blk bootloader.Framebuffer{

src/bootloader/uefi.zig

@@ -8,13 +8,14 @@ const uefi = lib.uefi;
 pub const BootServices = uefi.tables.BootServices;
 pub const ConfigurationTable = uefi.tables.ConfigurationTable;
 pub const Error = Status.EfiError;
-pub const FileInfo = uefi.protocols.FileInfo;
-pub const FileProtocol = uefi.protocols.FileProtocol;
-pub const GraphicsOutputProtocol = uefi.protocols.GraphicsOutputProtocol;
-pub const LoadedImageProtocol = uefi.protocols.LoadedImageProtocol;
+pub const FileInfo = uefi.FileInfo;
+// pub const FileProtocol = protocol.FileProtocol;
+// pub const GraphicsOutputProtocol = protocol.GraphicsOutputProtocol;
+// pub const LoadedImageProtocol = protocol.LoadedImageProtocol;
+// pub const SimpleFilesystemProtocol = protocol.SimpleFileSystemProtocol;
 pub const Handle = uefi.Handle;
 pub const MemoryDescriptor = uefi.tables.MemoryDescriptor;
-pub const SimpleFilesystemProtocol = uefi.protocols.SimpleFileSystemProtocol;
+pub const protocol = uefi.protocol;
 pub const Status = uefi.Status;
 pub const SystemTable = uefi.tables.SystemTable;
 pub const Try = Status.err;
@@ -25,9 +26,6 @@ pub const page_size = 0x1000;
 pub const page_shifter = lib.arch.page_shifter(page_size);
 
 const privileged = @import("privileged");
-const PhysicalAddress = privileged.PhysicalAddress;
-const VirtualAddress = privileged.VirtualAddress;
-const VirtualMemoryRegion = privileged.VirtualMemoryRegion;
 const stopCPU = privileged.arch.stopCPU;
 
 pub fn panic(comptime format: []const u8, arguments: anytype) noreturn {

src/common.zig

@@ -1,254 +1,25 @@
-const compiler_builtin = @import("builtin");
-pub const cpu = compiler_builtin.cpu;
-pub const os = compiler_builtin.os.tag;
-pub const build_mode = compiler_builtin.mode;
-pub const is_test = compiler_builtin.is_test;
+// This file is meant to be shared between all parts of the project, including build.zig
+const std = @import("std");
+const maxInt = std.math.maxInt;
+const containsAtLeast = std.mem.containsAtLeast;
+const Target = std.Target;
+const Cpu = Target.Cpu;
+const OptimizeMode = std.builtin.OptimizeMode;
 
-pub const kb = 1024;
-pub const mb = kb * 1024;
-pub const gb = mb * 1024;
-pub const tb = gb * 1024;
+const Allocator = std.mem.Allocator;
 
-pub const SizeUnit = enum(u64) {
-    byte = 1,
-    kilobyte = 1024,
-    megabyte = 1024 * 1024,
-    gigabyte = 1024 * 1024 * 1024,
-    terabyte = 1024 * 1024 * 1024 * 1024,
-};
+const builtin = @import("builtin");
+const cpu = builtin.cpu;
+const os = builtin.os.tag;
 
-pub const std = @import("std");
-pub const Target = std.Target;
-pub const Cpu = Target.Cpu;
-pub const CrossTarget = std.zig.CrossTarget;
-
-pub const log = std.log;
-
-pub const Atomic = std.atomic.Atomic;
-
-pub const Reader = std.io.Reader;
-pub const Writer = std.io.Writer;
-
-pub const FixedBufferStream = std.io.FixedBufferStream;
-pub const fixedBufferStream = std.io.fixedBufferStream;
-
-pub fn assert(ok: bool) void {
-    if (!ok) {
-        if (@inComptime()) {
-            @compileError("Assert failed!");
-        } else {
-            @panic("Assert failed!");
-        }
-    }
-}
-
-pub const deflate = std.compress.deflate;
-
-const debug = std.debug;
-pub const print = debug.print;
-pub const StackIterator = debug.StackIterator;
-pub const dwarf = std.dwarf;
-pub const ModuleDebugInfo = std.debug.ModuleDebugInfo;
-
-pub const elf = std.elf;
-
-const fmt = std.fmt;
-pub const format = std.fmt.format;
-pub const FormatOptions = fmt.FormatOptions;
-pub const bufPrint = fmt.bufPrint;
-pub const allocPrint = fmt.allocPrint;
-pub const comptimePrint = fmt.comptimePrint;
-pub const parseUnsigned = fmt.parseUnsigned;
-
-const heap = std.heap;
-pub const FixedBufferAllocator = heap.FixedBufferAllocator;
-
-pub const json = std.json;
-
-const mem = std.mem;
-pub const ZigAllocator = mem.Allocator;
-pub const equal = mem.eql;
-pub const length = mem.len;
-pub const startsWith = mem.startsWith;
-pub const endsWith = mem.endsWith;
-pub const indexOf = mem.indexOf;
-// Ideal for small inputs
-pub const indexOfPosLinear = mem.indexOfPosLinear;
-pub const lastIndexOf = mem.lastIndexOf;
-pub const asBytes = mem.asBytes;
-pub const readIntBig = mem.readIntBig;
-pub const readIntSliceBig = mem.readIntSliceBig;
-pub const concat = mem.concat;
-pub const sliceAsBytes = mem.sliceAsBytes;
-pub const bytesAsSlice = mem.bytesAsSlice;
-pub const alignForward = mem.alignForward;
-pub const alignBackward = mem.alignBackward;
-pub const isAligned = mem.isAligned;
-pub const isAlignedGeneric = mem.isAlignedGeneric;
-pub const reverse = mem.reverse;
-pub const tokenize = mem.tokenize;
-pub const containsAtLeast = mem.containsAtLeast;
-pub const sliceTo = mem.sliceTo;
-pub const swap = mem.swap;
-
-pub const random = std.rand;
-
-pub const testing = std.testing;
-
-pub const sort = std.sort;
-
-pub fn fieldSize(comptime T: type, field_name: []const u8) comptime_int {
-    var foo: T = undefined;
-    return @sizeOf(@TypeOf(@field(foo, field_name)));
-}
-
-const DiffError = error{
-    diff,
-};
-
-pub fn diff(file1: []const u8, file2: []const u8) !void {
-    assert(file1.len == file2.len);
-    var different_bytes: u64 = 0;
-    for (file1, 0..) |byte1, index| {
-        const byte2 = file2[index];
-        const is_different_byte = byte1 != byte2;
-        different_bytes += @intFromBool(is_different_byte);
-        if (is_different_byte) {
-            log.debug("Byte [0x{x}] is different: 0x{x} != 0x{x}", .{ index, byte1, byte2 });
-        }
-    }
-
-    if (different_bytes != 0) {
-        log.debug("Total different bytes: 0x{x}", .{different_bytes});
-        return DiffError.diff;
-    }
-}
-
-pub fn zeroes(comptime T: type) T {
-    var result: T = undefined;
-    const slice = asBytes(&result);
-    @memset(slice, 0);
-    return result;
-}
-
-const ascii = std.ascii;
-pub const upperString = ascii.upperString;
-pub const isUpper = ascii.isUpper;
-pub const isAlphabetic = ascii.isAlphabetic;
-
-const std_builtin = std.builtin;
-pub const AtomicRmwOp = std_builtin.AtomicRmwOp;
-pub const AtomicOrder = std_builtin.AtomicOrder;
-pub const Type = std_builtin.Type;
-pub const StackTrace = std_builtin.StackTrace;
-pub const SourceLocation = std_builtin.SourceLocation;
-
-pub fn FieldType(comptime T: type, comptime name: []const u8) type {
-    return @TypeOf(@field(@as(T, undefined), name));
-}
-
-// META PROGRAMMING
-pub const AutoEnumArray = std.enums.EnumArray;
-pub const fields = std.meta.fields;
-pub const IntType = std.meta.Int;
-pub const enumFromInt = std.meta.enumFromInt;
-pub const stringToEnum = std.meta.stringToEnum;
-pub const Tag = std.meta.Tag;
-
-const math = std.math;
-pub const maxInt = math.maxInt;
-pub const min = math.min;
-pub const divCeil = math.divCeil;
-pub const clamp = math.clamp;
-pub const isPowerOfTwo = math.isPowerOfTwo;
-pub const mul = math.mul;
-pub const cast = math.cast;
-
-pub const unicode = std.unicode;
-
-pub const uefi = std.os.uefi;
-
-pub const DiskType = enum(u32) {
-    virtio = 0,
-    nvme = 1,
-    ahci = 2,
-    ide = 3,
-    memory = 4,
-    bios = 5,
-
-    pub const count = enumCount(@This());
-};
-
-pub const FilesystemType = enum(u32) {
-    birth = 0,
-    ext2 = 1,
-    fat32 = 2,
-
-    pub const count = enumCount(@This());
-};
-
-pub fn enumFields(comptime E: type) []const Type.EnumField {
-    return @typeInfo(E).Enum.fields;
-}
-
-pub const enumValues = std.enums.values;
-
-pub fn enumCount(comptime E: type) usize {
-    return enumFields(E).len;
-}
-
-pub const PartitionTableType = enum {
-    mbr,
-    gpt,
-};
-
-pub const supported_architectures = [_]Cpu.Arch{
-    .x86_64,
-    //.aarch64,
-    //.riscv64,
-};
-
-pub fn architectureIndex(comptime arch: Cpu.Arch) comptime_int {
-    inline for (supported_architectures, 0..) |architecture, index| {
-        if (arch == architecture) return index;
-    }
-
-    @compileError("Architecture not found");
-}
-
-pub const architecture_bootloader_map = blk: {
-    var array: [supported_architectures.len][]const ArchitectureBootloader = undefined;
-
-    array[architectureIndex(.x86_64)] = &.{
-        .{
-            .id = .birth,
-            .protocols = &.{ .bios, .uefi },
-        },
-        .{
-            .id = .limine,
-            .protocols = &.{ .bios, .uefi },
-        },
-    };
-
-    // array[architectureIndex(.aarch64)] = &.{
-    //     .{
-    //         .id = .birth,
-    //         .protocols = &.{.uefi},
-    //     },
-    //     .{
-    //         .id = .limine,
-    //         .protocols = &.{.uefi},
-    //     },
-    // };
-
-    // array[architectureIndex(.riscv64)] = &.{
-    //     .{
-    //         .id = .birth,
-    //         .protocols = &.{.uefi},
-    //     },
-    // };
-
-    break :blk array;
+pub const Configuration = struct {
+    architecture: Cpu.Arch,
+    bootloader: Bootloader,
+    boot_protocol: Bootloader.Protocol,
+    execution_environment: ExecutionEnvironment,
+    optimize_mode: OptimizeMode,
+    execution_type: ExecutionType,
+    executable_kind: std.Build.CompileStep.Kind,
 };
 
 pub const Bootloader = enum(u32) {
@@ -261,147 +32,18 @@ pub const Bootloader = enum(u32) {
     };
 };
 
-pub const ArchitectureBootloader = struct {
-    id: Bootloader,
-    protocols: []const Bootloader.Protocol,
-};
-
-pub const TraditionalExecutionMode = enum(u1) {
-    privileged = 0,
-    user = 1,
-};
-
 pub const ExecutionEnvironment = enum {
     qemu,
 };
 
-pub const ImageConfig = struct {
-    sector_count: u64,
-    sector_size: u16,
-    partition_table: PartitionTableType,
-    partition: PartitionConfig,
-
-    pub const default_path = "config/image_config.json";
-
-    pub fn get(allocator: ZigAllocator, path: []const u8) !ImageConfig {
-        const image_config_file = try std.fs.cwd().readFileAlloc(allocator, path, maxInt(usize));
-        const parsed_image_configuration = try std.json.parseFromSlice(ImageConfig, allocator, image_config_file, .{});
-        return parsed_image_configuration.value;
-    }
-};
-
-pub const PartitionConfig = struct {
-    name: []const u8,
-    filesystem: FilesystemType,
-    first_lba: u64,
-};
-
-pub const QEMU = extern struct {
-    pub const isa_debug_exit = ISADebugExit{};
-
-    pub const ISADebugExit = extern struct {
-        io_base: u8 = 0xf4,
-        io_size: u8 = @sizeOf(u32),
-    };
-
-    pub const ExitCode = enum(u32) {
-        success = 0x10,
-        failure = 0x11,
-        _,
-    };
-};
-
-pub const OptimizeMode = std.builtin.OptimizeMode;
-
-pub const Configuration = struct {
-    architecture: Cpu.Arch,
-    bootloader: Bootloader,
-    boot_protocol: Bootloader.Protocol,
-    execution_environment: ExecutionEnvironment,
-    optimize_mode: OptimizeMode,
-    execution_type: ExecutionType,
-    executable_kind: std.Build.CompileStep.Kind,
-};
-
-pub const QEMUOptions = packed struct {
-    is_test: bool,
-    is_debug: bool,
-};
-
 pub const ExecutionType = enum {
     emulated,
     accelerated,
 };
 
-pub const Suffix = enum {
-    bootloader,
-    cpu_driver,
-    image,
-    complete,
-
-    pub fn fromConfiguration(suffix: Suffix, allocator: ZigAllocator, configuration: Configuration, prefix: ?[]const u8) ![]const u8 {
-        const cpu_driver_suffix = [_][]const u8{
-            @tagName(configuration.optimize_mode),
-            "_",
-            @tagName(configuration.architecture),
-            "_",
-            @tagName(configuration.executable_kind),
-        };
-
-        const bootloader_suffix = [_][]const u8{
-            @tagName(configuration.architecture),
-            "_",
-            @tagName(configuration.bootloader),
-            "_",
-            @tagName(configuration.boot_protocol),
-        };
-
-        const image_suffix = [_][]const u8{
-            @tagName(configuration.optimize_mode),
-            "_",
-        } ++ bootloader_suffix ++ [_][]const u8{
-            "_",
-            @tagName(configuration.executable_kind),
-        };
-
-        const complete_suffix = image_suffix ++ [_][]const u8{
-            "_",
-            @tagName(configuration.execution_type),
-            "_",
-            @tagName(configuration.execution_environment),
-        };
-
-        return try std.mem.concat(allocator, u8, &switch (suffix) {
-            .cpu_driver => if (prefix) |pf| [1][]const u8{pf} ++ cpu_driver_suffix else cpu_driver_suffix,
-            .bootloader => if (prefix) |pf| [1][]const u8{pf} ++ bootloader_suffix else bootloader_suffix,
-            .image => if (prefix) |pf| [1][]const u8{pf} ++ image_suffix else image_suffix,
-            .complete => if (prefix) |pf| [1][]const u8{pf} ++ complete_suffix else complete_suffix,
-        });
-    }
-};
-
-pub const Module = struct {
-    program: UserProgram,
-    name: []const u8,
-};
-pub const UserProgram = struct {
-    kind: Kind,
-    dependencies: []const Dependency,
-
-    pub const Kind = enum {
-        zig_exe,
-    };
-
-    pub const Dependency = struct {
-        foo: u64 = 0,
-    };
-};
-
-pub const BirthProgram = enum {
-    bootloader,
-    cpu,
-    user,
-    host,
+pub const TraditionalExecutionMode = enum(u1) {
+    privileged = 0,
+    user = 1,
 };
 
 pub fn canVirtualizeWithQEMU(architecture: Cpu.Arch, ci: bool) bool {
@@ -418,9 +60,6 @@ pub fn canVirtualizeWithQEMU(architecture: Cpu.Arch, ci: bool) bool {
     };
 }
 
-pub const default_cpu_name = "/cpu";
-pub const default_init_file = "/init";
-
 pub const ArgumentParser = struct {
     pub const null_specifier = "-";
 
@@ -501,5 +140,45 @@ pub const ArgumentParser = struct {
     };
 };
 
-pub const default_disk_size = 64 * 1024 * 1024;
-pub const default_sector_size = 0x200;
+fn enumCount(comptime E: type) comptime_int {
+    return @typeInfo(E).Enum.fields.len;
+}
+
+pub const QEMUOptions = packed struct {
+    is_test: bool,
+    is_debug: bool,
+};
+
+pub const PartitionTableType = enum {
+    mbr,
+    gpt,
+};
+
+pub const ImageConfig = struct {
+    sector_count: u64,
+    sector_size: u16,
+    partition_table: PartitionTableType,
+    partition: PartitionConfig,
+
+    pub const default_path = "config/image_config.json";
+
+    pub fn get(allocator: Allocator, path: []const u8) !ImageConfig {
+        const image_config_file = try std.fs.cwd().readFileAlloc(allocator, path, maxInt(usize));
+        const parsed_image_configuration = try std.json.parseFromSlice(ImageConfig, allocator, image_config_file, .{});
+        return parsed_image_configuration.value;
+    }
+};
+
+pub const PartitionConfig = struct {
+    name: []const u8,
+    filesystem: FilesystemType,
+    first_lba: u64,
+};
+
+pub const FilesystemType = enum(u32) {
+    birth = 0,
+    ext2 = 1,
+    fat32 = 2,
+
+    pub const count = enumCount(@This());
+};

src/cpu.zig

@@ -13,64 +13,44 @@ const PhysicalAddress = lib.PhysicalAddress;
 const PhysicalAddressSpace = lib.PhysicalAddressSpace;
 const PhysicalMemoryRegion = lib.PhysicalMemoryRegion;
 const stopCPU = privileged.arch.stopCPU;
-const VirtualAddress = privileged.VirtualAddress;
-const VirtualMemoryRegion = privileged.VirtualMemoryRegion;
+const VirtualAddress = lib.VirtualAddress;
+const VirtualMemoryRegion = lib.VirtualMemoryRegion;
+const paging = privileged.arch.paging;
 
 const birth = @import("birth");
 
-pub const test_runner = @import("cpu/test_runner.zig");
 pub const arch = @import("cpu/arch.zig");
-pub const capabilities = @import("cpu/capabilities.zig");
+pub const interface = @import("cpu/interface.zig");
+pub const init = @import("cpu/init.zig");
+
+const PageTableRegions = arch.init.PageTableRegions;
 
 pub export var stack: [0x8000]u8 align(0x1000) = undefined;
-pub export var page_allocator = PageAllocator{
-    .head = null,
-    .list_allocator = .{
-        .u = .{
-            .primitive = .{
-                .backing_4k_page = undefined,
-                .allocated = 0,
-            },
-        },
-        .primitive = true,
-    },
-};
 
 pub var bundle: []const u8 = &.{};
 pub var bundle_files: []const u8 = &.{};
 
+pub export var page_allocator = PageAllocator{};
 pub export var user_scheduler: *UserScheduler = undefined;
-pub export var driver: *align(lib.arch.valid_page_sizes[0]) Driver = undefined;
+pub export var heap = HeapImplementation(false){};
+pub var debug_info: lib.ModuleDebugInfo = undefined;
 pub export var page_tables: CPUPageTables = undefined;
 pub var file: []align(lib.default_sector_size) const u8 = undefined;
 pub export var core_id: u32 = 0;
 pub export var bsp = false;
 var panic_lock = lib.Spinlock.released;
 
-/// This data structure holds the information needed to run a core
-pub const Driver = extern struct {
-    init_root_capability: capabilities.RootDescriptor,
-    valid: bool,
-    padding: [padding_byte_count]u8 = .{0} ** padding_byte_count,
-    const padding_byte_count = lib.arch.valid_page_sizes[0] - @sizeOf(bool) - @sizeOf(capabilities.RootDescriptor);
-
-    pub inline fn getRootCapability(drv: *Driver) *capabilities.Root {
-        return drv.init_root_capability.value;
-    }
-
-    comptime {
-        // @compileLog(@sizeOf(Driver));
-        assert(lib.isAligned(@sizeOf(Driver), lib.arch.valid_page_sizes[0]));
-    }
-};
-
 /// This data structure holds the information needed to run a program in a core (cpu side)
 pub const UserScheduler = extern struct {
-    capability_root_node: capabilities.Root,
-    common: *birth.UserScheduler,
+    s: S,
     padding: [padding_byte_count]u8 = .{0} ** padding_byte_count,
 
-    const total_size = @sizeOf(capabilities.Root) + @sizeOf(*birth.UserScheduler);
+    const S = extern struct {
+        capability_root_node: interface.Root,
+        common: *birth.Scheduler.Common,
+    };
+
+    const total_size = @sizeOf(S);
     const aligned_size = lib.alignForward(usize, total_size, lib.arch.valid_page_sizes[0]);
     const padding_byte_count = aligned_size - total_size;
 
@@ -81,7 +61,7 @@ pub const UserScheduler = extern struct {
     }
 };
 
-const print_stack_trace = false;
+const print_stack_trace = true;
 var panic_count: usize = 0;
 
 inline fn panicPrologue(comptime format: []const u8, arguments: anytype) !void {
@@ -92,9 +72,9 @@ inline fn panicPrologue(comptime format: []const u8, arguments: anytype) !void {
     try writer.writeAll(lib.Color.get(.bold));
     try writer.writeAll(lib.Color.get(.red));
     try writer.writeAll("[CPU DRIVER] [PANIC] ");
-    try writer.writeAll(lib.Color.get(.reset));
     try writer.print(format, arguments);
     try writer.writeByte('\n');
+    try writer.writeAll(lib.Color.get(.reset));
 }
 
 inline fn panicEpilogue() noreturn {
@@ -103,64 +83,68 @@ inline fn panicEpilogue() noreturn {
     shutdown(.failure);
 }
 
-// inline fn printStackTrace(maybe_stack_trace: ?*lib.StackTrace) !void {
-//     if (maybe_stack_trace) |stack_trace| {
-//         var debug_info = try getDebugInformation();
-//         try writer.writeAll("Stack trace:\n");
-//         var frame_index: usize = 0;
-//         var frames_left: usize = @min(stack_trace.index, stack_trace.instruction_addresses.len);
-//
-//         while (frames_left != 0) : ({
-//             frames_left -= 1;
-//             frame_index = (frame_index + 1) % stack_trace.instruction_addresses.len;
-//         }) {
-//             const return_address = stack_trace.instruction_addresses[frame_index];
-//             try writer.print("[{}] ", .{frame_index});
-//             try printSourceAtAddress(&debug_info, return_address);
-//         }
-//     } else {
-//         try writer.writeAll("Stack trace not available\n");
-//     }
-// }
+inline fn printStackTrace(maybe_stack_trace: ?*lib.StackTrace) !void {
+    if (maybe_stack_trace) |stack_trace| {
+        try writer.writeAll("Stack trace:\n");
+        var frame_index: usize = 0;
+        var frames_left: usize = @min(stack_trace.index, stack_trace.instruction_addresses.len);
 
-// inline fn printStackTraceFromStackIterator(return_address: usize, frame_address: usize) !void {
-//     var debug_info = try getDebugInformation();
-//     var stack_iterator = lib.StackIterator.init(return_address, frame_address);
-//     var frame_index: usize = 0;
-//     try writer.writeAll("Stack trace:\n");
-//
-//     try printSourceAtAddress(&debug_info, return_address);
-//     while (stack_iterator.next()) |address| : (frame_index += 1) {
-//         try writer.print("[{}] ", .{frame_index});
-//         try printSourceAtAddress(&debug_info, address);
-//     }
-// }
+        while (frames_left != 0) : ({
+            frames_left -= 1;
+            frame_index = (frame_index + 1) % stack_trace.instruction_addresses.len;
+        }) {
+            const return_address = stack_trace.instruction_addresses[frame_index];
+            try writer.print("[{}] ", .{frame_index});
+            try printSourceAtAddress(return_address);
+            try writer.writeByte('\n');
+        }
+    } else {
+        try writer.writeAll("Stack trace not available\n");
+    }
+}
 
-// fn printSourceAtAddress(debug_info: *lib.ModuleDebugInfo, address: usize) !void {
-//     if (debug_info.findCompileUnit(address)) |compile_unit| {
-//         const symbol = .{
-//             .symbol_name = debug_info.getSymbolName(address) orelse "???",
-//             .compile_unit_name = compile_unit.die.getAttrString(debug_info, lib.dwarf.AT.name, debug_info.debug_str, compile_unit.*) catch "???",
-//             .line_info = debug_info.getLineNumberInfo(heap_allocator.toZig(), compile_unit.*, address) catch null,
-//         };
-//         try writer.print("0x{x}: {s}!{s} {s}:{}:{}\n", .{ address, symbol.symbol_name, symbol.compile_unit_name, symbol.line_info.?.file_name, symbol.line_info.?.line, symbol.line_info.?.column });
-//     } else |err| {
-//         return err;
-//     }
-// }
+inline fn printStackTraceFromStackIterator(return_address: usize, frame_address: usize) !void {
+    var stack_iterator = lib.StackIterator.init(return_address, frame_address);
+    var frame_index: usize = 0;
+    try writer.writeAll("Stack trace:\n");
+
+    while (stack_iterator.next()) |address| : (frame_index += 1) {
+        if (address == 0) break;
+        try writer.print("[{}] ", .{frame_index});
+        try printSourceAtAddress(address);
+        try writer.writeByte('\n');
+    }
+}
+
+fn printSourceAtAddress(address: usize) !void {
+    const compile_unit = debug_info.findCompileUnit(address) catch {
+        try writer.print("0x{x}: ???", .{address});
+        return;
+    };
+    const symbol_name = debug_info.getSymbolName(address) orelse "???";
+    const compile_unit_name = compile_unit.die.getAttrString(&debug_info, lib.dwarf.AT.name, debug_info.section(.debug_str), compile_unit.*) catch "???";
+    const line_info = debug_info.getLineNumberInfo(heap.allocator.zigUnwrap(), compile_unit.*, address) catch null;
+    const symbol = .{
+        .symbol_name = symbol_name,
+        .compile_unit_name = compile_unit_name,
+        .line_info = line_info,
+    };
+
+    const file_name = if (symbol.line_info) |li| li.file_name else "???";
+    const line = if (symbol.line_info) |li| li.line else 0;
+    const column = if (symbol.line_info) |li| li.column else 0;
+    try writer.print("0x{x}: {s}!{s} {s}:{}:{}", .{ address, symbol.symbol_name, symbol.compile_unit_name, file_name, line, column });
+}
 
 pub fn panicWithStackTrace(stack_trace: ?*lib.StackTrace, comptime format: []const u8, arguments: anytype) noreturn {
-    _ = stack_trace;
     panicPrologue(format, arguments) catch {};
-    // if (print_stack_trace) printStackTrace(stack_trace) catch {};
+    if (print_stack_trace) printStackTrace(stack_trace) catch {};
     panicEpilogue();
 }
 
 pub fn panicFromInstructionPointerAndFramePointer(return_address: usize, frame_address: usize, comptime format: []const u8, arguments: anytype) noreturn {
-    _ = frame_address;
-    _ = return_address;
     panicPrologue(format, arguments) catch {};
-    //if (print_stack_trace) printStackTraceFromStackIterator(return_address, frame_address) catch {};
+    if (print_stack_trace) printStackTraceFromStackIterator(return_address, frame_address) catch {};
     panicEpilogue();
 }
 
@@ -168,268 +152,410 @@ pub fn panic(comptime format: []const u8, arguments: anytype) noreturn {
     @call(.always_inline, panicFromInstructionPointerAndFramePointer, .{ @returnAddress(), @frameAddress(), format, arguments });
 }
 
-pub var syscall_count: usize = 0;
+pub var command_count: usize = 0;
 
 pub inline fn shutdown(exit_code: lib.QEMU.ExitCode) noreturn {
     log.debug("Printing stats...", .{});
-    log.debug("Syscall count: {}", .{syscall_count});
+    log.debug("System call count: {}", .{interface.system_call_count});
 
     privileged.shutdown(exit_code);
 }
 
-pub const PageAllocator = extern struct {
-    head: ?*Entry,
-    list_allocator: ListAllocator,
-    total_allocated_size: u32 = 0,
+pub const RegionList = extern struct {
+    regions: [list_region_count]PhysicalMemoryRegion = .{PhysicalMemoryRegion.invalid()} ** list_region_count,
+    metadata: Metadata = .{},
 
-    fn getPageAllocatorInterface(pa: *PageAllocator) PageAllocatorInterface {
-        return .{
-            .allocate = callbackAllocate,
-            .context = pa,
-            .context_type = .cpu,
-        };
+    pub const Metadata = extern struct {
+        reserved: usize = 0,
+        bitset: Bitset = .{},
+        previous: ?*RegionList = null,
+        next: ?*RegionList = null,
+
+        const Bitset = lib.data_structures.BitsetU64(list_region_count);
+
+        comptime {
+            assert(@sizeOf(Metadata) == expected_size);
+            assert(@bitSizeOf(usize) - list_region_count < 8);
+        }
+
+        const expected_size = 4 * @sizeOf(usize);
+    };
+
+    const Error = error{
+        OutOfMemory,
+        no_space,
+        misalignment_page_size,
+    };
+
+    pub fn allocateAligned(list: *RegionList, size: usize, alignment: usize) Error!PhysicalMemoryRegion {
+        assert(alignment % lib.arch.valid_page_sizes[0] == 0);
+
+        for (&list.regions, 0..) |*region, _index| {
+            const index: u6 = @intCast(_index);
+            assert(lib.isAligned(region.size, lib.arch.valid_page_sizes[0]));
+            assert(lib.isAligned(region.address.value(), lib.arch.valid_page_sizes[0]));
+
+            if (list.metadata.bitset.isSet(index)) {
+                if (lib.isAligned(region.address.value(), alignment)) {
+                    if (region.size >= size) {
+                        const result = region.takeSlice(size) catch unreachable;
+                        if (region.size == 0) {
+                            list.remove(@intCast(index));
                         }
 
-    fn callbackAllocate(context: ?*anyopaque, size: u64, alignment: u64, options: PageAllocatorInterface.AllocateOptions) Allocator.Allocate.Error!PhysicalMemoryRegion {
-        _ = options;
-        const pa = @as(?*PageAllocator, @ptrCast(@alignCast(context))) orelse return Allocator.Allocate.Error.OutOfMemory;
-        const result = try pa.allocate(size, alignment);
                         return result;
                     }
-
-    pub fn allocate(pa: *PageAllocator, size: u64, alignment: u64) Allocator.Allocate.Error!PhysicalMemoryRegion {
-        if (pa.head == null) {
-            @panic("head null");
                 }
-
-        const allocation = blk: {
-            var ptr = pa.head;
-            while (ptr) |entry| : (ptr = entry.next) {
-                if (lib.isAligned(entry.region.address.value(), alignment) and entry.region.size > size) {
-                    const result = PhysicalMemoryRegion{
-                        .address = entry.region.address,
-                        .size = size,
-                    };
-                    entry.region.address = entry.region.address.offset(size);
-                    entry.region.size -= size;
-
-                    pa.total_allocated_size += @as(u32, @intCast(size));
-                    // log.debug("Allocated 0x{x}", .{size});
-
-                    break :blk result;
             }
         }
 
-            ptr = pa.head;
+        return Error.OutOfMemory;
+    }
 
-            while (ptr) |entry| : (ptr = entry.next) {
-                const aligned_address = lib.alignForward(entry.region.address.value(), alignment);
-                const top = entry.region.top().value();
-                if (aligned_address < top and top - aligned_address > size) {
-                    // log.debug("Found region which we should be splitting: (0x{x}, 0x{x})", .{ entry.region.address.value(), entry.region.size });
-                    // log.debug("User asked for 0x{x} bytes with alignment 0x{x}", .{ size, alignment });
-                    // Split the addresses to obtain the desired result
-                    const first_region_size = aligned_address - entry.region.address.value();
-                    const first_region_address = entry.region.address;
-                    const first_region_next = entry.next;
+    pub fn remove(list: *RegionList, index: u6) void {
+        list.metadata.bitset.clear(index);
+    }
 
-                    const second_region_address = aligned_address + size;
-                    const second_region_size = top - aligned_address + size;
-
-                    const result = PhysicalMemoryRegion{
-                        .address = PhysicalAddress.new(aligned_address),
-                        .size = size,
+    pub const UnalignedAllocationResult = extern struct {
+        wasted: PhysicalMemoryRegion,
+        allocated: PhysicalMemoryRegion,
     };
 
-                    // log.debug("\nFirst region: (Address: 0x{x}. Size: 0x{x}).\nRegion in the middle (allocated): (Address: 0x{x}. Size: 0x{x}).\nSecond region: (Address: 0x{x}. Size: 0x{x})", .{ first_region_address, first_region_size, result.address.value(), result.size, second_region_address, second_region_size });
+    /// Slow path
+    pub fn allocateAlignedSplitting(list: *RegionList, size: usize, alignment: usize) !UnalignedAllocationResult {
+        for (&list.regions, 0..) |*region, _index| {
+            const index: u6 = @intCast(_index);
+            const aligned_region_address = lib.alignForward(usize, region.address.value(), alignment);
+            const wasted_space = aligned_region_address - region.address.value();
 
-                    const new_entry = pa.list_allocator.get();
-                    entry.* = .{
-                        .region = .{
-                            .address = first_region_address,
-                            .size = first_region_size,
-                        },
-                        .next = new_entry,
+            if (list.metadata.bitset.isSet(index)) {
+                const target_size = wasted_space + size;
+                if (region.size >= target_size) {
+                    const wasted_region = try region.takeSlice(wasted_space);
+                    const allocated_region = try region.takeSlice(size);
+
+                    if (region.size == 0) {
+                        list.remove(index);
+                    }
+
+                    return UnalignedAllocationResult{
+                        .wasted = wasted_region,
+                        .allocated = allocated_region,
                     };
-
-                    new_entry.* = .{
-                        .region = .{
-                            .address = PhysicalAddress.new(second_region_address),
-                            .size = second_region_size,
-                        },
-                        .next = first_region_next,
-                    };
-                    // log.debug("First entry: (Address: 0x{x}. Size: 0x{x})", .{ entry.region.address.value(), entry.region.size });
-                    // log.debug("Second entry: (Address: 0x{x}. Size: 0x{x})", .{ new_entry.region.address.value(), new_entry.region.size });
-
-                    // pa.total_allocated_size += @intCast(u32, size);
-                    // log.debug("Allocated 0x{x}", .{size});
-
-                    break :blk result;
+                }
             }
         }
 
-            log.err("Allocate error. Size: 0x{x}. Alignment: 0x{x}. Total allocated size: 0x{x}", .{ size, alignment, pa.total_allocated_size });
-            return Allocator.Allocate.Error.OutOfMemory;
+        log.err("allocateAlignedSplitting", .{});
+        return error.OutOfMemory;
+    }
+
+    pub fn allocate(list: *RegionList, size: usize) Error!PhysicalMemoryRegion {
+        return list.allocateAligned(size, lib.arch.valid_page_sizes[0]);
+    }
+
+    pub fn append(list: *RegionList, region: PhysicalMemoryRegion) Error!birth.interface.Memory {
+        var block_count: usize = 0;
+        while (true) : (block_count += 1) {
+            if (!list.metadata.bitset.isFull()) {
+                const region_index = list.metadata.bitset.allocate() catch continue;
+                const block_index = block_count;
+
+                list.regions[region_index] = region;
+
+                return .{
+                    .block = @intCast(block_index),
+                    .region = region_index,
                 };
+            } else {
+                return Error.no_space;
+            }
+        }
+    }
 
-        //log.debug("Physical allocation: 0x{x}, 0x{x}", .{ allocation.address.value(), allocation.size });
+    const cache_line_count = 16;
+    const list_region_count = @divExact((cache_line_count * lib.cache_line_size) - Metadata.expected_size, @sizeOf(PhysicalMemoryRegion));
 
-        @memset(allocation.toHigherHalfVirtualAddress().access(u8), 0);
+    comptime {
+        assert(@sizeOf(RegionList) % lib.cache_line_size == 0);
+    }
+};
+
+const UseCase = extern struct {
+    reason: Reason,
+    const Reason = enum(u8) {
+        heap,
+        privileged,
+        wasted,
+        user_protected,
+        user,
+        bootloader,
+    };
+};
+
+// TODO: make this more cache friendly
+const UsedRegionList = extern struct {
+    region: PhysicalMemoryRegion,
+    use_case: UseCase,
+    next: ?*UsedRegionList = null,
+};
+
+pub const PageAllocator = extern struct {
+    free_regions: ?*RegionList = null,
+    used_regions: ?*UsedRegionList = null,
+    used_region_buffer: ?*UsedRegionList = null,
+    free_byte_count: u64 = 0,
+    used_byte_count: u64 = 0,
+
+    pub fn allocate(allocator: *PageAllocator, size: usize, use_case: UseCase) lib.Allocator.Allocate.Error!PhysicalMemoryRegion {
+        const allocation = try allocator.allocateRaw(size);
+        try allocator.appendUsedRegion(allocation, use_case);
+        return allocation;
+    }
+
+    fn allocateRaw(allocator: *PageAllocator, size: usize) !PhysicalMemoryRegion {
+        var iterator = allocator.free_regions;
+        while (iterator) |region_list| : (iterator = region_list.metadata.next) {
+            const allocation = region_list.allocate(size) catch continue;
+            allocator.free_byte_count -= size;
+            allocator.used_byte_count += size;
 
             return allocation;
         }
 
-    pub inline fn fromBSP(bootloader_information: *bootloader.Information) InitializationError!PageAllocator {
-        const memory_map_entries = bootloader_information.getMemoryMapEntries();
-        const page_counters = bootloader_information.getPageCounters();
-
-        var total_size: usize = 0;
-        const page_shifter = lib.arch.page_shifter(lib.arch.valid_page_sizes[0]);
-
-        for (memory_map_entries, page_counters) |entry, page_counter| {
-            if (entry.type != .usable or !lib.isAligned(entry.region.size, lib.arch.valid_page_sizes[0]) or entry.region.address.value() < lib.mb) {
-                continue;
+        log.err("allocateRaw: out of memory. Used: 0x{x}. Free: 0x{x}", .{ allocator.used_byte_count, allocator.free_byte_count });
+        return error.OutOfMemory;
     }
 
-            total_size += entry.region.size - (page_counter << page_shifter);
+    /// The only purpose this serves is to do the trick when switching cr3
+    pub fn allocateAligned(allocator: *PageAllocator, size: usize, alignment: usize, use_case: UseCase) lib.Allocator.Allocate.Error!PhysicalMemoryRegion {
+        var iterator = allocator.free_regions;
+        while (iterator) |region_list| : (iterator = region_list.metadata.next) {
+            const unaligned_allocation = region_list.allocateAlignedSplitting(size, alignment) catch continue;
+            // TODO: do something with the wasted space
+            const total_allocation_size = unaligned_allocation.wasted.size + unaligned_allocation.allocated.size;
+            log.err("ALLOCATED: 0x{x}. WASTED: 0x{x}. TOTAL: 0x{x}", .{ unaligned_allocation.allocated.size, unaligned_allocation.wasted.size, total_allocation_size });
+
+            try allocator.appendUsedRegion(unaligned_allocation.allocated, use_case);
+            try allocator.appendUsedRegion(unaligned_allocation.wasted, .{ .reason = .wasted });
+
+            allocator.free_byte_count -= total_allocation_size;
+            allocator.used_byte_count += total_allocation_size;
+
+            return unaligned_allocation.allocated;
         }
 
-        const cpu_count = bootloader_information.smp.cpu_count;
-        const total_memory_to_take = total_size / cpu_count;
-
-        // Look for a 4K page to host the memory map
-        const backing_4k_page = for (memory_map_entries, page_counters) |entry, *page_counter| {
-            const occupied_size = page_counter.* << page_shifter;
-            const entry_size_left = entry.region.size - occupied_size;
-            if (entry_size_left != 0) {
-                if (entry.type != .usable or !lib.isAligned(entry.region.size, lib.arch.valid_page_sizes[0]) or entry.region.address.value() < lib.mb) continue;
-
-                assert(lib.isAligned(entry_size_left, lib.arch.valid_page_sizes[0]));
-                page_counter.* += 1;
-                break entry.region.address.offset(occupied_size);
-            }
-        } else return InitializationError.bootstrap_region_not_found;
-
-        var memory_taken: usize = 0;
-        var backing_4k_page_memory_allocated: usize = 0;
-
-        var last_entry: ?*Entry = null;
-        var first_entry: ?*Entry = null;
-
-        for (memory_map_entries, page_counters) |entry, *page_counter| {
-            if (entry.type != .usable or !lib.isAligned(entry.region.size, lib.arch.valid_page_sizes[0]) or entry.region.address.value() < lib.mb) continue;
-
-            const occupied_size = page_counter.* << page_shifter;
-
-            if (occupied_size < entry.region.size) {
-                const entry_size_left = entry.region.size - occupied_size;
-
-                var memory_taken_from_region: usize = 0;
-                while (memory_taken + memory_taken_from_region < total_memory_to_take) {
-                    if (memory_taken_from_region == entry_size_left) break;
-
-                    const size_to_take = @min(2 * lib.mb, entry_size_left);
-                    memory_taken_from_region += size_to_take;
+        @panic("TODO: PageAllocator.allocateAligned");
     }
 
-                memory_taken += memory_taken_from_region;
+    pub fn appendUsedRegion(allocator: *PageAllocator, physical_region: PhysicalMemoryRegion, use_case: UseCase) lib.Allocator.Allocate.Error!void {
+        const need_allocation = blk: {
+            var result: bool = true;
+            var iterator = allocator.used_region_buffer;
+            while (iterator) |it| : (iterator = it.next) {
+                result = it.region.size < @sizeOf(UsedRegionList);
+                if (!result) {
+                    break;
+                }
+            }
 
-                page_counter.* += @as(u32, @intCast(memory_taken_from_region >> page_shifter));
-                const region_descriptor = .{
-                    .address = entry.region.offset(occupied_size).address,
-                    .size = memory_taken_from_region,
+            break :blk result;
         };
 
-                if (backing_4k_page_memory_allocated >= lib.arch.valid_page_sizes[0]) return InitializationError.memory_exceeded;
-                const entry_address = backing_4k_page.offset(backing_4k_page_memory_allocated);
-                const new_entry = entry_address.toHigherHalfVirtualAddress().access(*Entry);
-                backing_4k_page_memory_allocated += @sizeOf(Entry);
-
-                new_entry.* = .{
-                    .region = .{
-                        .address = region_descriptor.address,
-                        .size = region_descriptor.size,
-                    },
-                    .next = null,
+        if (need_allocation) {
+            const allocation = try allocator.allocateRaw(lib.arch.valid_page_sizes[0]);
+            const new_buffer = allocation.address.toHigherHalfVirtualAddress().access(*UsedRegionList);
+            new_buffer.* = .{
+                .region = allocation,
+                .use_case = undefined,
+            };
+            _ = new_buffer.region.takeSlice(@sizeOf(UsedRegionList)) catch unreachable;
+            const used_region_allocation = new_buffer.region.takeSlice(@sizeOf(UsedRegionList)) catch unreachable;
+            const new_used_region = used_region_allocation.address.toHigherHalfVirtualAddress().access(*UsedRegionList);
+            new_used_region.* = .{
+                .region = allocation,
+                .use_case = .{ .reason = .privileged },
             };
 
-                if (last_entry) |e| {
-                    e.next = new_entry;
+            if (allocator.used_regions) |_| {
+                var iterator = allocator.used_regions;
+                _ = iterator;
+                @panic("TODO: iterate");
             } else {
-                    first_entry = new_entry;
+                allocator.used_regions = new_used_region;
             }
 
-                last_entry = new_entry;
-
-                if (memory_taken >= total_memory_to_take) break;
-            }
-        }
-
-        const result = .{
-            .head = first_entry,
-            .list_allocator = .{
-                .u = .{
-                    .primitive = .{
-                        .backing_4k_page = backing_4k_page,
-                        .allocated = backing_4k_page_memory_allocated,
-                    },
-                },
-                .primitive = true,
-            },
-        };
-
-        return result;
-    }
-
-    const ListAllocator = extern struct {
-        u: extern union {
-            primitive: extern struct {
-                backing_4k_page: PhysicalAddress,
-                allocated: u64,
-            },
-            normal: extern struct {
-                foo: u64,
-            },
-        },
-        primitive: bool,
-
-        pub fn get(list_allocator: *ListAllocator) *Entry {
-            switch (list_allocator.primitive) {
-                true => {
-                    if (list_allocator.u.primitive.allocated < 0x1000) {
-                        const result = list_allocator.u.primitive.backing_4k_page.offset(list_allocator.u.primitive.allocated).toHigherHalfVirtualAddress().access(*Entry);
-                        list_allocator.u.primitive.backing_4k_page = list_allocator.u.primitive.backing_4k_page.offset(@sizeOf(Entry));
-                        return result;
+            if (allocator.used_region_buffer) |_| {
+                var iterator = allocator.used_region_buffer;
+                _ = iterator;
+                @panic("TODO: iterate 2");
             } else {
-                        @panic("reached limit");
-                    }
-                },
-                false => {
-                    @panic("not primitive allocator not implemented");
-                },
+                allocator.used_region_buffer = new_buffer;
             }
+
+            assert(new_buffer.region.size < allocation.size);
         }
+
+        var iterator = allocator.used_region_buffer;
+        while (iterator) |it| : (iterator = it.next) {
+            if (it.region.size >= @sizeOf(UsedRegionList)) {
+                const new_used_region_allocation = it.region.takeSlice(@sizeOf(UsedRegionList)) catch unreachable;
+                const new_used_region = new_used_region_allocation.address.toHigherHalfVirtualAddress().access(*UsedRegionList);
+                new_used_region.* = .{
+                    .region = physical_region,
+                    .use_case = use_case,
                 };
 
-    pub const Entry = extern struct {
-        region: PhysicalMemoryRegion,
-        next: ?*Entry,
-    };
+                iterator = allocator.used_regions;
 
-    const InitializationError = error{
-        bootstrap_region_not_found,
-        memory_exceeded,
+                while (iterator) |i| : (iterator = i.next) {
+                    if (i.next == null) {
+                        i.next = new_used_region;
+                        return;
+                    }
+                }
+            }
+        }
+
+        if (true) @panic("TODO: PageAllocator.appendUsedRegion");
+        return error.OutOfMemory;
+    }
+
+    pub fn getPageTableAllocatorInterface(allocator: *PageAllocator) privileged.PageAllocator {
+        return .{
+            .allocate = pageTableAllocateCallback,
+            .context = allocator,
+            .context_type = .cpu,
         };
+    }
+
+    fn pageTableAllocateCallback(context: ?*anyopaque, size: u64, alignment: u64, options: privileged.PageAllocator.AllocateOptions) error{OutOfMemory}!lib.PhysicalMemoryRegion {
+        const allocator: *PageAllocator = @alignCast(@ptrCast(context orelse return error.OutOfMemory));
+        assert(alignment == lib.arch.valid_page_sizes[0]);
+        assert(size == lib.arch.valid_page_sizes[0]);
+        assert(options.count == 1);
+        assert(options.level_valid);
+
+        const page_table_allocation = try allocator.allocate(size, .{ .reason = .user_protected });
+        // log.debug("Page table allocation: 0x{x}", .{page_table_allocation.address.value()});
+
+        // TODO: is this right?
+        if (options.user) {
+            const user_page_tables = &user_scheduler.s.capability_root_node.dynamic.page_table;
+            const user_allocator = &user_scheduler.s.capability_root_node.heap.allocator;
+            const new_page_table_ref = try user_page_tables.appendPageTable(user_allocator, .{
+                .region = page_table_allocation,
+                .mapping = page_table_allocation.address.toHigherHalfVirtualAddress(),
+                .flags = .{ .level = options.level },
+            });
+
+            const indexed = options.virtual_address;
+            const indices = indexed.toIndices();
+
+            var page_table_ref = user_page_tables.user;
+            log.debug("Level: {s}", .{@tagName(options.level)});
+
+            for (0..@intFromEnum(options.level) - 1) |level_index| {
+                log.debug("Fetching {s} page table", .{@tagName(@as(paging.Level, @enumFromInt(level_index)))});
+                const page_table = user_page_tables.getPageTable(page_table_ref) catch @panic("WTF");
+                page_table_ref = page_table.children[indices[level_index]];
+            }
+
+            const parent_page_table = user_page_tables.getPageTable(page_table_ref) catch @panic("WTF");
+            parent_page_table.children[indices[@intFromEnum(options.level) - 1]] = new_page_table_ref;
+        }
+
+        return page_table_allocation;
+    }
 };
 
-// fn getDebugInformation() !lib.ModuleDebugInfo {
-//     const debug_info = lib.getDebugInformation(heap_allocator.toZig(), file) catch |err| {
-//         try writer.print("Failed to get debug information: {}", .{err});
-//         return err;
-//     };
-//
-//     return debug_info;
-// }
+pub const HeapRegion = extern struct {
+    region: VirtualMemoryRegion,
+    previous: ?*HeapRegion = null,
+    next: ?*HeapRegion = null,
+};
+
+pub fn HeapImplementation(comptime user: bool) type {
+    const use_case = .{ .reason = if (user) .user_protected else .heap };
+    _ = use_case;
+    return extern struct {
+        allocator: lib.Allocator = .{
+            .callbacks = .{
+                .allocate = callbackAllocate,
+            },
+        },
+        regions: ?*Region = null,
+
+        const Heap = @This();
+        const Region = HeapRegion;
+
+        pub fn create(heap_allocator: *Heap, comptime T: type) lib.Allocator.Allocate.Error!*T {
+            const result = try heap_allocator.allocate(@sizeOf(T), @alignOf(T));
+            return @ptrFromInt(result.address);
+        }
+
+        pub fn addBootstrapingRegion(heap_allocator: *Heap, region: VirtualMemoryRegion) !void {
+            assert(heap_allocator.regions == null);
+
+            var region_splitter = region;
+            const new_region_vmr = try region_splitter.takeSlice(@sizeOf(Region));
+            const new_region = new_region_vmr.address.access(*Region);
+            new_region.* = Region{
+                .region = region_splitter,
+            };
+
+            heap_allocator.regions = new_region;
+        }
+
+        // TODO: turn the other way around: make the callback call this function
+        pub fn allocate(heap_allocator: *Heap, size: u64, alignment: u64) lib.Allocator.Allocate.Error!lib.Allocator.Allocate.Result {
+            var iterator = heap_allocator.regions;
+            while (iterator) |region| : (iterator = region.next) {
+                if (region.region.address.isAligned(alignment)) {
+                    if (region.region.size >= size) {
+                        const virtual_region = region.region.takeSlice(size) catch unreachable;
+                        const should_remove = region.region.size == 0;
+                        if (should_remove) {
+                            // TODO: actually remove and reuse
+                            if (region.previous) |prev| prev.next = region.next;
+                        }
+
+                        return @bitCast(virtual_region);
+                    }
+                }
+            }
+
+            const new_size = lib.alignForward(usize, size + @sizeOf(HeapRegion), lib.arch.valid_page_sizes[0]);
+            assert(alignment <= lib.arch.valid_page_sizes[0]);
+            var new_physical_region = try page_allocator.allocate(new_size, .{ .reason = .heap });
+            const new_alloc = new_physical_region.takeSlice(@sizeOf(HeapRegion)) catch unreachable;
+            const new_heap_region = new_alloc.toHigherHalfVirtualAddress().address.access(*HeapRegion);
+            new_heap_region.* = .{
+                .region = new_physical_region.toHigherHalfVirtualAddress(),
+            };
+
+            iterator = heap.regions;
+            if (iterator) |_| {
+                while (iterator) |heap_region| : (iterator = heap_region.next) {
+                    if (heap_region.next == null) {
+                        heap_region.next = new_heap_region;
+                        break;
+                    }
+                }
+            } else {
+                @panic("NO");
+            }
+
+            return heap.allocate(size, alignment);
+        }
+
+        fn callbackAllocate(allocator: *Allocator, size: u64, alignment: u64) lib.Allocator.Allocate.Error!lib.Allocator.Allocate.Result {
+            // This assert is triggered by the Zig std library
+            //assert(lib.isAligned(size, alignment));
+            const heap_allocator = @fieldParentPtr(Heap, "allocator", allocator);
+            return heap_allocator.allocate(size, alignment);
+        }
+    };
+}
 
 pub const writer = privileged.E9Writer{ .context = {} };

src/cpu/arch/x86/64/syscall.zig

@@ -24,76 +24,10 @@ const pcid_mask = 1 << pcid_bit;
 /// - R10: argument 3
 /// - R8:  argument 4
 /// - R9:  argument 5
-fn birthSyscall(comptime Syscall: type, raw_arguments: birth.syscall.Arguments) Syscall.ErrorSet.Error!Syscall.Result {
-    cpu.syscall_count += 1;
-    comptime assert(Syscall == birth.capabilities.Syscall(Syscall.capability, Syscall.command));
-    const capability: birth.capabilities.Type = Syscall.capability;
-    const command: birth.capabilities.Command(capability) = Syscall.command;
-    const arguments = try Syscall.toArguments(raw_arguments);
-
-    return if (cpu.user_scheduler.capability_root_node.hasPermissions(capability, command)) switch (capability) {
-        .io => switch (command) {
-            .copy, .mint, .retype, .delete, .revoke, .create => unreachable,
-            .log => blk: {
-                const message = arguments;
-                cpu.writer.writeAll(message) catch unreachable;
-                comptime assert(Syscall.Result == usize);
-                break :blk message.len;
-            },
-        },
-        .cpu => switch (command) {
-            .copy, .mint, .retype, .delete, .revoke, .create => unreachable,
-            .get_core_id => cpu.core_id,
-            .shutdown => cpu.shutdown(.success),
-            .get_command_buffer => {
-                const command_buffer = arguments;
-                _ = command_buffer;
-                @panic("TODO: get_command_buffer");
-            },
-        },
-        .cpu_memory => switch (command) {
-            .allocate => blk: {
-                comptime assert(@TypeOf(arguments) == usize);
-                const size = arguments;
-                const physical_region = try cpu.user_scheduler.capability_root_node.allocatePages(size);
-                try cpu.user_scheduler.capability_root_node.allocateCPUMemory(physical_region, .{ .privileged = false });
-                break :blk physical_region.address;
-            },
-            else => @panic(@tagName(command)),
-        },
-        .ram => unreachable,
-        .boot => switch (command) {
-            .get_bundle_size => cpu.bundle.len,
-            .get_bundle_file_list_size => cpu.bundle_files.len,
-            else => @panic(@tagName(command)),
-        },
-        .process => switch (command) {
-            .exit => switch (arguments) {
-                true => cpu.shutdown(.success),
-                false => cpu.panic("User process panicked", .{}),
-            },
-            else => @panic(@tagName(command)),
-        },
-        .page_table => @panic("TODO: page_table"),
-    } else error.forbidden;
-}
-
-export fn syscall(registers: *const Registers) callconv(.C) birth.syscall.Result {
-    const options = @as(birth.syscall.Options, @bitCast(registers.syscall_number));
-    const arguments = birth.syscall.Arguments{ registers.rdi, registers.rsi, registers.rdx, registers.r10, registers.r8, registers.r9 };
-
-    return switch (options.general.convention) {
-        .birth => switch (options.birth.type) {
-            inline else => |capability| switch (@as(birth.capabilities.Command(capability), @enumFromInt(options.birth.command))) {
-                inline else => |command| blk: {
-                    const Syscall = birth.capabilities.Syscall(capability, command);
-                    const result: Syscall.Result = birthSyscall(Syscall, arguments) catch |err| break :blk Syscall.errorToRaw(err);
-                    break :blk Syscall.resultToRaw(result);
-                },
-            },
-        },
-        .linux => @panic("linux syscall"),
-    };
+export fn syscall(registers: *const Registers) callconv(.C) birth.interface.Raw.Result {
+    const options = @as(birth.interface.Raw.Options, @bitCast(registers.syscall_number));
+    const arguments = birth.interface.Raw.Arguments{ registers.rdi, registers.rsi, registers.rdx, registers.r10, registers.r8, registers.r9 };
+    return cpu.interface.processFromRaw(options, arguments);
 }
 
 /// SYSCALL documentation
@@ -107,7 +41,7 @@ export fn syscall(registers: *const Registers) callconv(.C) birth.syscall.Result
 /// - R10: argument 3
 /// - R8:  argument 4
 /// - R9:  argument 5
-pub fn entryPoint() callconv(.Naked) void {
+pub fn entryPoint() callconv(.Naked) noreturn {
     asm volatile (
         \\endbr64
         \\swapgs
@@ -252,8 +186,6 @@ pub fn entryPoint() callconv(.Naked) void {
     asm volatile (
         \\int3
         ::: "memory");
-
-    unreachable;
 }
 
 pub const Registers = extern struct {

src/cpu/arch/x86_64.zig

@@ -22,7 +22,7 @@ const VirtualMemoryRegion = lib.VirtualMemoryRegion;
 const cpu = @import("cpu");
 const Heap = cpu.Heap;
 
-const init = @import("./x86/64/init.zig");
+pub const init = @import("./x86/64/init.zig");
 pub const syscall = @import("./x86/64/syscall.zig");
 pub const entryPoint = init.entryPoint;
 
@@ -56,13 +56,33 @@ pub const Registers = extern struct {
 
 const interrupt_kind: u32 = 0;
 
+const PageFaultFlags = packed struct(u32) {
+    present: bool,
+    write: bool,
+    user: bool,
+    reserved_write: bool,
+    instruction_fetch: bool,
+    protection_key: bool,
+    shadow_stack: bool,
+    reserved0: u8 = 0,
+    software_guard_extensions: bool,
+    reserved: u16 = 0,
+};
+
 export fn interruptHandler(regs: *const InterruptRegisters, interrupt_number: u8) void {
     switch (interrupt_number) {
         local_timer_vector => {
             APIC.write(.eoi, 0);
             nextTimer(10);
         },
-        else => cpu.panicFromInstructionPointerAndFramePointer(regs.rip, regs.rbp, "Exception: 0x{x}", .{interrupt_number}),
+        else => {
+            if (interrupt_number == 0xe) {
+                const pagefault_flags: PageFaultFlags = @bitCast(@as(u32, @intCast(regs.error_code)));
+                const fault_address = privileged.arch.x86_64.registers.cr2.read();
+                log.err("Page 0x{x} not mapped at IP 0x{x}. Flags: {}", .{ fault_address, regs.rip, pagefault_flags });
+            }
+            cpu.panicFromInstructionPointerAndFramePointer(regs.rip, regs.rbp, "Exception 0x{x} at IP 0x{x}", .{ interrupt_number, regs.rip });
+        },
     }
 }
 
@@ -103,7 +123,7 @@ pub const invariant_tsc = false;
 pub const capability_address_space_size = 1 * lib.gb;
 pub const capability_address_space_start = capability_address_space_stack_top - capability_address_space_size;
 pub const capability_address_space_stack_top = 0xffff_ffff_8000_0000;
-pub const capability_address_space_stack_size = privileged.default_stack_size;
+pub const capability_address_space_stack_size = 10 * privileged.default_stack_size;
 pub const capability_address_space_stack_alignment = lib.arch.valid_page_sizes[0];
 pub const capability_address_space_stack_address = VirtualAddress.new(capability_address_space_stack_top - capability_address_space_stack_size);
 pub const code_64 = @offsetOf(GDT, "code_64");
@@ -263,3 +283,5 @@ pub const root_page_table_entry = @as(cpu.arch.PageTableEntry, @enumFromInt(0));
 pub const IOMap = extern struct {
     debug: bool,
 };
+
+pub const user_root_page_table_alignment = 2 * lib.arch.valid_page_sizes[0];

src/cpu/capabilities.zig

@@ -1,419 +0,0 @@
-const lib = @import("lib");
-const assert = lib.assert;
-const Allocator = lib.Allocator;
-const enumCount = lib.enumCount;
-const log = lib.log.scoped(.capabilities);
-
-const privileged = @import("privileged");
-const PhysicalAddress = lib.PhysicalAddress;
-const PhysicalMemoryRegion = lib.PhysicalMemoryRegion;
-const birth = @import("birth");
-const cpu = @import("cpu");
-
-pub const RootDescriptor = extern struct {
-    value: *Root,
-};
-
-pub const Static = enum {
-    cpu,
-    boot,
-    process,
-
-    pub const count = lib.enumCount(@This());
-
-    pub const Bitmap = @Type(.{
-        .Struct = blk: {
-            const full_bit_size = @max(@as(comptime_int, 1 << 3), @as(u8, @sizeOf(Static)) << 3);
-            break :blk .{
-                .layout = .Packed,
-                .backing_integer = lib.IntType(.unsigned, full_bit_size),
-                .fields = fields: {
-                    var fields: []const lib.Type.StructField = &.{};
-                    inline for (lib.enumFields(Static)) |static_field| {
-                        fields = fields ++ [1]lib.Type.StructField{.{
-                            .name = static_field.name,
-                            .type = bool,
-                            .default_value = null,
-                            .is_comptime = false,
-                            .alignment = 0,
-                        }};
-                    }
-
-                    assert(Static.count > 0);
-                    assert(@sizeOf(Static) > 0 or Static.count == 1);
-
-                    const padding_type = lib.IntType(.unsigned, full_bit_size - Static.count);
-
-                    fields = fields ++ [1]lib.Type.StructField{.{
-                        .name = "reserved",
-                        .type = padding_type,
-                        .default_value = &@as(padding_type, 0),
-                        .is_comptime = false,
-                        .alignment = 0,
-                    }};
-                    break :fields fields;
-                },
-                .decls = &.{},
-                .is_tuple = false,
-            };
-        },
-    });
-};
-
-pub const Dynamic = enum {
-    io,
-    ram, // Barrelfish equivalent: RAM (no PhysAddr)
-    cpu_memory, // Barrelfish equivalent: Frame
-    page_table, // Barrelfish equivalent: VNode
-    // irq_table,
-    // device_memory,
-    // scheduler,
-
-    pub const Map = extern struct {
-        io: IO,
-        ram: RAM,
-        cpu_memory: CPUMemory,
-        page_table: PageTables,
-
-        comptime {
-            inline for (lib.fields(Dynamic.Map), lib.fields(Dynamic)) |struct_field, enum_field| {
-                assert(lib.equal(u8, enum_field.name, struct_field.name));
-            }
-        }
-    };
-};
-
-pub const RAM = extern struct {
-    lists: [lib.arch.reverse_valid_page_sizes.len]?*Region = .{null} ** lib.arch.valid_page_sizes.len,
-
-    const AllocateError = error{
-        OutOfMemory,
-    };
-
-    inline fn getListIndex(size: usize) usize {
-        inline for (lib.arch.reverse_valid_page_sizes, 0..) |reverse_page_size, reverse_index| {
-            if (size >= reverse_page_size) return reverse_index;
-        }
-
-        unreachable;
-    }
-
-    pub const Region = extern struct {
-        region: PhysicalMemoryRegion,
-        next: ?*@This() = null,
-
-        const UnalignedAllocationResult = extern struct {
-            wasted: PhysicalMemoryRegion,
-            allocated: PhysicalMemoryRegion,
-        };
-
-        inline fn allocateUnaligned(free_ram: *Region, size: usize, alignment: usize) ?UnalignedAllocationResult {
-            const aligned_region_address = lib.alignForward(usize, free_ram.region.address.value(), alignment);
-            const wasted_space = aligned_region_address - free_ram.region.address.value();
-            if (free_ram.region.size >= wasted_space + size) {
-                const wasted_region = free_ram.region.takeSlice(wasted_space);
-                const allocated_region = free_ram.region.takeSlice(size);
-                return UnalignedAllocationResult{
-                    .wasted = wasted_region,
-                    .allocated = allocated_region,
-                };
-            }
-
-            return null;
-        }
-    };
-};
-
-pub const CPUMemory = extern struct {
-    privileged: RAM = .{},
-    user: RAM = .{},
-    flags: Flags,
-
-    const Flags = packed struct(u64) {
-        allocate: bool,
-        reserved: u63 = 0,
-    };
-};
-
-pub const PageTables = extern struct {
-    foo: u32 = 0,
-};
-
-pub const IO = extern struct {
-    debug: bool,
-};
-
-pub const Scheduler = extern struct {
-    handle: ?*cpu.UserScheduler = null,
-    memory: PhysicalMemoryRegion,
-};
-
-comptime {
-    assert(enumCount(Dynamic) + enumCount(Static) == enumCount(birth.capabilities.Type));
-}
-
-pub const Root = extern struct {
-    static: Static.Bitmap,
-    dynamic: Dynamic.Map,
-    scheduler: Scheduler,
-    heap: Heap = .{},
-    padding: [padding_byte_count]u8 = .{0} ** padding_byte_count,
-
-    const max_alignment = @max(@alignOf(Static.Bitmap), @alignOf(Dynamic.Map), @alignOf(Scheduler), @alignOf(Heap));
-    const total_size = lib.alignForward(usize, @sizeOf(Static.Bitmap) + @sizeOf(Dynamic.Map) + @sizeOf(Scheduler) + @sizeOf(Heap), max_alignment);
-    const page_aligned_size = lib.alignForward(usize, total_size, lib.arch.valid_page_sizes[0]);
-    const padding_byte_count = page_aligned_size - total_size;
-
-    comptime {
-        assert(@sizeOf(Root) % lib.arch.valid_page_sizes[0] == 0);
-    }
-
-    pub fn copy(root: *Root, other: *Root) void {
-        other.static = root.static;
-        // TODO:
-        other.dynamic = root.dynamic;
-    }
-
-    pub inline fn hasPermissions(root: *const Root, comptime capability_type: birth.capabilities.Type, command: birth.capabilities.Command(capability_type)) bool {
-        return switch (capability_type) {
-            // static capabilities
-            inline .cpu,
-            .boot,
-            .process,
-            => |static_capability| @field(root.static, @tagName(static_capability)),
-            // dynamic capabilities
-            .io => switch (command) {
-                .copy, .mint, .retype, .delete, .revoke, .create => unreachable,
-                .log => root.dynamic.io.debug,
-            },
-            .cpu_memory => root.dynamic.cpu_memory.flags.allocate,
-            .ram => unreachable,
-            .page_table => unreachable,
-        };
-    }
-
-    pub const AllocateError = error{
-        OutOfMemory,
-    };
-
-    // Fast path
-    pub fn allocatePages(root: *Root, size: usize) AllocateError!PhysicalMemoryRegion {
-        assert(size != 0);
-        assert(lib.isAligned(size, lib.arch.valid_page_sizes[0]));
-        var index = RAM.getListIndex(size);
-
-        const result = blk: {
-            while (true) : (index -= 1) {
-                const list = root.dynamic.ram.lists[index];
-                var iterator = list;
-
-                while (iterator) |free_ram| : (iterator = free_ram.next) {
-                    if (free_ram.region.size >= size) {
-                        if (free_ram.region.size >= size) {
-                            const result = free_ram.region.takeSlice(size);
-                            break :blk result;
-                        } else {
-                            @panic("TODO: cnsume all reigon");
-                        }
-                    }
-                }
-
-                if (index == 0) break;
-            }
-
-            return error.OutOfMemory;
-        };
-
-        @memset(result.toHigherHalfVirtualAddress().access(u8), 0);
-
-        return result;
-    }
-
-    // Slow uncommon path. Use cases:
-    // 1. CR3 switch. This is assumed to be privileged, so this function assumes privileged use of the memory
-    pub fn allocatePageCustomAlignment(root: *Root, size: usize, alignment: usize) AllocateError!PhysicalMemoryRegion {
-        assert(alignment > lib.arch.valid_page_sizes[0] and alignment < lib.arch.valid_page_sizes[1]);
-
-        comptime assert(lib.arch.valid_page_sizes.len == 3);
-        var index = RAM.getListIndex(size);
-
-        while (true) : (index -= 1) {
-            if (root.dynamic.ram.lists[index]) |smallest_region_list| {
-                var iterator: ?*cpu.capabilities.RAM.Region = smallest_region_list;
-                while (iterator) |free_ram| : (iterator = free_ram.next) {
-                    if (lib.isAligned(free_ram.region.address.value(), alignment)) {
-                        if (free_ram.region.size >= size) {
-                            const allocated_region = free_ram.region.takeSlice(size);
-                            return allocated_region;
-                        }
-                    } else if (free_ram.allocateUnaligned(size, alignment)) |unaligned_allocation| {
-                        try root.addRegion(&root.dynamic.ram, unaligned_allocation.wasted);
-                        return unaligned_allocation.allocated;
-                    }
-                }
-            }
-
-            if (index == 0) break;
-        }
-
-        return AllocateError.OutOfMemory;
-    }
-
-    fn allocateSingle(root: *Root, comptime T: type) AllocateError!*T {
-        var iterator = root.heap.first;
-        while (iterator) |heap_region| : (iterator = heap_region.next) {
-            if (heap_region.alignmentFits(@alignOf(T))) {
-                if (heap_region.sizeFits(@sizeOf(T))) {
-                    const allocated_region = heap_region.takeRegion(@sizeOf(T));
-                    const result = &allocated_region.toHigherHalfVirtualAddress().access(T)[0];
-                    return result;
-                }
-            } else {
-                @panic("ELSE");
-            }
-        }
-
-        const physical_region = try root.allocatePages(lib.arch.valid_page_sizes[0]);
-        const heap_region = physical_region.toHigherHalfVirtualAddress().address.access(*Heap.Region);
-        const first = root.heap.first;
-        heap_region.* = .{
-            .descriptor = physical_region.offset(@sizeOf(Heap.Region)),
-            .allocated_size = @sizeOf(Heap.Region),
-            .next = first,
-        };
-
-        root.heap.first = heap_region;
-
-        return try root.allocateSingle(T);
-    }
-
-    fn allocateMany(root: *Root, comptime T: type, count: usize) AllocateError![]T {
-        _ = count;
-        _ = root;
-
-        @panic("TODO many");
-    }
-
-    fn addRegion(root: *Root, ram: *RAM, physical_region: PhysicalMemoryRegion) !void {
-        const index = RAM.getListIndex(physical_region.size);
-        const new_region = try root.allocateSingle(RAM.Region);
-        new_region.* = RAM.Region{
-            .region = physical_region,
-            .next = root.dynamic.ram.lists[index],
-        };
-
-        ram.lists[index] = new_region;
-    }
-
-    pub const AllocateCPUMemoryOptions = packed struct {
-        privileged: bool,
-    };
-
-    pub fn allocateCPUMemory(root: *Root, physical_region: PhysicalMemoryRegion, options: AllocateCPUMemoryOptions) !void {
-        const ram_region = switch (options.privileged) {
-            true => &root.dynamic.cpu_memory.privileged,
-            false => &root.dynamic.cpu_memory.user,
-        };
-
-        try root.addRegion(ram_region, physical_region);
-    }
-
-    pub const Heap = extern struct {
-        first: ?*Region = null,
-
-        const AllocateError = error{
-            OutOfMemory,
-        };
-
-        pub fn new(physical_region: PhysicalMemoryRegion, previous_allocated_size: usize) Heap {
-            const allocated_size = previous_allocated_size + @sizeOf(Region);
-            assert(physical_region.size > allocated_size);
-            const region = physical_region.offset(previous_allocated_size).address.toHigherHalfVirtualAddress().access(*Region);
-            region.* = .{
-                .descriptor = physical_region,
-                .allocated_size = allocated_size,
-            };
-            return Heap{
-                .first = region,
-            };
-        }
-
-        fn create(heap: *Heap, comptime T: type) Heap.AllocateError!*T {
-            const result = try heap.allocate(T, 1);
-            return &result[0];
-        }
-
-        fn allocate(heap: *Heap, comptime T: type, count: usize) Heap.AllocateError![]T {
-            var iterator = heap.first;
-            while (iterator) |heap_region| {
-                const allocation = heap_region.allocate(T, count) catch continue;
-                return allocation;
-            }
-            @panic("TODO: allocate");
-        }
-
-        const Region = extern struct {
-            descriptor: PhysicalMemoryRegion,
-            allocated_size: usize,
-            next: ?*Region = null,
-
-            inline fn getFreeRegion(region: Region) PhysicalMemoryRegion {
-                const free_region = region.descriptor.offset(region.allocated_size);
-                assert(free_region.size > 0);
-                return free_region;
-            }
-
-            const AllocateError = error{
-                OutOfMemory,
-            };
-
-            fn takeRegion(region: *Region, size: usize) PhysicalMemoryRegion {
-                var free_region = region.getFreeRegion();
-                assert(free_region.size >= size);
-                const allocated_region = free_region.takeSlice(size);
-                region.allocated_size += size;
-                return allocated_region;
-            }
-
-            fn allocate(region: *Region, comptime T: type, count: usize) Region.AllocateError![]T {
-                const free_region = region.getFreeRegion();
-                _ = free_region;
-                _ = count;
-                @panic("TODO: region allocate");
-            }
-
-            fn create(region: *Region, comptime T: type) Region.AllocateError!*T {
-                const result = try region.allocate(T, 1);
-                return &result[0];
-            }
-
-            inline fn canAllocateDirectly(region: Region, size: usize, alignment: usize) bool {
-                const alignment_fits = region.alignmentFits(alignment);
-                const size_fits = region.sizeFits(size);
-                return alignment_fits and size_fits;
-            }
-
-            inline fn canAllocateSplitting(region: Region, size: usize, alignment: usize) bool {
-                const free_region = region.getFreeRegion();
-                const aligned_region_address = lib.alignForward(usize, free_region.address.value(), alignment);
-                const wasted_space = aligned_region_address - free_region.address.value();
-                log.warn("Wasted space: {} bytes", .{wasted_space});
-                _ = size;
-                @panic("TODO: canAllocateSplitting");
-            }
-
-            inline fn sizeFits(region: Region, size: usize) bool {
-                return region.descriptor.size - region.allocated_size >= size;
-            }
-
-            inline fn alignmentFits(region: Region, alignment: usize) bool {
-                const result = lib.isAligned(region.getFreeRegion().address.value(), alignment);
-                return result;
-            }
-        };
-    };
-};
-
-pub const RootPageTableEntry = extern struct {
-    address: PhysicalAddress,
-};

src/cpu/init.zig

@@ -0,0 +1,368 @@
+const birth = @import("birth");
+const bootloader = @import("bootloader");
+const cpu = @import("cpu");
+const lib = @import("lib");
+const privileged = @import("privileged");
+
+const assert = lib.assert;
+const log = lib.log;
+const PhysicalAddress = lib.PhysicalAddress;
+const PhysicalMemoryRegion = lib.PhysicalMemoryRegion;
+const VirtualAddress = lib.VirtualAddress;
+const VirtualMemoryRegion = lib.VirtualMemoryRegion;
+
+const RegionList = cpu.RegionList;
+const PageTableRegions = cpu.arch.init.PageTableRegions;
+
+const paging = privileged.arch.paging;
+pub const Error = error{
+    feature_requested_and_not_available,
+    no_files,
+    cpu_file_not_found,
+    init_file_not_found,
+    no_space_for_bootstrap_region,
+};
+
+pub fn initialize(bootloader_information: *bootloader.Information) !noreturn {
+    // bootloader_information.draw_context.clearScreen(0xffff7f50);
+    // Do an integrity check so that the bootloader information is in perfect state and there is no weird memory behavior.
+    // This is mainly due to the transition from a 32-bit bootloader to a 64-bit CPU driver in the x86-64 architecture.
+    try bootloader_information.checkIntegrity();
+    // Informing the bootloader information struct that we have reached the CPU driver and any bootloader
+    // functionality is not available anymore
+    bootloader_information.stage = .cpu;
+    // Check that the bootloader has loaded some files as the CPU driver needs them to go forward
+    cpu.bundle = bootloader_information.getSlice(.bundle);
+    if (cpu.bundle.len == 0) {
+        return Error.no_files;
+    }
+    cpu.bundle_files = bootloader_information.getSlice(.file_list);
+    if (cpu.bundle_files.len == 0) {
+        return Error.no_files;
+    }
+
+    try cpu.arch.init.initialize();
+
+    const memory_map_entries = bootloader_information.getMemoryMapEntries();
+    const page_counters = bootloader_information.getPageCounters();
+
+    const first_heap_allocation_size = 2 * lib.arch.valid_page_sizes[0];
+
+    var heap_region_metadata: struct {
+        region: PhysicalMemoryRegion,
+        free_size: u64,
+        index: usize,
+    } = for (memory_map_entries, page_counters, 0..) |mmap_entry, page_counter, index| {
+        if (mmap_entry.type == .usable) {
+            const free_region = mmap_entry.getFreeRegion(page_counter);
+            if (free_region.size >= first_heap_allocation_size) {
+                break .{
+                    .region = PhysicalMemoryRegion.new(.{
+                        .address = free_region.address,
+                        .size = free_region.size,
+                    }),
+                    .free_size = free_region.size - first_heap_allocation_size,
+                    .index = index,
+                };
+            }
+        }
+    } else return error.no_space_for_bootstrap_region;
+
+    const heap_region = try heap_region_metadata.region.takeSlice(first_heap_allocation_size);
+    try cpu.heap.addBootstrapingRegion(heap_region.toHigherHalfVirtualAddress());
+
+    const host_free_region_list = try cpu.heap.create(RegionList);
+
+    var free_size: u64 = 0;
+    _ = try host_free_region_list.append(heap_region_metadata.region);
+    free_size += heap_region_metadata.region.size;
+
+    var region_list_iterator = host_free_region_list;
+
+    for (memory_map_entries, page_counters, 0..) |memory_map_entry, page_counter, index| {
+        if (index == heap_region_metadata.index) continue;
+
+        if (memory_map_entry.type == .usable) {
+            const free_region = memory_map_entry.getFreeRegion(page_counter);
+
+            if (free_region.size > 0) {
+                assert(lib.isAligned(free_region.size, lib.arch.valid_page_sizes[0]));
+                _ = region_list_iterator.append(free_region) catch {
+                    const new_region_list = try cpu.heap.create(RegionList);
+                    region_list_iterator.metadata.next = new_region_list;
+                    new_region_list.metadata.previous = region_list_iterator;
+                    region_list_iterator = new_region_list;
+                    _ = try region_list_iterator.append(free_region);
+                };
+
+                free_size += free_region.size;
+            }
+        }
+    }
+
+    cpu.page_allocator.free_regions = host_free_region_list;
+    cpu.page_allocator.free_byte_count = free_size;
+
+    // Add used regions by the bootloader to the physical memory manager
+    for (memory_map_entries, page_counters) |memory_map_entry, page_counter| {
+        if (memory_map_entry.type == .usable) {
+            const used_region = memory_map_entry.getUsedRegion(page_counter);
+            if (used_region.size > 0) {
+                assert(lib.isAligned(used_region.size, lib.arch.valid_page_sizes[0]));
+                try cpu.page_allocator.appendUsedRegion(used_region, .{ .reason = .bootloader });
+            }
+        }
+    }
+
+    var used_regions = cpu.page_allocator.used_regions;
+    var used_memory_by_bootloader: usize = 0;
+    while (used_regions) |used_region| : (used_regions = used_region.next) {
+        if (used_region.use_case.reason == .bootloader) {
+            used_memory_by_bootloader += used_region.region.size;
+        }
+    }
+
+    log.debug("Used memory by the bootloader: 0x{x} bytes", .{used_memory_by_bootloader});
+
+    try cpu.page_allocator.appendUsedRegion(heap_region, .{ .reason = .heap });
+
+    switch (cpu.bsp) {
+        true => {
+            // Setup kernel debug information
+            cpu.debug_info = blk: {
+                const cpu_driver_executable_descriptor = try bootloader_information.getFileDescriptor("cpu_driver");
+                const elf_file = file: {
+                    const aligned_file_len = lib.alignForward(usize, cpu_driver_executable_descriptor.content.len, lib.arch.valid_page_sizes[0]);
+                    const elf_file_physical_allocation = try cpu.page_allocator.allocate(aligned_file_len, .{ .reason = .privileged });
+                    break :file elf_file_physical_allocation.toHigherHalfVirtualAddress().address.access([*]align(lib.arch.valid_page_sizes[0]) u8)[0..elf_file_physical_allocation.size];
+                };
+                lib.memcpy(elf_file[0..cpu_driver_executable_descriptor.content.len], cpu_driver_executable_descriptor.content);
+                const result = try lib.getDebugInformation(cpu.heap.allocator.zigUnwrap(), elf_file);
+                break :blk result;
+            };
+
+            const init_module_descriptor = try bootloader_information.getFileDescriptor("init");
+
+            try spawnInitBSP(init_module_descriptor.content, bootloader_information.cpu_page_tables);
+        },
+        false => @panic("TODO: implement APP"),
+    }
+}
+
+const ELF = lib.ELF(64);
+
+const SpawnInitCommonResult = extern struct {
+    scheduler: *cpu.UserScheduler,
+    entry_point: u64,
+};
+
+pub const MappingArgument = extern struct {
+    virtual: VirtualAddress,
+    physical: PhysicalAddress,
+    size: u64,
+};
+
+pub const InitFile = struct {
+    content: []const u8,
+    segments: []const Segment,
+};
+
+pub const Segment = extern struct {
+    virtual: VirtualAddress,
+    physical: PhysicalAddress,
+    memory_size: usize,
+    flags: privileged.Mapping.Flags,
+    file_offset: usize,
+    file_size: usize,
+};
+
+var once: bool = false;
+
+fn spawnInitCommon(init_file: []const u8, cpu_page_tables: paging.CPUPageTables) !SpawnInitCommonResult {
+    assert(!once);
+    once = true;
+    // TODO: delete in the future
+    assert(cpu.bsp);
+
+    const init_cpu_scheduler = try cpu.heap.create(cpu.UserScheduler);
+    init_cpu_scheduler.* = cpu.UserScheduler{
+        .s = .{
+            .common = undefined,
+            .capability_root_node = cpu.interface.Root{
+                .static = .{
+                    .cpu = true,
+                    .boot = true,
+                    .process = true,
+                },
+                .dynamic = .{
+                    .io = .{
+                        .debug = true,
+                    },
+                    .memory = .{},
+                    .cpu_memory = .{
+                        .flags = .{
+                            .allocate = true,
+                        },
+                    },
+                    .page_table = cpu.interface.PageTables{
+                        .privileged = undefined,
+                        .user = birth.interface.PageTable{
+                            .index = 0,
+                            .entry_type = .page_table,
+                        },
+                        // .vmm = try cpu.interface.VMM.new(),
+                        .can_map_page_tables = true,
+                        .page_tables = .{
+                            .ptr = undefined,
+                            .len = 0,
+                            .capacity = 0,
+                        },
+                        .leaves = .{
+                            .ptr = undefined,
+                            .len = 0,
+                            .capacity = 0,
+                        },
+                    },
+                    .command_buffer_submission = .{ .region = PhysicalMemoryRegion.invalid() },
+                    .command_buffer_completion = .{ .region = PhysicalMemoryRegion.invalid() },
+                    .memory_mapping = .{},
+                    .page_table_mapping = .{},
+                },
+                .scheduler = .{
+                    .memory = undefined,
+                    // .memory = scheduler_physical_region,
+                },
+            },
+        },
+    };
+
+    const init_elf = try ELF.Parser.init(init_file);
+    const entry_point = init_elf.getEntryPoint();
+    const program_headers = init_elf.getProgramHeaders();
+
+    var segment_buffer: [20]Segment = undefined;
+    var segment_count: usize = 0;
+    var segment_total_size: usize = 0;
+    var first_address: ?u64 = null;
+
+    for (program_headers) |program_header| {
+        if (program_header.type == .load) {
+            if (first_address == null) {
+                first_address = program_header.virtual_address;
+            }
+
+            const segment_size = lib.alignForward(usize, program_header.size_in_memory, lib.arch.valid_page_sizes[0]);
+            segment_total_size += segment_size;
+
+            const segment_virtual = VirtualAddress.new(program_header.virtual_address);
+            const segment_physical_region = try cpu.page_allocator.allocate(segment_size, .{ .reason = .user });
+
+            const segment = &segment_buffer[segment_count];
+            segment.* = .{
+                .physical = segment_physical_region.address,
+                .virtual = segment_virtual,
+                .memory_size = segment_size,
+                .flags = .{
+                    .execute = program_header.flags.executable,
+                    .write = program_header.flags.writable,
+                    .user = true,
+                    .huge_pages = false,
+                },
+                .file_offset = program_header.offset,
+                .file_size = program_header.size_in_file,
+            };
+
+            const src = init_file[segment.file_offset..][0..segment.file_size];
+            // It's necessary to use the higher half address here since the user mapping is not applied yet
+            const dst = segment_physical_region.toHigherHalfVirtualAddress().access(u8)[0..src.len];
+            lib.memcpy(dst, src);
+
+            segment_count += 1;
+        }
+    }
+
+    const init_start_address = first_address orelse @panic("WTF");
+    const init_top_address = init_start_address + segment_total_size;
+    const user_scheduler_virtual_address = VirtualAddress.new(init_top_address);
+    init_cpu_scheduler.s.common = user_scheduler_virtual_address.access(*birth.Scheduler.Common);
+
+    const user_scheduler_virtual_region = VirtualMemoryRegion.new(.{
+        .address = user_scheduler_virtual_address,
+        .size = lib.alignForward(usize, @sizeOf(birth.Scheduler), lib.arch.valid_page_sizes[0]),
+    });
+    // Align to 2MB
+    const user_initial_heap_top = lib.alignForward(usize, user_scheduler_virtual_region.top().value(), lib.arch.valid_page_sizes[1]);
+
+    const segments = segment_buffer[0..segment_count];
+
+    const user_virtual_region = VirtualMemoryRegion.new(.{
+        .address = VirtualAddress.new(init_start_address),
+        .size = user_initial_heap_top - init_start_address,
+    });
+    // const page_table_regions = try PageTableRegions.create(user_virtual_region, cpu_page_tables);
+    log.debug("Scheduler region", .{});
+    const scheduler_physical_region = try cpu.page_allocator.allocate(user_scheduler_virtual_region.size, .{ .reason = .user });
+    init_cpu_scheduler.s.capability_root_node.scheduler.memory = scheduler_physical_region;
+
+    const scheduler_virtual_region = VirtualMemoryRegion.new(.{
+        .address = user_scheduler_virtual_address,
+        .size = scheduler_physical_region.size,
+    });
+
+    scheduler_physical_region.address.toHigherHalfVirtualAddress().access(*birth.Scheduler.Common).self = user_scheduler_virtual_address.access(*birth.Scheduler.Common);
+
+    const heap_virtual_region = VirtualMemoryRegion.new(.{
+        .address = scheduler_virtual_region.top(),
+        .size = lib.alignForward(usize, scheduler_virtual_region.top().value(), 64 * lib.arch.valid_page_sizes[1]) - scheduler_virtual_region.top().value(),
+    });
+
+    log.debug("Heap region", .{});
+    const heap_physical_region = try cpu.page_allocator.allocate(heap_virtual_region.size, .{ .reason = .user });
+    @memset(heap_physical_region.toHigherHalfVirtualAddress().access(u8), 0);
+
+    assert(scheduler_physical_region.size == scheduler_virtual_region.size);
+    assert(heap_physical_region.size == heap_virtual_region.size);
+    // Setup common variables
+    const higher_half_scheduler_common = scheduler_physical_region.address.toHigherHalfVirtualAddress().access(*birth.Scheduler.Common);
+    higher_half_scheduler_common.disabled = true;
+    higher_half_scheduler_common.core_id = cpu.core_id;
+    higher_half_scheduler_common.heap = VirtualMemoryRegion.new(.{
+        .address = heap_virtual_region.address,
+        .size = heap_virtual_region.size,
+    });
+
+    try cpu.arch.init.setupMapping(init_cpu_scheduler, user_virtual_region, cpu_page_tables, .{
+        .content = init_file,
+        .segments = segments,
+    }, .{
+        .scheduler = .{
+            .physical = scheduler_physical_region.address,
+            .virtual = scheduler_virtual_region.address,
+            .size = scheduler_virtual_region.size,
+        },
+        .heap = .{
+            .physical = heap_physical_region.address,
+            .virtual = heap_virtual_region.address,
+            .size = heap_virtual_region.size,
+        },
+    });
+
+    return SpawnInitCommonResult{
+        // .page_table_regions = page_table_regions,
+        .scheduler = init_cpu_scheduler,
+        .entry_point = entry_point,
+    };
+}
+
+fn spawnInitBSP(init_file: []const u8, cpu_page_tables: paging.CPUPageTables) !noreturn {
+    const spawn_init = try spawnInitCommon(init_file, cpu_page_tables);
+    const init_scheduler = spawn_init.scheduler;
+    // const page_table_regions = spawn_init.page_table_regions;
+    const entry_point = spawn_init.entry_point;
+    const scheduler_common = init_scheduler.s.common;
+
+    cpu.user_scheduler = init_scheduler;
+
+    cpu.arch.init.setupSchedulerCommon(scheduler_common, entry_point);
+    scheduler_common.disabled_save_area.contextSwitch();
+}

src/cpu/interface.zig

@@ -0,0 +1,602 @@
+const lib = @import("lib");
+const assert = lib.assert;
+const Allocator = lib.Allocator;
+const enumCount = lib.enumCount;
+const log = lib.log.scoped(.capabilities);
+const SparseArray = lib.data_structures.SparseArray;
+const VirtualAddress = lib.VirtualAddress;
+
+const privileged = @import("privileged");
+const paging = privileged.arch.paging;
+const PhysicalAddress = lib.PhysicalAddress;
+const PhysicalMemoryRegion = lib.PhysicalMemoryRegion;
+const VirtualMemoryRegion = lib.VirtualMemoryRegion;
+const birth = @import("birth");
+const cpu = @import("cpu");
+const RegionList = cpu.RegionList;
+
+pub var system_call_count: usize = 0;
+
+pub fn processFromRaw(options: birth.interface.Raw.Options, arguments: birth.interface.Raw.Arguments) birth.interface.Raw.Result {
+    defer system_call_count += 1;
+    return switch (options.general.convention) {
+        .birth => switch (options.birth.type) {
+            inline else => |capability| switch (@as(birth.interface.Command.fromCapability(capability), @enumFromInt(options.birth.command))) {
+                inline else => |command| blk: {
+                    const Interface = birth.interface.Descriptor(capability, command);
+                    const result = processCommand(Interface, arguments) catch |err| {
+                        lib.log.err("Syscall ({s}, {s}) ended up in error: {}", .{ @tagName(capability), @tagName(command), err });
+                        break :blk Interface.fromError(err);
+                    };
+                    break :blk Interface.fromResult(result);
+                },
+            },
+        },
+        .emulated => @panic("TODO: emulated"),
+    };
+}
+
+pub fn processCommand(comptime Descriptor: type, raw_arguments: birth.interface.Raw.Arguments) Descriptor.Error!Descriptor.Result {
+    defer cpu.command_count += 1;
+    const capability = Descriptor.Capability;
+    const command = Descriptor.Command;
+    const arguments = try Descriptor.toArguments(raw_arguments);
+
+    const root = &cpu.user_scheduler.s.capability_root_node;
+    // log.err("\n========\nSyscall received: {s}, {s}\n========\n", .{ @tagName(capability), @tagName(command) });
+
+    assert(root.static.process);
+    const has_permissions = root.hasPermissions(Descriptor, arguments);
+
+    return if (has_permissions) switch (capability) {
+        .io => switch (command) {
+            .copy, .mint, .retype, .delete, .revoke, .create => unreachable,
+            .log => blk: {
+                const message = arguments;
+                cpu.writer.writeAll(message) catch unreachable;
+                comptime assert(Descriptor.Result == usize);
+                break :blk message.len;
+            },
+        },
+        .cpu => switch (command) {
+            .copy, .mint, .retype, .delete, .revoke, .create => unreachable,
+            .get_core_id => cpu.core_id,
+            .shutdown => cpu.shutdown(.success),
+            .get_command_buffer => {
+                const command_buffer = arguments;
+                _ = command_buffer;
+                @panic("TODO: get_command_buffer");
+            },
+        },
+        .cpu_memory => switch (command) {
+            else => @panic(@tagName(command)),
+        },
+        .command_buffer_completion, .command_buffer_submission => switch (command) {
+            .map => {
+                const region = @field(root.dynamic, @tagName(capability)).region;
+                assert(region.address.value() != 0);
+                assert(region.size != 0);
+                @panic("TODO: map");
+            }, // TODO
+            else => @panic(@tagName(command)),
+        },
+        .memory => switch (command) {
+            .allocate => blk: {
+                comptime assert(@TypeOf(arguments) == usize);
+                const size = arguments;
+                // TODO: we want more fine-grained control of the reason if we want more than a simple statistic
+                const result = try root.allocateMemory(size);
+                break :blk result.reference;
+            },
+            .retype => blk: {
+                const source = arguments.source;
+                const destination = arguments.destination;
+                const region_ptr = root.dynamic.memory.find(source) orelse unreachable;
+                const region_copy = region_ptr.*;
+                root.dynamic.memory.remove(source);
+                switch (destination) {
+                    .cpu_memory => {
+                        // TODO: delete properly
+                        const new_ref = root.dynamic.cpu_memory.allocated.append(region_copy) catch |err| {
+                            log.err("Error: {}", .{err});
+                            return error.OutOfMemory;
+                        };
+                        // TODO: delete properly
+
+                        break :blk @bitCast(new_ref);
+                    },
+                    .command_buffer_submission, .command_buffer_completion => {
+                        switch (destination) {
+                            inline .command_buffer_completion, .command_buffer_submission => |dst| @field(root.dynamic, @tagName(dst)).region = region_copy,
+                            else => @panic("WTF"),
+                        }
+                        // TODO: better value
+                        break :blk .{ .integer = 0 };
+                    },
+                    else => @panic("WTF"),
+                }
+                if (true) @panic("TODO: retype");
+                break :blk undefined;
+            },
+            else => @panic(@tagName(command)),
+        },
+        .boot => switch (command) {
+            .get_bundle_size => cpu.bundle.len,
+            .get_bundle_file_list_size => cpu.bundle_files.len,
+            else => @panic(@tagName(command)),
+        },
+        .process => switch (command) {
+            .exit => cpu.shutdown(switch (arguments) {
+                true => .success,
+                false => .failure,
+            }),
+            .panic => cpu.panic("User process panicked with exit code 0x{x}:\n==========\n{s}\n==========", .{ arguments.exit_code, arguments.message }),
+            else => @panic(@tagName(command)),
+        },
+        .page_table => switch (command) {
+            .get => {
+                const descriptor = arguments.descriptor;
+                assert(descriptor.entry_type == .page_table);
+
+                const block = try root.dynamic.page_table.page_tables.getChecked(descriptor.block);
+                const page_table = &block.array[descriptor.index];
+                log.debug("Page table: {}", .{page_table.flags.level});
+                @memcpy(arguments.buffer, &page_table.children);
+            },
+            .get_leaf => {
+                const descriptor = arguments.descriptor;
+                assert(descriptor.entry_type == .leaf);
+
+                const block = try root.dynamic.page_table.leaves.getChecked(descriptor.block);
+                const leaf = &block.array[descriptor.index];
+
+                const user_leaf = arguments.buffer;
+                user_leaf.* = leaf.common;
+            },
+            else => @panic("TODO: page_table other"),
+        },
+        .memory_mapping => {
+            @panic("TODO: memory_mapping");
+        },
+        .page_table_mapping => {
+            @panic("TODO: page_table_mapping");
+        },
+    } else error.forbidden;
+}
+
+pub const RootDescriptor = extern struct {
+    value: *Root,
+};
+
+pub const Static = enum {
+    cpu,
+    boot,
+    process,
+
+    pub const count = lib.enumCount(@This());
+
+    pub const Bitmap = @Type(.{
+        .Struct = blk: {
+            const full_bit_size = @max(@as(comptime_int, 1 << 3), @as(u8, @sizeOf(Static)) << 3);
+            break :blk .{
+                .layout = .Packed,
+                .backing_integer = @Type(.{
+                    .Int = .{
+                        .signedness = .unsigned,
+                        .bits = full_bit_size,
+                    },
+                }),
+                .fields = fields: {
+                    var fields: []const lib.Type.StructField = &.{};
+                    inline for (lib.enumFields(Static)) |static_field| {
+                        fields = fields ++ [1]lib.Type.StructField{.{
+                            .name = static_field.name,
+                            .type = bool,
+                            .default_value = null,
+                            .is_comptime = false,
+                            .alignment = 0,
+                        }};
+                    }
+
+                    assert(Static.count > 0);
+                    assert(@sizeOf(Static) > 0 or Static.count == 1);
+
+                    const padding_type = @Type(.{
+                        .Int = .{
+                            .signedness = .unsigned,
+                            .bits = full_bit_size - Static.count,
+                        },
+                    });
+
+                    fields = fields ++ [1]lib.Type.StructField{.{
+                        .name = "reserved",
+                        .type = padding_type,
+                        .default_value = &@as(padding_type, 0),
+                        .is_comptime = false,
+                        .alignment = 0,
+                    }};
+                    break :fields fields;
+                },
+                .decls = &.{},
+                .is_tuple = false,
+            };
+        },
+    });
+};
+
+pub const CommandBufferMemory = extern struct {
+    region: PhysicalMemoryRegion,
+};
+
+pub const Dynamic = enum {
+    io,
+    memory, // Barrelfish equivalent: Memory (no PhysAddr)
+    cpu_memory, // Barrelfish equivalent: Frame
+    page_table, // Barrelfish equivalent: VNode
+    command_buffer_submission,
+    command_buffer_completion,
+    memory_mapping, // Barrelfish equivalent: Frame mapping, Device Frame Mapping
+    page_table_mapping, // Barrelfish equivalent: VNode mapping
+    // irq_table,
+    // device_memory,
+    // scheduler,
+
+    pub const Map = extern struct {
+        io: IO,
+        memory: Memory,
+        cpu_memory: CPUMemory,
+        page_table: PageTables,
+        command_buffer_submission: CommandBufferMemory,
+        command_buffer_completion: CommandBufferMemory,
+        memory_mapping: Memory.Mapping,
+        page_table_mapping: PageTables.Mapping,
+
+        comptime {
+            inline for (lib.fields(Dynamic.Map), lib.fields(Dynamic)) |struct_field, enum_field| {
+                assert(lib.equal(u8, enum_field.name, struct_field.name));
+            }
+        }
+    };
+};
+
+pub const Memory = extern struct {
+    allocated: RegionList = .{},
+    allocate: bool = true,
+
+    pub const Mapping = extern struct {
+        foo: u32 = 0,
+    };
+
+    const AllocateError = error{
+        OutOfMemory,
+    };
+
+    fn find(memory: *Memory, memory_descriptor: birth.interface.Memory) ?*PhysicalMemoryRegion {
+        var iterator: ?*RegionList = &memory.allocated;
+        var block_index: usize = 0;
+
+        return blk: while (iterator) |list| : ({
+            iterator = list.metadata.next;
+            block_index += 1;
+        }) {
+            if (block_index == memory_descriptor.block) {
+                @panic("TODO: find");
+                // if (memory_descriptor.region < list.metadata.count) {
+                //     const region = &list.regions[memory_descriptor.region];
+                //     if (region.size != 0 and region.address.value() != 0) {
+                //         assert(lib.isAligned(region.size, lib.arch.valid_page_sizes[0]));
+                //         assert(lib.isAligned(region.address.value(), lib.arch.valid_page_sizes[0]));
+                //         break :blk region;
+                //     }
+                // }
+                //
+                // break :blk null;
+            } else if (block_index > memory_descriptor.block) {
+                break :blk null;
+            } else {
+                continue;
+            }
+        } else break :blk null;
+    }
+
+    inline fn getListIndex(size: usize) usize {
+        inline for (lib.arch.reverse_valid_page_sizes, 0..) |reverse_page_size, reverse_index| {
+            if (size >= reverse_page_size) return reverse_index;
+        }
+
+        @panic("WTF");
+    }
+
+    pub fn appendRegion(memory: *Memory, region: PhysicalMemoryRegion) !birth.interface.Memory {
+        var iterator: ?*RegionList = &memory.allocated;
+        while (iterator) |region_list| : (iterator = region_list.metadata.next) {
+            const result = region_list.append(region) catch continue;
+            return result;
+        }
+
+        return error.OutOfMemory;
+    }
+
+    pub fn remove(memory: *Memory, ref: birth.interface.Memory) void {
+        const region_index: u6 = @intCast(ref.region);
+        var block_index: u32 = 0;
+        var iterator: ?*RegionList = &memory.allocated;
+        while (iterator) |region_list| : ({
+            iterator = region_list.metadata.next;
+            block_index += 1;
+        }) {
+            if (block_index == ref.block) {
+                region_list.remove(region_index);
+                break;
+            } else if (block_index > ref.block) {
+                @panic("WTF");
+            } else continue;
+        } else {
+            @panic("WTF");
+        }
+    }
+};
+
+pub const CPUMemory = extern struct {
+    allocated: RegionList = .{},
+    flags: Flags = .{},
+
+    const Flags = packed struct(u64) {
+        allocate: bool = true,
+        reserved: u63 = 0,
+    };
+};
+
+pub const PageTable = extern struct {
+    region: PhysicalMemoryRegion,
+    mapping: VirtualAddress,
+    flags: Flags,
+    children: Children = .{.{}} ** children_count,
+
+    pub const Children = [children_count]birth.interface.PageTable;
+    pub const children_count = paging.page_table_entry_count;
+
+    pub const Flags = packed struct(u64) {
+        level: paging.Level,
+        reserved: u62 = 0,
+    };
+
+    pub const Array = extern struct {
+        array: [count]PageTable,
+        bitset: Bitset,
+        next: ?*Array = null,
+
+        pub const Bitset = lib.data_structures.BitsetU64(count);
+
+        pub const count = 32;
+
+        pub fn get(array: *Array, index: u6) !*PageTable {
+            if (array.bitset.isSet(index)) {
+                return &array.array[index];
+            } else {
+                return error.index_out_of_bounds;
+            }
+        }
+    };
+};
+
+pub const Leaf = extern struct {
+    common: birth.interface.Leaf,
+    physical: PhysicalAddress,
+    flags: Flags,
+
+    pub const Flags = packed struct(u64) {
+        size: Size,
+        reserved: u62 = 0,
+    };
+
+    pub const Size = enum(u2) {
+        @"4KB",
+        @"2MB",
+        @"1GB",
+    };
+
+    pub const Array = extern struct {
+        array: [count]Leaf,
+        bitset: Bitset,
+        next: ?*Array = null,
+        pub const Bitset = lib.data_structures.BitsetU64(count);
+        pub const count = 32;
+        pub fn get(array: *Array, index: u6) !*PageTable {
+            if (array.bitset.isSet(index)) {
+                return &array.array[index];
+            } else {
+                return error.index_out_of_bounds;
+            }
+        }
+    };
+};
+
+pub const PageTables = extern struct {
+    // This one has the kernel mapped
+    privileged: PageTable, // This one is separate as cannot be mapped
+    user: birth.interface.PageTable,
+    page_tables: SparseArray(*PageTable.Array),
+    leaves: SparseArray(*Leaf.Array),
+    // vmm: VMM,
+    can_map_page_tables: bool,
+
+    pub const Mapping = extern struct {
+        foo: u32 = 0,
+    };
+
+    const end = privileged.arch.paging.user_address_space_end;
+
+    fn getUser(page_tables: *const PageTables) ?PhysicalMemoryRegion {
+        if (page_tables.user.address.value() == 0) {
+            return null;
+        }
+
+        if (page_tables.user.size == 0) {
+            return null;
+        }
+
+        return page_tables.user;
+    }
+
+    pub fn switchPrivileged(page_tables: *const PageTables) void {
+        paging.Specific.fromPhysicalRegion(page_tables.privileged.region).makeCurrentPrivileged();
+    }
+
+    pub fn appendPageTable(page_tables: *PageTables, allocator: *Allocator, page_table: PageTable) !birth.interface.PageTable {
+        if (page_tables.page_tables.len > 0) {
+            const slice = page_tables.page_tables.ptr[0..page_tables.page_tables.len];
+            for (slice, 0..) |block, block_index| {
+                const index = block.bitset.allocate() catch continue;
+                block.array[index] = page_table;
+                return .{
+                    .index = index,
+                    .block = @intCast(block_index),
+                    .entry_type = .page_table,
+                    .present = true,
+                };
+            }
+        }
+
+        const page_table_array = try allocator.create(PageTable.Array);
+        _ = try page_tables.page_tables.append(allocator, page_table_array);
+        return appendPageTable(page_tables, allocator, page_table);
+    }
+
+    pub fn appendLeaf(page_tables: *PageTables, allocator: *Allocator, leaf: Leaf) !birth.interface.PageTable {
+        if (page_tables.leaves.len > 0) {
+            const slice = page_tables.leaves.ptr[0..page_tables.leaves.len];
+            for (slice, 0..) |block, block_index| {
+                const index = block.bitset.allocate() catch continue;
+                block.array[index] = leaf;
+
+                return .{
+                    .index = index,
+                    .block = @intCast(block_index),
+                    .entry_type = .leaf,
+                    .present = true,
+                };
+            }
+        }
+
+        const leaf_array = try allocator.create(Leaf.Array);
+        _ = try page_tables.leaves.append(allocator, leaf_array);
+        return appendLeaf(page_tables, allocator, leaf);
+    }
+
+    pub fn getPageTable(page_tables: *PageTables, page_table: birth.interface.PageTable) !*PageTable {
+        assert(page_table.entry_type == .page_table);
+        if (page_table.present) {
+            const page_table_block = try page_tables.page_tables.getChecked(page_table.block);
+            const result = try page_table_block.get(@intCast(page_table.index));
+            return result;
+        } else {
+            return error.not_present;
+        }
+    }
+};
+
+pub const IO = extern struct {
+    debug: bool,
+};
+
+pub const Scheduler = extern struct {
+    memory: PhysicalMemoryRegion,
+};
+
+comptime {
+    const dynamic_count = enumCount(Dynamic);
+    const static_count = enumCount(Static);
+    const total_count = enumCount(birth.interface.Capability);
+    assert(dynamic_count + static_count == total_count);
+}
+
+pub const Root = extern struct {
+    static: Static.Bitmap,
+    dynamic: Dynamic.Map,
+    scheduler: Scheduler,
+    heap: Heap = .{},
+    padding: [padding_byte_count]u8 = .{0} ** padding_byte_count,
+
+    const Heap = cpu.HeapImplementation(true);
+
+    const max_alignment = @max(@alignOf(Static.Bitmap), @alignOf(Dynamic.Map), @alignOf(Scheduler), @alignOf(Heap));
+    const total_size = lib.alignForward(usize, @sizeOf(Static.Bitmap) + @sizeOf(Dynamic.Map) + @sizeOf(Scheduler) + @sizeOf(Heap), max_alignment);
+    const page_aligned_size = lib.alignForward(usize, total_size, lib.arch.valid_page_sizes[0]);
+    const padding_byte_count = page_aligned_size - total_size;
+
+    comptime {
+        assert(@sizeOf(Root) % lib.arch.valid_page_sizes[0] == 0);
+    }
+
+    pub const AllocateError = error{
+        OutOfMemory,
+    };
+
+    fn hasPermissions(root: *Root, comptime Descriptor: type, arguments: Descriptor.Arguments) bool {
+        const capability = Descriptor.Capability;
+        const command = Descriptor.Command;
+
+        if (command == .retype) {
+            const can_retype: bool = switch (@TypeOf(arguments)) {
+                void => @panic("Retype on void"),
+                else => switch (arguments.destination) {
+                    inline else => |destination| blk: {
+                        const child_types = comptime capability.getChildTypes();
+                        inline for (child_types) |child_type| {
+                            if (child_type == destination) {
+                                break :blk true;
+                            }
+                        } else {
+                            break :blk false;
+                        }
+                    },
+                },
+            };
+
+            if (!can_retype) {
+                return false;
+            }
+        }
+
+        const has_permissions = switch (capability) {
+            // static capabilities
+            inline .cpu,
+            .boot,
+            => |static_capability| @field(root.static, @tagName(static_capability)),
+            .process => root.static.process or command == .panic,
+            // dynamic capabilities
+            .io => switch (command) {
+                .copy, .mint, .retype, .delete, .revoke, .create => unreachable,
+                .log => root.dynamic.io.debug,
+            },
+            .cpu_memory => root.dynamic.cpu_memory.flags.allocate,
+            .command_buffer_completion, .command_buffer_submission => true, //TODO
+            .memory => switch (command) {
+                .allocate => root.dynamic.memory.allocate,
+                .retype => root.dynamic.memory.find(arguments.source) != null,
+                else => @panic("TODO: else => memory"),
+            },
+            .page_table => root.dynamic.page_table.can_map_page_tables, // TODO
+            .memory_mapping => true, // TODO
+            .page_table_mapping => true, // TODO
+        };
+
+        return has_permissions;
+    }
+
+    pub const AllocateMemoryResult = extern struct {
+        region: PhysicalMemoryRegion,
+        reference: birth.interface.Memory,
+    };
+
+    pub fn allocateMemory(root: *Root, size: usize) !AllocateMemoryResult {
+        const physical_region = try cpu.page_allocator.allocate(size, .{ .reason = .user });
+        const reference = try root.dynamic.memory.appendRegion(physical_region);
+
+        return .{
+            .region = physical_region,
+            .reference = reference,
+        };
+    }
+};

src/cpu/main.zig

@@ -7,11 +7,8 @@ const stopCPU = privileged.arch.stopCPU;
 
 const cpu = @import("cpu");
 
-var lock: lib.Spinlock = .released;
-
 pub const std_options = struct {
     pub fn logFn(comptime level: lib.log.Level, comptime scope: @TypeOf(.EnumLiteral), comptime format: []const u8, args: anytype) void {
-        lock.acquire();
         cpu.writer.writeAll("[CPU DRIVER] ") catch unreachable;
         cpu.writer.writeByte('[') catch unreachable;
         cpu.writer.writeAll(@tagName(scope)) catch unreachable;
@@ -21,8 +18,6 @@ pub const std_options = struct {
         cpu.writer.writeAll("] ") catch unreachable;
         lib.format(cpu.writer, format, args) catch unreachable;
         cpu.writer.writeByte('\n') catch unreachable;
-
-        lock.release();
     }
 
     pub const log_level = lib.log.Level.debug;

src/cpu/test_runner.zig

@@ -1,38 +0,0 @@
-const lib = @import("lib");
-const assert = lib.assert;
-const log = lib.log.scoped(.TEST);
-const privileged = @import("privileged");
-const QEMU = lib.QEMU;
-
-const cpu = @import("cpu");
-
-const RunAllTestResult = error{
-    failure,
-};
-
-pub fn runAllTests() RunAllTestResult!void {
-    comptime assert(lib.is_test);
-    const test_functions = @import("builtin").test_functions;
-    var failed_test_count: usize = 0;
-    for (test_functions) |test_function| {
-        test_function.func() catch |err| {
-            log.err("Test failed: {}", .{err});
-            failed_test_count += 1;
-        };
-    }
-
-    const test_count = test_functions.len;
-    assert(QEMU.isa_debug_exit.io_size == @sizeOf(u32));
-    const exit_code = switch (failed_test_count) {
-        0 => blk: {
-            log.info("All {} tests passed.", .{test_count});
-            break :blk .success;
-        },
-        else => blk: {
-            log.info("Run {} tests. Failed {}.", .{ test_count, failed_test_count });
-            break :blk .failure;
-        },
-    };
-
-    cpu.shutdown(exit_code);
-}

src/host/runner/main.zig

@@ -251,12 +251,20 @@ pub fn main() anyerror!void {
                 if (arguments.log) |log_configuration| {
                     var log_what = host.ArrayList(u8).init(wrapped_allocator.zigUnwrap());
 
-                    if (log_configuration.guest_errors) try log_what.appendSlice("guest_errors,");
-                    if (log_configuration.interrupts) try log_what.appendSlice("int,");
-                    if (!arguments_result.ci and log_configuration.assembly) try log_what.appendSlice("in_asm,");
+                    if (log_configuration.guest_errors) {
+                        try log_what.appendSlice("guest_errors,");
+                    }
+
+                    if (log_configuration.interrupts) {
+                        try log_what.appendSlice("int,");
+                    }
+
+                    if (!arguments_result.ci and log_configuration.assembly) {
+                        try log_what.appendSlice("in_asm,");
+                    }
 
                     if (log_what.items.len > 0) {
-                        // Delete the last comma
+                        //Delete the last comma
                         _ = log_what.pop();
 
                         try argument_list.append("-d");
@@ -284,7 +292,7 @@ pub fn main() anyerror!void {
                 // GF2, when not found in the PATH, can give problems
                 const use_gf = switch (lib.os) {
                     .macos => false,
-                    .linux => false,
+                    .linux => true,
                     else => false,
                 };
 
@@ -292,7 +300,8 @@ pub fn main() anyerror!void {
                 if (use_gf) {
                     try command_line_gdb.append("gf2");
                 } else {
-                    try command_line_gdb.append("kitty");
+                    const terminal_emulator = "foot";
+                    try command_line_gdb.append(terminal_emulator);
                     try command_line_gdb.append(switch (lib.os) {
                         .linux => "gdb",
                         .macos => "x86_64-elf-gdb",
@@ -331,12 +340,12 @@ pub fn main() anyerror!void {
                 try debugger_process.spawn();
             }
 
-            var process = host.ChildProcess.init(argument_list.items, wrapped_allocator.zigUnwrap());
+            var emulator_process = host.ChildProcess.init(argument_list.items, wrapped_allocator.zigUnwrap());
             //process.stdout_behavior = .I;
-            const result = try process.spawnAndWait();
+            const emulator_process_result = try emulator_process.spawnAndWait();
 
-            if (result == .Exited) {
-                const exit_code = result.Exited;
+            if (emulator_process_result == .Exited) {
+                const exit_code = emulator_process_result.Exited;
                 if (exit_code & 1 != 0) {
                     const mask = lib.maxInt(@TypeOf(exit_code)) - 1;
                     const masked_exit_code = exit_code & mask;
@@ -354,7 +363,7 @@ pub fn main() anyerror!void {
                     } else log.err("QEMU exited with unexpected code: {}. Masked: {}", .{ exit_code, masked_exit_code });
                 } else log.err("QEMU exited with unexpected code: {}", .{exit_code});
             } else {
-                log.err("QEMU was {s}", .{@tagName(result)});
+                log.err("QEMU was {s}", .{@tagName(emulator_process_result)});
             }
 
             if (debugcon_file_used) {

src/lib.zig

@@ -1,6 +1,270 @@
 const common = @import("common.zig");
 pub usingnamespace common;
 
+const compiler_builtin = @import("builtin");
+pub const cpu = compiler_builtin.cpu;
+pub const os = compiler_builtin.os.tag;
+pub const build_mode = compiler_builtin.mode;
+pub const is_test = compiler_builtin.is_test;
+
+pub const kb = 1024;
+pub const mb = kb * 1024;
+pub const gb = mb * 1024;
+pub const tb = gb * 1024;
+
+pub const SizeUnit = enum(u64) {
+    byte = 1,
+    kilobyte = 1024,
+    megabyte = 1024 * 1024,
+    gigabyte = 1024 * 1024 * 1024,
+    terabyte = 1024 * 1024 * 1024 * 1024,
+};
+
+pub const std = @import("std");
+pub const Target = std.Target;
+pub const Cpu = Target.Cpu;
+pub const CrossTarget = std.zig.CrossTarget;
+
+pub const log = std.log;
+
+pub const data_structures = @import("lib/data_structures.zig");
+
+pub const Atomic = std.atomic.Atomic;
+
+pub const Reader = std.io.Reader;
+pub const Writer = std.io.Writer;
+
+pub const FixedBufferStream = std.io.FixedBufferStream;
+pub const fixedBufferStream = std.io.fixedBufferStream;
+
+pub fn assert(ok: bool) void {
+    if (!ok) {
+        if (@inComptime()) {
+            @compileError("Assert failed!");
+        } else {
+            @panic("Assert failed!");
+        }
+    }
+}
+
+pub const deflate = std.compress.deflate;
+
+const debug = std.debug;
+pub const print = debug.print;
+pub const StackIterator = debug.StackIterator;
+pub const dwarf = std.dwarf;
+pub const ModuleDebugInfo = std.debug.ModuleDebugInfo;
+
+pub const elf = std.elf;
+
+const fmt = std.fmt;
+pub const format = std.fmt.format;
+pub const FormatOptions = fmt.FormatOptions;
+pub const bufPrint = fmt.bufPrint;
+pub const allocPrint = fmt.allocPrint;
+pub const comptimePrint = fmt.comptimePrint;
+pub const parseUnsigned = fmt.parseUnsigned;
+
+const heap = std.heap;
+pub const FixedBufferAllocator = heap.FixedBufferAllocator;
+
+pub const json = std.json;
+
+const mem = std.mem;
+pub const ZigAllocator = mem.Allocator;
+pub const equal = mem.eql;
+pub const length = mem.len;
+pub const startsWith = mem.startsWith;
+pub const endsWith = mem.endsWith;
+pub const indexOf = mem.indexOf;
+// Ideal for small inputs
+pub const indexOfPosLinear = mem.indexOfPosLinear;
+pub const lastIndexOf = mem.lastIndexOf;
+pub const asBytes = mem.asBytes;
+pub const readIntBig = mem.readIntBig;
+pub const readIntSliceBig = mem.readIntSliceBig;
+pub const concat = mem.concat;
+pub const sliceAsBytes = mem.sliceAsBytes;
+pub const bytesAsSlice = mem.bytesAsSlice;
+pub const alignForward = mem.alignForward;
+pub const alignBackward = mem.alignBackward;
+pub const isAligned = mem.isAligned;
+pub const isAlignedGeneric = mem.isAlignedGeneric;
+pub const reverse = mem.reverse;
+pub const tokenize = mem.tokenize;
+pub const containsAtLeast = mem.containsAtLeast;
+pub const sliceTo = mem.sliceTo;
+pub const swap = mem.swap;
+
+pub const random = std.rand;
+
+pub const testing = std.testing;
+
+pub const sort = std.sort;
+
+pub fn fieldSize(comptime T: type, field_name: []const u8) comptime_int {
+    var foo: T = undefined;
+    return @sizeOf(@TypeOf(@field(foo, field_name)));
+}
+
+const DiffError = error{
+    diff,
+};
+
+pub fn diff(file1: []const u8, file2: []const u8) !void {
+    assert(file1.len == file2.len);
+    var different_bytes: u64 = 0;
+    for (file1, 0..) |byte1, index| {
+        const byte2 = file2[index];
+        const is_different_byte = byte1 != byte2;
+        different_bytes += @intFromBool(is_different_byte);
+        if (is_different_byte) {
+            log.debug("Byte [0x{x}] is different: 0x{x} != 0x{x}", .{ index, byte1, byte2 });
+        }
+    }
+
+    if (different_bytes != 0) {
+        log.debug("Total different bytes: 0x{x}", .{different_bytes});
+        return DiffError.diff;
+    }
+}
+
+pub fn zeroes(comptime T: type) T {
+    var result: T = undefined;
+    const slice = asBytes(&result);
+    @memset(slice, 0);
+    return result;
+}
+
+const ascii = std.ascii;
+pub const upperString = ascii.upperString;
+pub const isUpper = ascii.isUpper;
+pub const isAlphabetic = ascii.isAlphabetic;
+
+const std_builtin = std.builtin;
+pub const AtomicRmwOp = std_builtin.AtomicRmwOp;
+pub const AtomicOrder = std_builtin.AtomicOrder;
+pub const Type = std_builtin.Type;
+pub const StackTrace = std_builtin.StackTrace;
+pub const SourceLocation = std_builtin.SourceLocation;
+
+pub fn FieldType(comptime T: type, comptime name: []const u8) type {
+    return @TypeOf(@field(@as(T, undefined), name));
+}
+
+// META PROGRAMMING
+pub const AutoEnumArray = std.enums.EnumArray;
+pub const fields = std.meta.fields;
+pub const enumFromInt = std.meta.enumFromInt;
+pub const stringToEnum = std.meta.stringToEnum;
+pub const Tag = std.meta.Tag;
+
+const math = std.math;
+pub const maxInt = math.maxInt;
+pub const min = math.min;
+pub const divCeil = math.divCeil;
+pub const clamp = math.clamp;
+pub const isPowerOfTwo = math.isPowerOfTwo;
+pub const mul = math.mul;
+pub const cast = math.cast;
+
+pub const unicode = std.unicode;
+
+pub const uefi = std.os.uefi;
+
+pub const DiskType = enum(u32) {
+    virtio = 0,
+    nvme = 1,
+    ahci = 2,
+    ide = 3,
+    memory = 4,
+    bios = 5,
+
+    pub const count = enumCount(@This());
+};
+
+pub fn enumFields(comptime E: type) []const Type.EnumField {
+    return @typeInfo(E).Enum.fields;
+}
+
+pub const enumValues = std.enums.values;
+
+pub fn enumCount(comptime E: type) usize {
+    return enumFields(E).len;
+}
+
+pub const QEMU = extern struct {
+    pub const isa_debug_exit = ISADebugExit{};
+
+    pub const ISADebugExit = extern struct {
+        io_base: u8 = 0xf4,
+        io_size: u8 = @sizeOf(u32),
+    };
+
+    pub const ExitCode = enum(u32) {
+        success = 0x10,
+        failure = 0x11,
+        _,
+    };
+};
+
+pub const OptimizeMode = std.builtin.OptimizeMode;
+
+pub const Suffix = enum {
+    bootloader,
+    cpu_driver,
+    image,
+    complete,
+
+    pub fn fromConfiguration(suffix: Suffix, allocator: ZigAllocator, configuration: common.Configuration, prefix: ?[]const u8) ![]const u8 {
+        const cpu_driver_suffix = [_][]const u8{
+            @tagName(configuration.optimize_mode),
+            "_",
+            @tagName(configuration.architecture),
+            "_",
+            @tagName(configuration.executable_kind),
+        };
+
+        const bootloader_suffix = [_][]const u8{
+            @tagName(configuration.architecture),
+            "_",
+            @tagName(configuration.bootloader),
+            "_",
+            @tagName(configuration.boot_protocol),
+        };
+
+        const image_suffix = [_][]const u8{
+            @tagName(configuration.optimize_mode),
+            "_",
+        } ++ bootloader_suffix ++ [_][]const u8{
+            "_",
+            @tagName(configuration.executable_kind),
+        };
+
+        const complete_suffix = image_suffix ++ [_][]const u8{
+            "_",
+            @tagName(configuration.execution_type),
+            "_",
+            @tagName(configuration.execution_environment),
+        };
+
+        return try std.mem.concat(allocator, u8, &switch (suffix) {
+            .cpu_driver => if (prefix) |pf| [1][]const u8{pf} ++ cpu_driver_suffix else cpu_driver_suffix,
+            .bootloader => if (prefix) |pf| [1][]const u8{pf} ++ bootloader_suffix else bootloader_suffix,
+            .image => if (prefix) |pf| [1][]const u8{pf} ++ image_suffix else image_suffix,
+            .complete => if (prefix) |pf| [1][]const u8{pf} ++ complete_suffix else complete_suffix,
+        });
+    }
+};
+
+pub const default_cpu_name = "/cpu";
+pub const default_init_file = "/init";
+
+pub const default_disk_size = 64 * 1024 * 1024;
+pub const default_sector_size = 0x200;
+
+pub const cache_line_size = 64;
+
 pub const arch = @import("lib/arch.zig");
 /// This is done so the allocator can respect allocating from different address spaces
 pub const config = @import("lib/config.zig");
@@ -17,10 +281,9 @@ const extern_enum_array = @import("lib/extern_enum_array.zig");
 pub const EnumArray = extern_enum_array.EnumArray;
 
 pub fn memcpy(noalias destination: []u8, noalias source: []const u8) void {
-    @setRuntimeSafety(false);
     // Using this as the Zig implementation is really slow (at least in x86 with soft_float enabled
-    // if (common.cpu.arch == .x86 or common.cpu.arch == .x86_64 and common.Target.x86.featureSetHas(common.cpu.features, .soft_float)) {
-    const bytes_left = switch (common.cpu.arch) {
+    // if (cpu.arch == .x86 or cpu.arch == .x86_64 and Target.x86.featureSetHas(cpu.features, .soft_float)) {
+    const bytes_left = switch (cpu.arch) {
         .x86 => asm volatile (
             \\rep movsb
             : [ret] "={ecx}" (-> usize),
@@ -38,46 +301,16 @@ pub fn memcpy(noalias destination: []u8, noalias source: []const u8) void {
         else => @compileError("Unreachable"),
     };
 
-    common.assert(bytes_left == 0);
-    // } else {
-    //     @memcpy(destination, source);
-    // }
+    assert(bytes_left == 0);
 }
 
-// pub fn memset(comptime T: type, slice: []T, elem: T) void {
-//     @setRuntimeSafety(false);
-//
-//     const bytes_left = switch (T) {
-//         u8 => switch (common.cpu.arch) {
-//             .x86 => asm volatile (
-//                 \\rep stosb
-//                 : [ret] "={ecx}" (-> usize),
-//                 : [slice] "{edi}" (slice.ptr),
-//                   [len] "{ecx}" (slice.len),
-//                   [element] "{al}" (elem),
-//             ),
-//             .x86_64 => asm volatile (
-//                 \\rep movsb
-//                 : [ret] "={rcx}" (-> usize),
-//                 : [slice] "{rdi}" (slice.ptr),
-//                   [len] "{rcx}" (slice.len),
-//                   [element] "{al}" (elem),
-//             ),
-//             else => @compileError("Unsupported OS"),
-//         },
-//         else => @compileError("Type " ++ @typeName(T) ++ " not supported"),
-//     };
-//
-//     common.assert(bytes_left == 0);
-// }
-
 pub fn EnumStruct(comptime Enum: type, comptime Value: type) type {
-    const EnumFields = common.enumFields(Enum);
+    const EnumFields = enumFields(Enum);
     const MyEnumStruct = @Type(.{
         .Struct = .{
             .layout = .Extern,
             .fields = &blk: {
-                var arr = [1]common.Type.StructField{undefined} ** EnumFields.len;
+                var arr = [1]Type.StructField{undefined} ** EnumFields.len;
                 inline for (EnumFields) |EnumValue| {
                     arr[EnumValue.value] = .{
                         .name = EnumValue.name,
@@ -102,8 +335,8 @@ pub fn EnumStruct(comptime Enum: type, comptime Value: type) type {
         pub const Array = MyEnumArray;
     };
 
-    common.assert(@sizeOf(Union.Struct) == @sizeOf(Union.Array));
-    common.assert(@sizeOf(Union.Array) == @sizeOf(Union));
+    assert(@sizeOf(Union.Struct) == @sizeOf(Union.Array));
+    assert(@sizeOf(Union.Array) == @sizeOf(Union));
 
     return Union;
 }
@@ -115,7 +348,7 @@ pub const DirectoryTokenizer = struct {
     total_count: usize,
 
     pub fn init(string: []const u8) DirectoryTokenizer {
-        common.assert(string.len > 0);
+        assert(string.len > 0);
         var count: usize = 0;
 
         if (string[0] == '/') {
@@ -153,8 +386,8 @@ pub const DirectoryTokenizer = struct {
 
                 return tokenizer.string[original_index..];
             } else {
-                common.assert(original_index == tokenizer.string.len);
-                common.assert(tokenizer.given_count == tokenizer.total_count);
+                assert(original_index == tokenizer.string.len);
+                assert(tokenizer.given_count == tokenizer.total_count);
                 return null;
             }
         }
@@ -165,8 +398,8 @@ pub const DirectoryTokenizer = struct {
     }
 
     test "directory tokenizer" {
-        common.log.err("ajskdjsa", .{});
-        if (common.os != .freestanding) {
+        log.err("ajskdjsa", .{});
+        if (os != .freestanding) {
             const TestCase = struct {
                 path: []const u8,
                 expected_result: []const []const u8,
@@ -183,13 +416,13 @@ pub const DirectoryTokenizer = struct {
                 var result_count: usize = 0;
 
                 while (dir_tokenizer.next()) |dir| {
-                    try common.testing.expect(result_count < results.len);
-                    try common.testing.expectEqualStrings(case.expected_result[result_count], dir);
+                    try testing.expect(result_count < results.len);
+                    try testing.expectEqualStrings(case.expected_result[result_count], dir);
                     results[result_count] = dir;
                     result_count += 1;
                 }
 
-                try common.testing.expectEqual(case.expected_result.len, result_count);
+                try testing.expectEqual(case.expected_result.len, result_count);
             }
         }
     }
@@ -212,7 +445,7 @@ pub inline fn maybePtrSub(comptime T: type, ptr: ?*T, element_offset: usize) ?*T
 }
 
 test {
-    common.log.err("test not taken into the test suite");
+    log.err("test not taken into the test suite");
     _ = DirectoryTokenizer;
     _ = Filesystem;
     _ = PartitionTable;
@@ -237,7 +470,7 @@ pub const Allocator = extern struct {
     };
 
     /// Necessary to do this hack
-    const Callbacks = switch (common.cpu.arch) {
+    const Callbacks = switch (cpu.arch) {
         .x86 => extern struct {
             allocate: *const Allocate.Fn,
             allocate_padding: u32 = 0,
@@ -265,7 +498,7 @@ pub const Allocator = extern struct {
         return &result[0];
     }
 
-    pub fn wrap(zig_allocator: common.ZigAllocator) Wrapped {
+    pub fn wrap(zig_allocator: ZigAllocator) Wrapped {
         return .{
             .allocator = .{
                 .callbacks = .{
@@ -279,7 +512,7 @@ pub const Allocator = extern struct {
         };
     }
 
-    pub fn zigUnwrap(allocator: *Allocator) common.ZigAllocator {
+    pub fn zigUnwrap(allocator: *Allocator) ZigAllocator {
         return .{
             .ptr = allocator,
             .vtable = &zig_vtable,
@@ -293,11 +526,13 @@ pub const Allocator = extern struct {
     };
 
     pub fn zigAllocate(context: *anyopaque, size: usize, ptr_align: u8, return_address: usize) ?[*]u8 {
-        _ = context;
-        _ = size;
-        _ = ptr_align;
         _ = return_address;
-        return null;
+        const allocator: *Allocator = @ptrCast(@alignCast(context));
+        // Not understanding why Zig API is like this:
+        const alignment = @as(u64, 1) << @as(u6, @intCast(ptr_align));
+        const result = allocator.allocateBytes(size, alignment) catch return null;
+        assert(result.size >= size);
+        return @ptrFromInt(result.address);
     }
 
     pub fn zigResize(context: *anyopaque, buffer: []u8, buffer_alignment: u8, new_length: usize, return_address: usize) bool {
@@ -320,14 +555,14 @@ pub const Allocator = extern struct {
         allocator: Allocator,
         zig: extern struct {
             ptr: *anyopaque,
-            vtable: *const common.ZigAllocator.VTable,
+            vtable: *const ZigAllocator.VTable,
         },
 
         pub fn unwrap(wrapped_allocator: *Wrapped) *Allocator {
             return &wrapped_allocator.allocator;
         }
 
-        pub fn zigUnwrap(wrapped_allocator: *Wrapped) common.ZigAllocator {
+        pub fn zigUnwrap(wrapped_allocator: *Wrapped) ZigAllocator {
             return .{
                 .ptr = wrapped_allocator.zig.ptr,
                 .vtable = wrapped_allocator.zig.vtable,
@@ -337,7 +572,7 @@ pub const Allocator = extern struct {
         pub fn wrappedCallbackAllocate(allocator: *Allocator, size: u64, alignment: u64) Allocator.Allocate.Error!Allocator.Allocate.Result {
             const wrapped_allocator = @fieldParentPtr(Wrapped, "allocator", allocator);
             const zig_allocator = wrapped_allocator.zigUnwrap();
-            if (alignment > common.maxInt(u8)) {
+            if (alignment > maxInt(u8)) {
                 @panic("alignment supported by Zig is less than asked");
             }
             const zig_result = zig_allocator.vtable.alloc(zig_allocator.ptr, size, @as(u8, @intCast(alignment)), @returnAddress());
@@ -461,7 +696,7 @@ pub fn ELF(comptime bits: comptime_int) type {
                         return Parser.Error.invalid_magic;
                     }
 
-                    if (!common.equal(u8, &file_header.elf_id, FileHeader.elf_signature)) {
+                    if (!equal(u8, &file_header.elf_id, FileHeader.elf_signature)) {
                         return Parser.Error.invalid_signature;
                     }
 
@@ -484,7 +719,7 @@ pub fn ELF(comptime bits: comptime_int) type {
 
         pub const ProgramHeader = switch (is_64) {
             true => extern struct {
-                type: Type = .load,
+                type: @This().Type = .load,
                 flags: Flags, //= @enumToInt(Flags.readable) | @enumToInt(Flags.executable),
                 offset: u64,
                 virtual_address: u64,
@@ -518,7 +753,7 @@ pub fn ELF(comptime bits: comptime_int) type {
                     reserved: u29,
 
                     comptime {
-                        common.assert(@sizeOf(Flags) == @sizeOf(u32));
+                        assert(@sizeOf(Flags) == @sizeOf(u32));
                     }
                 };
             },
@@ -585,8 +820,8 @@ pub fn ELF(comptime bits: comptime_int) type {
 
 pub inline fn safeArchitectureCast(value: anytype) usize {
     return switch (@sizeOf(@TypeOf(value)) > @sizeOf(usize)) {
-        true => if (value <= common.maxInt(usize)) @as(usize, @truncate(value)) else {
-            common.log.err("PANIC: virtual address is longer than usize: 0x{x}", .{value});
+        true => if (value <= maxInt(usize)) @as(usize, @truncate(value)) else {
+            log.err("PANIC: virtual address is longer than usize: 0x{x}", .{value});
             @panic("safeArchitectureCast");
         },
         false => value,
@@ -598,11 +833,11 @@ pub const DereferenceError = error{
 };
 
 pub inline fn tryDereferenceAddress(value: anytype) DereferenceError!usize {
-    common.assert(@sizeOf(@TypeOf(value)) > @sizeOf(usize));
-    return if (value <= common.maxInt(usize)) @as(usize, @truncate(value)) else return DereferenceError.address_bigger_than_usize;
+    assert(@sizeOf(@TypeOf(value)) > @sizeOf(usize));
+    return if (value <= maxInt(usize)) @as(usize, @truncate(value)) else return DereferenceError.address_bigger_than_usize;
 }
 
-pub fn enumAddNames(comptime enum_fields: []const common.Type.EnumField, comptime names: []const []const u8) []const common.Type.EnumField {
+pub fn enumAddNames(comptime enum_fields: []const Type.EnumField, comptime names: []const []const u8) []const Type.EnumField {
     comptime var result = enum_fields;
     const previous_last_value = if (enum_fields.len > 0) enum_fields[enum_fields.len - 1].value else 0;
 
@@ -617,13 +852,13 @@ pub fn enumAddNames(comptime enum_fields: []const common.Type.EnumField, comptim
     return result;
 }
 
-pub fn ErrorSet(comptime error_names: []const []const u8, comptime predefined_fields: []const common.Type.EnumField) type {
-    comptime var error_fields: []const common.Type.Error = &.{};
-    comptime var enum_items: []const common.Type.EnumField = predefined_fields;
+pub fn ErrorSet(comptime error_names: []const []const u8, comptime predefined_fields: []const Type.EnumField) type {
+    comptime var error_fields: []const Type.Error = &.{};
+    comptime var enum_items: []const Type.EnumField = predefined_fields;
     comptime var enum_value = enum_items[enum_items.len - 1].value + 1;
 
     inline for (error_names) |error_name| {
-        enum_items = enum_items ++ [1]common.Type.EnumField{
+        enum_items = enum_items ++ [1]Type.EnumField{
             .{
                 .name = error_name,
                 .value = enum_value,
@@ -634,23 +869,23 @@ pub fn ErrorSet(comptime error_names: []const []const u8, comptime predefined_fi
     }
 
     inline for (enum_items) |item| {
-        error_fields = error_fields ++ [1]common.Type.Error{
+        error_fields = error_fields ++ [1]Type.Error{
             .{
                 .name = item.name,
             },
         };
     }
 
-    const EnumType = @Type(common.Type{
+    const EnumType = @Type(Type{
         .Enum = .{
-            .tag_type = u16,
+            .tag_type = u15,
             .fields = enum_items,
             .decls = &.{},
             .is_exhaustive = true,
         },
     });
 
-    const ErrorType = @Type(common.Type{
+    const ErrorType = @Type(Type{
         .ErrorSet = error_fields,
     });
 
@@ -660,12 +895,9 @@ pub fn ErrorSet(comptime error_names: []const []const u8, comptime predefined_fi
     };
 }
 
-pub fn getDebugInformation(allocator: common.ZigAllocator, elf_file: []align(common.default_sector_size) const u8) !common.ModuleDebugInfo {
-    const elf = common.elf;
-    var module_debug_info: common.ModuleDebugInfo = undefined;
-    _ = module_debug_info;
-    const hdr = @as(*const elf.Ehdr, @ptrCast(&elf_file[0]));
-    if (!common.equal(u8, hdr.e_ident[0..4], elf.MAGIC)) return error.InvalidElfMagic;
+pub fn getDebugInformation(allocator: ZigAllocator, elf_file: []align(arch.valid_page_sizes[0]) const u8) !ModuleDebugInfo {
+    const hdr = @as(*align(1) const elf.Ehdr, @ptrCast(&elf_file[0]));
+    if (!equal(u8, hdr.e_ident[0..4], elf.MAGIC)) return error.InvalidElfMagic;
     if (hdr.e_ident[elf.EI_VERSION] != 1) return error.InvalidElfVersion;
 
     const endian = .Little;
@@ -673,94 +905,110 @@ pub fn getDebugInformation(allocator: common.ZigAllocator, elf_file: []align(com
     const shoff = hdr.e_shoff;
     const str_section_off = shoff + @as(u64, hdr.e_shentsize) * @as(u64, hdr.e_shstrndx);
     const str_shdr = @as(
-        *const elf.Shdr,
-        @ptrCast(@alignCast(&elf_file[common.cast(usize, str_section_off) orelse return error.Overflow])),
+        *align(1) const elf.Shdr,
+        @ptrCast(&elf_file[cast(usize, str_section_off) orelse return error.Overflow]),
     );
     const header_strings = elf_file[str_shdr.sh_offset .. str_shdr.sh_offset + str_shdr.sh_size];
     const shdrs = @as(
-        [*]const elf.Shdr,
-        @ptrCast(@alignCast(&elf_file[shoff])),
+        [*]align(1) const elf.Shdr,
+        @ptrCast(&elf_file[shoff]),
     )[0..hdr.e_shnum];
 
-    var opt_debug_info: ?[]const u8 = null;
-    var opt_debug_abbrev: ?[]const u8 = null;
-    var opt_debug_str: ?[]const u8 = null;
-    var opt_debug_str_offsets: ?[]const u8 = null;
-    var opt_debug_line: ?[]const u8 = null;
-    var opt_debug_line_str: ?[]const u8 = null;
-    var opt_debug_ranges: ?[]const u8 = null;
-    var opt_debug_loclists: ?[]const u8 = null;
-    var opt_debug_rnglists: ?[]const u8 = null;
-    var opt_debug_addr: ?[]const u8 = null;
-    var opt_debug_names: ?[]const u8 = null;
-    var opt_debug_frame: ?[]const u8 = null;
+    var sections: dwarf.DwarfInfo.SectionArray = dwarf.DwarfInfo.null_section_array;
+
+    // Combine section list. This takes ownership over any owned sections from the parent scope.
+    errdefer for (sections) |section| if (section) |s| if (s.owned) allocator.free(s.data);
+
+    var separate_debug_filename: ?[]const u8 = null;
+    _ = separate_debug_filename;
+    var separate_debug_crc: ?u32 = null;
+    _ = separate_debug_crc;
 
     for (shdrs) |*shdr| {
-        if (shdr.sh_type == elf.SHT_NULL) continue;
+        if (shdr.sh_type == elf.SHT_NULL or shdr.sh_type == elf.SHT_NOBITS) continue;
+        const name = sliceTo(header_strings[shdr.sh_name..], 0);
 
-        const name = common.sliceTo(header_strings[shdr.sh_name..], 0);
-        if (common.equal(u8, name, ".debug_info")) {
-            opt_debug_info = try chopSlice(elf_file, shdr.sh_offset, shdr.sh_size);
-        } else if (common.equal(u8, name, ".debug_abbrev")) {
-            opt_debug_abbrev = try chopSlice(elf_file, shdr.sh_offset, shdr.sh_size);
-        } else if (common.equal(u8, name, ".debug_str")) {
-            opt_debug_str = try chopSlice(elf_file, shdr.sh_offset, shdr.sh_size);
-        } else if (common.equal(u8, name, ".debug_str_offsets")) {
-            opt_debug_str_offsets = try chopSlice(elf_file, shdr.sh_offset, shdr.sh_size);
-        } else if (common.equal(u8, name, ".debug_line")) {
-            opt_debug_line = try chopSlice(elf_file, shdr.sh_offset, shdr.sh_size);
-        } else if (common.equal(u8, name, ".debug_line_str")) {
-            opt_debug_line_str = try chopSlice(elf_file, shdr.sh_offset, shdr.sh_size);
-        } else if (common.equal(u8, name, ".debug_ranges")) {
-            opt_debug_ranges = try chopSlice(elf_file, shdr.sh_offset, shdr.sh_size);
-        } else if (common.equal(u8, name, ".debug_loclists")) {
-            opt_debug_loclists = try chopSlice(elf_file, shdr.sh_offset, shdr.sh_size);
-        } else if (common.equal(u8, name, ".debug_rnglists")) {
-            opt_debug_rnglists = try chopSlice(elf_file, shdr.sh_offset, shdr.sh_size);
-        } else if (common.equal(u8, name, ".debug_addr")) {
-            opt_debug_addr = try chopSlice(elf_file, shdr.sh_offset, shdr.sh_size);
-        } else if (common.equal(u8, name, ".debug_names")) {
-            opt_debug_names = try chopSlice(elf_file, shdr.sh_offset, shdr.sh_size);
-        } else if (common.equal(u8, name, ".debug_frame")) {
-            opt_debug_frame = try chopSlice(elf_file, shdr.sh_offset, shdr.sh_size);
-        }
+        if (equal(u8, name, ".gnu_debuglink")) {
+            @panic("WTF");
+            // const gnu_debuglink = try chopSlice(mapped_mem, shdr.sh_offset, shdr.sh_size);
+            // const debug_filename = mem.sliceTo(@as([*:0]const u8, @ptrCast(gnu_debuglink.ptr)), 0);
+            // const crc_offset = mem.alignForward(usize, @intFromPtr(&debug_filename[debug_filename.len]) + 1, 4) - @intFromPtr(gnu_debuglink.ptr);
+            // const crc_bytes = gnu_debuglink[crc_offset .. crc_offset + 4];
+            // separate_debug_crc = mem.readIntSliceNative(u32, crc_bytes);
+            // separate_debug_filename = debug_filename;
+            // continue;
         }
 
-    var di = common.dwarf.DwarfInfo{
+        var section_index: ?usize = null;
+        inline for (@typeInfo(dwarf.DwarfSection).Enum.fields, 0..) |section, i| {
+            if (equal(u8, "." ++ section.name, name)) section_index = i;
+        }
+        if (section_index == null) continue;
+        if (sections[section_index.?] != null) continue;
+
+        const section_bytes = try chopSlice(elf_file, shdr.sh_offset, shdr.sh_size);
+        sections[section_index.?] = if ((shdr.sh_flags & elf.SHF_COMPRESSED) > 0) blk: {
+            var section_stream = fixedBufferStream(section_bytes);
+            var section_reader = section_stream.reader();
+            const chdr = section_reader.readStruct(elf.Chdr) catch continue;
+            if (chdr.ch_type != .ZLIB) continue;
+
+            if (true) @panic("ZLIB");
+            break :blk undefined;
+            // var zlib_stream = std.compress.zlib.decompressStream(allocator, section_stream.reader()) catch continue;
+            // defer zlib_stream.deinit();
+            //
+            // var decompressed_section = try allocator.alloc(u8, chdr.ch_size);
+            // errdefer allocator.free(decompressed_section);
+            //
+            // const read = zlib_stream.reader().readAll(decompressed_section) catch continue;
+            // assert(read == decompressed_section.len);
+            //
+            // break :blk .{
+            //     .data = decompressed_section,
+            //     .virtual_address = shdr.sh_addr,
+            //     .owned = true,
+            // };
+        } else .{
+            .data = section_bytes,
+            .virtual_address = shdr.sh_addr,
+            .owned = false,
+        };
+    }
+
+    const missing_debug_info =
+        sections[@intFromEnum(dwarf.DwarfSection.debug_info)] == null or
+        sections[@intFromEnum(dwarf.DwarfSection.debug_abbrev)] == null or
+        sections[@intFromEnum(dwarf.DwarfSection.debug_str)] == null or
+        sections[@intFromEnum(dwarf.DwarfSection.debug_line)] == null;
+    assert(!missing_debug_info);
+
+    var di = dwarf.DwarfInfo{
         .endian = endian,
-        .debug_info = opt_debug_info orelse return error.MissingDebugInfo,
-        .debug_abbrev = opt_debug_abbrev orelse return error.MissingDebugInfo,
-        .debug_str = opt_debug_str orelse return error.MissingDebugInfo,
-        .debug_str_offsets = opt_debug_str_offsets,
-        .debug_line = opt_debug_line orelse return error.MissingDebugInfo,
-        .debug_line_str = opt_debug_line_str,
-        .debug_ranges = opt_debug_ranges,
-        .debug_loclists = opt_debug_loclists,
-        .debug_rnglists = opt_debug_rnglists,
-        .debug_addr = opt_debug_addr,
-        .debug_names = opt_debug_names,
-        .debug_frame = opt_debug_frame,
+        .sections = sections,
+        .is_macho = false,
     };
 
-    try common.dwarf.openDwarfDebugInfo(&di, allocator);
+    try dwarf.openDwarfDebugInfo(&di, allocator);
+
     return di;
 }
 
 fn chopSlice(ptr: []const u8, offset: u64, size: u64) error{Overflow}![]const u8 {
-    const start = common.cast(usize, offset) orelse return error.Overflow;
-    const end = start + (common.cast(usize, size) orelse return error.Overflow);
+    const start = cast(usize, offset) orelse return error.Overflow;
+    const end = start + (cast(usize, size) orelse return error.Overflow);
     return ptr[start..end];
 }
 
 pub fn RegionInterface(comptime Region: type) type {
     const type_info = @typeInfo(Region);
-    common.assert(type_info == .Struct);
-    common.assert(type_info.Struct.layout == .Extern);
-    common.assert(type_info.Struct.fields.len == 2);
-    const fields = type_info.Struct.fields;
-    common.assert(common.equal(u8, fields[0].name, "address"));
-    common.assert(common.equal(u8, fields[1].name, "size"));
-    const Addr = fields[0].type;
+    assert(type_info == .Struct);
+    assert(type_info.Struct.layout == .Extern);
+    assert(type_info.Struct.fields.len == 2);
+    const region_fields = type_info.Struct.fields;
+    assert(equal(u8, region_fields[0].name, "address"));
+    assert(equal(u8, region_fields[1].name, "size"));
+    const Addr = region_fields[0].type;
     const AddrT = getAddrT(Addr);
 
     return struct {
@@ -773,6 +1021,14 @@ pub fn RegionInterface(comptime Region: type) type {
                 .size = info.size,
             };
         }
+
+        pub inline fn invalid() Region {
+            return Region{
+                .address = Addr.invalid(),
+                .size = 0,
+            };
+        }
+
         pub inline fn fromRaw(info: struct {
             raw_address: AddrT,
             size: AddrT,
@@ -808,7 +1064,7 @@ pub fn RegionInterface(comptime Region: type) type {
 
         pub inline fn fromAnytype(any: anytype, info: struct {}) Region {
             _ = info;
-            common.assert(@typeInfo(@TypeOf(any)) == .Pointer);
+            assert(@typeInfo(@TypeOf(any)) == .Pointer);
             return Region{
                 .address = VirtualAddress.new(@intFromPtr(any)),
                 .size = @sizeOf(@TypeOf(any.*)),
@@ -833,7 +1089,7 @@ pub fn RegionInterface(comptime Region: type) type {
         }
 
         pub fn shrinked(region: Region, size: AddrT) Region {
-            common.assert(size <= region.size);
+            assert(size <= region.size);
             const result = Region{
                 .address = region.address,
                 .size = size,
@@ -842,8 +1098,22 @@ pub fn RegionInterface(comptime Region: type) type {
             return result;
         }
 
-        pub inline fn takeSlice(region: *Region, size: AddrT) Region {
-            common.assert(size <= region.size);
+        const TakeSliceError = error{
+            not_enough_space,
+        };
+
+        pub inline fn slice(region: *const Region, size: AddrT) Region {
+            assert(size <= region.size);
+            const result = .{
+                .address = region.address,
+                .size = size,
+            };
+
+            return result;
+        }
+
+        pub inline fn takeSlice(region: *Region, size: AddrT) !Region {
+            if (size <= region.size) {
                 const result = Region{
                     .address = region.address,
                     .size = size,
@@ -853,6 +1123,9 @@ pub fn RegionInterface(comptime Region: type) type {
                 return result;
             }
 
+            return TakeSliceError.not_enough_space;
+        }
+
         pub inline fn split(region: Region, comptime count: comptime_int) [count]Region {
             const region_size = @divExact(region.size, count);
             var result: [count]Region = undefined;
@@ -919,9 +1192,9 @@ pub const VirtualMemoryRegion = extern struct {
 
 fn getAddrT(comptime AddressEnum: type) type {
     const type_info = @typeInfo(AddressEnum);
-    common.assert(type_info == .Enum);
+    assert(type_info == .Enum);
     const AddrT = type_info.Enum.tag_type;
-    common.assert(switch (common.cpu.arch) {
+    assert(switch (cpu.arch) {
         .x86 => @sizeOf(AddrT) == 2 * @sizeOf(usize),
         else => @sizeOf(AddrT) == @sizeOf(usize),
     });
@@ -1023,12 +1296,12 @@ pub const VirtualAddress = enum(u64) {
     }
 
     pub inline fn toPhysicalAddress(virtual_address: VirtualAddress) PhysicalAddress {
-        common.assert(virtual_address.value() >= config.cpu_driver_higher_half_address);
+        assert(virtual_address.value() >= config.cpu_driver_higher_half_address);
         return @as(PhysicalAddress, @enumFromInt(virtual_address.value() - config.cpu_driver_higher_half_address));
     }
 
     pub inline fn toGuaranteedPhysicalAddress(virtual_address: VirtualAddress) PhysicalAddress {
-        common.assert(virtual_address.value() < config.cpu_driver_higher_half_address);
+        assert(virtual_address.value() < config.cpu_driver_higher_half_address);
         return PhysicalAddress.new(virtual_address.value());
     }
 };

src/lib/arch.zig

@@ -15,6 +15,8 @@ pub const current = switch (@import("builtin").cpu.arch) {
 pub const x86 = @import("arch/x86.zig");
 pub const x86_64 = @import("arch/x86_64.zig");
 
+pub const paging = x86_64.paging;
+
 pub const default_page_size = current.default_page_size;
 pub const reasonable_page_size = current.reasonable_page_size;
 

src/lib/arch/x86/common.zig

@@ -5,7 +5,7 @@ pub const CPUID = extern struct {
     ecx: u32,
 };
 
-pub inline fn cpuid(leaf: u32) CPUID {
+pub inline fn cpuid(leaf: u32, subleaf: u32) CPUID {
     var eax: u32 = undefined;
     var ebx: u32 = undefined;
     var edx: u32 = undefined;
@@ -18,6 +18,8 @@ pub inline fn cpuid(leaf: u32) CPUID {
           [edx] "={edx}" (edx),
           [ecx] "={ecx}" (ecx),
         : [leaf] "{eax}" (leaf),
+          [subleaf] "{ecx}" (subleaf),
+        : "memory"
     );
 
     return CPUID{

src/lib/arch/x86_64.zig

@@ -2,6 +2,39 @@ const lib = @import("lib");
 const x86 = @import("x86/common.zig");
 pub usingnamespace x86;
 
+pub const paging = struct {
+    pub const page_table_entry_size = @sizeOf(u64);
+    pub const page_table_size = lib.arch.valid_page_sizes[0];
+    pub const page_table_entry_count = @divExact(page_table_size, page_table_entry_size);
+    pub const page_table_alignment = page_table_size;
+    pub const page_table_mask = page_table_entry_count - 1;
+    pub const user_address_space_start = 0x200_000;
+    pub const user_address_space_end = 0x8000_0000_0000;
+    pub const root_page_table_level: Level = switch (Level) {
+        Level4 => Level.PML4,
+        Level5 => @compileError("TODO"),
+        else => @compileError("Unknown level"),
+    };
+
+    pub const Level = Level4;
+
+    pub const Level4 = enum(u2) {
+        PML4 = 0,
+        PDP = 1,
+        PD = 2,
+        PT = 3,
+
+        pub const count = lib.enumCount(@This());
+    };
+
+    pub const Level5 = enum(u3) {};
+
+    comptime {
+        lib.assert(page_table_alignment == page_table_size);
+        lib.assert(page_table_size == lib.arch.valid_page_sizes[0]);
+    }
+};
+
 pub const valid_page_sizes = [3]comptime_int{ 0x1000, 0x1000 * 0x200, 0x1000 * 0x200 * 0x200 };
 pub const reverse_valid_page_sizes = blk: {
     var reverse = valid_page_sizes;

src/lib/data_structures.zig

@@ -0,0 +1,127 @@
+const lib = @import("lib");
+const Allocator = lib.Allocator;
+const assert = lib.assert;
+const maxInt = lib.maxInt;
+
+pub fn BitsetU64(comptime bits: comptime_int) type {
+    assert(bits <= @bitSizeOf(u64));
+    const max_value = maxInt(@Type(.{
+        .Int = .{
+            .signedness = .unsigned,
+            .bits = bits,
+        },
+    }));
+
+    return packed struct(u64) {
+        value: u64 = 0,
+
+        const Error = error{
+            block_full,
+        };
+
+        pub inline fn allocate(bitset: *@This()) !u6 {
+            if (bitset.value & max_value != max_value) {
+                // log.debug("Bitset: 0b{b}", .{bitset.value});
+                const result: u6 = @intCast(@ctz(~bitset.value));
+                // log.debug("Result: {}", .{result});
+                assert(!bitset.isSet(result));
+                bitset.set(result);
+                return result;
+            } else {
+                return error.block_full;
+            }
+        }
+
+        pub inline fn set(bitset: *@This(), index: u6) void {
+            assert(index < bits);
+            bitset.value |= (@as(u64, 1) << index);
+        }
+
+        pub inline fn clear(bitset: *@This(), index: u6) void {
+            assert(index < bits);
+            bitset.value &= ~(@as(u64, 1) << index);
+        }
+
+        pub inline fn isSet(bitset: @This(), index: u6) bool {
+            assert(index < bits);
+            return bitset.value & (@as(u64, 1) << index) != 0;
+        }
+
+        pub inline fn isFull(bitset: @This()) bool {
+            return bitset.value == max_value;
+        }
+    };
+}
+
+pub fn SparseArray(comptime T: type) type {
+    return extern struct {
+        ptr: [*]T,
+        len: usize,
+        capacity: usize,
+
+        const Array = @This();
+
+        pub const Error = error{
+            index_out_of_bounds,
+        };
+
+        pub fn allocate(array: *Array, allocator: *Allocator) !*T {
+            try array.ensureCapacity(allocator, array.len + 1);
+            const index = array.len;
+            array.len += 1;
+            const slice = array.ptr[0..array.len];
+            return &slice[index];
+        }
+
+        pub fn append(array: *Array, allocator: *Allocator, element: T) !usize {
+            try array.ensureCapacity(allocator, array.len + 1);
+            const index = array.len;
+            array.len += 1;
+            const slice = array.ptr[0..array.len];
+            slice[index] = element;
+
+            return index;
+        }
+
+        fn ensureCapacity(array: *Array, allocator: *Allocator, desired_capacity: usize) !void {
+            if (array.capacity < desired_capacity) {
+                // Allocate a new array
+                const new_slice = try allocator.allocate(T, desired_capacity);
+                if (array.capacity == 0) {
+                    array.ptr = new_slice.ptr;
+                    array.capacity = new_slice.len;
+                } else {
+                    // Reallocate
+                    if (array.len > 0) {
+                        @memcpy(new_slice[0..array.len], array.ptr[0..array.len]);
+                    }
+
+                    // TODO: free
+
+                    array.ptr = new_slice.ptr;
+                    array.capacity = new_slice.len;
+                }
+            }
+        }
+
+        pub fn indexOf(array: *Array, ptr: *T) usize {
+            const base_int = @intFromPtr(array.ptr);
+            const ptr_int = @intFromPtr(ptr);
+            return @divExact(ptr_int - base_int, @sizeOf(T));
+        }
+
+        pub inline fn get(array: *Array, index: usize) T {
+            assert(array.len > index);
+            const slice = array.ptr[0..array.len];
+            return slice[index];
+        }
+
+        pub inline fn getChecked(array: *Array, index: usize) !T {
+            if (array.len > index) {
+                return array.get(index);
+            } else {
+                return error.index_out_of_bounds;
+            }
+        }
+    };
+}

src/lib/filesystem/fat32.zig

@@ -353,10 +353,7 @@ pub const Cache = extern struct {
         const aligned_file_size = lib.alignForward(usize, file_size, cache.disk.sector_size);
         const lba = cache.clusterToSector(first_cluster);
 
-        log.debug("Start disk callback", .{});
-
         const result = try cache.disk.callbacks.read(cache.disk, @divExact(aligned_file_size, cache.disk.sector_size), lba, file_buffer);
-        log.debug("End disk callback", .{});
         return result.buffer[0..file_size];
     }
 

src/privileged.zig

@@ -10,6 +10,7 @@ const assert = lib.assert;
 const log = lib.log;
 const maxInt = lib.maxInt;
 const Allocator = lib.Allocator;
+const VirtualAddress = lib.VirtualAddress;
 
 const bootloader = @import("bootloader");
 
@@ -64,7 +65,8 @@ pub const Mapping = extern struct {
         execute: bool = false,
         user: bool = false,
         secret: bool = false,
-        reserved: u26 = 0,
+        huge_pages: bool = true,
+        reserved: u25 = 0,
 
         pub inline fn empty() Flags {
             return .{};
@@ -86,6 +88,7 @@ pub const PageAllocator = struct {
         count: u16 = 1,
         level: arch.paging.Level,
         user: bool,
+        virtual_address: arch.paging.IndexedVirtualAddress,
     };
 
     pub inline fn allocatePageTable(page_allocator: PageAllocator, options: AllocatePageTablesOptions) !lib.PhysicalMemoryRegion {
@@ -94,6 +97,7 @@ pub const PageAllocator = struct {
             .level = options.level,
             .level_valid = true,
             .user = options.user,
+            .virtual_address = options.virtual_address,
         });
         return result;
     }
@@ -104,6 +108,7 @@ pub const PageAllocator = struct {
         level: arch.paging.Level = undefined,
         level_valid: bool = false,
         user: bool = false,
+        virtual_address: arch.paging.IndexedVirtualAddress,
     };
 
     const ContextType = enum(u32) {

src/privileged/arch/x86/64/paging.zig

@@ -10,7 +10,6 @@ const zeroes = lib.zeroes;
 const Allocator = lib.Allocator;
 
 const privileged = @import("privileged");
-const Heap = privileged.Heap;
 const PageAllocator = privileged.PageAllocator;
 
 const valid_page_sizes = lib.arch.x86_64.valid_page_sizes;
@@ -22,33 +21,12 @@ const PhysicalAddress = lib.PhysicalAddress;
 const VirtualAddress = lib.VirtualAddress;
 const PhysicalMemoryRegion = lib.PhysicalMemoryRegion;
 const PhysicalAddressSpace = lib.PhysicalAddressSpace;
-const Mapping = privileged.Mapping;
+pub const Mapping = privileged.Mapping;
 
 const bootloader = @import("bootloader");
 
-const page_table_level_count = 4;
-pub const page_table_mask = page_table_entry_count - 1;
-
-pub fn entryCount(comptime level: Level, limit: u64) u10 {
-    const index = baseFromVirtualAddress(level, limit - 1);
-    const result = @as(u10, index) + 1;
-    // @compileLog(limit, index, result);
-    return result;
-}
-
-// Comptime test
-comptime {
-    const va = 134217728;
-    const indices = computeIndices(va);
-    const pml4_index = baseFromVirtualAddress(.PML4, va);
-    const pdp_index = baseFromVirtualAddress(.PDP, va);
-    const pd_index = baseFromVirtualAddress(.PD, va);
-    const pt_index = baseFromVirtualAddress(.PT, va);
-    assert(pml4_index == indices[@intFromEnum(Level.PML4)]);
-    assert(pdp_index == indices[@intFromEnum(Level.PDP)]);
-    assert(pd_index == indices[@intFromEnum(Level.PD)]);
-    assert(pt_index == indices[@intFromEnum(Level.PT)]);
-}
+const paging = lib.arch.x86_64.paging;
+pub usingnamespace paging;
 
 const max_level_possible = 5;
 pub const IndexedVirtualAddress = packed struct(u64) {
@@ -67,12 +45,24 @@ pub const IndexedVirtualAddress = packed struct(u64) {
             return VirtualAddress.new(raw);
         }
     }
+
+    pub fn toIndices(indexed: IndexedVirtualAddress) [Level.count]u9 {
+        var result: [Level.count]u9 = undefined;
+        inline for (@typeInfo(Level).Enum.fields) |enum_field| {
+            result[@intFromEnum(@field(Level, enum_field.name))] = @field(indexed, enum_field.name);
+        }
+        return result;
+    }
 };
 
-pub fn baseFromVirtualAddress(comptime level: Level, virtual_address: u64) u9 {
-    const indexed = @as(IndexedVirtualAddress, @bitCast(virtual_address));
-    return @field(indexed, @tagName(level));
-}
+const Level = enum(u2) {
+    PML4 = 0,
+    PDP = 1,
+    PD = 2,
+    PT = 3,
+
+    const count = @typeInfo(Level).Enum.fields.len;
+};
 
 pub const CPUPageTables = extern struct {
     pml4_table: PhysicalAddress,
@@ -82,7 +72,7 @@ pub const CPUPageTables = extern struct {
 
     const base = 0xffff_ffff_8000_0000;
     const top = base + pte_count * lib.arch.valid_page_sizes[0];
-    const pte_count = page_table_entry_count - left_ptables;
+    const pte_count = paging.page_table_entry_count - left_ptables;
     pub const left_ptables = 4;
     pub const pml4_index = 0x1ff;
     pub const pdp_index = 0x1fe;
@@ -94,14 +84,12 @@ pub const CPUPageTables = extern struct {
         1; // PT
     const allocated_size = allocated_table_count * 0x1000;
 
-    const page_table_base = top;
-
     comptime {
         assert(top + (left_ptables * lib.arch.valid_page_sizes[0]) == base + lib.arch.valid_page_sizes[1]);
     }
 
     pub fn initialize(page_allocator: PageAllocator) !CPUPageTables {
-        const page_table_allocation = try page_allocator.allocate(page_allocator.context, allocated_size, lib.arch.valid_page_sizes[0], .{});
+        const page_table_allocation = try page_allocator.allocate(page_allocator.context, allocated_size, lib.arch.valid_page_sizes[0], .{ .virtual_address = @bitCast(@as(u64, 0)) });
 
         const page_tables = CPUPageTables{
             .pml4_table = page_table_allocation.address,
@@ -163,8 +151,8 @@ pub const CPUPageTables = extern struct {
         if (asked_virtual_address.offset(size).value() > top) return CPUPageTables.MapError.upper_limit_exceeded;
 
         const flags = general_flags.toArchitectureSpecific();
-        const indices = computeIndices(asked_virtual_address.value());
-        const index = indices[indices.len - 1];
+        const indexed: IndexedVirtualAddress = @bitCast(asked_virtual_address.value());
+        const index = indexed.PT;
         const iteration_count = @as(u32, @intCast(size >> lib.arch.page_shifter(lib.arch.valid_page_sizes[0])));
         const p_table = cpu_page_tables.p_table.toIdentityMappedVirtualAddress().access(*PTable);
         const p_table_slice = p_table[index .. index + iteration_count];
@@ -181,10 +169,26 @@ pub const CPUPageTables = extern struct {
 pub const Specific = extern struct {
     cr3: cr3 align(8),
 
+    pub fn current() Specific {
+        return .{
+            .cr3 = cr3.read(),
+        };
+    }
+
     pub inline fn makeCurrent(specific: Specific) void {
         specific.getUserCr3().write();
     }
 
+    pub inline fn makeCurrentPrivileged(specific: Specific) void {
+        specific.cr3.write();
+    }
+
+    pub fn fromPhysicalRegion(physical_memory_region: PhysicalMemoryRegion) Specific {
+        return Specific{
+            .cr3 = @bitCast(physical_memory_region.address.value()),
+        };
+    }
+
     pub fn fromPageTables(cpu_page_tables: CPUPageTables) Specific {
         return .{
             .cr3 = cr3.fromAddress(cpu_page_tables.pml4_table),
@@ -199,7 +203,7 @@ pub const Specific = extern struct {
             if (size >= reverse_page_size) {
                 const is_smallest_page_size = reverse_page_index == reverse_valid_page_sizes.len - 1;
 
-                if (is_smallest_page_size) {
+                if (is_smallest_page_size or !general_flags.huge_pages) {
                     var virtual_address = asked_virtual_address.value();
                     var physical_address = asked_physical_address.value();
 
@@ -247,8 +251,8 @@ pub const Specific = extern struct {
     }
 
     fn mapGeneric(specific: Specific, asked_physical_address: PhysicalAddress, asked_virtual_address: VirtualAddress, size: u64, comptime asked_page_size: comptime_int, flags: MemoryFlags, page_allocator: PageAllocator) !void {
-        if (!isAlignedGeneric(u64, asked_physical_address.value(), asked_page_size)) {
-            //log.debug("PA: {}. Page size: 0x{x}", .{ asked_physical_address, asked_page_size });
+        if (!isAlignedGeneric(u64, asked_physical_address.value(), lib.arch.valid_page_sizes[0])) {
+            log.debug("PA: {}. Page size: 0x{x}", .{ asked_physical_address, asked_page_size });
             @panic("Misaligned physical address in mapGeneric");
         }
         if (!isAlignedGeneric(u64, asked_virtual_address.value(), asked_page_size)) {
@@ -266,7 +270,7 @@ pub const Specific = extern struct {
         // TODO: batch better
         switch (asked_page_size) {
             // 1 GB
-            lib.arch.valid_page_sizes[0] * page_table_entry_count * page_table_entry_count => {
+            lib.arch.valid_page_sizes[0] * paging.page_table_entry_count * paging.page_table_entry_count => {
                 while (virtual_address < top_virtual_address) : ({
                     physical_address += asked_page_size;
                     virtual_address += asked_page_size;
@@ -275,7 +279,7 @@ pub const Specific = extern struct {
                 }
             },
             // 2 MB
-            lib.arch.valid_page_sizes[0] * page_table_entry_count => {
+            lib.arch.valid_page_sizes[0] * paging.page_table_entry_count => {
                 while (virtual_address < top_virtual_address) : ({
                     physical_address += asked_page_size;
                     virtual_address += asked_page_size;
@@ -297,67 +301,34 @@ pub const Specific = extern struct {
     }
 
     fn map1GBPage(specific: Specific, physical_address: u64, virtual_address: u64, flags: MemoryFlags, page_allocator: PageAllocator) !void {
-        const indices = computeIndices(virtual_address);
+        const indexed: IndexedVirtualAddress = @bitCast(virtual_address);
 
         const pml4_table = try getPML4Table(specific.cr3);
-        const pdp_table = try getPDPTable(pml4_table, indices, flags, page_allocator);
-        try mapPageTable1GB(pdp_table, indices, physical_address, flags);
+        const pdp_table = try getPDPTable(pml4_table, indexed, flags, page_allocator);
+        try mapPageTable1GB(pdp_table, indexed, physical_address, flags);
     }
 
     fn map2MBPage(specific: Specific, physical_address: u64, virtual_address: u64, flags: MemoryFlags, page_allocator: PageAllocator) !void {
-        const indices = computeIndices(virtual_address);
+        const indexed: IndexedVirtualAddress = @bitCast(virtual_address);
 
         const pml4_table = try getPML4Table(specific.cr3);
-        const pdp_table = try getPDPTable(pml4_table, indices, flags, page_allocator);
-        const pd_table = try getPDTable(pdp_table, indices, flags, page_allocator);
+        const pdp_table = try getPDPTable(pml4_table, indexed, flags, page_allocator);
+        const pd_table = try getPDTable(pdp_table, indexed, flags, page_allocator);
 
-        mapPageTable2MB(pd_table, indices, physical_address, flags) catch |err| {
+        mapPageTable2MB(pd_table, indexed, physical_address, flags) catch |err| {
             log.err("Virtual address: 0x{x}. Physical address: 0x{x}", .{ virtual_address, physical_address });
             return err;
         };
     }
 
     fn map4KPage(specific: Specific, physical_address: u64, virtual_address: u64, flags: MemoryFlags, page_allocator: PageAllocator) !void {
-        const indices = computeIndices(virtual_address);
+        const indexed: IndexedVirtualAddress = @bitCast(virtual_address);
 
         const pml4_table = try getPML4Table(specific.cr3);
-        const pdp_table = try getPDPTable(pml4_table, indices, flags, page_allocator);
-        const pd_table = try getPDTable(pdp_table, indices, flags, page_allocator);
-        const p_table = try getPTable(pd_table, indices, flags, page_allocator);
-        try mapPageTable4KB(p_table, indices, physical_address, flags);
-    }
-
-    pub inline fn switchTo(specific: *Specific, execution_mode: lib.TraditionalExecutionMode) void {
-        const mask = ~@as(u64, 1 << 12);
-        const masked_cr3 = (@as(u64, @bitCast(specific.cr3)) & mask);
-        const privileged_or = (@as(u64, @intFromEnum(execution_mode)) << 12);
-        const new_cr3 = @as(cr3, @bitCast(masked_cr3 | privileged_or));
-        specific.cr3 = new_cr3;
-    }
-
-    pub inline fn copyHigherHalfCommon(cpu_specific: Specific, pml4_physical_address: PhysicalAddress) void {
-        const cpu_side_pml4_table = pml4_physical_address.toHigherHalfVirtualAddress().access(*PML4Table);
-        const privileged_cpu_pml4_table = try getPML4Table(cpu_specific.cr3);
-        for (cpu_side_pml4_table[0x100..], privileged_cpu_pml4_table[0x100..]) |*pml4_entry, cpu_pml4_entry| {
-            pml4_entry.* = cpu_pml4_entry;
-        }
-    }
-
-    pub fn copyHigherHalfPrivileged(cpu_specific: Specific, pml4_physical_address: PhysicalAddress) void {
-        cpu_specific.copyHigherHalfCommon(pml4_physical_address);
-    }
-
-    pub fn copyHigherHalfUser(cpu_specific: Specific, pml4_physical_address: PhysicalAddress, page_allocator: *PageAllocator) !void {
-        cpu_specific.copyHigherHalfCommon(pml4_physical_address);
-
-        const pml4_table = pml4_physical_address.toHigherHalfVirtualAddress().access(*PML4Table);
-        const pml4_entry = pml4_table[0x1ff];
-        const pml4_entry_address = PhysicalAddress.new(unpackAddress(pml4_entry));
-        const pdp_table = pml4_entry_address.toHigherHalfVirtualAddress().access(*PDPTable);
-        const new_pdp_table_allocation = try page_allocator.allocate(0x1000, 0x1000);
-        const new_pdp_table = new_pdp_table_allocation.toHigherHalfVirtualAddress().access(PDPTE);
-        @memcpy(new_pdp_table, pdp_table);
-        new_pdp_table[0x1fd] = @as(PDPTE, @bitCast(@as(u64, 0)));
+        const pdp_table = try getPDPTable(pml4_table, indexed, flags, page_allocator);
+        const pd_table = try getPDTable(pdp_table, indexed, flags, page_allocator);
+        const p_table = try getPTable(pd_table, indexed, flags, page_allocator);
+        try mapPageTable4KB(p_table, indexed, physical_address, flags);
     }
 
     pub const TranslateError = error{
@@ -373,7 +344,7 @@ pub const Specific = extern struct {
     };
 
     pub fn translateAddress(specific: Specific, virtual_address: VirtualAddress, flags: MemoryFlags) !PhysicalAddress {
-        const indices = computeIndices(virtual_address.value());
+        const indexed: IndexedVirtualAddress = @bitCast(virtual_address.value());
         const is_desired = virtual_address.value() == 0xffff_ffff_8001_f000;
 
         const pml4_table = try getPML4Table(specific.cr3);
@@ -382,10 +353,10 @@ pub const Specific = extern struct {
         // }
 
         //log.debug("pml4 table: 0x{x}", .{@ptrToInt(pml4_table)});
-        const pml4_index = indices[@intFromEnum(Level.PML4)];
+        const pml4_index = indexed.PML4;
         const pml4_entry = pml4_table[pml4_index];
         if (!pml4_entry.present) {
-            log.err("Virtual address: 0x{x}.\nPML4 index: {}.\nValue: {}\n", .{ virtual_address.value(), pml4_index, pml4_entry });
+            log.err("Virtual address: 0x{x}.\nPML4 pointer: 0x{x}\nPML4 index: {}.\nValue: {}\n", .{ virtual_address.value(), @intFromPtr(pml4_table), pml4_index, pml4_entry });
             return TranslateError.pml4_entry_not_present;
         }
 
@@ -398,12 +369,12 @@ pub const Specific = extern struct {
             return TranslateError.pml4_entry_address_null;
         }
 
-        const pdp_table = try getPDPTable(pml4_table, indices, undefined, null);
+        const pdp_table = try getPDPTable(pml4_table, indexed, undefined, null);
         if (is_desired) {
             _ = try specific.translateAddress(VirtualAddress.new(@intFromPtr(pdp_table)), .{});
         }
         //log.debug("pdp table: 0x{x}", .{@ptrToInt(pdp_table)});
-        const pdp_index = indices[@intFromEnum(Level.PDP)];
+        const pdp_index = indexed.PDP;
         const pdp_entry = &pdp_table[pdp_index];
         if (!pdp_entry.present) {
             log.err("PDP index {} not present in PDP table 0x{x}", .{ pdp_index, @intFromPtr(pdp_table) });
@@ -435,7 +406,7 @@ pub const Specific = extern struct {
             _ = try specific.translateAddress(VirtualAddress.new(@intFromPtr(pd_table)), .{});
         }
         //log.debug("pd table: 0x{x}", .{@ptrToInt(pd_table)});
-        const pd_index = indices[@intFromEnum(Level.PD)];
+        const pd_index = indexed.PD;
         const pd_entry = &pd_table[pd_index];
         if (!pd_entry.present) {
             log.err("PD index: {}", .{pd_index});
@@ -468,11 +439,10 @@ pub const Specific = extern struct {
             _ = try specific.translateAddress(VirtualAddress.new(@intFromPtr(p_table)), .{});
         }
         // log.debug("p table: 0x{x}", .{@ptrToInt(p_table)});
-        const pt_index = indices[@intFromEnum(Level.PT)];
+        const pt_index = indexed.PT;
         const pt_entry = &p_table[pt_index];
         if (!pt_entry.present) {
             log.err("Virtual address 0x{x} not mapped", .{virtual_address.value()});
-            log.err("Indices: {any}", .{indices});
             log.err("PTE: 0x{x}", .{@intFromPtr(pt_entry)});
             log.err("PDE: 0x{x}", .{@intFromPtr(pd_entry)});
             log.err("PDPE: 0x{x}", .{@intFromPtr(pdp_entry)});
@@ -491,115 +461,20 @@ pub const Specific = extern struct {
         return pt_entry_address;
     }
 
-    pub fn setMappingFlags(specific: Specific, virtual_address: u64, flags: Mapping.Flags) !void {
-        const indices = computeIndices(virtual_address);
-
-        const vas_cr3 = specific.cr3;
-
-        const pml4_physical_address = vas_cr3.getAddress();
-
-        const pml4_table = try accessPageTable(pml4_physical_address, *PML4Table);
-        const pml4_entry = pml4_table[indices[@intFromEnum(Level.PML4)]];
-        if (!pml4_entry.present) {
-            return TranslateError.pml4_entry_not_present;
-        }
-
-        const pml4_entry_address = PhysicalAddress.new(unpackAddress(pml4_entry));
-        if (pml4_entry_address.value() == 0) {
-            return TranslateError.pml4_entry_address_null;
-        }
-
-        const pdp_table = try accessPageTable(pml4_entry_address, *PDPTable);
-        const pdp_entry = pdp_table[indices[@intFromEnum(Level.PDP)]];
-        if (!pdp_entry.present) {
-            return TranslateError.pdp_entry_not_present;
-        }
-
-        const pdp_entry_address = PhysicalAddress.new(unpackAddress(pdp_entry));
-        if (pdp_entry_address.value() == 0) {
-            return TranslateError.pdp_entry_address_null;
-        }
-
-        const pd_table = try accessPageTable(pdp_entry_address, *PDTable);
-        const pd_entry = pd_table[indices[@intFromEnum(Level.PD)]];
-        if (!pd_entry.present) {
-            return TranslateError.pd_entry_not_present;
-        }
-
-        const pd_entry_address = PhysicalAddress.new(unpackAddress(pd_entry));
-        if (pd_entry_address.value() == 0) {
-            return TranslateError.pd_entry_address_null;
-        }
-
-        const pt_table = try accessPageTable(pd_entry_address, *PTable);
-        const pt_entry = &pt_table[indices[@intFromEnum(Level.PT)]];
-        if (!pt_entry.present) {
-            return TranslateError.pd_entry_not_present;
-        }
-
-        pt_entry.write = flags.write;
-        pt_entry.user = flags.user;
-        pt_entry.page_level_cache_disable = flags.cache_disable;
-        pt_entry.global = flags.global;
-        pt_entry.execute_disable = !flags.execute;
-    }
-
-    pub fn debugMemoryMap(specific: Specific) !void {
-        log.debug("[START] Memory map dump 0x{x}\n", .{specific.cr3.getAddress().value()});
-
-        const pml4 = try specific.getCpuPML4Table();
-
-        for (pml4, 0..) |*pml4te, pml4_index| {
-            if (pml4te.present) {
-                const pdp_table = try accessPageTable(PhysicalAddress.new(unpackAddress(pml4te.*)), *PDPTable);
-
-                for (pdp_table, 0..) |*pdpte, pdp_index| {
-                    if (pdpte.present) {
-                        if (pdpte.page_size) {
-                            continue;
-                        }
-
-                        const pd_table = try accessPageTable(PhysicalAddress.new(unpackAddress(pdpte.*)), *PDTable);
-
-                        for (pd_table, 0..) |*pdte, pd_index| {
-                            if (pdte.present) {
-                                if (pdte.page_size) @panic("bbbb");
-
-                                const p_table = try accessPageTable(PhysicalAddress.new(unpackAddress(pdte.*)), *PTable);
-
-                                for (p_table, 0..) |*pte, pt_index| {
-                                    if (pte.present) {
-                                        const indexed_virtual_address = IndexedVirtualAddress{
-                                            .PML4 = @as(u9, @intCast(pml4_index)),
-                                            .PDP = @as(u9, @intCast(pdp_index)),
-                                            .PD = @as(u9, @intCast(pd_index)),
-                                            .PT = @as(u9, @intCast(pt_index)),
-                                        };
-
-                                        const virtual_address = indexed_virtual_address.toVirtualAddress();
-                                        const physical_address = unpackAddress(pte.*);
-                                        log.debug("0x{x} -> 0x{x}", .{ virtual_address.value(), physical_address });
-                                    }
-                                }
-                            }
-                        }
-                    }
-                }
-            }
-        }
-
-        log.debug("[END] Memory map dump", .{});
-    }
-
     inline fn getUserCr3(specific: Specific) cr3 {
-        assert(@as(u64, @bitCast(specific.cr3)) & page_table_size == 0);
-        return @as(cr3, @bitCast(@as(u64, @bitCast(specific.cr3)) | page_table_size));
+        assert(specific.isPrivileged());
+        return @as(cr3, @bitCast(@as(u64, @bitCast(specific.cr3)) | paging.page_table_size));
     }
 
     pub inline fn getCpuPML4Table(specific: Specific) !*PML4Table {
-        assert(@as(u64, @bitCast(specific.cr3)) & page_table_size == 0);
+        assert(specific.isPrivileged());
         return try specific.getPML4TableUnchecked();
     }
+
+    fn isPrivileged(specific: Specific) bool {
+        return @as(u64, @bitCast(specific.cr3)) & paging.page_table_size == 0;
+    }
+
     pub inline fn getUserPML4Table(specific: Specific) !*PML4Table {
         return try getPML4Table(specific.getUserCr3());
     }
@@ -609,8 +484,6 @@ pub const Specific = extern struct {
     }
 };
 
-const Indices = [enumCount(Level)]u16;
-
 const MapError = error{
     already_present_4kb,
     already_present_2mb,
@@ -650,8 +523,8 @@ fn getPML4Table(cr3r: cr3) !*PML4Table {
     return pml4_table;
 }
 
-fn getPDPTable(pml4_table: *PML4Table, indices: Indices, flags: MemoryFlags, maybe_page_allocator: ?PageAllocator) !*PDPTable {
-    const index = indices[@intFromEnum(Level.PML4)];
+fn getPDPTable(pml4_table: *PML4Table, virtual_address: IndexedVirtualAddress, flags: MemoryFlags, maybe_page_allocator: ?PageAllocator) !*PDPTable {
+    const index = virtual_address.PML4;
     const entry_pointer = &pml4_table[index];
 
     const table_physical_address = physical_address_blk: {
@@ -664,6 +537,7 @@ fn getPDPTable(pml4_table: *PML4Table, indices: Indices, flags: MemoryFlags, may
                 const entry_allocation = try page_allocator.allocatePageTable(.{
                     .level = .PDP,
                     .user = flags.user,
+                    .virtual_address = virtual_address,
                 });
 
                 entry_pointer.* = PML4TE{
@@ -706,8 +580,8 @@ pub inline fn getPageEntry(comptime Entry: type, physical_address: u64, flags: M
     };
 }
 
-fn mapPageTable1GB(pdp_table: *PDPTable, indices: Indices, physical_address: u64, flags: MemoryFlags) MapError!void {
-    const entry_index = indices[@intFromEnum(Level.PDP)];
+fn mapPageTable1GB(pdp_table: *PDPTable, indexed: IndexedVirtualAddress, physical_address: u64, flags: MemoryFlags) MapError!void {
+    const entry_index = indexed.PDP;
     const entry_pointer = &pdp_table[entry_index];
 
     if (entry_pointer.present) return MapError.already_present_1gb;
@@ -717,8 +591,8 @@ fn mapPageTable1GB(pdp_table: *PDPTable, indices: Indices, physical_address: u64
     entry_pointer.* = @as(PDPTE, @bitCast(getPageEntry(PDPTE_1GB, physical_address, flags)));
 }
 
-fn mapPageTable2MB(pd_table: *PDTable, indices: Indices, physical_address: u64, flags: MemoryFlags) !void {
-    const entry_index = indices[@intFromEnum(Level.PD)];
+fn mapPageTable2MB(pd_table: *PDTable, indexed: IndexedVirtualAddress, physical_address: u64, flags: MemoryFlags) !void {
+    const entry_index = indexed.PD;
     const entry_pointer = &pd_table[entry_index];
     const entry_value = entry_pointer.*;
 
@@ -727,13 +601,11 @@ fn mapPageTable2MB(pd_table: *PDTable, indices: Indices, physical_address: u64,
         return MapError.already_present_2mb;
     }
 
-    assert(isAlignedGeneric(u64, physical_address, valid_page_sizes[1]));
-
     entry_pointer.* = @as(PDTE, @bitCast(getPageEntry(PDTE_2MB, physical_address, flags)));
 }
 
-fn mapPageTable4KB(p_table: *PTable, indices: Indices, physical_address: u64, flags: MemoryFlags) !void {
-    const entry_index = indices[@intFromEnum(Level.PT)];
+fn mapPageTable4KB(p_table: *PTable, indexed: IndexedVirtualAddress, physical_address: u64, flags: MemoryFlags) !void {
+    const entry_index = indexed.PT;
     const entry_pointer = &p_table[entry_index];
 
     if (entry_pointer.present) {
@@ -750,8 +622,8 @@ const ToImplementError = error{
     page_size,
 };
 
-fn getPDTable(pdp_table: *PDPTable, indices: Indices, flags: MemoryFlags, page_allocator: PageAllocator) !*PDTable {
-    const entry_index = indices[@intFromEnum(Level.PDP)];
+fn getPDTable(pdp_table: *PDPTable, indexed: IndexedVirtualAddress, flags: MemoryFlags, page_allocator: PageAllocator) !*PDTable {
+    const entry_index = indexed.PDP;
     const entry_pointer = &pdp_table[entry_index];
 
     const table_physical_address = physical_address_blk: {
@@ -765,6 +637,7 @@ fn getPDTable(pdp_table: *PDPTable, indices: Indices, flags: MemoryFlags, page_a
             const entry_allocation = try page_allocator.allocatePageTable(.{
                 .level = .PD,
                 .user = flags.user,
+                .virtual_address = indexed,
             });
 
             entry_pointer.* = PDPTE{
@@ -781,8 +654,8 @@ fn getPDTable(pdp_table: *PDPTable, indices: Indices, flags: MemoryFlags, page_a
     return try accessPageTable(table_physical_address, *PDTable);
 }
 
-fn getPTable(pd_table: *PDTable, indices: Indices, flags: MemoryFlags, page_allocator: PageAllocator) !*PTable {
-    const entry_pointer = &pd_table[indices[@intFromEnum(Level.PD)]];
+fn getPTable(pd_table: *PDTable, indexed: IndexedVirtualAddress, flags: MemoryFlags, page_allocator: PageAllocator) !*PTable {
+    const entry_pointer = &pd_table[indexed.PD];
     const table_physical_address = physical_address_blk: {
         const entry_value = entry_pointer.*;
         if (entry_value.present) {
@@ -791,7 +664,11 @@ fn getPTable(pd_table: *PDTable, indices: Indices, flags: MemoryFlags, page_allo
                 return ToImplementError.page_size;
             } else break :physical_address_blk PhysicalAddress.new(unpackAddress(entry_value));
         } else {
-            const entry_allocation = try page_allocator.allocatePageTable(.{ .level = .PT, .user = flags.user });
+            const entry_allocation = try page_allocator.allocatePageTable(.{
+                .level = .PT,
+                .user = flags.user,
+                .virtual_address = indexed,
+            });
 
             entry_pointer.* = PDTE{
                 .present = true,
@@ -811,21 +688,6 @@ const half_entry_count = (@sizeOf(PML4Table) / @sizeOf(PML4TE)) / 2;
 
 const needed_physical_memory_for_bootstrapping_cpu_driver_address_space = @sizeOf(PML4Table) + @sizeOf(PDPTable) * 256;
 
-pub fn computeIndices(virtual_address: u64) Indices {
-    var indices: Indices = undefined;
-    var va = virtual_address;
-    va = va >> 12;
-    indices[3] = @as(u9, @truncate(va));
-    va = va >> 9;
-    indices[2] = @as(u9, @truncate(va));
-    va = va >> 9;
-    indices[1] = @as(u9, @truncate(va));
-    va = va >> 9;
-    indices[0] = @as(u9, @truncate(va));
-
-    return indices;
-}
-
 pub inline fn newFlags(general_flags: Mapping.Flags) MemoryFlags {
     return MemoryFlags{
         .write = general_flags.write,
@@ -856,28 +718,15 @@ pub const MemoryFlags = packed struct(u64) {
 
 const address_mask: u64 = 0x0000_00ff_ffff_f000;
 
-pub const Level = Level4;
-
-pub const Level4 = enum(u2) {
-    PML4 = 0,
-    PDP = 1,
-    PD = 2,
-    PT = 3,
-
-    pub const count = lib.enumCount(@This());
-};
-
-pub const Level5 = enum(u3) {};
-
 pub fn EntryTypeMapSize(comptime page_size: comptime_int) usize {
-    return switch (Level) {
-        Level4 => switch (page_size) {
+    return switch (paging.Level) {
+        paging.Level4 => switch (page_size) {
             lib.arch.valid_page_sizes[0] => 4,
             lib.arch.valid_page_sizes[1] => 3,
             lib.arch.valid_page_sizes[2] => 2,
             else => @compileError("Unknown page size"),
         },
-        Level5 => @compileError("TODO"),
+        paging.Level5 => @compileError("TODO"),
         else => @compileError("unreachable"),
     };
 }
@@ -886,28 +735,28 @@ pub fn EntryTypeMap(comptime page_size: comptime_int) [EntryTypeMapSize(page_siz
     const map_size = EntryTypeMapSize(page_size);
     const Result = [map_size]type;
     var result: Result = undefined;
-    switch (Level) {
-        Level4, Level5 => {
-            if (@hasField(Level, "pml5")) {
+    switch (paging.Level) {
+        paging.Level4, paging.Level5 => {
+            if (@hasField(paging.Level, "pml5")) {
                 @compileError("TODO: type_map[@enumToInt(Level.PML5)] =");
             }
 
-            result[@intFromEnum(Level.PML4)] = PML4TE;
+            result[@intFromEnum(paging.Level.PML4)] = PML4TE;
 
             if (page_size == lib.arch.valid_page_sizes[2]) {
-                assert(map_size == 2 + @intFromBool(Level == Level5));
-                result[@intFromEnum(Level.PDP)] = PDPTE_1GB;
+                assert(map_size == 2 + @intFromBool(paging.Level == paging.Level5));
+                result[@intFromEnum(paging.Level.PDP)] = PDPTE_1GB;
             } else {
-                result[@intFromEnum(Level.PDP)] = PDPTE;
+                result[@intFromEnum(paging.Level.PDP)] = PDPTE;
 
                 if (page_size == lib.arch.valid_page_sizes[1]) {
-                    assert(map_size == @as(usize, 3) + @intFromBool(Level == Level5));
-                    result[@intFromEnum(Level.PD)] = PDTE_2MB;
+                    assert(map_size == @as(usize, 3) + @intFromBool(paging.Level == paging.Level5));
+                    result[@intFromEnum(paging.Level.PD)] = PDTE_2MB;
                 } else {
                     assert(page_size == lib.arch.valid_page_sizes[0]);
 
-                    result[@intFromEnum(Level.PD)] = PDTE;
-                    result[@intFromEnum(Level.PT)] = PTE;
+                    result[@intFromEnum(paging.Level.PD)] = PDTE;
+                    result[@intFromEnum(paging.Level.PT)] = PTE;
                 }
             }
         },
@@ -1073,16 +922,7 @@ pub const PTE = packed struct(u64) {
     }
 };
 
-pub const PML4Table = [page_table_entry_count]PML4TE;
-pub const PDPTable = [page_table_entry_count]PDPTE;
-pub const PDTable = [page_table_entry_count]PDTE;
-pub const PTable = [page_table_entry_count]PTE;
-pub const page_table_entry_size = @sizeOf(u64);
-pub const page_table_size = lib.arch.valid_page_sizes[0];
-pub const page_table_entry_count = @divExact(page_table_size, page_table_entry_size);
-pub const page_table_alignment = page_table_size;
-
-comptime {
-    assert(page_table_alignment == page_table_size);
-    assert(page_table_size == lib.arch.valid_page_sizes[0]);
-}
+pub const PML4Table = [paging.page_table_entry_count]PML4TE;
+pub const PDPTable = [paging.page_table_entry_count]PDPTE;
+pub const PDTable = [paging.page_table_entry_count]PDTE;
+pub const PTable = [paging.page_table_entry_count]PTE;

src/user.zig

@@ -4,24 +4,20 @@ const assert = lib.assert;
 const ExecutionMode = lib.Syscall.ExecutionMode;
 
 const birth = @import("birth");
-const capabilities = birth.capabilities;
-pub const Syscall = birth.capabilities.Syscall;
+pub const Command = birth.interface.Command;
+pub const Interface = birth.interface.Descriptor;
+pub const Scheduler = birth.Scheduler;
 
 pub const arch = @import("user/arch.zig");
+pub const capabilities = @import("user/capabilities.zig");
 const core_state = @import("user/core_state.zig");
 pub const CoreState = core_state.CoreState;
-pub const PinnedState = core_state.PinnedState;
 pub const libc = @import("user/libc.zig");
 pub const thread = @import("user/thread.zig");
+pub const Thread = thread.Thread;
 pub const process = @import("user/process.zig");
-const vas = @import("user/virtual_address_space.zig");
+pub const Virtual = @import("user/virtual.zig");
 const VirtualAddress = lib.VirtualAddress;
-pub const VirtualAddressSpace = vas.VirtualAddressSpace;
-pub const MMUAwareVirtualAddressSpace = vas.MMUAwareVirtualAddressSpace;
-
-pub const PhysicalMap = @import("user/physical_map.zig").PhysicalMap;
-pub const PhysicalMemoryRegion = @import("user/physical_memory_region.zig").PhysicalMemoryRegion;
-pub const SlotAllocator = @import("user/slot_allocator.zig").SlotAllocator;
 
 comptime {
     @export(arch._start, .{ .linkage = .Strong, .name = "_start" });
@@ -29,8 +25,8 @@ comptime {
 
 pub const writer = lib.Writer(void, Writer.Error, Writer.write){ .context = {} };
 const Writer = extern struct {
-    const syscall = Syscall(.io, .log);
-    const Error = Writer.syscall.ErrorSet.Error;
+    const syscall = Interface(.io, .log);
+    const Error = Writer.syscall.Error;
 
     fn write(_: void, bytes: []const u8) Error!usize {
         const result = try Writer.syscall.blocking(bytes);
@@ -52,22 +48,16 @@ pub fn zigPanic(message: []const u8, _: ?*lib.StackTrace, _: ?usize) noreturn {
 }
 
 pub fn panic(comptime format: []const u8, arguments: anytype) noreturn {
-    lib.log.scoped(.PANIC).err(format, arguments);
+    var buffer: [0x100]u8 = undefined;
+    const message: []const u8 = lib.bufPrint(&buffer, format, arguments) catch "Failed to get panic message!";
     while (true) {
-        Syscall(.process, .exit).blocking(false) catch |err| log.err("Exit failed: {}", .{err});
+        Interface(.process, .panic).blocking(.{
+            .message = message,
+            .exit_code = 1,
+        }) catch |err| log.err("Exit failed: {}", .{err});
     }
 }
 
-pub const Scheduler = extern struct {
-    time_slice: u32,
-    core_id: u32,
-    core_state: CoreState,
-};
-
-pub inline fn currentScheduler() *Scheduler {
-    return arch.currentScheduler();
-}
-
 fn schedulerInitDisabled(scheduler: *arch.Scheduler) void {
     // Architecture-specific initialization
     scheduler.generic.time_slice = 1;
@@ -75,18 +65,38 @@ fn schedulerInitDisabled(scheduler: *arch.Scheduler) void {
 }
 
 pub var is_init = false;
-pub var command_buffer: birth.CommandBuffer = undefined;
+pub var command_buffer: Command.Buffer = undefined;
+const entry_count = 50;
 
-pub export fn start(scheduler: *arch.Scheduler, arg_init: bool) callconv(.C) noreturn {
+const CommandBufferCreateError = error{
+    invalid_entry_count,
+};
+
+fn createCommandBuffer(options: Command.Buffer.CreateOptions) !Command.Buffer {
+    // TODO: allow kernel to chop slices of memories
+    try capabilities.setupCommandFrame(Command.Submission, options.submission_entry_count);
+    try capabilities.setupCommandFrame(Command.Completion, options.completion_entry_count);
+    @panic("TODO: createCommandBuffer");
+}
+
+pub export fn start(scheduler: *Scheduler, arg_init: bool) callconv(.C) noreturn {
     assert(arg_init);
     is_init = arg_init;
     if (is_init) {
-        assert(scheduler.common.generic.setup_stack_lock.load(.Monotonic));
+        assert(scheduler.common.setup_stack_lock.load(.Monotonic));
     }
-    assert(scheduler.common.generic.disabled);
-    scheduler.initDisabled();
-    // command_buffer = Syscall(.cpu, .get_command_buffer).blocking(&command_buffer) catch @panic("Unable to get command buffer");
-    Syscall(.cpu, .shutdown).blocking({}) catch unreachable;
+
+    initialize() catch |err| panic("Failed to initialize: {}", .{err});
+    @import("root").main() catch |err| panic("Failed to execute main: {}", .{err});
+
+    while (true) {
+        @panic("TODO: after main");
+    }
+}
+
+fn initialize() !void {
+    currentScheduler().initializeAllocator();
+    _ = try Virtual.AddressSpace.create();
 }
 
 // export fn birthInitializeDisabled(scheduler: *arch.Scheduler, arg_init: bool) callconv(.C) noreturn {
@@ -98,45 +108,7 @@ pub export fn start(scheduler: *arch.Scheduler, arg_init: bool) callconv(.C) nor
 // }
 
 // Barrelfish: vregion
-pub const VirtualMemoryRegion = extern struct {
-    virtual_address_space: *VirtualAddressSpace,
-    physical_region: *PhysicalMemoryRegion,
-    offset: usize,
-    size: usize,
-    address: VirtualAddress,
-    flags: Flags,
-    next: ?*VirtualMemoryRegion = null,
-
-    pub const Flags = packed struct(u8) {
-        read: bool = false,
-        write: bool = false,
-        execute: bool = false,
-        cache_disabled: bool = false,
-        preferred_page_size: u2 = 0,
-        write_combining: bool = false,
-        reserved: u1 = 0,
-    };
-};
-
-pub const MoreCore = extern struct {
-    const InitializationError = error{
-        invalid_page_size,
-    };
-
-    pub fn init(page_size: usize) InitializationError!void {
-        blk: inline for (lib.arch.valid_page_sizes) |valid_page_size| {
-            if (valid_page_size == page_size) break :blk;
-        } else {
-            return InitializationError.invalid_page_size;
-        }
-
-        const morecore_state = process.getMoreCoreState();
-        morecore_state.mmu_state = try MMUAwareVirtualAddressSpace.initAligned(SlotAllocator.getDefault(), lib.arch.valid_page_sizes[1], lib.arch.valid_page_sizes[0], .{ .read = true, .write = true });
-
-        @panic("TODO: MoreCore.init");
-    }
-
-    pub const State = extern struct {
-        mmu_state: MMUAwareVirtualAddressSpace,
-    };
-};
+pub inline fn currentScheduler() *birth.Scheduler {
+    const result = arch.maybeCurrentScheduler().?;
+    return result;
+}

src/user/arch/x86_64.zig

@@ -16,28 +16,6 @@ const SlotAllocator = user.SlotAllocator;
 const Thread = user.Thread;
 const VirtualAddressSpace = user.VirtualAddressSpace;
 
-pub const Scheduler = extern struct {
-    common: birth.arch.UserScheduler,
-    generic: user.Scheduler,
-
-    pub fn initDisabled(scheduler: *Scheduler) void {
-        _ = scheduler;
-        // TODO:
-        // *set entry points?
-        // *set tls registers?
-    }
-
-    pub noinline fn restore(scheduler: *Scheduler, register_arena: *const RegisterArena) noreturn {
-        assert(scheduler.common.generic.disabled);
-        assert(scheduler.common.generic.has_work);
-
-        assert(register_arena.registers.rip > lib.arch.valid_page_sizes[0]);
-        assert(register_arena.registers.rflags.IF and register_arena.registers.rflags.reserved0);
-
-        register_arena.contextSwitch();
-    }
-};
-
 // CRT0
 pub fn _start() callconv(.Naked) noreturn {
     asm volatile (
@@ -46,8 +24,6 @@ pub fn _start() callconv(.Naked) noreturn {
         :
         : [startFunction] "r" (user.start),
     );
-
-    unreachable;
 }
 
 pub inline fn setInitialState(register_arena: *RegisterArena, entry: VirtualAddress, stack_virtual_address: VirtualAddress, arguments: birth.syscall.Arguments) void {
@@ -80,37 +56,3 @@ pub inline fn maybeCurrentScheduler() ?*user.Scheduler {
         : "memory"
     );
 }
-
-pub inline fn currentScheduler() *user.Scheduler {
-    const result = maybeCurrentScheduler().?;
-    return result;
-}
-
-/// This is an interface to user.PhysicalMap, providing the architecture-specific functionality
-pub const PhysicalMapInterface = struct {
-    pub fn determineAddress(physical_map: *PhysicalMap, physical_memory_region: PhysicalMemoryRegion, alignment: usize) !VirtualAddress {
-        _ = physical_memory_region;
-        _ = alignment;
-        assert(physical_map.virtual_address_space.regions != null);
-        log.debug("PMap: 0x{x}", .{@intFromPtr(physical_map.virtual_address_space.regions)});
-        log.debug("PMap: {?}", .{physical_map.virtual_address_space.regions});
-        @panic("TODO: PhysicalMapInterface.determineAddress");
-    }
-
-    pub fn initializeCurrent(physical_map: *PhysicalMap) !void {
-        _ = physical_map;
-        log.warn("TODO: PhysicalMapInterface.initializeCurrent", .{});
-    }
-
-    pub fn init(virtual_address_space: *VirtualAddressSpace, page_level: u3, slot_allocator: *SlotAllocator) !PhysicalMap {
-        var result = PhysicalMap{
-            .virtual_address_space = virtual_address_space,
-            .slot_allocator = slot_allocator,
-        };
-        _ = page_level;
-
-        try result.initPageTableManagement();
-
-        @panic("TODO: PhysicalMap.init");
-    }
-};

src/user/arch/x86_64/linker_script.ld

@@ -6,7 +6,7 @@ PHDRS {
 }
 
 SECTIONS {
-  . = 0x600000;
+  . = 0x200000;
   . = ALIGN(4K);
   .text . : {
     *(.text*)

src/user/capabilities.zig

@@ -1,20 +1,85 @@
 const lib = @import("lib");
+const log = lib.log;
 const assert = lib.assert;
 const birth = @import("birth");
+const user = @import("user");
+const Interface = user.Interface;
+
+const Command = birth.interface.Command;
 
 // TODO: ref
-pub fn frameCreate(ref: usize, bytes: usize) !usize {
-    return mappableCapabilityCreate(ref, .cpu_memory, bytes);
+pub fn frameCreate(bytes: usize) !birth.capabilities.RAM {
+    return mappableCapabilityCreate(.cpu_memory, bytes);
 }
 
-fn mappableCapabilityCreate(ref: usize, mappable_capability: birth.capabilities.Type.Mappable, bytes: usize) !usize {
-    _ = mappable_capability;
-    _ = ref;
+const CommandBufferFrameType = enum {
+    command_buffer_completion,
+    command_buffer_submission,
+};
+
+pub fn setupCommandFrame(comptime QueueType: type, entry_count: usize) !void {
+    assert(entry_count > 0);
+    comptime assert(@alignOf(QueueType) <= @sizeOf(QueueType.Header));
+    const total_size = lib.alignForward(usize, @sizeOf(QueueType.Header) + entry_count * @sizeOf(QueueType), lib.arch.valid_page_sizes[0]);
+    const capability = switch (QueueType) {
+        Command.Submission => .command_buffer_submission,
+        Command.Completion => .command_buffer_completion,
+        else => @compileError("Unexpected type"),
+    };
+
+    const allocation = try Interface(.ram, .allocate).blocking(total_size);
+    const dst_cap_frame = try retype(@bitCast(allocation), capability);
+    const flags = .{
+        .write = QueueType == Command.Submission,
+        .execute = false,
+    };
+    _ = try Interface(capability, .map).blocking(.{
+        .frame = dst_cap_frame,
+        .flags = flags,
+    });
+
+    @panic("TODO: setup frame");
+}
+
+fn mappableCapabilityCreate(capability: birth.capabilities.Type.Mappable, bytes: usize) !birth.capabilities.RAM {
     assert(bytes > 0);
+
+    return RamDescendant.create(capability, bytes);
 }
 
-fn ramDescendantCreate(
-    ref: usize,
-) !usize {
-    _ = ref;
+const Ram = extern struct {
+    pub fn allocate(size: usize) !usize {
+        _ = size;
+        log.err("TODO: allocate", .{});
+        return error.not_implemented;
+    }
+};
+
+const RamDescendant = extern struct {
+    capability: usize,
+    size: usize,
+
+    pub fn create(capability: birth.capabilities.Type.Mappable, size: usize) !birth.capabilities.RAM {
+        const allocation = try Interface(.ram, .allocate).blocking(size);
+        const generic_capability = switch (capability) {
+            inline else => |mappable_cap| @field(birth.interface.Capability, @tagName(mappable_cap)),
+        };
+        const result = try retype(@bitCast(allocation), generic_capability);
+
+        // TODO: check if the previous capability needs to be deleted (because maybe it should be deleted at the retype operation
+        // try destroy(@bitCast(allocation));
+        return @bitCast(result);
+    }
+};
+
+// TODO: make this more complex and generic to handle all cases
+pub fn retype(source: birth.interface.Reference, capability: birth.interface.Capability) !birth.interface.Reference {
+    const new_reference = try Interface(.ram, .retype).blocking(.{ .source = @bitCast(source), .destination = capability });
+    return new_reference;
+}
+
+pub fn destroy(capability: birth.capabilities.Reference) !void {
+    _ = capability;
+    log.err("TODO: destroy", .{});
+    return error.not_implemented;
 }

src/user/core_state.zig

@@ -1,27 +1,6 @@
 const user = @import("user");
-const MoreCore = user.MoreCore;
 const PhysicalMap = user.PhysicalMap;
 const PhysicalMemoryRegion = user.PhysicalMemoryRegion;
 const SlotAllocator = user.SlotAllocator;
 const VirtualAddressSpace = user.VirtualAddressSpace;
 const VirtualMemoryRegion = user.VirtualMemoryRegion;
-
-pub const PagingState = extern struct {
-    virtual_address_space: VirtualAddressSpace,
-    physical_map: PhysicalMap,
-};
-
-pub const PinnedState = extern struct {
-    physical_memory_region: PhysicalMemoryRegion.Pinned,
-    virtual_memory_region: VirtualMemoryRegion,
-    offset: usize,
-    // TODO: lists
-};
-
-pub const CoreState = extern struct {
-    paging: PagingState,
-    slot_allocator: SlotAllocator.State,
-    virtual_address_space: VirtualAddressSpace.State,
-    pinned: PinnedState,
-    more_core: MoreCore.State,
-};

src/user/libc.zig

@@ -1,7 +1,6 @@
 const user = @import("user");
 
 pub export fn malloc(size: usize) ?*anyopaque {
-    const morecore_state = user.process.getMoreCoreState();
-    const result = morecore_state.mmu_state.map(size) catch return null;
-    return result.ptr;
+    _ = size;
+    @panic("TODO: malloc");
 }

src/user/mmu_aware_virtual_address_space.zig

@@ -1,62 +0,0 @@
-const lib = @import("lib");
-const assert = lib.assert;
-const log = lib.log.scoped(.MMUAwareVirtualAddressSpace);
-
-const user = @import("user");
-const PhysicalMemoryRegion = user.PhysicalMemoryRegion;
-const SlotAllocator = user.SlotAllocator;
-const VirtualMemoryRegion = user.VirtualMemoryRegion;
-
-pub const MMUAwareVirtualAddressSpace = extern struct {
-    size: usize,
-    alignment: usize,
-    consumed: usize = 0,
-    /// This is a index into the architecture-specific page sizes
-    page_size: u8,
-    slot_allocator: *SlotAllocator,
-    physical_memory_region: PhysicalMemoryRegion.Anonymous,
-    virtual_memory_region: VirtualMemoryRegion,
-    // struct vregion vregion;           ///< Needs just one vregion
-    // struct memobj_anon memobj;        ///< Needs just one memobj
-    // lvaddr_t offset;    ///< Offset of free space in anon
-    // lvaddr_t mapoffset; ///< Offset into the anon that has been mapped in
-
-    pub fn init(size: usize) !MMUAwareVirtualAddressSpace {
-        const slot_allocator = SlotAllocator.getDefault();
-        const alignment = lib.arch.valid_page_sizes[0];
-        return initAligned(slot_allocator, size, alignment, .{ .write = true });
-    }
-
-    pub fn initAligned(slot_allocator: *SlotAllocator, size: usize, alignment: usize, flags: VirtualMemoryRegion.Flags) !MMUAwareVirtualAddressSpace {
-        assert(flags.preferred_page_size < lib.arch.valid_page_sizes.len);
-        var result = MMUAwareVirtualAddressSpace{
-            .size = size,
-            .alignment = alignment,
-            .page_size = flags.preferred_page_size,
-            .slot_allocator = slot_allocator,
-            .physical_memory_region = try PhysicalMemoryRegion.Anonymous.new(size),
-            .virtual_memory_region = undefined,
-        };
-        // TODO: fix this API
-        result.virtual_memory_region = try user.process.getVirtualAddressSpace().mapAligned(result.physical_memory_region.getGeneric().*, 0, size, alignment, flags);
-
-        // TODO: create memobj
-        // TODO: map memobj into vregion
-
-        @panic("TODO: MMUAwareVirtualAddressSpace.initAligned");
-    }
-
-    const Error = error{
-        alignment,
-    };
-
-    pub fn map(virtual_address_space: *MMUAwareVirtualAddressSpace, size: usize) ![]u8 {
-        if (!lib.isAligned(size, lib.arch.valid_page_sizes[0])) {
-            return error.alignment;
-        }
-        _ = virtual_address_space;
-        log.warn("[map] TODO: slot allocation", .{});
-        //virtual_address_space.slot_allocator.allocate();
-        @panic("TODO: MMUAwareVirtualAddressSpace.map");
-    }
-};

src/user/physical_map.zig

@@ -1,25 +0,0 @@
-const lib = @import("lib");
-const log = lib.log.scoped(.PhysicalMap);
-
-const user = @import("user");
-const SlotAllocator = user.SlotAllocator;
-const VirtualAddressSpace = user.VirtualAddressSpace;
-
-pub const PhysicalMap = extern struct {
-    virtual_address_space: *VirtualAddressSpace,
-    slot_allocator: *SlotAllocator,
-
-    pub usingnamespace user.arch.PhysicalMapInterface;
-
-    pub fn initPageTableManagement(physical_map: *PhysicalMap) !void {
-        const current_physical_map = user.process.getPhysicalMap();
-        log.debug("CURR: 0x{x}. PHYS: 0x{x}", .{ @intFromPtr(current_physical_map), @intFromPtr(physical_map) });
-        if (current_physical_map == physical_map) {
-            @panic("TODO: if");
-        } else {
-            log.warn("TODO: slab_init", .{});
-            _ = user.libc.malloc(lib.arch.valid_page_sizes[0]);
-            @panic("TODO: else");
-        }
-    }
-};

src/user/physical_memory_region.zig

@@ -1,81 +0,0 @@
-const lib = @import("lib");
-const assert = lib.assert;
-const log = lib.log.scoped(.PhysicalMemoryRegion);
-
-// Barrelfish: memobj
-pub const PhysicalMemoryRegion = extern struct {
-    size: usize,
-    type: Type,
-
-    pub const Type = enum(u8) {
-        anonymous = 0,
-        one_frame = 1,
-        pinned = 3,
-        //one_frame_lazy,
-        //one_frame_one_map,
-        // vfs,
-        // fixed,
-        // numa,
-        // append,
-
-        fn map(t: Type) type {
-            return switch (t) {
-                .anonymous => Anonymous,
-                .one_frame => OneFrame,
-                .pinned => Pinned,
-            };
-        }
-    };
-
-    pub const Anonymous = extern struct {
-        region: PhysicalMemoryRegion,
-
-        pub usingnamespace Interface(@This());
-
-        pub fn new(size: usize) !Anonymous {
-            const result = Anonymous{
-                .region = .{
-                    .size = size,
-                    .type = .anonymous,
-                },
-            };
-
-            log.warn("[Anonymous.new] TODO: initialize memory", .{});
-
-            return result;
-        }
-    };
-
-    pub const OneFrame = extern struct {
-        pub usingnamespace Interface(@This());
-    };
-
-    pub const Pinned = extern struct {
-        region: PhysicalMemoryRegion,
-        pub usingnamespace Interface(@This());
-
-        pub fn new(size: usize) !Pinned {
-            const result = Pinned{
-                .region = .{
-                    .size = size,
-                    .type = .pinned,
-                },
-            };
-
-            log.warn("[Pinned.new] TODO: initialize memory", .{});
-
-            return result;
-        }
-    };
-
-    fn Interface(comptime PhysicalMemoryRegionType: type) type {
-        assert(@hasField(PhysicalMemoryRegionType, "region"));
-        assert(@TypeOf(@field(@as(PhysicalMemoryRegionType, undefined), "region")) == PhysicalMemoryRegion);
-
-        return extern struct {
-            pub inline fn getGeneric(r: *PhysicalMemoryRegionType) *PhysicalMemoryRegion {
-                return &r.region;
-            }
-        };
-    }
-};

src/user/programs/device_manager/main.zig

@@ -9,10 +9,12 @@ pub const std_options = user.std_options;
 export var core_id: u32 = 0;
 
 pub fn main() !noreturn {
-    core_id = try Syscall(.cpu, .get_core_id).blocking({});
-    user.currentScheduler().core_id = core_id;
-    log.debug("Hello world! User space initialization from core #{}", .{core_id});
-    const allocation = try Syscall(.cpu_memory, .allocate).blocking(0x1000);
-    log.debug("Look allocation successful at 0x{x}", .{allocation.value()});
-    try Syscall(.cpu, .shutdown).blocking({});
+    @panic("TODO: main");
+
+    // core_id = try Syscall(.cpu, .get_core_id).blocking({});
+    // user.currentScheduler().core_id = core_id;
+    // log.debug("Hello world! User space initialization from core #{}", .{core_id});
+    // const allocation = try Syscall(.cpu_memory, .allocate).blocking(0x1000);
+    // log.debug("Look allocation successful at 0x{x}", .{allocation.value()});
+    // try Syscall(.cpu, .shutdown).blocking({});
 }

src/user/programs/init/main.zig

@@ -9,7 +9,7 @@ pub const std_options = user.std_options;
 
 export var core_id: u32 = 0;
 
-pub fn main() !noreturn {
+pub fn main() !void {
     // core_id = try syscall(.cpu, .get_core_id).blocking({});
     // user.currentScheduler().core_id = core_id;
     // log.debug("Hello world! User space initialization from core #{}", .{core_id});
@@ -21,5 +21,5 @@ pub fn main() !noreturn {
     // const aligned_bundle_size = lib.alignForward(usize, bundle_size, lib.arch.valid_page_sizes[0]);
     // const bundle_allocation = try syscall(.cpu_memory, .allocate).blocking(aligned_bundle_size);
     // log.debug("Look allocation successful at 0x{x}", .{bundle_allocation.value()});
-    try syscall(.cpu, .shutdown).blocking({});
+    // try syscall(.cpu, .shutdown).blocking({});
 }

src/user/slot_allocator.zig

@@ -1,28 +0,0 @@
-const log = @import("lib").log;
-const user = @import("user");
-
-pub const SlotAllocator = extern struct {
-    foo: u32 = 0,
-
-    /// This function is inlined because it's only called once
-    pub inline fn init() !void {
-        log.warn("TODO: implement the whole SlotAllocator.init", .{});
-        const state = user.process.getSlotAllocatorState();
-        const default_allocator = state.default_allocator;
-        _ = default_allocator;
-    }
-
-    pub fn getDefault() *SlotAllocator {
-        const process_slot_allocator_state = user.process.getSlotAllocatorState();
-        return &process_slot_allocator_state.default_allocator.allocator;
-    }
-
-    pub const State = extern struct {
-        default_allocator: MultiSlotAllocator,
-    };
-};
-
-pub const MultiSlotAllocator = extern struct {
-    allocator: SlotAllocator,
-    // TODO:
-};

src/user/thread.zig

@@ -9,48 +9,21 @@ const SlotAllocator = user.SlotAllocator;
 const VirtualAddress = lib.VirtualAddress;
 const VirtualAddressSpace = user.VirtualAddressSpace;
 
+const Thread = birth.Thread;
+
 const max_thread_count = 256;
 
-pub const Thread = extern struct {
-    self: *Thread,
-    previous: ?*Thread,
-    next: ?*Thread,
-    stack: [*]u8,
-    stack_top: [*]align(lib.arch.stack_alignment) u8,
-    register_arena: birth.arch.RegisterArena align(lib.arch.stack_alignment),
-    core_id: u32,
-
-    pub fn init(thread: *Thread, scheduler: *user.arch.Scheduler) void {
-        thread.self = thread;
-        thread.previous = null;
-        thread.next = null;
-        thread.core_id = scheduler.generic.core_id;
-    }
-};
-
-pub const Mutex = extern struct {
-    locked: bool = false,
-
-    pub inline fn internalLock(mutex: *volatile Mutex) void {
-        mutex.locked = true;
-    }
-};
-
-var static_stack: [0x10000]u8 align(lib.arch.stack_alignment) = undefined;
-var static_thread: Thread = undefined;
-var static_thread_lock = Mutex{};
-
-pub fn initDisabled(scheduler: *user.arch.Scheduler) noreturn {
-    const thread = &static_thread;
-    static_thread_lock.internalLock();
-    thread.stack = &static_stack;
-    thread.stack_top = static_stack[static_stack.len..];
+pub fn initBootstrap(scheduler: *user.arch.Scheduler) noreturn {
+    const thread = &scheduler.generic.bootstrap_thread;
+    thread.stack = &scheduler.common.generic.setup_stack;
+    thread.stack_top = @ptrFromInt(@intFromPtr(&scheduler.common.generic.setup_stack) + scheduler.common.generic.setup_stack.len);
     thread.init(scheduler);
 
     // TODO: use RAX as parameter?
 
     user.arch.setInitialState(&thread.register_arena, VirtualAddress.new(bootstrapThread), VirtualAddress.new(thread.stack_top), .{0} ** 6);
-
+    scheduler.generic.enqueueThread(thread);
+    scheduler.generic.current_thread = thread;
     scheduler.common.generic.has_work = true;
 
     scheduler.restore(&thread.register_arena);

src/user/virtual.zig

@@ -0,0 +1,100 @@
+const Virtual = @This();
+
+const birth = @import("birth");
+const lib = @import("lib");
+const user = @import("user");
+
+const assert = lib.assert;
+const log = lib.log;
+const SparseArray = lib.data_structures.SparseArray;
+const VirtualAddress = lib.VirtualAddress;
+
+const paging = lib.arch.paging;
+
+const Leaf = birth.interface.Leaf;
+
+pub const AddressSpace = extern struct {
+    // page_table: PageTable,
+    region: Virtual.AddressSpace.Region = .{},
+    minimum: VirtualAddress = VirtualAddress.new(paging.user_address_space_start),
+    maximum: VirtualAddress = VirtualAddress.new(paging.user_address_space_end),
+    root_page_table: PageTable = .{},
+    page_table_buffer: SparseArray(PageTable) = .{
+        .ptr = undefined,
+        .len = 0,
+        .capacity = 0,
+    },
+    leaf_buffer: SparseArray(Leaf) = .{
+        .ptr = undefined,
+        .len = 0,
+        .capacity = 0,
+    },
+
+    const Region = extern struct {
+        list: Virtual.Region.List = .{},
+        block_count: usize = 0,
+    };
+
+    pub fn create() !*AddressSpace {
+        const scheduler = user.currentScheduler();
+        const virtual_address_space = try scheduler.fast_allocator.create(AddressSpace);
+        virtual_address_space.* = .{};
+
+        try virtual_address_space.collectPageTables(&virtual_address_space.root_page_table, .{});
+
+        @panic("TODO: create");
+    }
+
+    fn collectPageTables(virtual_address_space: *Virtual.AddressSpace, page_table: *PageTable, descriptor: birth.interface.PageTable) !void {
+        try user.Interface(.page_table, .get).blocking(.{
+            .descriptor = descriptor,
+            .buffer = &page_table.children_handles,
+        });
+
+        const allocator = &user.currentScheduler().fast_allocator;
+
+        for (page_table.children_handles, &page_table.indices) |child, *index| {
+            if (child.present) {
+                switch (child.entry_type) {
+                    .page_table => {
+                        const page_table_index = virtual_address_space.page_table_buffer.len;
+                        const new_page_table = try virtual_address_space.page_table_buffer.allocate(allocator);
+                        //user.currentScheduler().fast_allocator.create(PageTable);
+                        index.* = @intCast(page_table_index);
+
+                        try virtual_address_space.collectPageTables(new_page_table, child);
+                    },
+                    .leaf => {
+                        const new_leaf = try virtual_address_space.leaf_buffer.allocate(allocator);
+                        index.* = @intCast(virtual_address_space.leaf_buffer.indexOf(new_leaf));
+                        try getLeaf(child, new_leaf);
+                        log.debug("New leaf: {}", .{new_leaf});
+                    },
+                }
+            }
+        }
+    }
+
+    fn getLeaf(leaf_descriptor: birth.interface.PageTable, leaf: *Leaf) !void {
+        try user.Interface(.page_table, .get_leaf).blocking(.{
+            .descriptor = leaf_descriptor,
+            .buffer = leaf,
+        });
+    }
+};
+
+pub const Region = extern struct {
+    foo: u32 = 0,
+
+    pub const List = extern struct {
+        regions: [region_count]Region = .{.{}} ** region_count,
+        next: ?*List = null,
+
+        const region_count = 20;
+    };
+};
+
+pub const PageTable = extern struct {
+    children_handles: [512]birth.interface.PageTable = .{.{}} ** 512,
+    indices: [512]u32 = .{0} ** 512,
+};

src/user/virtual_address_space.zig

@@ -1,60 +0,0 @@
-const lib = @import("lib");
-const log = lib.log;
-
-const user = @import("user");
-const PhysicalMap = user.PhysicalMap;
-const PhysicalMemoryRegion = user.PhysicalMemoryRegion;
-const VirtualMemoryRegion = user.VirtualMemoryRegion;
-
-pub const MMUAwareVirtualAddressSpace = @import("mmu_aware_virtual_address_space.zig").MMUAwareVirtualAddressSpace;
-
-pub const VirtualAddressSpace = extern struct {
-    physical_map: *PhysicalMap,
-    // TODO: layout
-    regions: ?*VirtualMemoryRegion = null,
-
-    /// The function is inlined because it's only called once
-    pub inline fn initializeCurrent() !void {
-        log.debug("VirtualAddressSpace.initializeCurrent", .{});
-        const virtual_address_space = user.process.getVirtualAddressSpace();
-        const physical_map = user.process.getPhysicalMap();
-        virtual_address_space.physical_map = physical_map;
-
-        const root_page_level = 0;
-        physical_map.* = try PhysicalMap.init(virtual_address_space, root_page_level, user.process.getSlotAllocator());
-        // This should be an inline call as this the only time this function is called
-        try physical_map.initializeCurrent();
-
-        try virtual_address_space.pinnedInit();
-
-        log.warn("TODO: VirtualAddressSpace.initializeCurrent is incomplete!", .{});
-    }
-
-    pub inline fn pinnedInit(virtual_address_space: *VirtualAddressSpace) !void {
-        const pinned_state = user.process.getPinnedState();
-        const pinned_size = 128 * lib.mb;
-        pinned_state.physical_memory_region = try PhysicalMemoryRegion.Pinned.new(pinned_size);
-
-        pinned_state.virtual_memory_region = try virtual_address_space.map(pinned_state.physical_memory_region.getGeneric().*, 0, pinned_size, .{ .write = true });
-        log.warn("TODO: VirtualAddressSpace.pinnedInit", .{});
-    }
-
-    pub inline fn map(virtual_address_space: *VirtualAddressSpace, physical_memory_region: PhysicalMemoryRegion, offset: usize, size: usize, flags: VirtualMemoryRegion.Flags) !VirtualMemoryRegion {
-        const alignment = lib.arch.valid_page_sizes[0];
-        return virtual_address_space.mapAligned(physical_memory_region, offset, size, alignment, flags);
-    }
-
-    pub fn mapAligned(virtual_address_space: *VirtualAddressSpace, physical_memory_region: PhysicalMemoryRegion, offset: usize, size: usize, alignment: usize, flags: VirtualMemoryRegion.Flags) !VirtualMemoryRegion {
-        const virtual_address = try virtual_address_space.physical_map.determineAddress(physical_memory_region, alignment);
-        _ = virtual_address;
-        _ = offset;
-        _ = size;
-        _ = flags;
-        @panic("TODO: VirtualAddressSpace.mapAligned");
-    }
-
-    pub const State = extern struct {
-        virtual_address_space: VirtualAddressSpace,
-        physical_map: PhysicalMap,
-    };
-};