system: Add a memory manager stub

boot/easyboot/menu.cfg

@@ -5,3 +5,4 @@ default 1 1000
 menuentry Astryon default
     kernel core
     module init
+    module memory

system/build.zig

@@ -1,9 +1,11 @@
 const std = @import("std");
 const init = @import("init/build.zig");
+const memory = @import("memory/build.zig");
 
 pub fn buildAsSubmodule(b: *std.Build, build_step: *std.Build.Step, optimize: std.builtin.OptimizeMode, system_module: *std.Build.Module) void {
     const system_step = b.step("system", "Build core system services");
     init.buildAsSubmodule(b, system_step, optimize, system_module);
+    memory.buildAsSubmodule(b, system_step, optimize, system_module);
 
     build_step.dependOn(system_step);
 }

system/memory/build.zig

@@ -0,0 +1,45 @@
+const std = @import("std");
+
+const here = "system/memory";
+
+pub fn buildAsSubmodule(b: *std.Build, build_step: *std.Build.Step, optimize: std.builtin.OptimizeMode, system_module: *std.Build.Module) void {
+    var disabled_features = std.Target.Cpu.Feature.Set.empty;
+    var enabled_features = std.Target.Cpu.Feature.Set.empty;
+
+    disabled_features.addFeature(@intFromEnum(std.Target.x86.Feature.mmx));
+    disabled_features.addFeature(@intFromEnum(std.Target.x86.Feature.sse));
+    disabled_features.addFeature(@intFromEnum(std.Target.x86.Feature.sse2));
+    disabled_features.addFeature(@intFromEnum(std.Target.x86.Feature.avx));
+    disabled_features.addFeature(@intFromEnum(std.Target.x86.Feature.avx2));
+    enabled_features.addFeature(@intFromEnum(std.Target.x86.Feature.soft_float));
+
+    const target_query = std.Target.Query{
+        .cpu_arch = std.Target.Cpu.Arch.x86_64,
+        .os_tag = std.Target.Os.Tag.freestanding,
+        .abi = std.Target.Abi.none,
+        .cpu_features_sub = disabled_features,
+        .cpu_features_add = enabled_features,
+    };
+
+    const memory = b.addExecutable(.{
+        .name = "memory",
+        .root_source_file = b.path(here ++ "/main.zig"),
+        .target = b.resolveTargetQuery(target_query),
+        .optimize = optimize,
+        .code_model = .default,
+    });
+
+    memory.root_module.addImport("system", system_module);
+
+    const install = b.addInstallArtifact(memory, .{
+        .dest_dir = .{
+            .override = .{ .custom = "boot/" },
+        },
+    });
+
+    var memory_step = b.step("memory", "Build the memory manager");
+    memory_step.dependOn(&memory.step);
+    memory_step.dependOn(&install.step);
+
+    build_step.dependOn(memory_step);
+}

system/memory/main.zig

@@ -0,0 +1,16 @@
+const system = @import("system");
+
+const vm = system.vm;
+const syscalls = system.syscalls;
+
+fn setTokens() void {
+    var tokens: u64 = 0;
+    tokens |= @intFromEnum(system.kernel.Token.PhysicalMemory);
+    syscalls.setTokens(syscalls.getThreadId(), tokens) catch {};
+}
+
+export fn _start(_: u64, _: u64) callconv(.C) noreturn {
+    setTokens();
+
+    while (true) {}
+}