loader: initial loader code

2026-10-30 14:58:21 +00:00 · 2026-07-16 19:48:01 -04:00
parent 26ec72fb36
commit a79c7a07cb
35 changed files with 1197 additions and 548 deletions
@@ -0,0 +1,117 @@
+const std = @import("std");
+const limine = @import("limine.zig");
+const r = @import("root");
+
+pub export var limine_base_revision: [3]u64 linksection(".limine_requests") = limine.base_revision(6);
+
+pub export var framebuffer_request: limine.FramebufferRequest linksection(".limine_requests") = .{
+    .id = limine.framebuffer_request_id,
+    .revision = 0,
+    .response = null,
+};
+
+pub export var limine_requests_start_marker: [4]u64 linksection(".limine_requests_start") = limine.requests_start_marker;
+pub export var limine_requests_end_marker: [2]u64 linksection(".limine_requests_end") = limine.requests_end_marker;
+
+pub export var memmap_request: limine.MemmapRequest linksection(".limine_requests") = .{
+    .id = limine.memmap_request_id,
+    .revision = 0,
+    .response = null,
+};
+
+pub export var rsdp_request: limine.RsdpRequest linksection(".limine_requests") = .{
+    .id = limine.rsdp_request_id,
+    .revision = 0,
+    .response = null,
+};
+
+pub export var cmdline_request: limine.CmdlineRequest linksection(".limine_requests") = .{
+    .id = limine.cmdline_request_id,
+    .revision = 0,
+    .response = null,
+};
+
+pub export var hhdm_request: limine.HHDMRequest linksection(".limine_requests") = .{
+    .id = limine.hhdm_request_id,
+    .revision = 0,
+    .response = null,
+};
+
+pub export var kernel_request: limine.ExecutableAddressRequest linksection(".limine_requests") = .{
+    .id = limine.executable_address_request_id,
+    .revision = 0,
+    .response = null,
+};
+
+pub export var module_request: limine.ModuleRequest linksection(".limine_requests") = .{
+    .id = limine.module_request_id,
+    .revision = 0,
+    .response = null,
+};
+
+pub fn p2v(pa: usize) usize {
+    return hhdm_request.response.?.offset + pa;
+}
+
+pub fn get_image_layout() r.ImageLayout {
+    const resp = kernel_request.response.?;
+
+    return .{
+        .physical_base = resp.physical_base,
+        .virtual_base = resp.virtual_base,
+    };
+}
+
+export fn loader_entry() callconv(.c) void {
+    const mmap = memmap_request.response.?;
+
+    std.log.info("hi", .{});
+
+    for (0..mmap.entry_count) |i| {
+        const entry = mmap.entries.?[i];
+
+        r.mem.add_entry(entry.base, entry.length, switch (entry.type) {
+            .AcpiNvs => .AcpiNvs,
+            .BootloaderReclaimable => .LoaderReclaimable,
+            .AcpiReclaimable => .AcpiReclaimable,
+            .Usable => .Free,
+            else => .Reserved,
+        });
+    }
+
+    if (framebuffer_request.response) |resp| {
+        const fb = resp.framebuffers[0];
+
+        r.loader_info.framebuffer = .{
+            .address = @intFromPtr(fb.address),
+            .height = @intCast(fb.height),
+            .width = @intCast(fb.width),
+            .bpp = @intCast(fb.bpp),
+            .pitch = @intCast(fb.pitch),
+        };
+    }
+
+    if (rsdp_request.response) |resp| {
+        r.loader_info.rsdp = @intFromPtr(resp.rsdp);
+    }
+
+    var kernel: ?*anyopaque = null;
+
+    if (module_request.response) |resp| {
+        const modules = resp.modules.?[0..resp.module_count];
+
+        for (modules) |mod| {
+            const str = std.mem.span(mod.string);
+
+            if (std.mem.eql(u8, str, "kernel")) {
+                kernel = mod.address;
+            }
+        }
+    }
+
+    if (kernel == null) {
+        @panic("loader: kernel not found");
+    }
+
+    r.main(kernel.?);
+}