feat: amd64 interrupts

src/kern/amd64/init.zig

@@ -0,0 +1,37 @@
+const amd64 = @import("arch");
+const int = @import("int.zig");
+const b = @import("base");
+
+var gdt = extern struct {
+    entries: [9]u64 align(1),
+    tss: amd64.TssDescriptor align(1),
+}{
+    .entries = .{
+        0, // null
+        0x00009a000000ffff, // code16
+        0x000093000000ffff, // data16
+        0x00cf9a000000ffff, // code32
+        0x00cf93000000ffff, // data32
+        0x00af9b000000ffff, // kernel code64
+        0x00af93000000ffff, // kernel data64
+        0x00aff3000000ffff, // user code64
+        0x00affb000000ffff, // user data64
+    },
+
+    .tss = undefined,
+};
+
+extern fn gdt_load(gdtr: *const amd64.Gdtr) callconv(.{ .x86_64_sysv = .{} }) void;
+
+pub fn early_init() linksection(b.init) void {
+    const gdtr: amd64.Gdtr = .{
+        .limit = @sizeOf(@TypeOf(gdt)) - 1,
+        .base = @intFromPtr(&gdt),
+    };
+
+    gdt_load(&gdtr);
+
+    int.init();
+
+    asm volatile ("int3");
+}