Added AP initialization code

include/sys/amd64/hw/gdt.h

@@ -34,4 +34,6 @@ typedef struct {
     uintptr_t offset;
 } __attribute__((packed)) amd64_gdt_ptr_t;
 
+extern amd64_gdt_ptr_t amd64_gdtr;
+
 void amd64_gdt_init(void);

include/sys/amd64/hw/idt.h

@@ -1,3 +1,11 @@
 #pragma once
+#include "sys/types.h"
+
+struct amd64_idtr {
+    uint16_t size;
+    uintptr_t offset;
+} __attribute__((packed));
+
+extern const struct amd64_idtr amd64_idtr;
 
 void amd64_idt_init(void);