Reload GDT from c

src/kernel/cpu/cpu.c

@@ -1,7 +1,11 @@
 #include <cpu.h>
 #include <interrupts.h>
 
+uint64_t gdt[2];
+void gdt_init(uint64_t *);
+
 void cpu_init()
 {
   interrupt_init();
+  gdt_init(gdt);
 }

src/kernel/cpu/gdt.c

@@ -1,5 +1,6 @@
 #include <stdint.h>
 #include <cpu.h>
+#include <memory.h>
 
 #define GDT_CODE      (3<<11)
 #define GDT_DPL(lvl)  ((lvl)<<13)
@@ -26,3 +27,15 @@ struct gdt BootGDT[] = {
 };
 
 struct gdtp GDTp = {2*8-1, BootGDT};
+
+
+void gdt_init(uint64_t *_gdt)
+{
+  struct gdt *gdt = (struct gdt *)_gdt;
+  memcpy(gdt, BootGDT, sizeof(BootGDT));
+
+  GDTp.len = 2*8 - 1;
+  GDTp.gdt = gdt;
+
+  load_gdt(&GDTp);
+}

src/kernel/cpu/registers.S

@@ -5,6 +5,20 @@ load_idt:
   lidt [rdi]
   ret
 
+.global load_gdt
+load_gdt:
+  lgdt [rdi]
+  mov ax, 0x0
+  mov ss, ax
+  mov ds, ax
+  mov es, ax
+  movabs rax, offset .load_gdt
+  pushq 0x8
+  push rax
+  retfq
+.load_gdt:
+  ret
+
 .global read_cr0
 read_cr0:
   mov rax, cr0

src/kernel/include/cpu.h

@@ -4,7 +4,9 @@
 void cpu_init();
 
 
+
 void load_idt(void *);
+void load_gdt(void *);
 
 uint64_t read_cr0();
 uint64_t read_cr2();