[MEMORY] GDT

kernel/arch/gdt.c

@@ -0,0 +1,25 @@
+#include <gdt.h>
+#include <stdint.h>
+#include <debug.h>
+
+uint64_t gdt[5];
+struct gdtp_st gdt_p;
+#define GDT gdt
+#define GDTP gdt_p
+
+
+void gdt_init()
+{
+
+  GDT[0] = 0;
+  GDT[SEG_KCODE/8] = (uint64_t)(GDT_PRESENT | GDT_CODEDATA | GDT_WRITE | GDT_EXECUTE | GDT_64BIT);
+  GDT[SEG_KDATA/8] = (GDT_PRESENT | GDT_CODEDATA | GDT_WRITE);
+  GDT[SEG_UCODE/8] = (GDT_PRESENT | GDT_CODEDATA | GDT_WRITE | GDT_EXECUTE | GDT_64BIT | GDT_RING3);
+  GDT[SEG_UDATA/8] = (GDT_PRESENT | GDT_CODEDATA | GDT_WRITE | GDT_RING3);
+
+  GDTP.len = 5*8-1;
+  GDTP.addr = (uint64_t)&GDT[0];
+
+  load_gdt(&GDTP);
+
+}