first commit

kernel/src/sys/arch/x86_64/gdt.h

@@ -0,0 +1,37 @@
+#pragma once
+
+#include <stdint.h>
+
+typedef struct {
+  uint16_t length;
+  uint16_t base;
+  uint8_t  base1;
+  uint8_t  flags;
+  uint8_t  flags1;
+  uint8_t  base2;
+  uint32_t base3;
+  uint32_t resv;
+} __attribute__((packed)) tss_entry;
+
+typedef struct {
+  uint64_t gdt_entries[9];
+  tss_entry tss_entry;
+} __attribute__((packed)) gdt_table;
+
+typedef struct {
+  uint16_t size;
+  uint64_t address;
+} __attribute__((packed)) gdtr;
+
+
+typedef struct {
+  uint32_t resv;
+  uint64_t rsp[3];
+  uint64_t resv1;
+  uint64_t ist[7];
+  uint64_t resv2;
+  uint16_t resv3;
+  uint16_t iopb;
+} __attribute__((packed)) tssr; // Per CPU
+
+void gdt_init();