From 04f2123499b6a58cf2382da838d2692634cb9271 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Thomas=20Lov=C3=A9n?= <thomasloven@gmail.com>
Date: Fri, 16 Feb 2018 12:38:25 +0100
Subject: [PATCH] Move BootGDT definition to C

---
 src/kernel/boot/boot.S     |  4 ++--
 src/kernel/boot/boot_GDT.S | 14 --------------
 src/kernel/cpu/gdt.c       | 28 ++++++++++++++++++++++++++++
 src/kernel/include/gdt.h   |  6 ------
 4 files changed, 30 insertions(+), 22 deletions(-)
 delete mode 100644 src/kernel/boot/boot_GDT.S
 create mode 100644 src/kernel/cpu/gdt.c
 delete mode 100644 src/kernel/include/gdt.h

diff --git a/src/kernel/boot/boot.S b/src/kernel/boot/boot.S
index 312a8a7..7818a45 100644
--- a/src/kernel/boot/boot.S
+++ b/src/kernel/boot/boot.S
@@ -43,7 +43,7 @@ _start:
   mov cr0, eax
 
   //; Load a new GDT
-  lgdt [V2P(BootGDTp)]
+  lgdt [V2P(GDTp)]
 
   //; and update the code selector by a long jump
 jmp 0x8:V2P(long_mode_start)
@@ -76,7 +76,7 @@ upper_memory:
   mov cr3, rax
 
   //; Reload GDT
-  movabs rax, offset BootGDTp
+  movabs rax, offset GDTp
   lgdt [rax]
   mov rax, 0x0
   mov ss, rax
diff --git a/src/kernel/boot/boot_GDT.S b/src/kernel/boot/boot_GDT.S
deleted file mode 100644
index 82f8165..0000000
--- a/src/kernel/boot/boot_GDT.S
+++ /dev/null
@@ -1,14 +0,0 @@
-#include <gdt.h>
-#include <memory.h>
-.intel_syntax noprefix
-
-.section .rodata
-.align PAGE_SIZE
-.global BootGDT
-.global BootGDTp
-BootGDT:
-  .long 0, 0
-  .long 0, (GDT_PRESENT | GDT_DPL(0) | GDT_CODE | GDT_LONG)
-BootGDTp:
-  .short 2*8-1
-  .quad offset BootGDT
diff --git a/src/kernel/cpu/gdt.c b/src/kernel/cpu/gdt.c
new file mode 100644
index 0000000..fa2b878
--- /dev/null
+++ b/src/kernel/cpu/gdt.c
@@ -0,0 +1,28 @@
+#include <stdint.h>
+#include <cpu.h>
+
+#define GDT_CODE      (3<<11)
+#define GDT_DPL(lvl)  ((lvl)<<13)
+#define GDT_PRESENT   (1<<15)
+#define GDT_LONG      (1<<21)
+
+
+struct gdt
+{
+  uint32_t _;
+  uint32_t flags;
+}__attribute__((packed));
+
+struct gdtp
+{
+  uint16_t len;
+  struct gdt *gdt;
+}__attribute__((packed));
+
+
+struct gdt BootGDT[] = {
+  {0, 0},
+  {0, GDT_PRESENT | GDT_DPL(0) | GDT_CODE | GDT_LONG}
+};
+
+struct gdtp GDTp = {2*8-1, BootGDT};
diff --git a/src/kernel/include/gdt.h b/src/kernel/include/gdt.h
deleted file mode 100644
index 73b958c..0000000
--- a/src/kernel/include/gdt.h
+++ /dev/null
@@ -1,6 +0,0 @@
-#pragma once
-
-#define GDT_CODE      (3<<11)
-#define GDT_DPL(lvl)  ((lvl)<<13)
-#define GDT_PRESENT   (1<<15)
-#define GDT_LONG      (1<<21)