From d9443c7fdf756212bb52ffc934b1166038bc2ad3 Mon Sep 17 00:00:00 2001
From: Loic Guegan <manzerbredes@mailbox.org>
Date: Wed, 21 Apr 2021 12:23:54 +0200
Subject: Refactoring

---
 src/boot/boot.S | 29 +++++++++++++++++++++++++----
 1 file changed, 25 insertions(+), 4 deletions(-)

(limited to 'src/boot/boot.S')

diff --git a/src/boot/boot.S b/src/boot/boot.S
index 676ace7..8391e70 100644
--- a/src/boot/boot.S
+++ b/src/boot/boot.S
@@ -1,6 +1,5 @@
 .globl  _start
 .globl MB_INFO
-.extern boucane
 .extern _bss_start
 .extern _bss_end
 .extern boucane
@@ -49,7 +48,16 @@ MB_INFO:
 
 _start:
 mov %ebx,(MB_INFO)
-
+# Zeroing the .bss section
+mov $_bss_start, %eax
+mov $_bss_end, %ebx
+start_zeroing:
+    movb $0x0, (%eax)
+    cmp %eax, %ebx
+    je end_zeroing
+    inc %eax
+    jmp start_zeroing
+end_zeroing:
 # ----- Setup PAE Paging (identity on the first 10MB)
 mov $8192, %ecx # 8*4096/4 (8 tables of 4096 byte each divide by 4 because of movl)
 mov $0, %eax
@@ -104,7 +112,20 @@ lgdt (gdtr)
 jmp $0x08, $new_cs
 new_cs:
 
+mov $0x10, %ax
+mov %ax, %ds
+mov %ax, %es
+mov %ax, %fs
+mov %ax, %gs
+mov %ax, %ss
+
+# Pay attention here!
+# You are in long mode here
+# Thus if you want to add any instructions
+# You should use .code64 before
+
 # Run boucane
+.code64
 jmp boucane
 
 # GDT
@@ -121,8 +142,8 @@ gdt64:
     gdt64_ds:
     .long 0
     .byte 0
-    .byte 0b10000000
+    .byte 0b10010010
     .word 0
 gdtr:
     .word . - gdt64 - 1
-    .quad gdt64
\ No newline at end of file
+    .quad gdt64
-- 
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