From e7586f635ee71080b990b0b5b63e5fde66414fab Mon Sep 17 00:00:00 2001
From: Adrien Bourmault <neox@os-k.eu>
Date: Wed, 6 Mar 2019 09:05:24 +0100
Subject: [PATCH] Revert "LONG MODE MULTIBOOT WORKS gsp!"

This reverts commit 641bfe6db892f94711354fc2b60f6c037e9c37f3.
---
 boot/loader/loader.asm         |  59 +++++++++++++++++----------------
 boot/loader/mem/management.inc |  28 ----------------
 build/obj/boot/loader.bin      | Bin 12649 -> 12644 bytes
 3 files changed, 31 insertions(+), 56 deletions(-)

diff --git a/boot/loader/loader.asm b/boot/loader/loader.asm
index 09b565b..586d18e 100644
--- a/boot/loader/loader.asm
+++ b/boot/loader/loader.asm
@@ -38,7 +38,7 @@ _start:
     mov es, ax                          ; And es because it is jealous
     ;mov [Bootdrv], dl
     xor dl, dl
-    jmp 0x0000:_loader                  ; pas sûr
+    jmp 0x0000:main                     ; pas sûr
 
 ;; Magnificent multiboot header for GRUB ------------------------------------ ;;
 MB_header:
@@ -60,7 +60,7 @@ MB_start:
     push eax                            ; 2nd argument is magic number
     push ebx                            ; 1st argument multiboot info pointer
     mov ecx, eax
-    call _loader
+    call main
     add esp, 8                          ; Cleanup arguments "A la MIPS"
     jmp Die                             ; Aufwiedersehen
 
@@ -79,39 +79,42 @@ Die:
     jmp $
 
 ;; THE CODE ----------------------------------------------------------------- ;;
-
-; ---------------------------------------------------------------------------- ;
-;  _loader                                                                     ;
-;                                                                              ;
-;  This is the function that initiates the launch of OS/K. It verifies that    ;
-;  Grub has properly loaded this loader and makes the appropriate setup so     ;
-;  that the kernel will work properly                                          ;
-;                                                                              ;
-;  Why this original design ? Because it works well and prevent us to cause    ;
-;  triple faults by aligment error or too long jumps (yup, it can be a problem);
-;                                                                              ;
-; ---------------------------------------------------------------------------- ;
-_loader:
-    jmp lbegin
-
-%include "boot/loader/multiboot/check.inc"
-lbegin:
+main:
     call MB_check
-    jmp lnext
 
-%include "boot/loader/cpu/cpuid.inc"
-lnext:
     call Check_cpuid
     call Is64Bits
-    jmp lnext2
 
-%include "boot/loader/mem/structures.inc"
-lnext2:
     call Setup_paging
-    jmp lnext3
-%include "boot/loader/mem/management.inc"
 
-lnext3:
+    ;; Registering paging
+    mov eax, PML4_table
+    mov cr3, eax                    ; Load PML4 to cr3
+
+    mov eax, cr4
+    or eax, 1 << 5
+    mov cr4, eax                    ; Enable PAE
+
+    ;; Activate long mode
+    mov ecx, 0xC0000080             ; address of MSR
+    rdmsr                           ; read MSR
+    or eax, 1 << 8                  ; LME = 1. (Long Mode Enable)
+    wrmsr                           ; write MSR
+
+    ;; Enable paging
+    mov eax, cr0
+    or eax, 1 << 31                 ; make MSR bit 31 (PG = Paging) to 1 :
+                                    ;    |1|000000000000000000000000000000
+                                    ;     |
+                                    ;     `------ Paging bit
+    mov cr0, eax
+
     mov dword [0xb8000], 0x2f4b2f4f
     ret
 
+;; INCLUDES ----------------------------------------------------------------- ;;
+%include "boot/loader/cpu/cpuid.inc"
+%include "boot/loader/multiboot/check.inc"
+%include "boot/loader/mem/structures.inc"
+%include "boot/loader/mem/management.inc"
+
diff --git a/boot/loader/mem/management.inc b/boot/loader/mem/management.inc
index 3634666..3790a9d 100644
--- a/boot/loader/mem/management.inc
+++ b/boot/loader/mem/management.inc
@@ -52,31 +52,3 @@ Setup_paging:
     jne .map_p2_table               ; else map the next entry
 
     ret
-
-; ---------------------------------------------------------------------------- ;
-;    Enable long mode and paging                                               ;
-; ---------------------------------------------------------------------------- ;
-Go64:
-    ;; Registering paging
-    mov eax, PML4_table
-    mov cr3, eax                    ; Load PML4 to cr3
-
-    mov eax, cr4
-    or eax, 1 << 5
-    mov cr4, eax                    ; Enable PAE
-
-    ;; Activate long mode
-    mov ecx, 0xC0000080             ; address of MSR
-    rdmsr                           ; read MSR
-    or eax, 1 << 8                  ; LME = 1. (Long Mode Enable)
-    wrmsr                           ; write MSR
-
-    ;; Enable paging
-    mov eax, cr0
-    or eax, 1 << 31                 ; make MSR bit 31 (PG = Paging) to 1 :
-                                    ;    |1|000000000000000000000000000000
-                                    ;     |
-                                    ;     `------ Paging bit
-    mov cr0, eax
-
-    ret
diff --git a/build/obj/boot/loader.bin b/build/obj/boot/loader.bin
index faf31098a145ef011cb83636a3ffd826bcb67367..182a3e209f7fadaa2e907c05e87f344e1c0f846e 100644
GIT binary patch
delta 150
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z|NlQHqVu3B1A_uXz}z_zfpaZSlrSFNVEEDxDAo9rX~SCWQXt>pr5%v3!N|e5@rsOr
p#10KX0fy!i%!@S`1%QStLOFty`3=SRKwQVhpA1Y445d#F0|5RJH?jZ#

delta 155
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z6A?Jq@<a(xk>Tt17mtC8UhDx9FO>`!7$!{kz;J<KGY_MTf&2?51_p-L={r6M2rx9C
zU|#%zL4aY$2L&icV6uaum>`Jj*!YtHsI>IS;T<0sCbp^b96rv<(7?^$ukWpY7yy`?
BMb7{L