From bb25b7ea35174175d61de546e449e84bcc273bc0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Thomas=20Lov=C3=A9n?= <thomasloven@gmail.com>
Date: Wed, 15 Nov 2017 21:43:00 +0100
Subject: [PATCH] Change comment style, and more commenting

---
 src/kernel/boot/boot.S | 29 ++++++++++++++++++++---------
 1 file changed, 20 insertions(+), 9 deletions(-)

diff --git a/src/kernel/boot/boot.S b/src/kernel/boot/boot.S
index cc0383f..d359815 100644
--- a/src/kernel/boot/boot.S
+++ b/src/kernel/boot/boot.S
@@ -11,7 +11,7 @@ BootStack:
 
 .code32
 error:
-  // Print "ERR!" in upper left corner
+  //; Print "ERR!" in upper left corner
   mov [0xb8000], dword ptr 0x4f004f00
   mov [0xb8004], dword ptr 0x4f004f00
   mov [0xb8000], byte ptr 'E'
@@ -21,39 +21,39 @@ error:
   jmp $
 
 check_cpuid:
-  // Save EFLAGS
+  //; Save EFLAGS
   pushfd
 
-  // Try to modify EFLAGS.ID
+  //; Try to modify EFLAGS.ID
   pushfd
   xor dword ptr [esp], 1<<21
   popfd
 
-  //Read EFLAGS into eax
+  //;Read EFLAGS into eax
   pushfd
   pop eax
 
-  // Restore original EFLAGS
+  //; Restore original EFLAGS
   popfd
 
-  // Check if EFLAGS.ID was modified
+  //; Check if EFLAGS.ID was modified
   xor eax, [esp+4]
   and eax, 1<<21
   jz error
   ret
 
 check_longmode:
-  // cpuid 0x8000 0000
+  //; cpuid 0x8000 0000
   mov eax, 0x80000000
   cpuid
   cmp eax, 0x80000001
   jb error
 
-  // cpuid 0x8000 0001
+  //; cpuid 0x8000 0001
   mov eax, 0x80000001
   cpuid
 
-  // Test for long mode flag
+  //; Test for long mode flag
   test edx, 1<<29
   jz error
   ret
@@ -67,29 +67,39 @@ _start:
   call check_cpuid
   call check_longmode
 
+  //; Set CR4.PAE
+  //; enabling Page Address Extension
   mov eax, cr4
   or eax, 1<<5
   mov cr4, eax
 
+  //; Load a P4 page table
   mov eax, offset BootP4
   mov cr3, eax
 
+  //; Set EFER.LME
+  //; enabling Long Mode
   mov ecx, 0x0C0000080
   rdmsr
   or eax, 1<<8
   wrmsr
 
+  //; Set CR0.PG
+  //; enabling Paging
   mov eax, cr0
   or eax, 1<<31
   mov cr0, eax
 
+  //; Load a new GDT
   lgdt [BootGDTp]
 
+  //; and update the code selector by a long jump
   jmp 0x8:long_mode_start
 
 .code64
   long_mode_start:
 
+  //; Clear out all other selectors
   mov eax, 0x0
   mov ss, eax
   mov ds, eax
@@ -97,4 +107,5 @@ _start:
   mov fs, eax
   mov gs, eax
 
+  //; Loop infinitely
   jmp $