Made Kernel 'Higher-Half' and enabled paging.

git-svn-id: https://spexeah.com:8443/svn/Asuro@85 6dbc8c32-bb84-406f-8558-d1cf31a0ab0c

src/stub/stub.asm

@@ -10,12 +10,12 @@
 ;
 ; Export entrypoint
 ;
-[global kstart]
+global _loader
  
 ;
 ; Import kernel entrypoint
 ;
-[extern kmain]
+extern kmain
  
 ;
 ; Posible multiboot header flags
@@ -36,9 +36,18 @@ MULTIBOOT_HEADER_CHECKSUM       equ     -(MULTIBOOT_HEADER_MAGIC + MULTIBOOT_HEA
 ; Kernel stack size
 ;
 KERNEL_STACKSIZE                equ     0x4000
+KERNEL_VIRTUAL_BASE 		  equ	0xC0000000
+KERNEL_PAGE_NUMBER			  equ	(KERNEL_VIRTUAL_BASE >> 22)
  
+section .data
+align 0x1000
+BootPageDirectory:
+	dd 0x00000083
+	times (KERNEL_PAGE_NUMBER - 1) dd 0
+	dd 0x00000083
+	times (1024 - KERNEL_PAGE_NUMBER - 1) dd 0
+
 section .text
- 
 ;
 ; Multiboot header
 ;
@@ -50,16 +59,38 @@ dd MULTIBOOT_HEADER_CHECKSUM
 ;
 ; Entrypoint
 ;
+loader equ _loader
+global loader
+
+_loader:
+	mov ecx, (BootPageDirectory - KERNEL_VIRTUAL_BASE)
+	mov cr3, ecx
+	
+	mov ecx, cr4
+	or ecx, 0x00000010
+	mov cr4, ecx
+
+	mov ecx, cr0
+	or ecx, 0x80000000
+	mov cr0, ecx
+
+	lea ecx, [kstart]
+	jmp ecx
+
 kstart:
+	   mov dword [BootPageDirectory], 0
+        invlpg [0]	   
+		
         mov esp, KERNEL_STACK+KERNEL_STACKSIZE  ;Create kernel stack
         push eax                                ;Multiboot magic number
+	   add ebx, KERNEL_VIRTUAL_BASE
         push ebx                                ;Multiboot info
         call kmain                              ;Call kernel entrypoint
         cli                                     ;Clear interrupts
         hlt                                     ;Halt machine
  
 section .bss
- 
+
 ;
 ; Kernel stack location
 ;