audk/MdePkg/Library/BaseLib/Ia32/EnablePaging64.asm

73 lines
2.2 KiB
NASM

;------------------------------------------------------------------------------
;
; Copyright (c) 2006, Intel Corporation
; All rights reserved. This program and the accompanying materials
; are licensed and made available under the terms and conditions of the BSD License
; which accompanies this distribution. The full text of the license may be found at
; http://opensource.org/licenses/bsd-license.php
;
; THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
; WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
;
; Module Name:
;
; EnablePaging64.Asm
;
; Abstract:
;
; AsmEnablePaging64 function
;
; Notes:
;
;------------------------------------------------------------------------------
.686p
.model flat,C
.code
InternalX86EnablePaging64 PROC
cli
mov ebx, [esp + 4] ; save CS
mov eax, OFFSET cs_address
mov word ptr [eax], bx ; Update CS selector for far jump
mov eax, cr4
or al, (1 SHL 5)
mov cr4, eax ; enable PAE
mov ecx, 0c0000080h
rdmsr
or ah, 1 ; set LME
wrmsr
mov eax, cr0
bts eax, 31
mov cr0, eax ; enable paging
retf
jmp go_to_long_mode
go_to_long_mode:
;
; This is the next instruction after enabling paging. Jump to long mode
;
db 067h
db 0eah ; Far Jump Offset:Selector to reload CS
dd OFFSET in_long_mode ; Offset is ensuing instruction boundary
cs_address:
dw 0h ; CS selector will be updated at runtime
in_long_mode: ; now in long mode
DB 67h, 48h
mov ebx, [esp + 8] ; mov rbx, [esp]
DB 67h, 48h
mov ecx, [esp + 10h] ; mov rcx, [esp + 8]
DB 67h, 48h
mov edx, [esp + 18h] ; mov rdx, [esp + 10h]
DB 67h, 48h
mov esp, [esp + 20h] ; mov rsp, [esp + 18h]
DB 48h
call ebx ; call rbx
jmp $
InternalX86EnablePaging64 ENDP
END