audk/MdePkg/Library/BaseLib/X64/DisablePaging64.asm

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;------------------------------------------------------------------------------
;
; 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:
;
; DisablePaging64.Asm
;
; Abstract:
;
; AsmDisablePaging64 function
;
; Notes:
;
;------------------------------------------------------------------------------
.code
InternalX86DisablePaging64 PROC
cli
shl rcx, 32
lea eax, @F
mov ecx, eax
push rcx
mov ebx, edx
mov esi, r8d
mov edi, r9d
mov eax, [rsp + 28h]
retf
@@:
mov esp, eax ; set up new stack
mov rax, cr0
btr eax, 31
mov cr0, rax ; disable paging
mov ecx, 0c0000080h
rdmsr
and ah, NOT 1 ; clear LME
wrmsr
mov rax, cr4
and al, NOT (1 SHL 5) ; clear PAE
mov cr4, rax
push rdi
push rsi
call rbx
jmp $
InternalX86DisablePaging64 ENDP
END