audk/MdePkg/Library/BaseLib/X64/EnableCache.nasm

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NASM
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;------------------------------------------------------------------------------
;
; Copyright (c) 2006 - 2008, Intel Corporation. All rights reserved.<BR>
; 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:
;
; EnableCache.Asm
;
; Abstract:
;
; Flush all caches with a WBINVD instruction, clear the CD bit of CR0 to 0, and clear
; the NW bit of CR0 to 0
;
; Notes:
;
;------------------------------------------------------------------------------
DEFAULT REL
SECTION .text
;------------------------------------------------------------------------------
; VOID
; EFIAPI
; AsmEnableCache (
; VOID
; );
;------------------------------------------------------------------------------
global ASM_PFX(AsmEnableCache)
ASM_PFX(AsmEnableCache):
wbinvd
mov rax, cr0
btr rax, 29
btr rax, 30
mov cr0, rax
ret