audk/OldMdePkg/Library/BaseLib/X64/WriteMsr64.asm

42 lines
1.2 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:
;
; WriteMsr64.Asm
;
; Abstract:
;
; AsmWriteMsr64 function
;
; Notes:
;
;------------------------------------------------------------------------------
.code
;------------------------------------------------------------------------------
; UINT64
; EFIAPI
; AsmWriteMsr64 (
; IN UINT32 Index,
; IN UINT64 Value
; );
;------------------------------------------------------------------------------
AsmWriteMsr64 PROC
mov rax, rdx ; meanwhile, rax <- return value
shr rdx, 20h ; edx:eax contains the value to write
wrmsr
ret
AsmWriteMsr64 ENDP
END