audk/MdePkg/Library/BaseLib/X64/CpuId.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:
;
; CpuId.Asm
;
; Abstract:
;
; AsmCpuid function
;
; Notes:
;
;------------------------------------------------------------------------------
.code
;------------------------------------------------------------------------------
; VOID
; EFIAPI
; AsmCpuid (
; IN UINT32 RegisterInEax,
; OUT UINT32 *RegisterOutEax OPTIONAL,
; OUT UINT32 *RegisterOutEbx OPTIONAL,
; OUT UINT32 *RegisterOutEcx OPTIONAL,
; OUT UINT32 *RegisterOutEdx OPTIONAL
; )
;------------------------------------------------------------------------------
AsmCpuid PROC USES rbx
mov eax, ecx
push rax ; save Index on stack
push rdx
cpuid
test r9, r9
jz @F
mov [r9], ecx
@@:
pop rcx
jrcxz @F
mov [rcx], eax
@@:
mov rcx, r8
jrcxz @F
mov [rcx], ebx
@@:
mov rcx, [rsp + 38h]
jrcxz @F
mov [rcx], edx
@@:
pop rax ; restore Index to rax as return value
ret
AsmCpuid ENDP
END