MdePkg/Library/BaseLib/X64/CpuId.S File Reference
Detailed Description
#------------------------------------------------------------------------------
#
# Copyright (c) 2006 - 2008, 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.S
#
# Abstract:
#
# AsmCpuid function
#
# Notes:
#
#------------------------------------------------------------------------------
#------------------------------------------------------------------------------
# VOID
# EFIAPI
# AsmCpuid (
# IN UINT32 RegisterInEax,
# OUT UINT32 *RegisterOutEax OPTIONAL,
# OUT UINT32 *RegisterOutEbx OPTIONAL,
# OUT UINT32 *RegisterOutEcx OPTIONAL,
# OUT UINT32 *RegisterOutEdx OPTIONAL
# )
#------------------------------------------------------------------------------
ASM_GLOBAL
ASM_PFX(AsmCpuid)
ASM_PFX(AsmCpuid):
push rbx
mov ecx, eax
push rax # save Index on stack
push rdx
cpuid
test r9, r9
jz L1
mov ecx, (r9)
L1:
pop rcx
jrcxz L2
mov eax, (rcx)
L2:
mov r8, rcx
jrcxz L3
mov ebx, (rcx)
L3:
mov 0x38(rsp), rcx
jrcxz L4
mov edx, (rcx)
L4:
pop rax # restore Index to rax as return value
pop rbx
ret