MdePkg/Library/BaseLib/X64/CpuIdEx.nasm

;------------------------------------------------------------------------------
;
; Copyright (c) 2006 - 2008, Intel Corporation. All rights reserved.<BR>
; SPDX-License-Identifier: BSD-2-Clause-Patent
;
; Module Name:
;
;   CpuIdEx.Asm
;
; Abstract:
;
;   AsmCpuidEx function
;
; Notes:
;
;------------------------------------------------------------------------------

    DEFAULT REL
    SECTION .text

;------------------------------------------------------------------------------
;  UINT32
;  EFIAPI
;  AsmCpuidEx (
;    IN   UINT32  RegisterInEax,
;    IN   UINT32  RegisterInEcx,
;    OUT  UINT32  *RegisterOutEax  OPTIONAL,
;    OUT  UINT32  *RegisterOutEbx  OPTIONAL,
;    OUT  UINT32  *RegisterOutEcx  OPTIONAL,
;    OUT  UINT32  *RegisterOutEdx  OPTIONAL
;    )
;------------------------------------------------------------------------------
global ASM_PFX(AsmCpuidEx)
ASM_PFX(AsmCpuidEx):
    push    rbx
    mov     eax, ecx
    mov     ecx, edx
    push    rax                         ; save Index on stack
    cpuid
    mov     r10, [rsp + 0x38]
    test    r10, r10
    jz      .0
    mov     [r10], ecx
.0:
    mov     rcx, r8
    jrcxz   .1
    mov     [rcx], eax
.1:
    mov     rcx, r9
    jrcxz   .2
    mov     [rcx], ebx
.2:
    mov     rcx, [rsp + 0x40]
    jrcxz   .3
    mov     [rcx], edx
.3:
    pop     rax                         ; restore Index to rax as return value
    pop     rbx
    ret