MdePkg/Library/BaseLib/X64/CpuId.nasm

   1 ;------------------------------------------------------------------------------
   2 ;
   3 ; Copyright (c) 2006 - 2008, Intel Corporation. All rights reserved.<BR>
   4 ; SPDX-License-Identifier: BSD-2-Clause-Patent
   5 ;
   6 ; Module Name:
   7 ;
   8 ;   CpuId.Asm
   9 ;
  10 ; Abstract:
  11 ;
  12 ;   AsmCpuid function
  13 ;
  14 ; Notes:
  15 ;
  16 ;------------------------------------------------------------------------------
  17
  18     DEFAULT REL
  19     SECTION .text
  20
  21 ;------------------------------------------------------------------------------
  22 ;  VOID
  23 ;  EFIAPI
  24 ;  AsmCpuid (
  25 ;    IN   UINT32  RegisterInEax,
  26 ;    OUT  UINT32  *RegisterOutEax  OPTIONAL,
  27 ;    OUT  UINT32  *RegisterOutEbx  OPTIONAL,
  28 ;    OUT  UINT32  *RegisterOutEcx  OPTIONAL,
  29 ;    OUT  UINT32  *RegisterOutEdx  OPTIONAL
  30 ;    )
  31 ;------------------------------------------------------------------------------
  32 global ASM_PFX(AsmCpuid)
  33 ASM_PFX(AsmCpuid):
  34     push    rbx
  35     mov     eax, ecx
  36     push    rax                         ; save Index on stack
  37     push    rdx
  38     cpuid
  39     test    r9, r9
  40     jz      .0
  41     mov     [r9], ecx
  42 .0:
  43     pop     rcx
  44     jrcxz   .1
  45     mov     [rcx], eax
  46 .1:
  47     mov     rcx, r8
  48     jrcxz   .2
  49     mov     [rcx], ebx
  50 .2:
  51     mov     rcx, [rsp + 0x38]
  52     jrcxz   .3
  53     mov     [rcx], edx
  54 .3:
  55     pop     rax                         ; restore Index to rax as return value
  56     pop     rbx
  57     ret
  58