MdePkg/Library/BaseLib/Ia32/CpuIdEx.c

   1 /** @file
   2   AsmCpuidEx function.
   3
   4   Copyright (c) 2006 - 2007, Intel Corporation<BR>
   5   All rights reserved. This program and the accompanying materials
   6   are licensed and made available under the terms and conditions of the BSD License
   7   which accompanies this distribution.  The full text of the license may be found at
   8   http://opensource.org/licenses/bsd-license.php
   9
  10   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  11   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  12
  13 **/
  14
  15 //
  16 // Include common header file for this module.
  17 //
  18 #include "CommonHeader.h"
  19
  20 UINT32
  21 EFIAPI
  22 AsmCpuidEx (
  23   IN      UINT32                    Index,
  24   IN      UINT32                    SubIndex,
  25   OUT     UINT32                    *RegisterEax,  OPTIONAL
  26   OUT     UINT32                    *RegisterEbx,  OPTIONAL
  27   OUT     UINT32                    *RegisterEcx,  OPTIONAL
  28   OUT     UINT32                    *RegisterEdx   OPTIONAL
  29   )
  30 {
  31   _asm {
  32     mov     eax, Index
  33     mov     ecx, SubIndex
  34     cpuid
  35     push    ecx
  36     mov     ecx, RegisterEax
  37     jecxz   SkipEax
  38     mov     [ecx], eax
  39 SkipEax:
  40     mov     ecx, RegisterEbx
  41     jecxz   SkipEbx
  42     mov     [ecx], ebx
  43 SkipEbx:
  44     pop     eax
  45     mov     ecx, RegisterEcx
  46     jecxz   SkipEcx
  47     mov     [ecx], eax
  48 SkipEcx:
  49     mov     ecx, RegisterEdx
  50     jecxz   SkipEdx
  51     mov     [ecx], edx
  52 SkipEdx:
  53     mov     eax, Index
  54   }
  55 }