MdePkg/Library/BaseLib/X64/CpuId.asm

   1 ;------------------------------------------------------------------------------
   2 ;
   3 ; Copyright (c) 2006, Intel Corporation
   4 ; All rights reserved. This program and the accompanying materials
   5 ; are licensed and made available under the terms and conditions of the BSD License
   6 ; which accompanies this distribution.  The full text of the license may be found at
   7 ; http://opensource.org/licenses/bsd-license.php
   8 ;
   9 ; THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  10 ; WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  11 ;
  12 ; Module Name:
  13 ;
  14 ;   CpuId.Asm
  15 ;
  16 ; Abstract:
  17 ;
  18 ;   AsmCpuid function
  19 ;
  20 ; Notes:
  21 ;
  22 ;------------------------------------------------------------------------------
  23
  24     .code
  25
  26 ;------------------------------------------------------------------------------
  27 ;  VOID
  28 ;  EFIAPI
  29 ;  AsmCpuid (
  30 ;    IN   UINT32  RegisterInEax,
  31 ;    OUT  UINT32  *RegisterOutEax  OPTIONAL,
  32 ;    OUT  UINT32  *RegisterOutEbx  OPTIONAL,
  33 ;    OUT  UINT32  *RegisterOutEcx  OPTIONAL,
  34 ;    OUT  UINT32  *RegisterOutEdx  OPTIONAL
  35 ;    )
  36 ;------------------------------------------------------------------------------
  37 AsmCpuid    PROC    USES    rbx
  38     mov     eax, ecx
  39     push    rax                         ; save Index on stack
  40     push    rdx
  41     cpuid
  42     test    r9, r9
  43     jz      @F
  44     mov     [r9], ecx
  45 @@:
  46     pop     rcx
  47     jrcxz   @F
  48     mov     [rcx], eax
  49 @@:
  50     mov     rcx, r8
  51     jrcxz   @F
  52     mov     [rcx], ebx
  53 @@:
  54     mov     rcx, [rsp + 38h]
  55     jrcxz   @F
  56     mov     [rcx], edx
  57 @@:
  58     pop     rax                         ; restore Index to rax as return value
  59     ret
  60 AsmCpuid    ENDP
  61
  62     END