MdePkg/Library/BaseLib/X64/CpuId.nasm

   1 ;------------------------------------------------------------------------------
   2 ;
   3 ; Copyright (c) 2006 - 2008, Intel Corporation. All rights reserved.<BR>
   4 ; 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     DEFAULT REL
  25     SECTION .text
  26
  27 ;------------------------------------------------------------------------------
  28 ;  VOID
  29 ;  EFIAPI
  30 ;  AsmCpuid (
  31 ;    IN   UINT32  RegisterInEax,
  32 ;    OUT  UINT32  *RegisterOutEax  OPTIONAL,
  33 ;    OUT  UINT32  *RegisterOutEbx  OPTIONAL,
  34 ;    OUT  UINT32  *RegisterOutEcx  OPTIONAL,
  35 ;    OUT  UINT32  *RegisterOutEdx  OPTIONAL
  36 ;    )
  37 ;------------------------------------------------------------------------------
  38 global ASM_PFX(AsmCpuid)
  39 ASM_PFX(AsmCpuid):
  40     push    rbx
  41     mov     eax, ecx
  42     push    rax                         ; save Index on stack
  43     push    rdx
  44     cpuid
  45     test    r9, r9
  46     jz      .0
  47     mov     [r9], ecx
  48 .0:
  49     pop     rcx
  50     jrcxz   .1
  51     mov     [rcx], eax
  52 .1:
  53     mov     rcx, r8
  54     jrcxz   .2
  55     mov     [rcx], ebx
  56 .2:
  57     mov     rcx, [rsp + 0x38]
  58     jrcxz   .3
  59     mov     [rcx], edx
  60 .3:
  61     pop     rax                         ; restore Index to rax as return value
  62     pop     rbx
  63     ret
  64