MdePkg/Library/BaseLib/X64/CpuId.S

   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.S
  15 #
  16 # Abstract:
  17 #
  18 #   AsmCpuid function
  19 #
  20 # Notes:
  21 #
  22 #------------------------------------------------------------------------------
  23
  24 #------------------------------------------------------------------------------
  25 #  VOID
  26 #  EFIAPI
  27 #  AsmCpuid (
  28 #    IN   UINT32  RegisterInEax,
  29 #    OUT  UINT32  *RegisterOutEax  OPTIONAL,
  30 #    OUT  UINT32  *RegisterOutEbx  OPTIONAL,
  31 #    OUT  UINT32  *RegisterOutEcx  OPTIONAL,
  32 #    OUT  UINT32  *RegisterOutEdx  OPTIONAL
  33 #    )
  34 #------------------------------------------------------------------------------
  35 ASM_GLOBAL ASM_PFX(AsmCpuid)
  36 ASM_PFX(AsmCpuid):
  37     push    %rbx
  38     mov     %ecx, %eax
  39     push    %rax                         # save Index on stack
  40     push    %rdx
  41     cpuid
  42     test    %r9, %r9
  43     jz      L1
  44     mov     %ecx, (%r9)
  45 L1:
  46     pop     %rcx
  47     jrcxz   L2
  48     mov     %eax, (%rcx)
  49 L2:
  50     mov     %r8, %rcx
  51     jrcxz   L3
  52     mov     %ebx, (%rcx)
  53 L3:
  54     mov     0x38(%rsp), %rcx
  55     jrcxz   L4
  56     mov     %edx, (%rcx)
  57 L4:
  58     pop     %rax                         # restore Index to rax as return value
  59     pop     %rbx
  60     ret