/* If Eax is not NULL, then the value of EAX after CPUID is returned in Eax. If Ebx is not NULL, then the value of EBX after CPUID is returned in Ebx. If Ecx is not NULL, then the value of ECX after CPUID is returned in Ecx. If Edx is not NULL, then the value of EDX after CPUID is returned in Edx. */
UINT32 EFIAPI AsmCpuidEx(IN UINT32 Index, IN UINT32 SubIndex, OUT UINT32 *RegisterEax OPTIONAL, OUT UINT32 *RegisterEbx OPTIONAL, OUT UINT32 *RegisterEcx OPTIONAL, OUT UINT32 *RegisterEdx OPTIONAL)
/* If Eax is not NULL, then the value of EAX after CPUID is returned in Eax. If Ebx is not NULL, then the value of EBX after CPUID is returned in Ebx. If Ecx is not NULL, then the value of ECX after CPUID is returned in Ecx. If Edx is not NULL, then the value of EDX after CPUID is returned in Edx. */
UINT32 EFIAPI AsmCpuidEx(IN UINT32 Index, IN UINT32 SubIndex, OUT UINT32 *RegisterEax OPTIONAL, OUT UINT32 *RegisterEbx OPTIONAL, OUT UINT32 *RegisterEcx OPTIONAL, OUT UINT32 *RegisterEdx OPTIONAL)
{
  _asm {
    mov     eax, Index
    mov     ecx, SubIndex
    cpuid
    push    ecx
    mov     ecx, RegisterEax
    jecxz   SkipEax
    mov     [ecx], eax
SkipEax:
    mov     ecx, RegisterEbx
    jecxz   SkipEbx
    mov     [ecx], ebx
SkipEbx:
    pop     eax
    mov     ecx, RegisterEcx
    jecxz   SkipEcx
    mov     [ecx], eax
SkipEcx:
    mov     ecx, RegisterEdx
    jecxz   SkipEdx
    mov     [ecx], edx
SkipEdx:
    mov     eax, Index
  }
}