UefiCpuPkg/Library/BaseUefiCpuLib/BaseUefiCpuLib.c

   1 /** @file
   2   This library defines some routines that are generic for IA32 family CPU.
   3
   4   The library routines are UEFI specification compliant.
   5
   6   Copyright (c) 2020, AMD Inc. All rights reserved.<BR>
   7   Copyright (c) 2021, Intel Corporation. All rights reserved.<BR>
   8   SPDX-License-Identifier: BSD-2-Clause-Patent
   9
  10 **/
  11
  12 #include <Register/Intel/Cpuid.h>
  13 #include <Register/Amd/Cpuid.h>
  14
  15 #include <Library/BaseLib.h>
  16 #include <Library/UefiCpuLib.h>
  17
  18 /**
  19   Determine if the standard CPU signature is "AuthenticAMD".
  20
  21   @retval TRUE  The CPU signature matches.
  22   @retval FALSE The CPU signature does not match.
  23
  24 **/
  25 BOOLEAN
  26 EFIAPI
  27 StandardSignatureIsAuthenticAMD (
  28   VOID
  29   )
  30 {
  31   UINT32  RegEbx;
  32   UINT32  RegEcx;
  33   UINT32  RegEdx;
  34
  35   AsmCpuid (CPUID_SIGNATURE, NULL, &RegEbx, &RegEcx, &RegEdx);
  36   return (RegEbx == CPUID_SIGNATURE_AUTHENTIC_AMD_EBX &&
  37           RegEcx == CPUID_SIGNATURE_AUTHENTIC_AMD_ECX &&
  38           RegEdx == CPUID_SIGNATURE_AUTHENTIC_AMD_EDX);
  39 }
  40
  41 /**
  42   Return the 32bit CPU family and model value.
  43
  44   @return CPUID[01h].EAX with Processor Type and Stepping ID cleared.
  45 **/
  46 UINT32
  47 EFIAPI
  48 GetCpuFamilyModel (
  49   VOID
  50   )
  51 {
  52   CPUID_VERSION_INFO_EAX  Eax;
  53
  54   AsmCpuid (CPUID_VERSION_INFO, &Eax.Uint32, NULL, NULL, NULL);
  55
  56   //
  57   // Mask other fields than Family and Model.
  58   //
  59   Eax.Bits.SteppingId    = 0;
  60   Eax.Bits.ProcessorType = 0;
  61   Eax.Bits.Reserved1     = 0;
  62   Eax.Bits.Reserved2     = 0;
  63   return Eax.Uint32;
  64 }
  65
  66 /**
  67   Return the CPU stepping ID.
  68   @return CPU stepping ID value in CPUID[01h].EAX.
  69 **/
  70 UINT8
  71 EFIAPI
  72 GetCpuSteppingId (
  73   VOID
  74   )
  75 {
  76   CPUID_VERSION_INFO_EAX  Eax;
  77
  78   AsmCpuid (CPUID_VERSION_INFO, &Eax.Uint32, NULL, NULL, NULL);
  79
  80   return (UINT8)Eax.Bits.SteppingId;
  81 }