SecurityPkg/Tcg/Tcg2Config/TpmDetection.c

   1 /** @file
   2   TPM1.2/dTPM2.0 auto detection.
   3
   4 Copyright (c) 2015 - 2018, Intel Corporation. All rights reserved.<BR>
   5 SPDX-License-Identifier: BSD-2-Clause-Patent
   6
   7 **/
   8
   9
  10 #include <PiPei.h>
  11 #include <Ppi/ReadOnlyVariable2.h>
  12
  13 #include <Library/BaseLib.h>
  14 #include <Library/BaseMemoryLib.h>
  15 #include <Library/DebugLib.h>
  16 #include <Library/PeiServicesLib.h>
  17 #include <Library/PcdLib.h>
  18 #include <Library/Tpm12DeviceLib.h>
  19 #include <Library/Tpm12CommandLib.h>
  20 #include <IndustryStandard/Tpm12.h>
  21
  22 #include "Tcg2ConfigNvData.h"
  23
  24 /**
  25   This routine check both SetupVariable and real TPM device, and return final TpmDevice configuration.
  26
  27   @param  SetupTpmDevice  TpmDevice configuration in setup driver
  28
  29   @return TpmDevice configuration
  30 **/
  31 UINT8
  32 DetectTpmDevice (
  33   IN UINT8 SetupTpmDevice
  34   )
  35 {
  36   EFI_STATUS                        Status;
  37   EFI_BOOT_MODE                     BootMode;
  38   TCG2_DEVICE_DETECTION             Tcg2DeviceDetection;
  39   EFI_PEI_READ_ONLY_VARIABLE2_PPI   *VariablePpi;
  40   UINTN                             Size;
  41
  42   Status = PeiServicesGetBootMode (&BootMode);
  43   ASSERT_EFI_ERROR (Status);
  44
  45   //
  46   // In S3, we rely on normal boot Detection, because we save to ReadOnly Variable in normal boot.
  47   //
  48   if (BootMode == BOOT_ON_S3_RESUME) {
  49     DEBUG ((EFI_D_INFO, "DetectTpmDevice: S3 mode\n"));
  50
  51     Status = PeiServicesLocatePpi (&gEfiPeiReadOnlyVariable2PpiGuid, 0, NULL, (VOID **) &VariablePpi);
  52     ASSERT_EFI_ERROR (Status);
  53
  54     Size = sizeof(TCG2_DEVICE_DETECTION);
  55     ZeroMem (&Tcg2DeviceDetection, sizeof(Tcg2DeviceDetection));
  56     Status = VariablePpi->GetVariable (
  57                             VariablePpi,
  58                             TCG2_DEVICE_DETECTION_NAME,
  59                             &gTcg2ConfigFormSetGuid,
  60                             NULL,
  61                             &Size,
  62                             &Tcg2DeviceDetection
  63                             );
  64     if (!EFI_ERROR (Status) &&
  65         (Tcg2DeviceDetection.TpmDeviceDetected >= TPM_DEVICE_MIN) &&
  66         (Tcg2DeviceDetection.TpmDeviceDetected <= TPM_DEVICE_MAX)) {
  67       DEBUG ((EFI_D_ERROR, "TpmDevice from DeviceDetection: %x\n", Tcg2DeviceDetection.TpmDeviceDetected));
  68       return Tcg2DeviceDetection.TpmDeviceDetected;
  69     }
  70   }
  71
  72   DEBUG ((EFI_D_INFO, "DetectTpmDevice:\n"));
  73
  74   // dTPM available and not disabled by setup
  75   // We need check if it is TPM1.2 or TPM2.0
  76   // So try TPM1.2 command at first
  77
  78   Status = Tpm12RequestUseTpm ();
  79   if (EFI_ERROR (Status)) {
  80     //
  81     // dTPM not available
  82     //
  83     return TPM_DEVICE_NULL;
  84   }
  85
  86   if (BootMode == BOOT_ON_S3_RESUME) {
  87     Status = Tpm12Startup (TPM_ST_STATE);
  88   } else {
  89     Status = Tpm12Startup (TPM_ST_CLEAR);
  90   }
  91   if (EFI_ERROR (Status)) {
  92     return TPM_DEVICE_2_0_DTPM;
  93   }
  94
  95   // NO initialization needed again.
  96   Status = PcdSet8S (PcdTpmInitializationPolicy, 0);
  97   ASSERT_EFI_ERROR (Status);
  98   return TPM_DEVICE_1_2;
  99 }