SecurityPkg/Tcg/Tcg2Config/TpmDetection.c

/** @file
  TPM1.2/dTPM2.0 auto detection.

Copyright (c) 2015 - 2016, Intel Corporation. All rights reserved.<BR>
This program and the accompanying materials 
are licensed and made available under the terms and conditions of the BSD License 
which accompanies this distribution.  The full text of the license may be found at 
http://opensource.org/licenses/bsd-license.php

THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, 
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.

**/


#include <PiPei.h>
#include <Ppi/ReadOnlyVariable2.h>

#include <Library/BaseLib.h>
#include <Library/BaseMemoryLib.h>
#include <Library/DebugLib.h>
#include <Library/PeiServicesLib.h>
#include <Library/PcdLib.h>
#include <Library/Tpm12DeviceLib.h>
#include <Library/Tpm12CommandLib.h>
#include <IndustryStandard/Tpm12.h>

#include "Tcg2ConfigNvData.h"

/**
  This routine check both SetupVariable and real TPM device, and return final TpmDevice configuration.

  @param  SetupTpmDevice  TpmDevice configuration in setup driver

  @return TpmDevice configuration
**/
UINT8
DetectTpmDevice (
  IN UINT8 SetupTpmDevice
  )
{
  EFI_STATUS                        Status;
  EFI_BOOT_MODE                     BootMode;
  TCG2_DEVICE_DETECTION             Tcg2DeviceDetection;
  EFI_PEI_READ_ONLY_VARIABLE2_PPI   *VariablePpi;
  UINTN                             Size;

  Status = PeiServicesGetBootMode (&BootMode);
  ASSERT_EFI_ERROR (Status);

  //
  // In S3, we rely on normal boot Detection, because we save to ReadOnly Variable in normal boot.
  //
  if (BootMode == BOOT_ON_S3_RESUME) {
    DEBUG ((EFI_D_INFO, "DetectTpmDevice: S3 mode\n"));

    Status = PeiServicesLocatePpi (&gEfiPeiReadOnlyVariable2PpiGuid, 0, NULL, (VOID **) &VariablePpi);
    ASSERT_EFI_ERROR (Status);

    Size = sizeof(TCG2_DEVICE_DETECTION);
    ZeroMem (&Tcg2DeviceDetection, sizeof(Tcg2DeviceDetection));
    Status = VariablePpi->GetVariable (
                            VariablePpi,
                            TCG2_DEVICE_DETECTION_NAME,
                            &gTcg2ConfigFormSetGuid,
                            NULL,
                            &Size,
                            &Tcg2DeviceDetection
                            );
    if (!EFI_ERROR (Status) &&
        (Tcg2DeviceDetection.TpmDeviceDetected >= TPM_DEVICE_MIN) &&
        (Tcg2DeviceDetection.TpmDeviceDetected <= TPM_DEVICE_MAX)) {
      DEBUG ((EFI_D_ERROR, "TpmDevice from DeviceDetection: %x\n", Tcg2DeviceDetection.TpmDeviceDetected));
      return Tcg2DeviceDetection.TpmDeviceDetected;
    }
  }

  DEBUG ((EFI_D_INFO, "DetectTpmDevice:\n"));

  // dTPM available and not disabled by setup
  // We need check if it is TPM1.2 or TPM2.0
  // So try TPM1.2 command at first

  Status = Tpm12RequestUseTpm ();
  if (EFI_ERROR (Status)) {
    //
    // dTPM not available
    //
    return TPM_DEVICE_NULL;
  }

  if (BootMode == BOOT_ON_S3_RESUME) {
    Status = Tpm12Startup (TPM_ST_STATE);
  } else {
    Status = Tpm12Startup (TPM_ST_CLEAR);
  }
  if (EFI_ERROR (Status)) {
    return TPM_DEVICE_2_0_DTPM;
  }

  // NO initialization needed again.
  Status = PcdSet8S (PcdTpmInitializationPolicy, 0);
  ASSERT_EFI_ERROR (Status);
  return TPM_DEVICE_1_2;
}