OvmfPkg/Tcg/Tcg2Config/Tpm12Support.c

   1 /** @file
   2   Implement the InternalTpm12Detect() function on top of the Tpm12DeviceLib
   3   class.
   4
   5   Copyright (C) 2020, Red Hat, Inc.
   6
   7   SPDX-License-Identifier: BSD-2-Clause-Patent
   8 **/
   9
  10 #include <Library/BaseLib.h>
  11 #include <Library/Tpm12DeviceLib.h>
  12
  13 #include "Tpm12Support.h"
  14
  15 #pragma pack (1)
  16 typedef struct {
  17   TPM_RSP_COMMAND_HDR    Hdr;
  18   TPM_CURRENT_TICKS      CurrentTicks;
  19 } TPM_RSP_GET_TICKS;
  20 #pragma pack ()
  21
  22 /**
  23   Probe for the TPM for 1.2 version, by sending TPM1.2 GetTicks
  24
  25   Sending a TPM1.2 command to a TPM2 should return a TPM1.2
  26   header (tag = 0xc4) and error code (TPM_BADTAG = 0x1e)
  27
  28   @retval EFI_SUCCESS  TPM version 1.2 probing successful.
  29
  30   @return              Error codes propagated from Tpm12SubmitCommand().
  31 **/
  32 STATIC
  33 EFI_STATUS
  34 TestTpm12 (
  35   )
  36 {
  37   EFI_STATUS           Status;
  38   TPM_RQU_COMMAND_HDR  Command;
  39   TPM_RSP_GET_TICKS    Response;
  40   UINT32               Length;
  41
  42   Command.tag       = SwapBytes16 (TPM_TAG_RQU_COMMAND);
  43   Command.paramSize = SwapBytes32 (sizeof (Command));
  44   Command.ordinal   = SwapBytes32 (TPM_ORD_GetTicks);
  45
  46   Length = sizeof (Response);
  47   Status = Tpm12SubmitCommand (
  48              sizeof (Command),
  49              (UINT8 *)&Command,
  50              &Length,
  51              (UINT8 *)&Response
  52              );
  53   if (EFI_ERROR (Status)) {
  54     return Status;
  55   }
  56
  57   return EFI_SUCCESS;
  58 }
  59
  60 /**
  61   Detect the presence of a TPM with interface version 1.2.
  62
  63   @retval EFI_SUCCESS      TPM-1.2 available. The Tpm12RequestUseTpm() and
  64                            Tpm12SubmitCommand(TPM_ORD_GetTicks) operations
  65                            (from the Tpm12DeviceLib class) have succeeded.
  66
  67   @return                  Error codes propagated from Tpm12RequestUseTpm() and
  68                            Tpm12SubmitCommand().
  69 **/
  70 EFI_STATUS
  71 InternalTpm12Detect (
  72   VOID
  73   )
  74 {
  75   EFI_STATUS  Status;
  76
  77   Status = Tpm12RequestUseTpm ();
  78   if (EFI_ERROR (Status)) {
  79     return Status;
  80   }
  81
  82   return TestTpm12 ();
  83 }