1 files changed, 79 insertions, 0 deletions
diff --git a/OvmfPkg/Tcg/Tcg2Config/Tpm12Support.c b/OvmfPkg/Tcg/Tcg2Config/Tpm12Support.c
new file mode 100644
index 0000000000..4f5a775c7a
--- /dev/null
+++ b/OvmfPkg/Tcg/Tcg2Config/Tpm12Support.c
@@ -0,0 +1,79 @@
+/** @file
+  Implement the InternalTpm12Detect() function on top of the Tpm12DeviceLib
+  class.
+
+  Copyright (C) 2020, Red Hat, Inc.
+
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+**/
+
+#include <Library/BaseLib.h>
+#include <Library/Tpm12DeviceLib.h>
+
+#include "Tpm12Support.h"
+
+#pragma pack (1)
+typedef struct {
+  TPM_RSP_COMMAND_HDR   Hdr;
+  TPM_CURRENT_TICKS     CurrentTicks;
+} TPM_RSP_GET_TICKS;
+#pragma pack ()
+
+/**
+  Probe for the TPM for 1.2 version, by sending TPM1.2 GetTicks
+
+  Sending a TPM1.2 command to a TPM2 should return a TPM1.2
+  header (tag = 0xc4) and error code (TPM_BADTAG = 0x1e)
+
+  @retval EFI_SUCCESS  TPM version 1.2 probing successful.
+
+  @return              Error codes propagated from Tpm12SubmitCommand().
+**/
+STATIC
+EFI_STATUS
+TestTpm12 (
+  )
+{
+  EFI_STATUS           Status;
+  TPM_RQU_COMMAND_HDR  Command;
+  TPM_RSP_GET_TICKS    Response;
+  UINT32               Length;
+
+  Command.tag       = SwapBytes16 (TPM_TAG_RQU_COMMAND);
+  Command.paramSize = SwapBytes32 (sizeof (Command));
+  Command.ordinal   = SwapBytes32 (TPM_ORD_GetTicks);
+
+  Length = sizeof (Response);
+  Status = Tpm12SubmitCommand (sizeof (Command), (UINT8 *)&Command, &Length,
+             (UINT8 *)&Response);
+  if (EFI_ERROR (Status)) {
+    return Status;
+  }
+
+  return EFI_SUCCESS;
+}
+
+/**
+  Detect the presence of a TPM with interface version 1.2.
+
+  @retval EFI_SUCCESS      TPM-1.2 available. The Tpm12RequestUseTpm() and
+                           Tpm12SubmitCommand(TPM_ORD_GetTicks) operations
+                           (from the Tpm12DeviceLib class) have succeeded.
+
+  @return                  Error codes propagated from Tpm12RequestUseTpm() and
+                           Tpm12SubmitCommand().
+**/
+EFI_STATUS
+InternalTpm12Detect (
+  VOID
+  )
+{
+  EFI_STATUS Status;
+
+  Status = Tpm12RequestUseTpm ();
+  if (EFI_ERROR (Status)) {
+    return Status;
+  }
+
+  return TestTpm12 ();
+}