SecurityPkg/Tcg/Tcg2Smm/Tcg2Smm.c - device/linaro/bootloader/edk2 - Git at Google

 /** @file
   It updates TPM2 items in ACPI table and registers SMI2 callback
   functions for Tcg2 physical presence, ClearMemory, and sample
   for dTPM StartMethod.

   Caution: This module requires additional review when modified.
   This driver will have external input - variable and ACPINvs data in SMM mode.
   This external input must be validated carefully to avoid security issue.

   PhysicalPresenceCallback() and MemoryClearCallback() will receive untrusted input and do some check.

 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 "Tcg2Smm.h"

 typedef enum {
   PtpInterfaceTis,
   PtpInterfaceFifo,
   PtpInterfaceCrb,
   PtpInterfaceMax,
 } PTP_INTERFACE_TYPE;

 /**
   Return PTP interface type.

   @param[in] Register                Pointer to PTP register.

   @return PTP interface type.
 **/
 PTP_INTERFACE_TYPE
 GetPtpInterface (
   IN VOID *Register
   )
 {
   PTP_CRB_INTERFACE_IDENTIFIER  InterfaceId;
   PTP_FIFO_INTERFACE_CAPABILITY InterfaceCapability;

   //
   // Check interface id
   //
   InterfaceId.Uint32 = MmioRead32 ((UINTN)&((PTP_CRB_REGISTERS *)Register)->InterfaceId);
   InterfaceCapability.Uint32 = MmioRead32 ((UINTN)&((PTP_FIFO_REGISTERS *)Register)->InterfaceCapability);

   if (InterfaceId.Bits.InterfaceType == PTP_INTERFACE_IDENTIFIER_INTERFACE_TYPE_TIS) {
     return PtpInterfaceTis;
   }

   if ((InterfaceId.Bits.InterfaceType == PTP_INTERFACE_IDENTIFIER_INTERFACE_TYPE_CRB) &&
       (InterfaceId.Bits.InterfaceVersion == PTP_INTERFACE_IDENTIFIER_INTERFACE_VERSION_CRB) &&
       (InterfaceId.Bits.CapCRB != 0)) {
     return PtpInterfaceCrb;
   }

   if ((InterfaceId.Bits.InterfaceType == PTP_INTERFACE_IDENTIFIER_INTERFACE_TYPE_FIFO) &&
       (InterfaceId.Bits.InterfaceVersion == PTP_INTERFACE_IDENTIFIER_INTERFACE_VERSION_FIFO) &&
       (InterfaceId.Bits.CapFIFO != 0) &&
       (InterfaceCapability.Bits.InterfaceVersion == INTERFACE_CAPABILITY_INTERFACE_VERSION_PTP)) {
     return PtpInterfaceFifo;
   }

   //
   // No Ptp interface available
   //
   return PtpInterfaceMax;
 }

 EFI_TPM2_ACPI_TABLE  mTpm2AcpiTemplate = {
   {
     EFI_ACPI_5_0_TRUSTED_COMPUTING_PLATFORM_2_TABLE_SIGNATURE,
     sizeof (mTpm2AcpiTemplate),
     EFI_TPM2_ACPI_TABLE_REVISION,
     //
     // Compiler initializes the remaining bytes to 0
     // These fields should be filled in in production
     //
   },
   0, // Flags
   0, // Control Area
   EFI_TPM2_ACPI_TABLE_START_METHOD_TIS, // StartMethod
 };

 EFI_SMM_VARIABLE_PROTOCOL  *mSmmVariable;
 TCG_NVS                    *mTcgNvs;

 /**
   Software SMI callback for TPM physical presence which is called from ACPI method.

   Caution: This function may receive untrusted input.
   Variable and ACPINvs are external input, so this function will validate
   its data structure to be valid value.

   @param[in]      DispatchHandle  The unique handle assigned to this handler by SmiHandlerRegister().
   @param[in]      Context         Points to an optional handler context which was specified when the
                                   handler was registered.
   @param[in, out] CommBuffer      A pointer to a collection of data in memory that will
                                   be conveyed from a non-SMM environment into an SMM environment.
   @param[in, out] CommBufferSize  The size of the CommBuffer.

   @retval EFI_SUCCESS             The interrupt was handled successfully.

 **/
 EFI_STATUS
 EFIAPI
 PhysicalPresenceCallback (
   IN EFI_HANDLE                  DispatchHandle,
   IN CONST VOID                  *Context,
   IN OUT VOID                    *CommBuffer,
   IN OUT UINTN                   *CommBufferSize
   )
 {
   UINT32                MostRecentRequest;
   UINT32                Response;
   UINT32                OperationRequest;
   UINT32                RequestParameter;


   if (mTcgNvs->PhysicalPresence.Parameter == TCG_ACPI_FUNCTION_RETURN_REQUEST_RESPONSE_TO_OS) {
     mTcgNvs->PhysicalPresence.ReturnCode = Tcg2PhysicalPresenceLibReturnOperationResponseToOsFunction (
                                              &MostRecentRequest,
                                              &Response
                                              );
     mTcgNvs->PhysicalPresence.LastRequest = MostRecentRequest;
     mTcgNvs->PhysicalPresence.Response = Response;
     return EFI_SUCCESS;
   } else if ((mTcgNvs->PhysicalPresence.Parameter == TCG_ACPI_FUNCTION_SUBMIT_REQUEST_TO_BIOS)
           || (mTcgNvs->PhysicalPresence.Parameter == TCG_ACPI_FUNCTION_SUBMIT_REQUEST_TO_BIOS_2)) {

     OperationRequest = mTcgNvs->PhysicalPresence.Request;
     RequestParameter = mTcgNvs->PhysicalPresence.RequestParameter;
     mTcgNvs->PhysicalPresence.ReturnCode = Tcg2PhysicalPresenceLibSubmitRequestToPreOSFunctionEx (
                                              &OperationRequest,
                                              &RequestParameter
                                              );
     mTcgNvs->PhysicalPresence.Request = OperationRequest;
     mTcgNvs->PhysicalPresence.RequestParameter = RequestParameter;
   } else if (mTcgNvs->PhysicalPresence.Parameter == TCG_ACPI_FUNCTION_GET_USER_CONFIRMATION_STATUS_FOR_REQUEST) {
     mTcgNvs->PhysicalPresence.ReturnCode = Tcg2PhysicalPresenceLibGetUserConfirmationStatusFunction (mTcgNvs->PPRequestUserConfirm);
   }

   return EFI_SUCCESS;
 }


 /**
   Software SMI callback for MemoryClear which is called from ACPI method.

   Caution: This function may receive untrusted input.
   Variable and ACPINvs are external input, so this function will validate
   its data structure to be valid value.

   @param[in]      DispatchHandle  The unique handle assigned to this handler by SmiHandlerRegister().
   @param[in]      Context         Points to an optional handler context which was specified when the
                                   handler was registered.
   @param[in, out] CommBuffer      A pointer to a collection of data in memory that will
                                   be conveyed from a non-SMM environment into an SMM environment.
   @param[in, out] CommBufferSize  The size of the CommBuffer.

   @retval EFI_SUCCESS             The interrupt was handled successfully.

 **/
 EFI_STATUS
 EFIAPI
 MemoryClearCallback (
   IN EFI_HANDLE                  DispatchHandle,
   IN CONST VOID                  *Context,
   IN OUT VOID                    *CommBuffer,
   IN OUT UINTN                   *CommBufferSize
   )
 {
   EFI_STATUS                     Status;
   UINTN                          DataSize;
   UINT8                          MorControl;

   mTcgNvs->MemoryClear.ReturnCode = MOR_REQUEST_SUCCESS;
   if (mTcgNvs->MemoryClear.Parameter == ACPI_FUNCTION_DSM_MEMORY_CLEAR_INTERFACE) {
     MorControl = (UINT8) mTcgNvs->MemoryClear.Request;
   } else if (mTcgNvs->MemoryClear.Parameter == ACPI_FUNCTION_PTS_CLEAR_MOR_BIT) {
     DataSize = sizeof (UINT8);
     Status = mSmmVariable->SmmGetVariable (
                              MEMORY_OVERWRITE_REQUEST_VARIABLE_NAME,
                              &gEfiMemoryOverwriteControlDataGuid,
                              NULL,
                              &DataSize,
                              &MorControl
                              );
     if (EFI_ERROR (Status)) {
       mTcgNvs->MemoryClear.ReturnCode = MOR_REQUEST_GENERAL_FAILURE;
       DEBUG ((EFI_D_ERROR, "[TPM] Get MOR variable failure! Status = %r\n", Status));
       return EFI_SUCCESS;
     }

     if (MOR_CLEAR_MEMORY_VALUE (MorControl) == 0x0) {
       return EFI_SUCCESS;
     }
     MorControl &= ~MOR_CLEAR_MEMORY_BIT_MASK;
   }

   DataSize = sizeof (UINT8);
   Status = mSmmVariable->SmmSetVariable (
                            MEMORY_OVERWRITE_REQUEST_VARIABLE_NAME,
                            &gEfiMemoryOverwriteControlDataGuid,
                            EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS,
                            DataSize,
                            &MorControl
                            );
   if (EFI_ERROR (Status)) {
     mTcgNvs->MemoryClear.ReturnCode = MOR_REQUEST_GENERAL_FAILURE;
     DEBUG ((EFI_D_ERROR, "[TPM] Set MOR variable failure! Status = %r\n", Status));
   }

   return EFI_SUCCESS;
 }

 /**
   Find the operation region in TCG ACPI table by given Name and Size,
   and initialize it if the region is found.

   @param[in, out] Table          The TPM item in ACPI table.
   @param[in]      Name           The name string to find in TPM table.
   @param[in]      Size           The size of the region to find.

   @return                        The allocated address for the found region.

 **/
 VOID *
 AssignOpRegion (
   EFI_ACPI_DESCRIPTION_HEADER    *Table,
   UINT32                         Name,
   UINT16                         Size
   )
 {
   EFI_STATUS                     Status;
   AML_OP_REGION_32_8             *OpRegion;
   EFI_PHYSICAL_ADDRESS           MemoryAddress;

   MemoryAddress = SIZE_4GB - 1;

   //
   // Patch some pointers for the ASL code before loading the SSDT.
   //
   for (OpRegion  = (AML_OP_REGION_32_8 *) (Table + 1);
        OpRegion <= (AML_OP_REGION_32_8 *) ((UINT8 *) Table + Table->Length);
        OpRegion  = (AML_OP_REGION_32_8 *) ((UINT8 *) OpRegion + 1)) {
     if ((OpRegion->OpRegionOp  == AML_EXT_REGION_OP) &&
         (OpRegion->NameString  == Name) &&
         (OpRegion->DWordPrefix == AML_DWORD_PREFIX) &&
         (OpRegion->BytePrefix  == AML_BYTE_PREFIX)) {

       Status = gBS->AllocatePages(AllocateMaxAddress, EfiACPIMemoryNVS, EFI_SIZE_TO_PAGES (Size), &MemoryAddress);
       ASSERT_EFI_ERROR (Status);
       ZeroMem ((VOID *)(UINTN)MemoryAddress, Size);
       OpRegion->RegionOffset = (UINT32) (UINTN) MemoryAddress;
       OpRegion->RegionLen    = (UINT8) Size;
       break;
     }
   }

   return (VOID *) (UINTN) MemoryAddress;
 }

 /**
   Patch version string of Physical Presence interface supported by platform. The initial string tag in TPM
 ACPI table is "$PV".

   @param[in, out] Table          The TPM item in ACPI table.
   @param[in]      PPVer          Version string of Physical Presence interface supported by platform.

   @return                        The allocated address for the found region.

 **/
 EFI_STATUS
 UpdatePPVersion (
   EFI_ACPI_DESCRIPTION_HEADER    *Table,
   CHAR8                          *PPVer
   )
 {
   EFI_STATUS  Status;
   UINT8       *DataPtr;

   //
   // Patch some pointers for the ASL code before loading the SSDT.
   //
   for (DataPtr  = (UINT8 *)(Table + 1);
        DataPtr <= (UINT8 *) ((UINT8 *) Table + Table->Length - PHYSICAL_PRESENCE_VERSION_SIZE);
        DataPtr += 1) {
     if (AsciiStrCmp((CHAR8 *)DataPtr,  PHYSICAL_PRESENCE_VERSION_TAG) == 0) {
       Status = AsciiStrCpyS((CHAR8 *)DataPtr, PHYSICAL_PRESENCE_VERSION_SIZE, PPVer);
       DEBUG((EFI_D_INFO, "TPM2 Physical Presence Interface Version update status 0x%x\n", Status));
       return Status;
     }
   }

   return EFI_NOT_FOUND;
 }

 /**
   Initialize and publish TPM items in ACPI table.

   @retval   EFI_SUCCESS     The TCG ACPI table is published successfully.
   @retval   Others          The TCG ACPI table is not published.

 **/
 EFI_STATUS
 PublishAcpiTable (
   VOID
   )
 {
   EFI_STATUS                     Status;
   EFI_ACPI_TABLE_PROTOCOL        *AcpiTable;
   UINTN                          TableKey;
   EFI_ACPI_DESCRIPTION_HEADER    *Table;
   UINTN                          TableSize;

   Status = GetSectionFromFv (
              &gEfiCallerIdGuid,
              EFI_SECTION_RAW,
              0,
              (VOID **) &Table,
              &TableSize
              );
   ASSERT_EFI_ERROR (Status);

   //
   // Update Table version before measuring it to PCR
   //
   Status = UpdatePPVersion(Table, (CHAR8 *)PcdGetPtr(PcdTcgPhysicalPresenceInterfaceVer));
   ASSERT_EFI_ERROR (Status);

   //
   // Measure to PCR[0] with event EV_POST_CODE ACPI DATA
   //
   TpmMeasureAndLogData(
     0,
     EV_POST_CODE,
     EV_POSTCODE_INFO_ACPI_DATA,
     ACPI_DATA_LEN,
     Table,
     TableSize
     );


   ASSERT (Table->OemTableId == SIGNATURE_64 ('T', 'p', 'm', '2', 'T', 'a', 'b', 'l'));
   CopyMem (Table->OemId, PcdGetPtr (PcdAcpiDefaultOemId), sizeof (Table->OemId) );
   mTcgNvs = AssignOpRegion (Table, SIGNATURE_32 ('T', 'N', 'V', 'S'), (UINT16) sizeof (TCG_NVS));
   ASSERT (mTcgNvs != NULL);

   //
   // Publish the TPM ACPI table. Table is re-checksumed.
   //
   Status = gBS->LocateProtocol (&gEfiAcpiTableProtocolGuid, NULL, (VOID **) &AcpiTable);
   ASSERT_EFI_ERROR (Status);

   TableKey = 0;
   Status = AcpiTable->InstallAcpiTable (
                         AcpiTable,
                         Table,
                         TableSize,
                         &TableKey
                         );
   ASSERT_EFI_ERROR (Status);

   return Status;
 }

 /**
   Publish TPM2 ACPI table

   @retval   EFI_SUCCESS     The TPM2 ACPI table is published successfully.
   @retval   Others          The TPM2 ACPI table is not published.

 **/
 EFI_STATUS
 PublishTpm2 (
   VOID
   )
 {
   EFI_STATUS                     Status;
   EFI_ACPI_TABLE_PROTOCOL        *AcpiTable;
   UINTN                          TableKey;
   UINT64                         OemTableId;
   EFI_TPM2_ACPI_CONTROL_AREA     *ControlArea;
   PTP_INTERFACE_TYPE             InterfaceType;

   //
   // Measure to PCR[0] with event EV_POST_CODE ACPI DATA
   //
   TpmMeasureAndLogData(
     0,
     EV_POST_CODE,
     EV_POSTCODE_INFO_ACPI_DATA,
     ACPI_DATA_LEN,
     &mTpm2AcpiTemplate,
     sizeof(mTpm2AcpiTemplate)
     );

   InterfaceType = GetPtpInterface ((VOID *) (UINTN) PcdGet64 (PcdTpmBaseAddress));
   switch (InterfaceType) {
   case PtpInterfaceCrb:
     mTpm2AcpiTemplate.StartMethod = EFI_TPM2_ACPI_TABLE_START_METHOD_COMMAND_RESPONSE_BUFFER_INTERFACE;
     mTpm2AcpiTemplate.AddressOfControlArea = PcdGet64 (PcdTpmBaseAddress) + 0x40;
     ControlArea = (EFI_TPM2_ACPI_CONTROL_AREA *)(UINTN)mTpm2AcpiTemplate.AddressOfControlArea;
     ControlArea->CommandSize  = 0xF80;
     ControlArea->ResponseSize = 0xF80;
     ControlArea->Command      = PcdGet64 (PcdTpmBaseAddress) + 0x80;
     ControlArea->Response     = PcdGet64 (PcdTpmBaseAddress) + 0x80;
     break;
   case PtpInterfaceFifo:
   case PtpInterfaceTis:
     break;
   default:
     DEBUG((EFI_D_ERROR, "TPM2 InterfaceType get error! %d\n", InterfaceType));
     break;
   }

   CopyMem (mTpm2AcpiTemplate.Header.OemId, PcdGetPtr (PcdAcpiDefaultOemId), sizeof (mTpm2AcpiTemplate.Header.OemId));
   OemTableId = PcdGet64 (PcdAcpiDefaultOemTableId);
   CopyMem (&mTpm2AcpiTemplate.Header.OemTableId, &OemTableId, sizeof (UINT64));
   mTpm2AcpiTemplate.Header.OemRevision      = PcdGet32 (PcdAcpiDefaultOemRevision);
   mTpm2AcpiTemplate.Header.CreatorId        = PcdGet32 (PcdAcpiDefaultCreatorId);
   mTpm2AcpiTemplate.Header.CreatorRevision  = PcdGet32 (PcdAcpiDefaultCreatorRevision);

   //
   // Construct ACPI table
   //
   Status = gBS->LocateProtocol (&gEfiAcpiTableProtocolGuid, NULL, (VOID **) &AcpiTable);
   ASSERT_EFI_ERROR (Status);

   Status = AcpiTable->InstallAcpiTable (
                         AcpiTable,
                         &mTpm2AcpiTemplate,
                         sizeof(mTpm2AcpiTemplate),
                         &TableKey
                         );
   ASSERT_EFI_ERROR (Status);

   return Status;
 }

 /**
   The driver's entry point.

   It install callbacks for TPM physical presence and MemoryClear, and locate
   SMM variable to be used in the callback function.

   @param[in] ImageHandle  The firmware allocated handle for the EFI image.
   @param[in] SystemTable  A pointer to the EFI System Table.

   @retval EFI_SUCCESS     The entry point is executed successfully.
   @retval Others          Some error occurs when executing this entry point.

 **/
 EFI_STATUS
 EFIAPI
 InitializeTcgSmm (
   IN EFI_HANDLE                  ImageHandle,
   IN EFI_SYSTEM_TABLE            *SystemTable
   )
 {
   EFI_STATUS                     Status;
   EFI_SMM_SW_DISPATCH2_PROTOCOL  *SwDispatch;
   EFI_SMM_SW_REGISTER_CONTEXT    SwContext;
   EFI_HANDLE                     SwHandle;

   if (!CompareGuid (PcdGetPtr(PcdTpmInstanceGuid), &gEfiTpmDeviceInstanceTpm20DtpmGuid)){
     DEBUG ((EFI_D_ERROR, "No TPM2 DTPM instance required!\n"));
     return EFI_UNSUPPORTED;
   }

   Status = PublishAcpiTable ();
   ASSERT_EFI_ERROR (Status);

   //
   // Get the Sw dispatch protocol and register SMI callback functions.
   //
   Status = gSmst->SmmLocateProtocol (&gEfiSmmSwDispatch2ProtocolGuid, NULL, (VOID**)&SwDispatch);
   ASSERT_EFI_ERROR (Status);
   SwContext.SwSmiInputValue = (UINTN) -1;
   Status = SwDispatch->Register (SwDispatch, PhysicalPresenceCallback, &SwContext, &SwHandle);
   ASSERT_EFI_ERROR (Status);
   if (EFI_ERROR (Status)) {
     return Status;
   }
   mTcgNvs->PhysicalPresence.SoftwareSmi = (UINT8) SwContext.SwSmiInputValue;

   SwContext.SwSmiInputValue = (UINTN) -1;
   Status = SwDispatch->Register (SwDispatch, MemoryClearCallback, &SwContext, &SwHandle);
   ASSERT_EFI_ERROR (Status);
   if (EFI_ERROR (Status)) {
     return Status;
   }
   mTcgNvs->MemoryClear.SoftwareSmi = (UINT8) SwContext.SwSmiInputValue;

   //
   // Locate SmmVariableProtocol.
   //
   Status = gSmst->SmmLocateProtocol (&gEfiSmmVariableProtocolGuid, NULL, (VOID**)&mSmmVariable);
   ASSERT_EFI_ERROR (Status);

   //
   // Set TPM2 ACPI table
   //
   Status = PublishTpm2 ();
   ASSERT_EFI_ERROR (Status);


   return EFI_SUCCESS;
 }
	/** @file
	It updates TPM2 items in ACPI table and registers SMI2 callback
	functions for Tcg2 physical presence, ClearMemory, and sample
	for dTPM StartMethod.

	Caution: This module requires additional review when modified.
	This driver will have external input - variable and ACPINvs data in SMM mode.
	This external input must be validated carefully to avoid security issue.

	PhysicalPresenceCallback() and MemoryClearCallback() will receive untrusted input and do some check.

	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 "Tcg2Smm.h"

	typedef enum {
	PtpInterfaceTis,
	PtpInterfaceFifo,
	PtpInterfaceCrb,
	PtpInterfaceMax,
	} PTP_INTERFACE_TYPE;

	/**
	Return PTP interface type.

	@param[in] Register Pointer to PTP register.

	@return PTP interface type.
	**/
	PTP_INTERFACE_TYPE
	GetPtpInterface (
	IN VOID *Register
	)
	{
	PTP_CRB_INTERFACE_IDENTIFIER InterfaceId;
	PTP_FIFO_INTERFACE_CAPABILITY InterfaceCapability;

	//
	// Check interface id
	//
	InterfaceId.Uint32 = MmioRead32 ((UINTN)&((PTP_CRB_REGISTERS *)Register)->InterfaceId);
	InterfaceCapability.Uint32 = MmioRead32 ((UINTN)&((PTP_FIFO_REGISTERS *)Register)->InterfaceCapability);

	if (InterfaceId.Bits.InterfaceType == PTP_INTERFACE_IDENTIFIER_INTERFACE_TYPE_TIS) {
	return PtpInterfaceTis;
	}

	if ((InterfaceId.Bits.InterfaceType == PTP_INTERFACE_IDENTIFIER_INTERFACE_TYPE_CRB) &&
	(InterfaceId.Bits.InterfaceVersion == PTP_INTERFACE_IDENTIFIER_INTERFACE_VERSION_CRB) &&
	(InterfaceId.Bits.CapCRB != 0)) {
	return PtpInterfaceCrb;
	}

	if ((InterfaceId.Bits.InterfaceType == PTP_INTERFACE_IDENTIFIER_INTERFACE_TYPE_FIFO) &&
	(InterfaceId.Bits.InterfaceVersion == PTP_INTERFACE_IDENTIFIER_INTERFACE_VERSION_FIFO) &&
	(InterfaceId.Bits.CapFIFO != 0) &&
	(InterfaceCapability.Bits.InterfaceVersion == INTERFACE_CAPABILITY_INTERFACE_VERSION_PTP)) {
	return PtpInterfaceFifo;
	}

	//
	// No Ptp interface available
	//
	return PtpInterfaceMax;
	}

	EFI_TPM2_ACPI_TABLE mTpm2AcpiTemplate = {
	{
	EFI_ACPI_5_0_TRUSTED_COMPUTING_PLATFORM_2_TABLE_SIGNATURE,
	sizeof (mTpm2AcpiTemplate),
	EFI_TPM2_ACPI_TABLE_REVISION,
	//
	// Compiler initializes the remaining bytes to 0
	// These fields should be filled in in production
	//
	},
	0, // Flags
	0, // Control Area
	EFI_TPM2_ACPI_TABLE_START_METHOD_TIS, // StartMethod
	};

	EFI_SMM_VARIABLE_PROTOCOL *mSmmVariable;
	TCG_NVS *mTcgNvs;

	/**
	Software SMI callback for TPM physical presence which is called from ACPI method.

	Caution: This function may receive untrusted input.
	Variable and ACPINvs are external input, so this function will validate
	its data structure to be valid value.

	@param[in] DispatchHandle The unique handle assigned to this handler by SmiHandlerRegister().
	@param[in] Context Points to an optional handler context which was specified when the
	handler was registered.
	@param[in, out] CommBuffer A pointer to a collection of data in memory that will
	be conveyed from a non-SMM environment into an SMM environment.
	@param[in, out] CommBufferSize The size of the CommBuffer.

	@retval EFI_SUCCESS The interrupt was handled successfully.

	**/
	EFI_STATUS
	EFIAPI
	PhysicalPresenceCallback (
	IN EFI_HANDLE DispatchHandle,
	IN CONST VOID *Context,
	IN OUT VOID *CommBuffer,
	IN OUT UINTN *CommBufferSize
	)
	{
	UINT32 MostRecentRequest;
	UINT32 Response;
	UINT32 OperationRequest;
	UINT32 RequestParameter;


	if (mTcgNvs->PhysicalPresence.Parameter == TCG_ACPI_FUNCTION_RETURN_REQUEST_RESPONSE_TO_OS) {
	mTcgNvs->PhysicalPresence.ReturnCode = Tcg2PhysicalPresenceLibReturnOperationResponseToOsFunction (
	&MostRecentRequest,
	&Response
	);
	mTcgNvs->PhysicalPresence.LastRequest = MostRecentRequest;
	mTcgNvs->PhysicalPresence.Response = Response;
	return EFI_SUCCESS;
	} else if ((mTcgNvs->PhysicalPresence.Parameter == TCG_ACPI_FUNCTION_SUBMIT_REQUEST_TO_BIOS)
	\|\| (mTcgNvs->PhysicalPresence.Parameter == TCG_ACPI_FUNCTION_SUBMIT_REQUEST_TO_BIOS_2)) {

	OperationRequest = mTcgNvs->PhysicalPresence.Request;
	RequestParameter = mTcgNvs->PhysicalPresence.RequestParameter;
	mTcgNvs->PhysicalPresence.ReturnCode = Tcg2PhysicalPresenceLibSubmitRequestToPreOSFunctionEx (
	&OperationRequest,
	&RequestParameter
	);
	mTcgNvs->PhysicalPresence.Request = OperationRequest;
	mTcgNvs->PhysicalPresence.RequestParameter = RequestParameter;
	} else if (mTcgNvs->PhysicalPresence.Parameter == TCG_ACPI_FUNCTION_GET_USER_CONFIRMATION_STATUS_FOR_REQUEST) {
	mTcgNvs->PhysicalPresence.ReturnCode = Tcg2PhysicalPresenceLibGetUserConfirmationStatusFunction (mTcgNvs->PPRequestUserConfirm);
	}

	return EFI_SUCCESS;
	}


	/**
	Software SMI callback for MemoryClear which is called from ACPI method.

	Caution: This function may receive untrusted input.
	Variable and ACPINvs are external input, so this function will validate
	its data structure to be valid value.

	@param[in] DispatchHandle The unique handle assigned to this handler by SmiHandlerRegister().
	@param[in] Context Points to an optional handler context which was specified when the
	handler was registered.
	@param[in, out] CommBuffer A pointer to a collection of data in memory that will
	be conveyed from a non-SMM environment into an SMM environment.
	@param[in, out] CommBufferSize The size of the CommBuffer.

	@retval EFI_SUCCESS The interrupt was handled successfully.

	**/
	EFI_STATUS
	EFIAPI
	MemoryClearCallback (
	IN EFI_HANDLE DispatchHandle,
	IN CONST VOID *Context,
	IN OUT VOID *CommBuffer,
	IN OUT UINTN *CommBufferSize
	)
	{
	EFI_STATUS Status;
	UINTN DataSize;
	UINT8 MorControl;

	mTcgNvs->MemoryClear.ReturnCode = MOR_REQUEST_SUCCESS;
	if (mTcgNvs->MemoryClear.Parameter == ACPI_FUNCTION_DSM_MEMORY_CLEAR_INTERFACE) {
	MorControl = (UINT8) mTcgNvs->MemoryClear.Request;
	} else if (mTcgNvs->MemoryClear.Parameter == ACPI_FUNCTION_PTS_CLEAR_MOR_BIT) {
	DataSize = sizeof (UINT8);
	Status = mSmmVariable->SmmGetVariable (
	MEMORY_OVERWRITE_REQUEST_VARIABLE_NAME,
	&gEfiMemoryOverwriteControlDataGuid,
	NULL,
	&DataSize,
	&MorControl
	);
	if (EFI_ERROR (Status)) {
	mTcgNvs->MemoryClear.ReturnCode = MOR_REQUEST_GENERAL_FAILURE;
	DEBUG ((EFI_D_ERROR, "[TPM] Get MOR variable failure! Status = %r\n", Status));
	return EFI_SUCCESS;
	}

	if (MOR_CLEAR_MEMORY_VALUE (MorControl) == 0x0) {
	return EFI_SUCCESS;
	}
	MorControl &= ~MOR_CLEAR_MEMORY_BIT_MASK;
	}

	DataSize = sizeof (UINT8);
	Status = mSmmVariable->SmmSetVariable (
	MEMORY_OVERWRITE_REQUEST_VARIABLE_NAME,
	&gEfiMemoryOverwriteControlDataGuid,
	EFI_VARIABLE_NON_VOLATILE \| EFI_VARIABLE_BOOTSERVICE_ACCESS \| EFI_VARIABLE_RUNTIME_ACCESS,
	DataSize,
	&MorControl
	);
	if (EFI_ERROR (Status)) {
	mTcgNvs->MemoryClear.ReturnCode = MOR_REQUEST_GENERAL_FAILURE;
	DEBUG ((EFI_D_ERROR, "[TPM] Set MOR variable failure! Status = %r\n", Status));
	}

	return EFI_SUCCESS;
	}

	/**
	Find the operation region in TCG ACPI table by given Name and Size,
	and initialize it if the region is found.

	@param[in, out] Table The TPM item in ACPI table.
	@param[in] Name The name string to find in TPM table.
	@param[in] Size The size of the region to find.

	@return The allocated address for the found region.

	**/
	VOID *
	AssignOpRegion (
	EFI_ACPI_DESCRIPTION_HEADER *Table,
	UINT32 Name,
	UINT16 Size
	)
	{
	EFI_STATUS Status;
	AML_OP_REGION_32_8 *OpRegion;
	EFI_PHYSICAL_ADDRESS MemoryAddress;

	MemoryAddress = SIZE_4GB - 1;

	//
	// Patch some pointers for the ASL code before loading the SSDT.
	//
	for (OpRegion = (AML_OP_REGION_32_8 *) (Table + 1);
	OpRegion <= (AML_OP_REGION_32_8 ) ((UINT8 ) Table + Table->Length);
	OpRegion = (AML_OP_REGION_32_8 ) ((UINT8 ) OpRegion + 1)) {
	if ((OpRegion->OpRegionOp == AML_EXT_REGION_OP) &&
	(OpRegion->NameString == Name) &&
	(OpRegion->DWordPrefix == AML_DWORD_PREFIX) &&
	(OpRegion->BytePrefix == AML_BYTE_PREFIX)) {

	Status = gBS->AllocatePages(AllocateMaxAddress, EfiACPIMemoryNVS, EFI_SIZE_TO_PAGES (Size), &MemoryAddress);
	ASSERT_EFI_ERROR (Status);
	ZeroMem ((VOID *)(UINTN)MemoryAddress, Size);
	OpRegion->RegionOffset = (UINT32) (UINTN) MemoryAddress;
	OpRegion->RegionLen = (UINT8) Size;
	break;
	}
	}

	return (VOID *) (UINTN) MemoryAddress;
	}

	/**
	Patch version string of Physical Presence interface supported by platform. The initial string tag in TPM
	ACPI table is "$PV".

	@param[in, out] Table The TPM item in ACPI table.
	@param[in] PPVer Version string of Physical Presence interface supported by platform.

	@return The allocated address for the found region.

	**/
	EFI_STATUS
	UpdatePPVersion (
	EFI_ACPI_DESCRIPTION_HEADER *Table,
	CHAR8 *PPVer
	)
	{
	EFI_STATUS Status;
	UINT8 *DataPtr;

	//
	// Patch some pointers for the ASL code before loading the SSDT.
	//
	for (DataPtr = (UINT8 *)(Table + 1);
	DataPtr <= (UINT8 ) ((UINT8 ) Table + Table->Length - PHYSICAL_PRESENCE_VERSION_SIZE);
	DataPtr += 1) {
	if (AsciiStrCmp((CHAR8 *)DataPtr, PHYSICAL_PRESENCE_VERSION_TAG) == 0) {
	Status = AsciiStrCpyS((CHAR8 *)DataPtr, PHYSICAL_PRESENCE_VERSION_SIZE, PPVer);
	DEBUG((EFI_D_INFO, "TPM2 Physical Presence Interface Version update status 0x%x\n", Status));
	return Status;
	}
	}

	return EFI_NOT_FOUND;
	}

	/**
	Initialize and publish TPM items in ACPI table.

	@retval EFI_SUCCESS The TCG ACPI table is published successfully.
	@retval Others The TCG ACPI table is not published.

	**/
	EFI_STATUS
	PublishAcpiTable (
	VOID
	)
	{
	EFI_STATUS Status;
	EFI_ACPI_TABLE_PROTOCOL *AcpiTable;
	UINTN TableKey;
	EFI_ACPI_DESCRIPTION_HEADER *Table;
	UINTN TableSize;

	Status = GetSectionFromFv (
	&gEfiCallerIdGuid,
	EFI_SECTION_RAW,
	0,
	(VOID **) &Table,
	&TableSize
	);
	ASSERT_EFI_ERROR (Status);

	//
	// Update Table version before measuring it to PCR
	//
	Status = UpdatePPVersion(Table, (CHAR8 *)PcdGetPtr(PcdTcgPhysicalPresenceInterfaceVer));
	ASSERT_EFI_ERROR (Status);

	//
	// Measure to PCR[0] with event EV_POST_CODE ACPI DATA
	//
	TpmMeasureAndLogData(
	0,
	EV_POST_CODE,
	EV_POSTCODE_INFO_ACPI_DATA,
	ACPI_DATA_LEN,
	Table,
	TableSize
	);


	ASSERT (Table->OemTableId == SIGNATURE_64 ('T', 'p', 'm', '2', 'T', 'a', 'b', 'l'));
	CopyMem (Table->OemId, PcdGetPtr (PcdAcpiDefaultOemId), sizeof (Table->OemId) );
	mTcgNvs = AssignOpRegion (Table, SIGNATURE_32 ('T', 'N', 'V', 'S'), (UINT16) sizeof (TCG_NVS));
	ASSERT (mTcgNvs != NULL);

	//
	// Publish the TPM ACPI table. Table is re-checksumed.
	//
	Status = gBS->LocateProtocol (&gEfiAcpiTableProtocolGuid, NULL, (VOID **) &AcpiTable);
	ASSERT_EFI_ERROR (Status);

	TableKey = 0;
	Status = AcpiTable->InstallAcpiTable (
	AcpiTable,
	Table,
	TableSize,
	&TableKey
	);
	ASSERT_EFI_ERROR (Status);

	return Status;
	}

	/**
	Publish TPM2 ACPI table

	@retval EFI_SUCCESS The TPM2 ACPI table is published successfully.
	@retval Others The TPM2 ACPI table is not published.

	**/
	EFI_STATUS
	PublishTpm2 (
	VOID
	)
	{
	EFI_STATUS Status;
	EFI_ACPI_TABLE_PROTOCOL *AcpiTable;
	UINTN TableKey;
	UINT64 OemTableId;
	EFI_TPM2_ACPI_CONTROL_AREA *ControlArea;
	PTP_INTERFACE_TYPE InterfaceType;

	//
	// Measure to PCR[0] with event EV_POST_CODE ACPI DATA
	//
	TpmMeasureAndLogData(
	0,
	EV_POST_CODE,
	EV_POSTCODE_INFO_ACPI_DATA,
	ACPI_DATA_LEN,
	&mTpm2AcpiTemplate,
	sizeof(mTpm2AcpiTemplate)
	);

	InterfaceType = GetPtpInterface ((VOID *) (UINTN) PcdGet64 (PcdTpmBaseAddress));
	switch (InterfaceType) {
	case PtpInterfaceCrb:
	mTpm2AcpiTemplate.StartMethod = EFI_TPM2_ACPI_TABLE_START_METHOD_COMMAND_RESPONSE_BUFFER_INTERFACE;
	mTpm2AcpiTemplate.AddressOfControlArea = PcdGet64 (PcdTpmBaseAddress) + 0x40;
	ControlArea = (EFI_TPM2_ACPI_CONTROL_AREA *)(UINTN)mTpm2AcpiTemplate.AddressOfControlArea;
	ControlArea->CommandSize = 0xF80;
	ControlArea->ResponseSize = 0xF80;
	ControlArea->Command = PcdGet64 (PcdTpmBaseAddress) + 0x80;
	ControlArea->Response = PcdGet64 (PcdTpmBaseAddress) + 0x80;
	break;
	case PtpInterfaceFifo:
	case PtpInterfaceTis:
	break;
	default:
	DEBUG((EFI_D_ERROR, "TPM2 InterfaceType get error! %d\n", InterfaceType));
	break;
	}

	CopyMem (mTpm2AcpiTemplate.Header.OemId, PcdGetPtr (PcdAcpiDefaultOemId), sizeof (mTpm2AcpiTemplate.Header.OemId));
	OemTableId = PcdGet64 (PcdAcpiDefaultOemTableId);
	CopyMem (&mTpm2AcpiTemplate.Header.OemTableId, &OemTableId, sizeof (UINT64));
	mTpm2AcpiTemplate.Header.OemRevision = PcdGet32 (PcdAcpiDefaultOemRevision);
	mTpm2AcpiTemplate.Header.CreatorId = PcdGet32 (PcdAcpiDefaultCreatorId);
	mTpm2AcpiTemplate.Header.CreatorRevision = PcdGet32 (PcdAcpiDefaultCreatorRevision);

	//
	// Construct ACPI table
	//
	Status = gBS->LocateProtocol (&gEfiAcpiTableProtocolGuid, NULL, (VOID **) &AcpiTable);
	ASSERT_EFI_ERROR (Status);

	Status = AcpiTable->InstallAcpiTable (
	AcpiTable,
	&mTpm2AcpiTemplate,
	sizeof(mTpm2AcpiTemplate),
	&TableKey
	);
	ASSERT_EFI_ERROR (Status);

	return Status;
	}

	/**
	The driver's entry point.

	It install callbacks for TPM physical presence and MemoryClear, and locate
	SMM variable to be used in the callback function.

	@param[in] ImageHandle The firmware allocated handle for the EFI image.
	@param[in] SystemTable A pointer to the EFI System Table.

	@retval EFI_SUCCESS The entry point is executed successfully.
	@retval Others Some error occurs when executing this entry point.

	**/
	EFI_STATUS
	EFIAPI
	InitializeTcgSmm (
	IN EFI_HANDLE ImageHandle,
	IN EFI_SYSTEM_TABLE *SystemTable
	)
	{
	EFI_STATUS Status;
	EFI_SMM_SW_DISPATCH2_PROTOCOL *SwDispatch;
	EFI_SMM_SW_REGISTER_CONTEXT SwContext;
	EFI_HANDLE SwHandle;

	if (!CompareGuid (PcdGetPtr(PcdTpmInstanceGuid), &gEfiTpmDeviceInstanceTpm20DtpmGuid)){
	DEBUG ((EFI_D_ERROR, "No TPM2 DTPM instance required!\n"));
	return EFI_UNSUPPORTED;
	}

	Status = PublishAcpiTable ();
	ASSERT_EFI_ERROR (Status);

	//
	// Get the Sw dispatch protocol and register SMI callback functions.
	//
	Status = gSmst->SmmLocateProtocol (&gEfiSmmSwDispatch2ProtocolGuid, NULL, (VOID**)&SwDispatch);
	ASSERT_EFI_ERROR (Status);
	SwContext.SwSmiInputValue = (UINTN) -1;
	Status = SwDispatch->Register (SwDispatch, PhysicalPresenceCallback, &SwContext, &SwHandle);
	ASSERT_EFI_ERROR (Status);
	if (EFI_ERROR (Status)) {
	return Status;
	}
	mTcgNvs->PhysicalPresence.SoftwareSmi = (UINT8) SwContext.SwSmiInputValue;

	SwContext.SwSmiInputValue = (UINTN) -1;
	Status = SwDispatch->Register (SwDispatch, MemoryClearCallback, &SwContext, &SwHandle);
	ASSERT_EFI_ERROR (Status);
	if (EFI_ERROR (Status)) {
	return Status;
	}
	mTcgNvs->MemoryClear.SoftwareSmi = (UINT8) SwContext.SwSmiInputValue;

	//
	// Locate SmmVariableProtocol.
	//
	Status = gSmst->SmmLocateProtocol (&gEfiSmmVariableProtocolGuid, NULL, (VOID**)&mSmmVariable);
	ASSERT_EFI_ERROR (Status);

	//
	// Set TPM2 ACPI table
	//
	Status = PublishTpm2 ();
	ASSERT_EFI_ERROR (Status);


	return EFI_SUCCESS;
	}