Tcg2Smm.c File Reference

#include "Tcg2Smm.h"

Go to the source code of this file.

Functions
EFI_STATUS EFIAPI	TpmNvsCommunciate (IN EFI_HANDLE DispatchHandle, IN CONST VOID *RegisterContext, IN OUT VOID *CommBuffer, IN OUT UINTN *CommBufferSize)
EFI_STATUS EFIAPI	PhysicalPresenceCallback (IN EFI_HANDLE DispatchHandle, IN CONST VOID *Context, IN OUT VOID *CommBuffer, IN OUT UINTN *CommBufferSize)
EFI_STATUS EFIAPI	TcgMmReadyToLock (IN CONST EFI_GUID *Protocol, IN VOID *Interface, IN EFI_HANDLE Handle)
EFI_STATUS	InitializeTcgCommon (VOID)

Variables
EFI_SMM_VARIABLE_PROTOCOL *	mSmmVariable = NULL
TCG_NVS *	mTcgNvs = NULL
UINTN	mPpSoftwareSmi
UINTN	mMcSoftwareSmi
EFI_HANDLE	mReadyToLockHandle

Detailed Description

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 - 2024, Intel Corporation. All rights reserved.
Copyright (c) Microsoft Corporation. SPDX-License-Identifier: BSD-2-Clause-Patent

Definition in file Tcg2Smm.c.

Function Documentation

InitializeTcgCommon()

EFI_STATUS InitializeTcgCommon

(

VOID

)

The driver's common initialization routine.

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

Return values

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

Definition at line 214 of file Tcg2Smm.c.

PhysicalPresenceCallback()

EFI_STATUS EFIAPI PhysicalPresenceCallback	(	IN EFI_HANDLE	DispatchHandle,
		IN CONST VOID *	Context,
		IN OUT VOID *	CommBuffer,
		IN OUT UINTN *	CommBufferSize
	)

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.

Parameters

[in]	DispatchHandle	The unique handle assigned to this handler by SmiHandlerRegister().
[in]	Context	Points to an optional handler context which was specified when the handler was registered.
[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.
[in,out]	CommBufferSize	The size of the CommBuffer.

Return values

EFI_SUCCESS

The interrupt was handled successfully.

Definition at line 135 of file Tcg2Smm.c.

TcgMmReadyToLock()

EFI_STATUS EFIAPI TcgMmReadyToLock	(	IN CONST EFI_GUID *	Protocol,
		IN VOID *	Interface,
		IN EFI_HANDLE	Handle
	)

Notification for SMM ReadyToLock protocol.

Parameters

[in]	Protocol	Points to the protocol's unique identifier.
[in]	Interface	Points to the interface instance.
[in]	Handle	The handle on which the interface was installed.

Return values

EFI_SUCCESS

Notification runs successfully.

Definition at line 185 of file Tcg2Smm.c.

TpmNvsCommunciate()

EFI_STATUS EFIAPI TpmNvsCommunciate	(	IN EFI_HANDLE	DispatchHandle,
		IN CONST VOID *	RegisterContext,
		IN OUT VOID *	CommBuffer,
		IN OUT UINTN *	CommBufferSize
	)

Communication service SMI Handler entry.

This handler takes requests to exchange Mmi channel and Nvs address between MM and DXE.

Caution: This function may receive untrusted input. Communicate buffer and buffer size are external input, so this function will do basic validation.

Parameters

[in]	DispatchHandle	The unique handle assigned to this handler by SmiHandlerRegister().
[in]	RegisterContext	Points to an optional handler context which was specified when the handler was registered.
[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.
[in,out]	CommBufferSize	The size of the CommBuffer.

Return values

EFI_SUCCESS	The interrupt was handled and quiesced. No other handlers should still be called.
EFI_UNSUPPORTED	An unknown test function was requested.
EFI_ACCESS_DENIED	Part of the communication buffer lies in an invalid region.

Definition at line 49 of file Tcg2Smm.c.

Variable Documentation

mMcSoftwareSmi

UINTN mMcSoftwareSmi

Definition at line 23 of file Tcg2Smm.c.

mPpSoftwareSmi

UINTN mPpSoftwareSmi

Definition at line 22 of file Tcg2Smm.c.

mReadyToLockHandle

EFI_HANDLE mReadyToLockHandle

Definition at line 24 of file Tcg2Smm.c.

mSmmVariable

EFI_SMM_VARIABLE_PROTOCOL* mSmmVariable = NULL

Definition at line 20 of file Tcg2Smm.c.

mTcgNvs

TCG_NVS* mTcgNvs = NULL

Definition at line 21 of file Tcg2Smm.c.