TcgSmm.c File Reference

#include "TcgSmm.h"

Go to the source code of this file.

Functions
EFI_STATUS EFIAPI	PhysicalPresenceCallback (IN EFI_HANDLE DispatchHandle, IN CONST VOID *Context, IN OUT VOID *CommBuffer, IN OUT UINTN *CommBufferSize)
EFI_STATUS EFIAPI	MemoryClearCallback (IN EFI_HANDLE DispatchHandle, IN CONST VOID *Context, IN OUT VOID *CommBuffer, IN OUT UINTN *CommBufferSize)
VOID *	AssignOpRegion (EFI_ACPI_DESCRIPTION_HEADER *Table, UINT32 Name, UINT16 Size)
EFI_STATUS	PublishAcpiTable (VOID)
EFI_STATUS EFIAPI	InitializeTcgSmm (IN EFI_HANDLE ImageHandle, IN EFI_SYSTEM_TABLE *SystemTable)

Variables
EFI_SMM_VARIABLE_PROTOCOL *	mSmmVariable
TCG_NVS *	mTcgNvs

Detailed Description

It updates TPM items in ACPI table and registers SMI callback functions for physical presence and ClearMemory.

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) 2011 - 2018, Intel Corporation. All rights reserved.
SPDX-License-Identifier: BSD-2-Clause-Patent

Definition in file TcgSmm.c.

Function Documentation

AssignOpRegion()

VOID * AssignOpRegion	(	EFI_ACPI_DESCRIPTION_HEADER *	Table,
		UINT32	Name,
		UINT16	Size
	)

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

Parameters

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

Returns

The allocated address for the found region.

Definition at line 313 of file TcgSmm.c.

InitializeTcgSmm()

EFI_STATUS EFIAPI InitializeTcgSmm	(	IN EFI_HANDLE	ImageHandle,
		IN EFI_SYSTEM_TABLE *	SystemTable
	)

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.

Parameters

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

Return values

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

Definition at line 426 of file TcgSmm.c.

MemoryClearCallback()

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

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.

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 245 of file TcgSmm.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 40 of file TcgSmm.c.

PublishAcpiTable()

EFI_STATUS PublishAcpiTable

(

VOID

)

Initialize and publish TPM items in ACPI table.

Return values

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

Definition at line 357 of file TcgSmm.c.

Variable Documentation

mSmmVariable

EFI_SMM_VARIABLE_PROTOCOL* mSmmVariable

Definition at line 18 of file TcgSmm.c.

mTcgNvs

TCG_NVS* mTcgNvs

Definition at line 19 of file TcgSmm.c.