#include "VariableParsing.h"
#include "VariableRuntimeCache.h"

Functions
EFI_STATUS	FlushPendingRuntimeVariableCacheUpdates (VOID)

EFI_STATUS	SynchronizeRuntimeVariableCache (IN VARIABLE_RUNTIME_CACHE *VariableRuntimeCache, IN UINTN Offset, IN UINTN Length)

Variables
VARIABLE_MODULE_GLOBAL *	mVariableModuleGlobal

VARIABLE_STORE_HEADER *	mNvVariableCache

Detailed Description

Functions related to managing the UEFI variable runtime cache. This file should only include functions used by the SMM UEFI variable driver.

Caution: This module requires additional review when modified. This driver will have external input - variable data. They may be input in SMM mode. This external input must be validated carefully to avoid security issue like buffer overflow, integer overflow.

Copyright (c) 2019, Intel Corporation. All rights reserved.
SPDX-License-Identifier: BSD-2-Clause-Patent

Definition in file VariableRuntimeCache.c.

Function Documentation

◆ FlushPendingRuntimeVariableCacheUpdates()

EFI_STATUS FlushPendingRuntimeVariableCacheUpdates ( VOID )

Copies any pending updates to runtime variable caches.

Return values

EFI_UNSUPPORTED	The volatile store to be updated is not initialized properly.
EFI_SUCCESS	The volatile store was updated successfully.

Definition at line 29 of file VariableRuntimeCache.c.

◆ SynchronizeRuntimeVariableCache()

EFI_STATUS SynchronizeRuntimeVariableCache	(	IN VARIABLE_RUNTIME_CACHE *	VariableRuntimeCache,
		IN UINTN	Offset,
		IN UINTN	Length
	)

Synchronizes the runtime variable caches with all pending updates outside runtime.

Ensures all conditions are met to maintain coherency for runtime cache updates. This function will attempt to write the given update (and any other pending updates) if the ReadLock is available. Otherwise, the update is added as a pending update for the given variable store and it will be flushed to the runtime cache at the next opportunity the ReadLock is available.

Parameters

[in]	VariableRuntimeCache	Variable runtime cache structure for the runtime cache being synchronized.
[in]	Offset	Offset in bytes to apply the update.
[in]	Length	Length of data in bytes of the update.

Return values

EFI_SUCCESS	The update was added as a pending update successfully. If the variable runtime cache ReadLock was available, the runtime cache was updated successfully.
EFI_UNSUPPORTED	The volatile store to be updated is not initialized properly.

Definition at line 114 of file VariableRuntimeCache.c.

Variable Documentation

◆ mNvVariableCache

VARIABLE_STORE_HEADER* mNvVariableCache

extern

Define a memory cache that improves the search performance for a variable. For EmuNvMode == TRUE, it will be equal to NonVolatileVariableBase.

Definition at line 39 of file Variable.c.

◆ mVariableModuleGlobal

VARIABLE_MODULE_GLOBAL* mVariableModuleGlobal