#include "Variable.h"
#include "VariableNonVolatile.h"
#include "VariableParsing.h"
#include "VariableRuntimeCache.h"

Functions
EFI_STATUS	UpdateVariableStore (IN VARIABLE_GLOBAL Global, IN BOOLEAN Volatile, IN BOOLEAN SetByIndex, IN EFI_FIRMWARE_VOLUME_BLOCK_PROTOCOL Fvb, IN UINTN DataPtrIndex, IN UINT32 DataSize, IN UINT8 *Buffer)

VOID	RecordVarErrorFlag (IN VAR_ERROR_FLAG Flag, IN CHAR16 VariableName, IN EFI_GUID VendorGuid, IN UINT32 Attributes, IN UINTN VariableSize)

VOID	InitializeVarErrorFlag (VOID)

BOOLEAN	IsUserVariable (IN VARIABLE_HEADER *Variable)

VOID	CalculateCommonUserVariableTotalSize (VOID)

VOID	InitializeVariableQuota (VOID)

EFI_STATUS	Reclaim (IN EFI_PHYSICAL_ADDRESS VariableBase, OUT UINTN LastVariableOffset, IN BOOLEAN IsVolatile, IN OUT VARIABLE_POINTER_TRACK UpdatingPtrTrack, IN VARIABLE_HEADER *NewVariable, IN UINTN NewVariableSize)

EFI_STATUS	FindVariable (IN CHAR16 VariableName, IN EFI_GUID VendorGuid, OUT VARIABLE_POINTER_TRACK PtrTrack, IN VARIABLE_GLOBAL Global, IN BOOLEAN IgnoreRtCheck)

UINTN	GetIndexFromSupportedLangCodes (IN CHAR8 SupportedLang, IN CHAR8 Lang, IN BOOLEAN Iso639Language)

CHAR8 *	GetLangFromSupportedLangCodes (IN CHAR8 *SupportedLang, IN UINTN Index, IN BOOLEAN Iso639Language)

CHAR8 *EFIAPI	VariableGetBestLanguage (IN CONST CHAR8 *SupportedLanguages, IN UINTN Iso639Language,...)

BOOLEAN EFIAPI	CheckRemainingSpaceForConsistencyInternal (IN UINT32 Attributes, IN VA_LIST Marker)

BOOLEAN EFIAPI	CheckRemainingSpaceForConsistency (IN UINT32 Attributes,...)

EFI_STATUS	AutoUpdateLangVariable (IN CHAR16 VariableName, IN VOID Data, IN UINTN DataSize)

EFI_STATUS	UpdateVariable (IN CHAR16 VariableName, IN EFI_GUID VendorGuid, IN VOID Data, IN UINTN DataSize, IN UINT32 Attributes OPTIONAL, IN UINT32 KeyIndex OPTIONAL, IN UINT64 MonotonicCount OPTIONAL, IN OUT VARIABLE_POINTER_TRACK CacheVariable, IN EFI_TIME *TimeStamp OPTIONAL)

EFI_STATUS EFIAPI	VariableServiceGetVariable (IN CHAR16 VariableName, IN EFI_GUID VendorGuid, OUT UINT32 Attributes OPTIONAL, IN OUT UINTN DataSize, OUT VOID *Data OPTIONAL)

EFI_STATUS EFIAPI	VariableServiceGetNextVariableName (IN OUT UINTN VariableNameSize, IN OUT CHAR16 VariableName, IN OUT EFI_GUID *VendorGuid)

EFI_STATUS EFIAPI	VariableServiceSetVariable (IN CHAR16 VariableName, IN EFI_GUID VendorGuid, IN UINT32 Attributes, IN UINTN DataSize, IN VOID *Data)

EFI_STATUS EFIAPI	VariableServiceQueryVariableInfoInternal (IN UINT32 Attributes, OUT UINT64 MaximumVariableStorageSize, OUT UINT64 RemainingVariableStorageSize, OUT UINT64 *MaximumVariableSize)

EFI_STATUS EFIAPI	VariableServiceQueryVariableInfo (IN UINT32 Attributes, OUT UINT64 MaximumVariableStorageSize, OUT UINT64 RemainingVariableStorageSize, OUT UINT64 *MaximumVariableSize)

VOID	ReclaimForOS (VOID)

UINTN	GetMaxVariableSize (VOID)

VOID	FlushHobVariableToFlash (IN CHAR16 VariableName, IN EFI_GUID VendorGuid)

EFI_STATUS	VariableWriteServiceInitialize (VOID)

VOID *	ConvertNormalVarStorageToAuthVarStorage (VARIABLE_STORE_HEADER *NormalVarStorage)

EFI_STATUS	GetHobVariableStore (IN EFI_GUID *VariableGuid)

EFI_STATUS	VariableCommonInitialize (VOID)

EFI_STATUS	GetFvbInfoByAddress (IN EFI_PHYSICAL_ADDRESS Address, OUT EFI_HANDLE FvbHandle OPTIONAL, OUT EFI_FIRMWARE_VOLUME_BLOCK_PROTOCOL *FvbProtocol OPTIONAL)

Variables
VARIABLE_MODULE_GLOBAL *	mVariableModuleGlobal

VARIABLE_STORE_HEADER *	mNvVariableCache = NULL

EFI_FIRMWARE_VOLUME_HEADER *	mNvFvHeaderCache = NULL

VARIABLE_INFO_ENTRY *	gVariableInfo = NULL

BOOLEAN	mEndOfDxe = FALSE

VAR_CHECK_REQUEST_SOURCE	mRequestSource = VarCheckFromUntrusted

VAR_ERROR_FLAG	mCurrentBootVarErrFlag = VAR_ERROR_FLAG_NO_ERROR

VARIABLE_ENTRY_PROPERTY	mVariableEntryProperty []

AUTH_VAR_LIB_CONTEXT_IN	mAuthContextIn

AUTH_VAR_LIB_CONTEXT_OUT	mAuthContextOut

Detailed Description

The common variable operation routines shared by DXE_RUNTIME variable module and DXE_SMM variable module.

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.

VariableServiceGetNextVariableName () and VariableServiceQueryVariableInfo() are external API. They need check input parameter.

VariableServiceGetVariable() and VariableServiceSetVariable() are external API to receive datasize and data buffer. The size should be checked carefully.

VariableServiceSetVariable() should also check authenticate data to avoid buffer overflow, integer overflow. It should also check attribute to avoid authentication bypass.

Copyright (c) 2006 - 2020, Intel Corporation. All rights reserved.
(C) Copyright 2015-2018 Hewlett Packard Enterprise Development LP
Copyright (c) Microsoft Corporation.
Copyright (c) 2022, ARM Limited. All rights reserved.

SPDX-License-Identifier: BSD-2-Clause-Patent

Definition in file Variable.c.

Function Documentation

◆ AutoUpdateLangVariable()

EFI_STATUS AutoUpdateLangVariable	(	IN CHAR16 *	VariableName,
		IN VOID *	Data,
		IN UINTN	DataSize
	)

Hook the operations in PlatformLangCodes, LangCodes, PlatformLang and Lang.

When setting Lang/LangCodes, simultaneously update PlatformLang/PlatformLangCodes.

According to UEFI spec, PlatformLangCodes/LangCodes are only set once in firmware initialization, and are read-only. Therefore, in variable driver, only store the original value for other use.

Parameters

[in]	VariableName	Name of variable.
[in]	Data	Variable data.
[in]	DataSize	Size of data. 0 means delete.

Return values

EFI_SUCCESS	The update operation is successful or ignored.
EFI_WRITE_PROTECTED	Update PlatformLangCodes/LangCodes at runtime.
EFI_OUT_OF_RESOURCES	No enough variable space to do the update operation.
Others	Other errors happened during the update operation.

Definition at line 1415 of file Variable.c.

◆ CalculateCommonUserVariableTotalSize()

VOID CalculateCommonUserVariableTotalSize ( VOID )

Calculate common user variable total size.

Definition at line 445 of file Variable.c.

◆ CheckRemainingSpaceForConsistency()

BOOLEAN EFIAPI CheckRemainingSpaceForConsistency	(	IN UINT32	Attributes,
			...
	)

This function is to check if the remaining variable space is enough to set all Variables from argument list successfully. The purpose of the check is to keep the consistency of the Variables to be in variable storage.

Note: Variables are assumed to be in same storage. The set sequence of Variables will be same with the sequence of VariableEntry from argument list, so follow the argument sequence to check the Variables.

Parameters

[in]	Attributes	Variable attributes for Variable entries.
	...	The variable argument list with type VARIABLE_ENTRY_CONSISTENCY *. A NULL terminates the list. The VariableSize of VARIABLE_ENTRY_CONSISTENCY is the variable data size as input. It will be changed to variable total size as output.

Return values

TRUE	Have enough variable space to set the Variables successfully.
FALSE	No enough variable space to set the Variables successfully.

Definition at line 1377 of file Variable.c.

◆ CheckRemainingSpaceForConsistencyInternal()

BOOLEAN EFIAPI CheckRemainingSpaceForConsistencyInternal	(	IN UINT32	Attributes,
		IN VA_LIST	Marker
	)

This function is to check if the remaining variable space is enough to set all Variables from argument list successfully. The purpose of the check is to keep the consistency of the Variables to be in variable storage.

Note: Variables are assumed to be in same storage. The set sequence of Variables will be same with the sequence of VariableEntry from argument list, so follow the argument sequence to check the Variables.

Parameters

[in]	Attributes	Variable attributes for Variable entries.
[in]	Marker	VA_LIST style variable argument list. The variable argument list with type VARIABLE_ENTRY_CONSISTENCY *. A NULL terminates the list. The VariableSize of VARIABLE_ENTRY_CONSISTENCY is the variable data size as input. It will be changed to variable total size as output.

Return values

TRUE	Have enough variable space to set the Variables successfully.
FALSE	No enough variable space to set the Variables successfully.

Definition at line 1240 of file Variable.c.

◆ ConvertNormalVarStorageToAuthVarStorage()

VOID * ConvertNormalVarStorageToAuthVarStorage ( VARIABLE_STORE_HEADER * NormalVarStorage )

Convert normal variable storage to the allocated auth variable storage.

Parameters

[in] NormalVarStorage Pointer to the normal variable storage header

Return values

the	allocated auth variable storage

Definition at line 3512 of file Variable.c.

◆ FindVariable()

EFI_STATUS FindVariable	(	IN CHAR16 *	VariableName,
		IN EFI_GUID *	VendorGuid,
		OUT VARIABLE_POINTER_TRACK *	PtrTrack,
		IN VARIABLE_GLOBAL *	Global,
		IN BOOLEAN	IgnoreRtCheck
	)

Finds variable in storage blocks of volatile and non-volatile storage areas.

This code finds variable in storage blocks of volatile and non-volatile storage areas. If VariableName is an empty string, then we just return the first qualified variable without comparing VariableName and VendorGuid. If IgnoreRtCheck is TRUE, then we ignore the EFI_VARIABLE_RUNTIME_ACCESS attribute check at runtime when searching existing variable, only VariableName and VendorGuid are compared. Otherwise, variables without EFI_VARIABLE_RUNTIME_ACCESS are not visible at runtime.

Parameters

[in]	VariableName	Name of the variable to be found.
[in]	VendorGuid	Vendor GUID to be found.
[out]	PtrTrack	VARIABLE_POINTER_TRACK structure for output, including the range searched and the target position.
[in]	Global	Pointer to VARIABLE_GLOBAL structure, including base of volatile variable storage area, base of NV variable storage area, and a lock.
[in]	IgnoreRtCheck	Ignore EFI_VARIABLE_RUNTIME_ACCESS attribute check at runtime when searching variable.

Return values

EFI_INVALID_PARAMETER	If VariableName is not an empty string, while VendorGuid is NULL.
EFI_SUCCESS	Variable successfully found.
EFI_NOT_FOUND	Variable not found

Definition at line 851 of file Variable.c.

◆ FlushHobVariableToFlash()

VOID FlushHobVariableToFlash	(	IN CHAR16 *	VariableName,
		IN EFI_GUID *	VendorGuid
	)

Flush the HOB variable to flash.

Parameters

[in]	VariableName	Name of variable has been updated or deleted.
[in]	VendorGuid	Guid of variable has been updated or deleted.

Definition at line 3283 of file Variable.c.

◆ GetFvbInfoByAddress()

EFI_STATUS GetFvbInfoByAddress	(	IN EFI_PHYSICAL_ADDRESS	Address,
		OUT EFI_HANDLE *FvbHandle	OPTIONAL,
		OUT EFI_FIRMWARE_VOLUME_BLOCK_PROTOCOL **FvbProtocol	OPTIONAL
	)

Get the proper fvb handle and/or fvb protocol by the given Flash address.

Parameters

[in]	Address	The Flash address.
[out]	FvbHandle	In output, if it is not NULL, it points to the proper FVB handle.
[out]	FvbProtocol	In output, if it is not NULL, it points to the proper FVB protocol.

Definition at line 3811 of file Variable.c.

◆ GetHobVariableStore()

EFI_STATUS GetHobVariableStore ( IN EFI_GUID * VariableGuid )

Get HOB variable store.

Parameters

[in] VariableGuid NV variable store signature.

Return values

EFI_SUCCESS	Function successfully executed.
EFI_OUT_OF_RESOURCES	Fail to allocate enough memory resource.

Definition at line 3621 of file Variable.c.

◆ GetIndexFromSupportedLangCodes()

UINTN GetIndexFromSupportedLangCodes	(	IN CHAR8 *	SupportedLang,
		IN CHAR8 *	Lang,
		IN BOOLEAN	Iso639Language
	)

Get index from supported language codes according to language string.

This code is used to get corresponding index in supported language codes. It can handle RFC4646 and ISO639 language tags. In ISO639 language tags, take 3-characters as a delimitation to find matched string and calculate the index. In RFC4646 language tags, take semicolon as a delimitation to find matched string and calculate the index.

For example: SupportedLang = "engfraengfra" Lang = "eng" Iso639Language = TRUE The return value is "0". Another example: SupportedLang = "en;fr;en-US;fr-FR" Lang = "fr-FR" Iso639Language = FALSE The return value is "3".

Parameters

SupportedLang	Platform supported language codes.
Lang	Configured language.
Iso639Language	A bool value to signify if the handler is operated on ISO639 or RFC4646.

Return values

The	index of language in the language codes.

Definition at line 930 of file Variable.c.

◆ GetLangFromSupportedLangCodes()

CHAR8 * GetLangFromSupportedLangCodes	(	IN CHAR8 *	SupportedLang,
		IN UINTN	Index,
		IN BOOLEAN	Iso639Language
	)

Get language string from supported language codes according to index.

This code is used to get corresponding language strings in supported language codes. It can handle RFC4646 and ISO639 language tags. In ISO639 language tags, take 3-characters as a delimitation. Find language string according to the index. In RFC4646 language tags, take semicolon as a delimitation. Find language string according to the index.

For example: SupportedLang = "engfraengfra" Index = "1" Iso639Language = TRUE The return value is "fra". Another example: SupportedLang = "en;fr;en-US;fr-FR" Index = "1" Iso639Language = FALSE The return value is "fr".

Parameters

SupportedLang	Platform supported language codes.
Index	The index in supported language codes.
Iso639Language	A bool value to signify if the handler is operated on ISO639 or RFC4646.

Return values

The	language string in the language codes.

Definition at line 1017 of file Variable.c.

◆ GetMaxVariableSize()

UINTN GetMaxVariableSize ( VOID )

Get maximum variable size, covering both non-volatile and volatile variables.

Returns: Maximum variable size.

Definition at line 3257 of file Variable.c.

◆ InitializeVarErrorFlag()

VOID InitializeVarErrorFlag ( VOID )

Initialize variable error flag.

Before EndOfDxe, the variable indicates the last boot variable error flag, then it means the last boot variable error flag must be got before EndOfDxe. After EndOfDxe, the variable indicates the current boot variable error flag, then it means the current boot variable error flag must be got after EndOfDxe.

Definition at line 362 of file Variable.c.

◆ InitializeVariableQuota()

VOID InitializeVariableQuota ( VOID )

Initialize variable quota.

Definition at line 488 of file Variable.c.

◆ IsUserVariable()

BOOLEAN IsUserVariable ( IN VARIABLE_HEADER * Variable )

Is user variable?

Parameters

[in] Variable Pointer to variable header.

Return values

TRUE	User variable.
FALSE	System variable.

Definition at line 415 of file Variable.c.

◆ Reclaim()

EFI_STATUS Reclaim	(	IN EFI_PHYSICAL_ADDRESS	VariableBase,
		OUT UINTN *	LastVariableOffset,
		IN BOOLEAN	IsVolatile,
		IN OUT VARIABLE_POINTER_TRACK *	UpdatingPtrTrack,
		IN VARIABLE_HEADER *	NewVariable,
		IN UINTN	NewVariableSize
	)

Variable store garbage collection and reclaim operation.

Parameters

[in]	VariableBase	Base address of variable store.
[out]	LastVariableOffset	Offset of last variable.
[in]	IsVolatile	The variable store is volatile or not; if it is non-volatile, need FTW.
[in,out]	UpdatingPtrTrack	Pointer to updating variable pointer track structure.
[in]	NewVariable	Pointer to new variable.
[in]	NewVariableSize	New variable size.

Returns: EFI_SUCCESS Reclaim operation has finished successfully.; EFI_OUT_OF_RESOURCES No enough memory resources or variable space.; Others Unexpect error happened during reclaim operation.

Definition at line 518 of file Variable.c.

◆ ReclaimForOS()

VOID ReclaimForOS ( VOID )

This function reclaims variable storage if free size is below the threshold.

Caution: This function may be invoked at SMM mode. Care must be taken to make sure not security issue.

Definition at line 3202 of file Variable.c.

◆ RecordVarErrorFlag()

VOID RecordVarErrorFlag	(	IN VAR_ERROR_FLAG	Flag,
		IN CHAR16 *	VariableName,
		IN EFI_GUID *	VendorGuid,
		IN UINT32	Attributes,
		IN UINTN	VariableSize
	)

Record variable error flag.

Parameters

[in]	Flag	Variable error flag to record.
[in]	VariableName	Name of variable.
[in]	VendorGuid	Guid of variable.
[in]	Attributes	Attributes of the variable.
[in]	VariableSize	Size of the variable.

Definition at line 272 of file Variable.c.

◆ UpdateVariable()

EFI_STATUS UpdateVariable	(	IN CHAR16 *	VariableName,
		IN EFI_GUID *	VendorGuid,
		IN VOID *	Data,
		IN UINTN	DataSize,
		IN UINT32 Attributes	OPTIONAL,
		IN UINT32 KeyIndex	OPTIONAL,
		IN UINT64 MonotonicCount	OPTIONAL,
		IN OUT VARIABLE_POINTER_TRACK *	CacheVariable,
		IN EFI_TIME *TimeStamp	OPTIONAL
	)

Update the variable region with Variable information. If EFI_VARIABLE_AUTHENTICATED_WRITE_ACCESS is set, index of associated public key is needed.

Parameters

[in]	VariableName	Name of variable.
[in]	VendorGuid	Guid of variable.
[in]	Data	Variable data.
[in]	DataSize	Size of data. 0 means delete.
[in]	Attributes	Attributes of the variable.
[in]	KeyIndex	Index of associated public key.
[in]	MonotonicCount	Value of associated monotonic count.
[in,out]	CacheVariable	The variable information which is used to keep track of variable usage.
[in]	TimeStamp	Value of associated TimeStamp.

Return values

EFI_SUCCESS	The update operation is success.
EFI_OUT_OF_RESOURCES	Variable region is full, can not write other data into this region.

Definition at line 1678 of file Variable.c.

◆ UpdateVariableStore()

EFI_STATUS UpdateVariableStore	(	IN VARIABLE_GLOBAL *	Global,
		IN BOOLEAN	Volatile,
		IN BOOLEAN	SetByIndex,
		IN EFI_FIRMWARE_VOLUME_BLOCK_PROTOCOL *	Fvb,
		IN UINTN	DataPtrIndex,
		IN UINT32	DataSize,
		IN UINT8 *	Buffer
	)

This function writes data to the FWH at the correct LBA even if the LBAs are fragmented.

Parameters

Global	Pointer to VARAIBLE_GLOBAL structure.
Volatile	Point out the Variable is Volatile or Non-Volatile.
SetByIndex	TRUE if target pointer is given as index. FALSE if target pointer is absolute.
Fvb	Pointer to the writable FVB protocol.
DataPtrIndex	Pointer to the Data from the end of VARIABLE_STORE_HEADER structure.
DataSize	Size of data to be written.
Buffer	Pointer to the buffer from which data is written.

Return values

EFI_INVALID_PARAMETER	Parameters not valid.
EFI_UNSUPPORTED	Fvb is a NULL for Non-Volatile variable update.
EFI_OUT_OF_RESOURCES	The remaining size is not enough.
EFI_SUCCESS	Variable store successfully updated.

Definition at line 123 of file Variable.c.

◆ VariableCommonInitialize()

EFI_STATUS VariableCommonInitialize ( VOID )

Initializes variable store area for non-volatile and volatile variable.

Return values

EFI_SUCCESS	Function successfully executed.
EFI_OUT_OF_RESOURCES	Fail to allocate enough memory resource.

Definition at line 3703 of file Variable.c.

◆ VariableGetBestLanguage()

CHAR8 *EFIAPI VariableGetBestLanguage	(	IN CONST CHAR8 *	SupportedLanguages,
		IN UINTN	Iso639Language,
			...
	)

Returns a pointer to an allocated buffer that contains the best matching language from a set of supported languages.

This function supports both ISO 639-2 and RFC 4646 language codes, but language code types may not be mixed in a single call to this function. This function supports a variable argument list that allows the caller to pass in a prioritized list of language codes to test against all the language codes in SupportedLanguages.

If SupportedLanguages is NULL, then ASSERT().

Parameters

[in]	SupportedLanguages	A pointer to a Null-terminated ASCII string that contains a set of language codes in the format specified by Iso639Language.
[in]	Iso639Language	If not zero, then all language codes are assumed to be in ISO 639-2 format. If zero, then all language codes are assumed to be in RFC 4646 language format
[in]	...	A variable argument list that contains pointers to Null-terminated ASCII strings that contain one or more language codes in the format specified by Iso639Language. The first language code from each of these language code lists is used to determine if it is an exact or close match to any of the language codes in SupportedLanguages. Close matches only apply to RFC 4646 language codes, and the matching algorithm from RFC 4647 is used to determine if a close match is present. If an exact or close match is found, then the matching language code from SupportedLanguages is returned. If no matches are found, then the next variable argument parameter is evaluated. The variable argument list is terminated by a NULL.

Return values

NULL	The best matching language could not be found in SupportedLanguages.
NULL	There are not enough resources available to return the best matching language.
Other	A pointer to a Null-terminated ASCII string that is the best matching language in SupportedLanguages.

Definition at line 1118 of file Variable.c.

◆ VariableServiceGetNextVariableName()

EFI_STATUS EFIAPI VariableServiceGetNextVariableName	(	IN OUT UINTN *	VariableNameSize,
		IN OUT CHAR16 *	VariableName,
		IN OUT EFI_GUID *	VendorGuid
	)

This code Finds the Next available variable.

Caution: This function may receive untrusted input. This function may be invoked in SMM mode. This function will do basic validation, before parse the data.

Parameters

VariableNameSize	The size of the VariableName buffer. The size must be large enough to fit input string supplied in VariableName buffer.
VariableName	Pointer to variable name.
VendorGuid	Variable Vendor Guid.

Return values

EFI_SUCCESS	The function completed successfully.
EFI_NOT_FOUND	The next variable was not found.
EFI_BUFFER_TOO_SMALL	The VariableNameSize is too small for the result. VariableNameSize has been updated with the size needed to complete the request.
EFI_INVALID_PARAMETER	VariableNameSize is NULL.
EFI_INVALID_PARAMETER	VariableName is NULL.
EFI_INVALID_PARAMETER	VendorGuid is NULL.
EFI_INVALID_PARAMETER	The input values of VariableName and VendorGuid are not a name and GUID of an existing variable.
EFI_INVALID_PARAMETER	Null-terminator is not found in the first VariableNameSize bytes of the input VariableName buffer.
EFI_DEVICE_ERROR	The variable could not be retrieved due to a hardware error.
EFI_UNSUPPORTED	After ExitBootServices() has been called, this return code may be returned if no variable storage is supported. The platform should describe this runtime service as unsupported at runtime via an EFI_RT_PROPERTIES_TABLE configuration table.

Definition at line 2502 of file Variable.c.

◆ VariableServiceGetVariable()

EFI_STATUS EFIAPI VariableServiceGetVariable	(	IN CHAR16 *	VariableName,
		IN EFI_GUID *	VendorGuid,
		OUT UINT32 *Attributes	OPTIONAL,
		IN OUT UINTN *	DataSize,
		OUT VOID *Data	OPTIONAL
	)

This code finds variable in storage blocks (Volatile or Non-Volatile).

Caution: This function may receive untrusted input. This function may be invoked in SMM mode, and datasize is external input. This function will do basic validation, before parse the data.

Parameters

VariableName	Name of Variable to be found.
VendorGuid	Variable vendor GUID.
Attributes	Attribute value of the variable found.
DataSize	Size of Data found. If size is less than the data, this value contains the required size.
Data	The buffer to return the contents of the variable. May be NULL with a zero DataSize in order to determine the size buffer needed.

Return values

EFI_SUCCESS	The function completed successfully.
EFI_NOT_FOUND	The variable was not found.
EFI_BUFFER_TOO_SMALL	The DataSize is too small for the result.
EFI_INVALID_PARAMETER	VariableName is NULL.
EFI_INVALID_PARAMETER	VendorGuid is NULL.
EFI_INVALID_PARAMETER	DataSize is NULL.
EFI_INVALID_PARAMETER	The DataSize is not too small and Data is NULL.
EFI_DEVICE_ERROR	The variable could not be retrieved due to a hardware error.
EFI_SECURITY_VIOLATION	The variable could not be retrieved due to an authentication failure.
EFI_UNSUPPORTED	After ExitBootServices() has been called, this return code may be returned if no variable storage is supported. The platform should describe this runtime service as unsupported at runtime via an EFI_RT_PROPERTIES_TABLE configuration table.

Definition at line 2407 of file Variable.c.

◆ VariableServiceQueryVariableInfo()

EFI_STATUS EFIAPI VariableServiceQueryVariableInfo	(	IN UINT32	Attributes,
		OUT UINT64 *	MaximumVariableStorageSize,
		OUT UINT64 *	RemainingVariableStorageSize,
		OUT UINT64 *	MaximumVariableSize
	)

This code returns information about the EFI variables.

Caution: This function may receive untrusted input. This function may be invoked in SMM mode. This function will do basic validation, before parse the data.

Parameters

Attributes	Attributes bitmask to specify the type of variables on which to return information.
MaximumVariableStorageSize	Pointer to the maximum size of the storage space available for the EFI variables associated with the attributes specified.
RemainingVariableStorageSize	Pointer to the remaining size of the storage space available for EFI variables associated with the attributes specified.
MaximumVariableSize	Pointer to the maximum size of an individual EFI variables associated with the attributes specified.

Returns: EFI_INVALID_PARAMETER An invalid combination of attribute bits was supplied.; EFI_SUCCESS Query successfully.; EFI_UNSUPPORTED The attribute is not supported on this platform.

Definition at line 3120 of file Variable.c.

◆ VariableServiceQueryVariableInfoInternal()

EFI_STATUS EFIAPI VariableServiceQueryVariableInfoInternal	(	IN UINT32	Attributes,
		OUT UINT64 *	MaximumVariableStorageSize,
		OUT UINT64 *	RemainingVariableStorageSize,
		OUT UINT64 *	MaximumVariableSize
	)

This code returns information about the EFI variables.

Caution: This function may receive untrusted input. This function may be invoked in SMM mode. This function will do basic validation, before parse the data.

Parameters

Attributes	Attributes bitmask to specify the type of variables on which to return information.
MaximumVariableStorageSize	Pointer to the maximum size of the storage space available for the EFI variables associated with the attributes specified.
RemainingVariableStorageSize	Pointer to the remaining size of the storage space available for EFI variables associated with the attributes specified.
MaximumVariableSize	Pointer to the maximum size of an individual EFI variables associated with the attributes specified.

Returns: EFI_SUCCESS Query successfully.

Definition at line 2940 of file Variable.c.

◆ VariableServiceSetVariable()

EFI_STATUS EFIAPI VariableServiceSetVariable	(	IN CHAR16 *	VariableName,
		IN EFI_GUID *	VendorGuid,
		IN UINT32	Attributes,
		IN UINTN	DataSize,
		IN VOID *	Data
	)

This code sets variable in storage blocks (Volatile or Non-Volatile).

Caution: This function may receive untrusted input. This function may be invoked in SMM mode, and datasize and data are external input. This function will do basic validation, before parse the data. This function will parse the authentication carefully to avoid security issues, like buffer overflow, integer overflow. This function will check attribute carefully to avoid authentication bypass.

Parameters

VariableName	Name of Variable to be found.
VendorGuid	Variable vendor GUID.
Attributes	Attribute value of the variable found
DataSize	Size of Data found. If size is less than the data, this value contains the required size.
Data	Data pointer.

Return values

EFI_SUCCESS	The function completed successfully.
EFI_NOT_FOUND	The variable was not found.
EFI_BUFFER_TOO_SMALL	The DataSize is too small for the result.
EFI_INVALID_PARAMETER	VariableName is NULL.
EFI_INVALID_PARAMETER	VendorGuid is NULL.
EFI_INVALID_PARAMETER	DataSize is NULL.
EFI_INVALID_PARAMETER	The DataSize is not too small and Data is NULL.
EFI_DEVICE_ERROR	The variable could not be retrieved due to a hardware error.
EFI_SECURITY_VIOLATION	The variable could not be retrieved due to an authentication failure.
EFI_UNSUPPORTED	After ExitBootServices() has been called, this return code may be returned if no variable storage is supported. The platform should describe this runtime service as unsupported at runtime via an EFI_RT_PROPERTIES_TABLE configuration table.

Definition at line 2612 of file Variable.c.

◆ VariableWriteServiceInitialize()

EFI_STATUS VariableWriteServiceInitialize ( VOID )

Initializes variable write service.

Return values

EFI_SUCCESS	Function successfully executed.
Others	Fail to initialize the variable service.

Definition at line 3415 of file Variable.c.

Variable Documentation

◆ gVariableInfo

VARIABLE_INFO_ENTRY* gVariableInfo = NULL

The memory entry used for variable statistics data.

Definition at line 49 of file Variable.c.

◆ mAuthContextIn

AUTH_VAR_LIB_CONTEXT_IN mAuthContextIn

Initial value:

= {
  AUTH_VAR_LIB_CONTEXT_IN_STRUCT_VERSION,
  
  
  
  0,
  
  
  
  0,
  VariableExLibFindVariable,
  VariableExLibFindNextVariable,
  VariableExLibUpdateVariable,
  VariableExLibGetScratchBuffer,
  VariableExLibCheckRemainingSpaceForConsistency,
  VariableExLibAtRuntime,
}

Definition at line 81 of file Variable.c.

◆ mAuthContextOut

AUTH_VAR_LIB_CONTEXT_OUT mAuthContextOut

Definition at line 99 of file Variable.c.

◆ mCurrentBootVarErrFlag

VAR_ERROR_FLAG mCurrentBootVarErrFlag = VAR_ERROR_FLAG_NO_ERROR

Definition at line 65 of file Variable.c.

◆ mEndOfDxe

BOOLEAN mEndOfDxe = FALSE

The flag to indicate whether the platform has left the DXE phase of execution.

Definition at line 54 of file Variable.c.

◆ mNvFvHeaderCache

EFI_FIRMWARE_VOLUME_HEADER* mNvFvHeaderCache = NULL

Memory cache of Fv Header.

Definition at line 44 of file Variable.c.

◆ mNvVariableCache

VARIABLE_STORE_HEADER* mNvVariableCache = NULL

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.

◆ mRequestSource

VAR_CHECK_REQUEST_SOURCE mRequestSource = VarCheckFromUntrusted

It indicates the var check request source. In the implementation, DXE is regarded as untrusted, and SMM is trusted.

Definition at line 60 of file Variable.c.

◆ mVariableEntryProperty

VARIABLE_ENTRY_PROPERTY mVariableEntryProperty[]

Initial value:

= {
  {
    &gEdkiiVarErrorFlagGuid,
    VAR_ERROR_FLAG_NAME,
    {
      VAR_CHECK_VARIABLE_PROPERTY_REVISION,
      VAR_CHECK_VARIABLE_PROPERTY_READ_ONLY,
      VARIABLE_ATTRIBUTE_NV_BS_RT,
      sizeof (VAR_ERROR_FLAG),
      sizeof (VAR_ERROR_FLAG)
    }
  },
}

Definition at line 67 of file Variable.c.

◆ mVariableModuleGlobal

VARIABLE_MODULE_GLOBAL* mVariableModuleGlobal

Definition at line 33 of file Variable.c.

Functions

Variables

Detailed Description

Function Documentation

◆ AutoUpdateLangVariable()

◆ CalculateCommonUserVariableTotalSize()

◆ CheckRemainingSpaceForConsistency()

◆ CheckRemainingSpaceForConsistencyInternal()

◆ ConvertNormalVarStorageToAuthVarStorage()

◆ FindVariable()

◆ FlushHobVariableToFlash()

◆ GetFvbInfoByAddress()

◆ GetHobVariableStore()

◆ GetIndexFromSupportedLangCodes()

◆ GetLangFromSupportedLangCodes()

◆ GetMaxVariableSize()

◆ InitializeVarErrorFlag()

◆ InitializeVariableQuota()

◆ IsUserVariable()

◆ Reclaim()

◆ ReclaimForOS()

◆ RecordVarErrorFlag()

◆ UpdateVariable()

◆ UpdateVariableStore()

◆ VariableCommonInitialize()

◆ VariableGetBestLanguage()

◆ VariableServiceGetNextVariableName()

◆ VariableServiceGetVariable()

◆ VariableServiceQueryVariableInfo()

◆ VariableServiceQueryVariableInfoInternal()

◆ VariableServiceSetVariable()

◆ VariableWriteServiceInitialize()

Variable Documentation

◆ gVariableInfo

◆ mAuthContextIn

◆ mAuthContextOut

◆ mCurrentBootVarErrFlag

◆ mEndOfDxe

◆ mNvFvHeaderCache

◆ mNvVariableCache

◆ mRequestSource

◆ mVariableEntryProperty

◆ mVariableModuleGlobal