VariableParsing.c File Reference

#include "VariableParsing.h"

Go to the source code of this file.

Functions
BOOLEAN	IsValidVariableHeader (IN VARIABLE_HEADER *Variable, IN VARIABLE_HEADER *VariableStoreEnd)
VARIABLE_STORE_STATUS	GetVariableStoreStatus (IN VARIABLE_STORE_HEADER *VarStoreHeader)
UINTN	GetVariableHeaderSize (IN BOOLEAN AuthFormat)
UINTN	NameSizeOfVariable (IN VARIABLE_HEADER *Variable, IN BOOLEAN AuthFormat)
VOID	SetNameSizeOfVariable (IN VARIABLE_HEADER *Variable, IN UINTN NameSize, IN BOOLEAN AuthFormat)
UINTN	DataSizeOfVariable (IN VARIABLE_HEADER *Variable, IN BOOLEAN AuthFormat)
VOID	SetDataSizeOfVariable (IN VARIABLE_HEADER *Variable, IN UINTN DataSize, IN BOOLEAN AuthFormat)
CHAR16 *	GetVariableNamePtr (IN VARIABLE_HEADER *Variable, IN BOOLEAN AuthFormat)
EFI_GUID *	GetVendorGuidPtr (IN VARIABLE_HEADER *Variable, IN BOOLEAN AuthFormat)
UINT8 *	GetVariableDataPtr (IN VARIABLE_HEADER *Variable, IN BOOLEAN AuthFormat)
UINTN	GetVariableDataOffset (IN VARIABLE_HEADER *Variable, IN BOOLEAN AuthFormat)
VARIABLE_HEADER *	GetNextVariablePtr (IN VARIABLE_HEADER *Variable, IN BOOLEAN AuthFormat)
VARIABLE_HEADER *	GetStartPointer (IN VARIABLE_STORE_HEADER *VarStoreHeader)
VARIABLE_HEADER *	GetEndPointer (IN VARIABLE_STORE_HEADER *VarStoreHeader)
BOOLEAN	VariableCompareTimeStampInternal (IN EFI_TIME *FirstTime, IN EFI_TIME *SecondTime)
EFI_STATUS	FindVariableEx (IN CHAR16 *VariableName, IN EFI_GUID *VendorGuid, IN BOOLEAN IgnoreRtCheck, IN OUT VARIABLE_POINTER_TRACK *PtrTrack, IN BOOLEAN AuthFormat)
EFI_STATUS EFIAPI	VariableServiceGetNextVariableInternal (IN CHAR16 *VariableName, IN EFI_GUID *VendorGuid, IN VARIABLE_STORE_HEADER **VariableStoreList, OUT VARIABLE_HEADER **VariablePtr, IN BOOLEAN AuthFormat)
VOID	UpdateVariableInfo (IN CHAR16 *VariableName, IN EFI_GUID *VendorGuid, IN BOOLEAN Volatile, IN BOOLEAN Read, IN BOOLEAN Write, IN BOOLEAN Delete, IN BOOLEAN Cache, IN OUT VARIABLE_INFO_ENTRY **VariableInfo)

Detailed Description

Functions in this module are associated with variable parsing operations and are intended to be usable across variable driver source files.

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

Definition in file VariableParsing.c.

Function Documentation

DataSizeOfVariable()

UINTN DataSizeOfVariable	(	IN VARIABLE_HEADER *	Variable,
		IN BOOLEAN	AuthFormat
	)

This code gets the size of variable data.

Parameters

[in]	Variable	Pointer to the Variable Header.
[in]	AuthFormat	TRUE indicates authenticated variables are used. FALSE indicates authenticated variables are not used.

Returns

Size of variable in bytes.

Definition at line 184 of file VariableParsing.c.

FindVariableEx()

EFI_STATUS FindVariableEx	(	IN CHAR16 *	VariableName,
		IN EFI_GUID *	VendorGuid,
		IN BOOLEAN	IgnoreRtCheck,
		IN OUT VARIABLE_POINTER_TRACK *	PtrTrack,
		IN BOOLEAN	AuthFormat
	)

Find the variable in the specified variable store.

Parameters

[in]	VariableName	Name of the variable to be found
[in]	VendorGuid	Vendor GUID to be found.
[in]	IgnoreRtCheck	Ignore EFI_VARIABLE_RUNTIME_ACCESS attribute check at runtime when searching variable.
[in,out]	PtrTrack	Variable Track Pointer structure that contains Variable Information.
[in]	AuthFormat	TRUE indicates authenticated variables are used. FALSE indicates authenticated variables are not used.

Return values

EFI_SUCCESS	Variable found successfully
EFI_NOT_FOUND	Variable not found

Definition at line 463 of file VariableParsing.c.

GetEndPointer()

VARIABLE_HEADER * GetEndPointer

(

IN VARIABLE_STORE_HEADER *

VarStoreHeader

)

Gets the pointer to the end of the variable storage area.

This function gets pointer to the end of the variable storage area, according to the input variable store header.

Parameters

[in]

VarStoreHeader

Pointer to the Variable Store Header.

Returns

Pointer to the end of the variable storage area.

Definition at line 406 of file VariableParsing.c.

GetNextVariablePtr()

VARIABLE_HEADER * GetNextVariablePtr	(	IN VARIABLE_HEADER *	Variable,
		IN BOOLEAN	AuthFormat
	)

This code gets the pointer to the next variable header.

Parameters

[in]	Variable	Pointer to the Variable Header.
[in]	AuthFormat	TRUE indicates authenticated variables are used. FALSE indicates authenticated variables are not used.

Returns

Pointer to next variable header.

Definition at line 356 of file VariableParsing.c.

GetStartPointer()

VARIABLE_HEADER * GetStartPointer

(

IN VARIABLE_STORE_HEADER *

VarStoreHeader

)

Gets the pointer to the first variable header in given variable store area.

Parameters

[in]

VarStoreHeader

Pointer to the Variable Store Header.

Returns

Pointer to the first variable header.

Definition at line 383 of file VariableParsing.c.

GetVariableDataOffset()

UINTN GetVariableDataOffset	(	IN VARIABLE_HEADER *	Variable,
		IN BOOLEAN	AuthFormat
	)

This code gets the variable data offset related to variable header.

Parameters

[in]	Variable	Pointer to the Variable Header.
[in]	AuthFormat	TRUE indicates authenticated variables are used. FALSE indicates authenticated variables are not used.

Returns

Variable Data offset.

Definition at line 327 of file VariableParsing.c.

GetVariableDataPtr()

UINT8 * GetVariableDataPtr	(	IN VARIABLE_HEADER *	Variable,
		IN BOOLEAN	AuthFormat
	)

This code gets the pointer to the variable data.

Parameters

[in]	Variable	Pointer to the Variable Header.
[in]	AuthFormat	TRUE indicates authenticated variables are used. FALSE indicates authenticated variables are not used.

Returns

Pointer to Variable Data.

Definition at line 299 of file VariableParsing.c.

GetVariableHeaderSize()

UINTN GetVariableHeaderSize

(

IN BOOLEAN

AuthFormat

)

This code gets the size of variable header.

Parameters

[in]

AuthFormat

TRUE indicates authenticated variables are used. FALSE indicates authenticated variables are not used.

Returns

Size of variable header in bytes in type UINTN.

Definition at line 88 of file VariableParsing.c.

GetVariableNamePtr()

CHAR16 * GetVariableNamePtr	(	IN VARIABLE_HEADER *	Variable,
		IN BOOLEAN	AuthFormat
	)

This code gets the pointer to the variable name.

Parameters

[in]	Variable	Pointer to the Variable Header.
[in]	AuthFormat	TRUE indicates authenticated variables are used. FALSE indicates authenticated variables are not used.

Returns

Pointer to Variable Name which is Unicode encoding.

Definition at line 253 of file VariableParsing.c.

GetVariableStoreStatus()

VARIABLE_STORE_STATUS GetVariableStoreStatus

(

IN VARIABLE_STORE_HEADER *

VarStoreHeader

)

This code gets the current status of Variable Store.

Parameters

[in]

VarStoreHeader

Pointer to the Variable Store Header.

Return values

EfiRaw	Variable store status is raw.
EfiValid	Variable store status is valid.
EfiInvalid	Variable store status is invalid.

Definition at line 52 of file VariableParsing.c.

GetVendorGuidPtr()

EFI_GUID * GetVendorGuidPtr	(	IN VARIABLE_HEADER *	Variable,
		IN BOOLEAN	AuthFormat
	)

This code gets the pointer to the variable guid.

Parameters

[in]	Variable	Pointer to the Variable Header.
[in]	AuthFormat	TRUE indicates authenticated variables are used. FALSE indicates authenticated variables are not used.

Returns

A EFI_GUID* pointer to Vendor Guid.

Definition at line 272 of file VariableParsing.c.

IsValidVariableHeader()

BOOLEAN IsValidVariableHeader	(	IN VARIABLE_HEADER *	Variable,
		IN VARIABLE_HEADER *	VariableStoreEnd
	)

This code checks if variable header is valid or not.

Parameters

[in]	Variable	Pointer to the Variable Header.
[in]	VariableStoreEnd	Pointer to the Variable Store End.

Return values

TRUE	Variable header is valid.
FALSE	Variable header is not valid.

Definition at line 24 of file VariableParsing.c.

NameSizeOfVariable()

UINTN NameSizeOfVariable	(	IN VARIABLE_HEADER *	Variable,
		IN BOOLEAN	AuthFormat
	)

This code gets the size of name of variable.

Parameters

[in]	Variable	Pointer to the variable header.
[in]	AuthFormat	TRUE indicates authenticated variables are used. FALSE indicates authenticated variables are not used.

Returns

UINTN Size of variable in bytes.

Definition at line 115 of file VariableParsing.c.

SetDataSizeOfVariable()

VOID SetDataSizeOfVariable	(	IN VARIABLE_HEADER *	Variable,
		IN UINTN	DataSize,
		IN BOOLEAN	AuthFormat
	)

This code sets the size of variable data.

Parameters

[in]	Variable	Pointer to the Variable Header.
[in]	DataSize	Data size to set.
[in]	AuthFormat	TRUE indicates authenticated variables are used. FALSE indicates authenticated variables are not used.

Definition at line 225 of file VariableParsing.c.

SetNameSizeOfVariable()

VOID SetNameSizeOfVariable	(	IN VARIABLE_HEADER *	Variable,
		IN UINTN	NameSize,
		IN BOOLEAN	AuthFormat
	)

This code sets the size of name of variable.

Parameters

[in]	Variable	Pointer to the Variable Header.
[in]	NameSize	Name size to set.
[in]	AuthFormat	TRUE indicates authenticated variables are used. FALSE indicates authenticated variables are not used.

Definition at line 156 of file VariableParsing.c.

UpdateVariableInfo()

VOID UpdateVariableInfo	(	IN CHAR16 *	VariableName,
		IN EFI_GUID *	VendorGuid,
		IN BOOLEAN	Volatile,
		IN BOOLEAN	Read,
		IN BOOLEAN	Write,
		IN BOOLEAN	Delete,
		IN BOOLEAN	Cache,
		IN OUT VARIABLE_INFO_ENTRY **	VariableInfo
	)

Routine used to track statistical information about variable usage. The data is stored in the EFI system table so it can be accessed later. VariableInfo.efi can dump out the table. Only Boot Services variable accesses are tracked by this code. The PcdVariableCollectStatistics build flag controls if this feature is enabled.

A read that hits in the cache will have Read and Cache true for the transaction. Data is allocated by this routine, but never freed.

Parameters

[in]	VariableName	Name of the Variable to track.
[in]	VendorGuid	Guid of the Variable to track.
[in]	Volatile	TRUE if volatile FALSE if non-volatile.
[in]	Read	TRUE if GetVariable() was called.
[in]	Write	TRUE if SetVariable() was called.
[in]	Delete	TRUE if deleted via SetVariable().
[in]	Cache	TRUE for a cache hit.
[in,out]	VariableInfo	Pointer to a pointer of VARIABLE_INFO_ENTRY structures.

Definition at line 729 of file VariableParsing.c.

VariableCompareTimeStampInternal()

BOOLEAN VariableCompareTimeStampInternal	(	IN EFI_TIME *	FirstTime,
		IN EFI_TIME *	SecondTime
	)

Compare two EFI_TIME data.

Parameters

[in]	FirstTime	A pointer to the first EFI_TIME data.
[in]	SecondTime	A pointer to the second EFI_TIME data.

Return values

TRUE	The FirstTime is not later than the SecondTime.
FALSE	The FirstTime is later than the SecondTime.

Definition at line 428 of file VariableParsing.c.

VariableServiceGetNextVariableInternal()

EFI_STATUS EFIAPI VariableServiceGetNextVariableInternal	(	IN CHAR16 *	VariableName,
		IN EFI_GUID *	VendorGuid,
		IN VARIABLE_STORE_HEADER **	VariableStoreList,
		OUT VARIABLE_HEADER **	VariablePtr,
		IN BOOLEAN	AuthFormat
	)

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

[in]	VariableName	Pointer to variable name.
[in]	VendorGuid	Variable Vendor Guid.
[in]	VariableStoreList	A list of variable stores that should be used to get the next variable. The maximum number of entries is the max value of VARIABLE_STORE_TYPE.
[out]	VariablePtr	Pointer to variable header address.
[in]	AuthFormat	TRUE indicates authenticated variables are used. FALSE indicates authenticated variables are not used.

Return values

EFI_SUCCESS	The function completed successfully.
EFI_NOT_FOUND	The next variable was not found.
EFI_INVALID_PARAMETER	If VariableName is not an empty string, while VendorGuid is NULL.
EFI_INVALID_PARAMETER	The input values of VariableName and VendorGuid are not a name and GUID of an existing variable.

Definition at line 544 of file VariableParsing.c.