#include "Variable.h"
#include <Protocol/VariablePolicy.h>
#include <Library/VariablePolicyLib.h>

Functions
EFI_STATUS EFIAPI	ProtocolIsVariablePolicyEnabled (OUT BOOLEAN *State)

VOID EFIAPI	RecordSecureBootPolicyVarData (VOID)

BOOLEAN	AtRuntime (VOID)

EFI_LOCK *	InitializeLock (IN OUT EFI_LOCK *Lock, IN EFI_TPL Priority)

VOID	AcquireLockOnlyAtBootTime (IN EFI_LOCK *Lock)

VOID	ReleaseLockOnlyAtBootTime (IN EFI_LOCK *Lock)

EFI_STATUS	GetFtwProtocol (OUT VOID **FtwProtocol)

EFI_STATUS	GetFvbByHandle (IN EFI_HANDLE FvBlockHandle, OUT EFI_FIRMWARE_VOLUME_BLOCK_PROTOCOL **FvBlock)

EFI_STATUS	GetFvbCountAndBuffer (OUT UINTN NumberHandles, OUT EFI_HANDLE *Buffer)

VOID EFIAPI	VariableClassAddressChangeEvent (IN EFI_EVENT Event, IN VOID *Context)

VOID EFIAPI	OnReadyToBoot (EFI_EVENT Event, VOID *Context)

VOID EFIAPI	OnEndOfDxe (EFI_EVENT Event, VOID *Context)

VOID	VariableWriteServiceInitializeDxe (VOID)

VOID EFIAPI	FtwNotificationEvent (IN EFI_EVENT Event, IN VOID *Context)

STATIC EFI_STATUS EFIAPI	MapCreateEventEx (IN UINT32 Type, IN EFI_TPL NotifyTpl, IN EFI_EVENT_NOTIFY NotifyFunction OPTIONAL, IN CONST VOID NotifyContext OPTIONAL, IN CONST EFI_GUID EventGroup OPTIONAL, OUT EFI_EVENT *Event)

STATIC VOID	SaveAcpiGlobalVariable (IN EFI_SYSTEM_TABLE *SystemTable)

STATIC VOID	RestoreAcpiGlobalVariable (IN EFI_SYSTEM_TABLE *SystemTable)

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

Variables
EFI_HANDLE	mHandle = NULL

EFI_EVENT	mVirtualAddressChangeEvent = NULL

VOID *	mFtwRegistration = NULL

VOID ***	mVarCheckAddressPointer = NULL

UINTN	mVarCheckAddressPointerCount = 0

EDKII_VARIABLE_LOCK_PROTOCOL	mVariableLock = { VariableLockRequestToLock }

EDKII_VARIABLE_POLICY_PROTOCOL	mVariablePolicyProtocol

EDKII_VAR_CHECK_PROTOCOL	mVarCheck

STATIC EFI_GUID	mAcpiGlobalVariableGuid

STATIC VOID *	mAcpiGlobalVariable = NULL

STATIC UINT32	mAcpiGlobalVariableAttributes

Detailed Description

Implement all four UEFI Runtime Variable services for the nonvolatile and volatile storage space and install variable architecture protocol.

Modified to work with UEFI1.1 for Apple firmware, and for immediate install.

Copyright (C) 2013, Red Hat, Inc. Copyright (c) 2006 - 2019, Intel Corporation. All rights reserved.
(C) Copyright 2015 Hewlett Packard Enterprise Development LP
Copyright (c) Microsoft Corporation.
Additional modifications Copyright (c) 2022 Mike Beaton SPDX-License-Identifier: BSD-2-Clause-Patent

Definition in file VariableDxe.c.

Function Documentation

◆ AcquireLockOnlyAtBootTime()

VOID AcquireLockOnlyAtBootTime ( IN EFI_LOCK * Lock )

Acquires lock only at boot time. Simply returns at runtime.

This is a temperary function that will be removed when EfiAcquireLock() in UefiLib can handle the call in UEFI Runtimer driver in RT phase. It calls EfiAcquireLock() at boot time, and simply returns at runtime.

Parameters

Lock	A pointer to the lock to acquire.

Definition at line 122 of file VariableDxe.c.

◆ AtRuntime()

BOOLEAN AtRuntime ( VOID )

Return TRUE if ExitBootServices () has been called.

Return values

TRUE	If ExitBootServices () has been called.

Definition at line 77 of file VariableDxe.c.

◆ FtwNotificationEvent()

VOID EFIAPI FtwNotificationEvent	(	IN EFI_EVENT	Event,
		IN VOID *	Context )

Fault Tolerant Write protocol notification event handler.

Non-Volatile variable write may needs FTW protocol to reclaim when writting variable.

Parameters

[in]	Event	Event whose notification function is being invoked.
[in]	Context	Pointer to the notification function's context.

Definition at line 428 of file VariableDxe.c.

◆ GetFtwProtocol()

EFI_STATUS GetFtwProtocol ( OUT VOID ** FtwProtocol )

Retrieve the Fault Tolerent Write protocol interface.

Parameters

[out] FtwProtocol The interface of Ftw protocol

Return values

EFI_SUCCESS	The FTW protocol instance was found and returned in FtwProtocol.
EFI_NOT_FOUND	The FTW protocol instance was not found.
EFI_INVALID_PARAMETER	SarProtocol is NULL.

Definition at line 164 of file VariableDxe.c.

◆ GetFvbByHandle()

EFI_STATUS GetFvbByHandle	(	IN EFI_HANDLE	FvBlockHandle,
		OUT EFI_FIRMWARE_VOLUME_BLOCK_PROTOCOL **	FvBlock )

Retrieve the FVB protocol interface by HANDLE.

Parameters

[in]	FvBlockHandle	The handle of FVB protocol that provides services for reading, writing, and erasing the target block.
[out]	FvBlock	The interface of FVB protocol

Return values

EFI_SUCCESS	The interface information for the specified protocol was returned.
EFI_UNSUPPORTED	The device does not support the FVB protocol.
EFI_INVALID_PARAMETER	FvBlockHandle is not a valid EFI_HANDLE or FvBlock is NULL.

Definition at line 194 of file VariableDxe.c.

◆ GetFvbCountAndBuffer()

EFI_STATUS GetFvbCountAndBuffer	(	OUT UINTN *	NumberHandles,
		OUT EFI_HANDLE **	Buffer )

Function returns an array of handles that support the FVB protocol in a buffer allocated from pool.

Parameters

[out]	NumberHandles	The number of handles returned in Buffer.
[out]	Buffer	A pointer to the buffer to return the requested array of handles that support FVB protocol.

Return values

EFI_SUCCESS	The array of handles was returned in Buffer, and the number of handles in Buffer was returned in NumberHandles.
EFI_NOT_FOUND	No FVB handle was found.
EFI_OUT_OF_RESOURCES	There is not enough pool memory to store the matching results.
EFI_INVALID_PARAMETER	NumberHandles is NULL or Buffer is NULL.

Definition at line 225 of file VariableDxe.c.

◆ InitializeLock()

EFI_LOCK * InitializeLock	(	IN OUT EFI_LOCK *	Lock,
		IN EFI_TPL	Priority )

Initializes a basic mutual exclusion lock.

This function initializes a basic mutual exclusion lock to the released state and returns the lock. Each lock provides mutual exclusion access at its task priority level. Since there is no preemption or multiprocessor support in EFI, acquiring the lock only consists of raising to the locks TPL. If Lock is NULL, then ASSERT(). If Priority is not a valid TPL value, then ASSERT().

Parameters

Lock	A pointer to the lock data structure to initialize.
Priority	EFI TPL is associated with the lock.

Returns: The lock.

Definition at line 101 of file VariableDxe.c.

◆ MapCreateEventEx()

STATIC EFI_STATUS EFIAPI MapCreateEventEx	(	IN UINT32	Type,
		IN EFI_TPL	NotifyTpl,
		IN EFI_EVENT_NOTIFY NotifyFunction	OPTIONAL,
		IN CONST VOID *NotifyContext	OPTIONAL,
		IN CONST EFI_GUID *EventGroup	OPTIONAL,
		OUT EFI_EVENT *	Event )

Definition at line 534 of file VariableDxe.c.

◆ OnEndOfDxe()

VOID EFIAPI OnEndOfDxe	(	EFI_EVENT	Event,
		VOID *	Context )

Notification function of EFI_END_OF_DXE_EVENT_GROUP_GUID event group.

This is a notification function registered on EFI_END_OF_DXE_EVENT_GROUP_GUID event group.

Parameters

Event	Event whose notification function is being invoked.
Context	Pointer to the notification function's context.

Definition at line 357 of file VariableDxe.c.

◆ OnReadyToBoot()

VOID EFIAPI OnReadyToBoot	(	EFI_EVENT	Event,
		VOID *	Context )

Notification function of EVT_GROUP_READY_TO_BOOT event group.

This is a notification function registered on EVT_GROUP_READY_TO_BOOT event group. When the Boot Manager is about to load and execute a boot option, it reclaims variable storage if free size is below the threshold.

Parameters

Event	Event whose notification function is being invoked.
Context	Pointer to the notification function's context.

Definition at line 311 of file VariableDxe.c.

◆ ProtocolIsVariablePolicyEnabled()

EFI_STATUS EFIAPI ProtocolIsVariablePolicyEnabled ( OUT BOOLEAN * State )

This API function returns whether or not the policy engine is currently being enforced.

Parameters

[out] State Pointer to a return value for whether the policy enforcement is currently enabled.

Return values

EFI_SUCCESS
Others	An error has prevented this command from completing.

Definition at line 523 of file VariableDxe.c.

◆ RecordSecureBootPolicyVarData()

VOID EFIAPI RecordSecureBootPolicyVarData ( VOID )

Some Secure Boot Policy Variable may update following other variable changes(SecureBoot follows PK change, etc). Record their initial State when variable write service is ready.

Definition at line 321 of file Measurement.c.

◆ ReleaseLockOnlyAtBootTime()

VOID ReleaseLockOnlyAtBootTime ( IN EFI_LOCK * Lock )

Releases lock only at boot time. Simply returns at runtime.

This is a temperary function which will be removed when EfiReleaseLock() in UefiLib can handle the call in UEFI Runtimer driver in RT phase. It calls EfiReleaseLock() at boot time and simply returns at runtime.

Parameters

Lock	A pointer to the lock to release.

Definition at line 144 of file VariableDxe.c.

◆ RestoreAcpiGlobalVariable()

STATIC VOID RestoreAcpiGlobalVariable ( IN EFI_SYSTEM_TABLE * SystemTable )

Definition at line 608 of file VariableDxe.c.

◆ SaveAcpiGlobalVariable()

STATIC VOID SaveAcpiGlobalVariable ( IN EFI_SYSTEM_TABLE * SystemTable )

Definition at line 569 of file VariableDxe.c.

◆ VariableClassAddressChangeEvent()

VOID EFIAPI VariableClassAddressChangeEvent	(	IN EFI_EVENT	Event,
		IN VOID *	Context )

Notification function of EVT_SIGNAL_VIRTUAL_ADDRESS_CHANGE.

This is a notification function registered on EVT_SIGNAL_VIRTUAL_ADDRESS_CHANGE event. It convers pointer to new virtual address.

Parameters

Event	Event whose notification function is being invoked.
Context	Pointer to the notification function's context.

Definition at line 257 of file VariableDxe.c.

◆ VariableServiceInitialize()

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

Variable Driver main entry point. The Variable driver places the 4 EFI runtime services in the EFI System Table and installs arch protocols for variable read and write services being available. It also registers a notification function for an EVT_SIGNAL_VIRTUAL_ADDRESS_CHANGE event.

Parameters

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

Return values

EFI_SUCCESS Variable service successfully initialized.

Definition at line 645 of file VariableDxe.c.

◆ VariableWriteServiceInitializeDxe()

VOID VariableWriteServiceInitializeDxe ( VOID )

Initializes variable write service for DXE.

Definition at line 386 of file VariableDxe.c.

Variable Documentation

◆ mAcpiGlobalVariable

STATIC VOID* mAcpiGlobalVariable = NULL

Definition at line 54 of file VariableDxe.c.

◆ mAcpiGlobalVariableAttributes

STATIC UINT32 mAcpiGlobalVariableAttributes

Definition at line 58 of file VariableDxe.c.

◆ mAcpiGlobalVariableGuid

STATIC EFI_GUID mAcpiGlobalVariableGuid

Initial value:

= {
  0xAF9FFD67, 0xEC10, 0x488A, { 0x9D, 0xFC, 0x6C, 0xBF, 0x5E, 0xE2, 0x2C, 0x2E }
}

Definition at line 48 of file VariableDxe.c.

◆ mFtwRegistration

VOID* mFtwRegistration = NULL

Definition at line 30 of file VariableDxe.c.

◆ mHandle

EFI_HANDLE mHandle = NULL

Definition at line 28 of file VariableDxe.c.

◆ mVarCheck

EDKII_VAR_CHECK_PROTOCOL mVarCheck

Initial value:

= {
  VarCheckRegisterSetVariableCheckHandler,
  VarCheckVariablePropertySet,
  VarCheckVariablePropertyGet
}

Definition at line 42 of file VariableDxe.c.

◆ mVarCheckAddressPointer

VOID*** mVarCheckAddressPointer = NULL

Definition at line 31 of file VariableDxe.c.

◆ mVarCheckAddressPointerCount

UINTN mVarCheckAddressPointerCount = 0

Definition at line 32 of file VariableDxe.c.

◆ mVariableLock

EDKII_VARIABLE_LOCK_PROTOCOL mVariableLock = { VariableLockRequestToLock }

Definition at line 33 of file VariableDxe.c.

◆ mVariablePolicyProtocol

EDKII_VARIABLE_POLICY_PROTOCOL mVariablePolicyProtocol

Initial value:

= {
  EDKII_VARIABLE_POLICY_PROTOCOL_REVISION,
  DisableVariablePolicy,
  ProtocolIsVariablePolicyEnabled,
  RegisterVariablePolicy,
  DumpVariablePolicy,
  LockVariablePolicy
}

Definition at line 34 of file VariableDxe.c.

◆ mVirtualAddressChangeEvent

EFI_EVENT mVirtualAddressChangeEvent = NULL

Definition at line 29 of file VariableDxe.c.

Functions

Variables

Detailed Description

Function Documentation

◆ AcquireLockOnlyAtBootTime()

◆ AtRuntime()

◆ FtwNotificationEvent()

◆ GetFtwProtocol()

◆ GetFvbByHandle()

◆ GetFvbCountAndBuffer()

◆ InitializeLock()

◆ MapCreateEventEx()

◆ OnEndOfDxe()

◆ OnReadyToBoot()

◆ ProtocolIsVariablePolicyEnabled()

◆ RecordSecureBootPolicyVarData()

◆ ReleaseLockOnlyAtBootTime()

◆ RestoreAcpiGlobalVariable()

◆ SaveAcpiGlobalVariable()

◆ VariableClassAddressChangeEvent()

◆ VariableServiceInitialize()

◆ VariableWriteServiceInitializeDxe()

Variable Documentation

◆ mAcpiGlobalVariable

◆ mAcpiGlobalVariableAttributes

◆ mAcpiGlobalVariableGuid

◆ mFtwRegistration

◆ mHandle

◆ mVarCheck

◆ mVarCheckAddressPointer

◆ mVarCheckAddressPointerCount

◆ mVariableLock

◆ mVariablePolicyProtocol

◆ mVirtualAddressChangeEvent