[edk2-devel] [edk2-platforms] [PATCH v2 2/4] MinPlatformPkg: Add VariableWriteLib
Nate DeSimone
nathaniel.l.desimone at intel.com
Sun Apr 4 09:40:37 UTC 2021
VariableWriteLib is a phase agnostic library for writing
to UEFI Variables. This library provides the MinSetVariable(),
MinQueryVariableInfo(), MinIsVariableRequestToLockSupported(),
and MinVariableRequestToLock() APIs which are usable in DXE
and SMM.
Cc: Chasel Chiu <chasel.chiu at intel.com>
Cc: Liming Gao <gaoliming at byosoft.com.cn>
Cc: Eric Dong <eric.dong at intel.com>
Cc: Michael Kubacki <michael.kubacki at microsoft.com>
Cc: Isaac Oram <isaac.w.oram at intel.com>
Signed-off-by: Nate DeSimone <nathaniel.l.desimone at intel.com>
---
.../MinPlatformPkg/Include/Dsc/CoreDxeLib.dsc | 2 +
.../Include/Library/VariableWriteLib.h | 129 +++++++++
.../DxeRuntimeVariableWriteLib.c | 256 ++++++++++++++++++
.../DxeRuntimeVariableWriteLib.inf | 49 ++++
.../SmmVariableWriteCommon.c | 167 ++++++++++++
.../StandaloneMmVariableWriteLib.inf | 45 +++
.../StandaloneMmVariableWriteLibConstructor.c | 48 ++++
.../TraditionalMmVariableWriteLib.inf | 44 +++
...TraditionalMmVariableWriteLibConstructor.c | 48 ++++
.../Intel/MinPlatformPkg/MinPlatformPkg.dsc | 1 +
10 files changed, 789 insertions(+)
create mode 100644 Platform/Intel/MinPlatformPkg/Include/Library/VariableWriteLib.h
create mode 100644 Platform/Intel/MinPlatformPkg/Library/DxeRuntimeVariableWriteLib/DxeRuntimeVariableWriteLib.c
create mode 100644 Platform/Intel/MinPlatformPkg/Library/DxeRuntimeVariableWriteLib/DxeRuntimeVariableWriteLib.inf
create mode 100644 Platform/Intel/MinPlatformPkg/Library/SmmVariableWriteLib/SmmVariableWriteCommon.c
create mode 100644 Platform/Intel/MinPlatformPkg/Library/SmmVariableWriteLib/StandaloneMmVariableWriteLib.inf
create mode 100644 Platform/Intel/MinPlatformPkg/Library/SmmVariableWriteLib/StandaloneMmVariableWriteLibConstructor.c
create mode 100644 Platform/Intel/MinPlatformPkg/Library/SmmVariableWriteLib/TraditionalMmVariableWriteLib.inf
create mode 100644 Platform/Intel/MinPlatformPkg/Library/SmmVariableWriteLib/TraditionalMmVariableWriteLibConstructor.c
diff --git a/Platform/Intel/MinPlatformPkg/Include/Dsc/CoreDxeLib.dsc b/Platform/Intel/MinPlatformPkg/Include/Dsc/CoreDxeLib.dsc
index 0db1250ab7..57847e6a4d 100644
--- a/Platform/Intel/MinPlatformPkg/Include/Dsc/CoreDxeLib.dsc
+++ b/Platform/Intel/MinPlatformPkg/Include/Dsc/CoreDxeLib.dsc
@@ -48,6 +48,7 @@
[LibraryClasses.common.DXE_CORE, LibraryClasses.common.DXE_DRIVER, LibraryClasses.common.DXE_RUNTIME_DRIVER, LibraryClasses.common.UEFI_DRIVER, LibraryClasses.common.UEFI_APPLICATION]
VariableReadLib|MinPlatformPkg/Library/DxeRuntimeVariableReadLib/DxeRuntimeVariableReadLib.inf
+ VariableWriteLib|MinPlatformPkg/Library/DxeRuntimeVariableWriteLib/DxeRuntimeVariableWriteLib.inf
[LibraryClasses.common.DXE_CORE]
HobLib|MdePkg/Library/DxeCoreHobLib/DxeCoreHobLib.inf
@@ -93,6 +94,7 @@
Tcg2PhysicalPresenceLib|SecurityPkg/Library/SmmTcg2PhysicalPresenceLib/SmmTcg2PhysicalPresenceLib.inf
BaseCryptLib|CryptoPkg/Library/BaseCryptLib/SmmCryptLib.inf
VariableReadLib|MinPlatformPkg/Library/SmmVariableReadLib/TraditionalMmVariableReadLib.inf
+ VariableWriteLib|MinPlatformPkg/Library/SmmVariableWriteLib/TraditionalMmVariableWriteLib.inf
[LibraryClasses.common.SMM_CORE]
PcdLib|MdePkg/Library/DxePcdLib/DxePcdLib.inf
diff --git a/Platform/Intel/MinPlatformPkg/Include/Library/VariableWriteLib.h b/Platform/Intel/MinPlatformPkg/Include/Library/VariableWriteLib.h
new file mode 100644
index 0000000000..c52aec93ec
--- /dev/null
+++ b/Platform/Intel/MinPlatformPkg/Include/Library/VariableWriteLib.h
@@ -0,0 +1,129 @@
+/** @file
+ Variable Write Lib
+
+ This library provides phase agnostic access to the UEFI Variable Services.
+ This is done by implementing a wrapper on top of the phase specific mechanism
+ for writing to UEFI variables. For example, the DXE implementation accesses
+ the UEFI Runtime Services Table, and the SMM implementation uses
+ EFI_SMM_VARIABLE_PROTOCOL.
+
+ Using this library allows code to be written in a generic manner that can be
+ used in DXE or SMM without modification.
+
+ Copyright (c) 2021, Intel Corporation. All rights reserved.<BR>
+ SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <Uefi/UefiBaseType.h>
+
+/**
+ Sets the value of a variable.
+
+ @param[in] VariableName A Null-terminated string that is the name of the vendor's variable.
+ Each VariableName is unique for each VendorGuid. VariableName must
+ contain 1 or more characters. If VariableName is an empty string,
+ then EFI_INVALID_PARAMETER is returned.
+ @param[in] VendorGuid A unique identifier for the vendor.
+ @param[in] Attributes Attributes bitmask to set for the variable.
+ @param[in] DataSize The size in bytes of the Data buffer. Unless the EFI_VARIABLE_APPEND_WRITE or
+ EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS attribute is set, a size of zero
+ causes the variable to be deleted. When the EFI_VARIABLE_APPEND_WRITE attribute is
+ set, then a SetVariable() call with a DataSize of zero will not cause any change to
+ the variable value (the timestamp associated with the variable may be updated however
+ even if no new data value is provided,see the description of the
+ EFI_VARIABLE_AUTHENTICATION_2 descriptor below. In this case the DataSize will not
+ be zero since the EFI_VARIABLE_AUTHENTICATION_2 descriptor will be populated).
+ @param[in] Data The contents for the variable.
+
+ @retval EFI_SUCCESS The firmware has successfully stored the variable and its data as
+ defined by the Attributes.
+ @retval EFI_INVALID_PARAMETER An invalid combination of attribute bits, name, and GUID was supplied, or the
+ DataSize exceeds the maximum allowed.
+ @retval EFI_INVALID_PARAMETER VariableName is an empty string.
+ @retval EFI_OUT_OF_RESOURCES Not enough storage is available to hold the variable and its data.
+ @retval EFI_DEVICE_ERROR The variable could not be retrieved due to a hardware error.
+ @retval EFI_WRITE_PROTECTED The variable in question is read-only.
+ @retval EFI_WRITE_PROTECTED The variable in question cannot be deleted.
+ @retval EFI_SECURITY_VIOLATION The variable could not be written due to EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACESS being set,
+ but the AuthInfo does NOT pass the validation check carried out by the firmware.
+
+ @retval EFI_NOT_FOUND The variable trying to be updated or deleted was not found.
+
+**/
+EFI_STATUS
+EFIAPI
+VarLibSetVariable (
+ IN CHAR16 *VariableName,
+ IN EFI_GUID *VendorGuid,
+ IN UINT32 Attributes,
+ IN UINTN DataSize,
+ IN VOID *Data
+ );
+
+/**
+ Returns information about the EFI variables.
+
+ @param[in] Attributes Attributes bitmask to specify the type of variables on
+ which to return information.
+ @param[out] MaximumVariableStorageSize On output the maximum size of the storage space
+ available for the EFI variables associated with the
+ attributes specified.
+ @param[out] RemainingVariableStorageSize Returns the remaining size of the storage space
+ available for the EFI variables associated with the
+ attributes specified.
+ @param[out] MaximumVariableSize Returns the maximum size of the individual EFI
+ variables associated with the attributes specified.
+
+ @retval EFI_SUCCESS Valid answer returned.
+ @retval EFI_INVALID_PARAMETER An invalid combination of attribute bits was supplied
+ @retval EFI_UNSUPPORTED The attribute is not supported on this platform, and the
+ MaximumVariableStorageSize,
+ RemainingVariableStorageSize, MaximumVariableSize
+ are undefined.
+**/
+EFI_STATUS
+EFIAPI
+VarLibQueryVariableInfo (
+ IN UINT32 Attributes,
+ OUT UINT64 *MaximumVariableStorageSize,
+ OUT UINT64 *RemainingVariableStorageSize,
+ OUT UINT64 *MaximumVariableSize
+ );
+
+/**
+ Indicates if the VarLibVariableRequestToLock() API is supported by the current
+ VariableWriteLib implementation. At time of writting, this API is not
+ available in SMM or after ExitBootServices.
+
+ @retval TRUE The VarLibVariableRequestToLock() API is supported
+ @retval FALSE The VarLibVariableRequestToLock() API is not supported
+**/
+BOOLEAN
+EFIAPI
+VarLibIsVariableRequestToLockSupported (
+ VOID
+ );
+
+/**
+ Mark a variable that will become read-only after leaving the DXE phase of execution.
+ Write request coming from SMM environment through EFI_SMM_VARIABLE_PROTOCOL is allowed.
+
+ @param[in] This The EDKII_VARIABLE_LOCK_PROTOCOL instance.
+ @param[in] VariableName A pointer to the variable name that will be made read-only subsequently.
+ @param[in] VendorGuid A pointer to the vendor GUID that will be made read-only subsequently.
+
+ @retval EFI_SUCCESS The variable specified by the VariableName and the VendorGuid was marked
+ as pending to be read-only.
+ @retval EFI_INVALID_PARAMETER VariableName or VendorGuid is NULL.
+ Or VariableName is an empty string.
+ @retval EFI_ACCESS_DENIED EFI_END_OF_DXE_EVENT_GROUP_GUID or EFI_EVENT_GROUP_READY_TO_BOOT has
+ already been signaled.
+ @retval EFI_OUT_OF_RESOURCES There is not enough resource to hold the lock request.
+**/
+EFI_STATUS
+EFIAPI
+VarLibVariableRequestToLock (
+ IN CHAR16 *VariableName,
+ IN EFI_GUID *VendorGuid
+ );
diff --git a/Platform/Intel/MinPlatformPkg/Library/DxeRuntimeVariableWriteLib/DxeRuntimeVariableWriteLib.c b/Platform/Intel/MinPlatformPkg/Library/DxeRuntimeVariableWriteLib/DxeRuntimeVariableWriteLib.c
new file mode 100644
index 0000000000..3b7f377bc2
--- /dev/null
+++ b/Platform/Intel/MinPlatformPkg/Library/DxeRuntimeVariableWriteLib/DxeRuntimeVariableWriteLib.c
@@ -0,0 +1,256 @@
+/** @file
+ DXE Variable Write Lib
+
+ This library provides phase agnostic access to the UEFI Variable Services.
+ This is done by implementing a wrapper on top of the phase specific mechanism
+ for writing to UEFI variables. For example, the DXE implementation accesses
+ the UEFI Runtime Services Table, and the SMM implementation uses
+ EFI_SMM_VARIABLE_PROTOCOL.
+
+ Using this library allows code to be written in a generic manner that can be
+ used in DXE or SMM without modification.
+
+ Copyright (c) 2021, Intel Corporation. All rights reserved.<BR>
+ SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <Uefi.h>
+
+#include <Guid/EventGroup.h>
+#include <Protocol/VariableLock.h>
+
+#include <Library/UefiLib.h>
+#include <Library/DebugLib.h>
+#include <Library/UefiBootServicesTableLib.h>
+#include <Library/UefiRuntimeServicesTableLib.h>
+
+STATIC EDKII_VARIABLE_LOCK_PROTOCOL *mVariableWriteLibVariableLock = NULL;
+
+/**
+ Sets the value of a variable.
+
+ @param[in] VariableName A Null-terminated string that is the name of the vendor's variable.
+ Each VariableName is unique for each VendorGuid. VariableName must
+ contain 1 or more characters. If VariableName is an empty string,
+ then EFI_INVALID_PARAMETER is returned.
+ @param[in] VendorGuid A unique identifier for the vendor.
+ @param[in] Attributes Attributes bitmask to set for the variable.
+ @param[in] DataSize The size in bytes of the Data buffer. Unless the EFI_VARIABLE_APPEND_WRITE or
+ EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS attribute is set, a size of zero
+ causes the variable to be deleted. When the EFI_VARIABLE_APPEND_WRITE attribute is
+ set, then a SetVariable() call with a DataSize of zero will not cause any change to
+ the variable value (the timestamp associated with the variable may be updated however
+ even if no new data value is provided,see the description of the
+ EFI_VARIABLE_AUTHENTICATION_2 descriptor below. In this case the DataSize will not
+ be zero since the EFI_VARIABLE_AUTHENTICATION_2 descriptor will be populated).
+ @param[in] Data The contents for the variable.
+
+ @retval EFI_SUCCESS The firmware has successfully stored the variable and its data as
+ defined by the Attributes.
+ @retval EFI_INVALID_PARAMETER An invalid combination of attribute bits, name, and GUID was supplied, or the
+ DataSize exceeds the maximum allowed.
+ @retval EFI_INVALID_PARAMETER VariableName is an empty string.
+ @retval EFI_OUT_OF_RESOURCES Not enough storage is available to hold the variable and its data.
+ @retval EFI_DEVICE_ERROR The variable could not be retrieved due to a hardware error.
+ @retval EFI_WRITE_PROTECTED The variable in question is read-only.
+ @retval EFI_WRITE_PROTECTED The variable in question cannot be deleted.
+ @retval EFI_SECURITY_VIOLATION The variable could not be written due to EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACESS being set,
+ but the AuthInfo does NOT pass the validation check carried out by the firmware.
+
+ @retval EFI_NOT_FOUND The variable trying to be updated or deleted was not found.
+
+**/
+EFI_STATUS
+EFIAPI
+VarLibSetVariable (
+ IN CHAR16 *VariableName,
+ IN EFI_GUID *VendorGuid,
+ IN UINT32 Attributes,
+ IN UINTN DataSize,
+ IN VOID *Data
+ )
+{
+ EFI_STATUS Status = EFI_UNSUPPORTED;
+
+ if (gRT != NULL) {
+ Status = gRT->SetVariable (
+ VariableName,
+ VendorGuid,
+ Attributes,
+ DataSize,
+ Data
+ );
+ }
+ return Status;
+}
+
+/**
+ Returns information about the EFI variables.
+
+ @param[in] Attributes Attributes bitmask to specify the type of variables on
+ which to return information.
+ @param[out] MaximumVariableStorageSize On output the maximum size of the storage space
+ available for the EFI variables associated with the
+ attributes specified.
+ @param[out] RemainingVariableStorageSize Returns the remaining size of the storage space
+ available for the EFI variables associated with the
+ attributes specified.
+ @param[out] MaximumVariableSize Returns the maximum size of the individual EFI
+ variables associated with the attributes specified.
+
+ @retval EFI_SUCCESS Valid answer returned.
+ @retval EFI_INVALID_PARAMETER An invalid combination of attribute bits was supplied
+ @retval EFI_UNSUPPORTED The attribute is not supported on this platform, and the
+ MaximumVariableStorageSize,
+ RemainingVariableStorageSize, MaximumVariableSize
+ are undefined.
+**/
+EFI_STATUS
+EFIAPI
+VarLibQueryVariableInfo (
+ IN UINT32 Attributes,
+ OUT UINT64 *MaximumVariableStorageSize,
+ OUT UINT64 *RemainingVariableStorageSize,
+ OUT UINT64 *MaximumVariableSize
+ )
+{
+ EFI_STATUS Status = EFI_UNSUPPORTED;
+
+ if (gRT != NULL) {
+ Status = gRT->QueryVariableInfo (
+ Attributes,
+ MaximumVariableStorageSize,
+ RemainingVariableStorageSize,
+ MaximumVariableSize
+ );
+ }
+ return Status;
+}
+
+/**
+ Indicates if the VarLibVariableRequestToLock() API is supported by the current
+ VariableWriteLib implementation. At time of writting, this API is not
+ available in SMM or after ExitBootServices.
+
+ @retval TRUE The VarLibVariableRequestToLock() API is supported
+ @retval FALSE The VarLibVariableRequestToLock() API is not supported
+**/
+BOOLEAN
+EFIAPI
+VarLibIsVariableRequestToLockSupported (
+ VOID
+ )
+{
+ if (mVariableWriteLibVariableLock != NULL) {
+ return TRUE;
+ } else {
+ return FALSE;
+ }
+}
+
+/**
+ Mark a variable that will become read-only after leaving the DXE phase of execution.
+ Write request coming from SMM environment through EFI_SMM_VARIABLE_PROTOCOL is allowed.
+
+ @param[in] This The EDKII_VARIABLE_LOCK_PROTOCOL instance.
+ @param[in] VariableName A pointer to the variable name that will be made read-only subsequently.
+ @param[in] VendorGuid A pointer to the vendor GUID that will be made read-only subsequently.
+
+ @retval EFI_SUCCESS The variable specified by the VariableName and the VendorGuid was marked
+ as pending to be read-only.
+ @retval EFI_INVALID_PARAMETER VariableName or VendorGuid is NULL.
+ Or VariableName is an empty string.
+ @retval EFI_ACCESS_DENIED EFI_END_OF_DXE_EVENT_GROUP_GUID or EFI_EVENT_GROUP_READY_TO_BOOT has
+ already been signaled.
+ @retval EFI_OUT_OF_RESOURCES There is not enough resource to hold the lock request.
+**/
+EFI_STATUS
+EFIAPI
+VarLibVariableRequestToLock (
+ IN CHAR16 *VariableName,
+ IN EFI_GUID *VendorGuid
+ )
+{
+ EFI_STATUS Status = EFI_UNSUPPORTED;
+
+ if (mVariableWriteLibVariableLock != NULL) {
+ Status = mVariableWriteLibVariableLock->RequestToLock (
+ mVariableWriteLibVariableLock,
+ VariableName,
+ VendorGuid
+ );
+ }
+ return Status;
+}
+
+/**
+ Exit Boot Services Event notification handler.
+
+ @param[in] Event Event whose notification function is being invoked.
+ @param[in] Context Pointer to the notification function's context.
+
+**/
+VOID
+EFIAPI
+DxeRuntimeVariableWriteLibOnExitBootServices (
+ IN EFI_EVENT Event,
+ IN VOID *Context
+ )
+{
+ mVariableWriteLibVariableLock = NULL;
+}
+
+/**
+ The constructor function acquires the Variable Lock Protocol
+
+ @param ImageHandle The firmware allocated handle for the EFI image.
+ @param SystemTable A pointer to the EFI System Table.
+
+ @retval EFI_SUCCESS The constructor always returns RETURN_SUCCESS.
+
+**/
+EFI_STATUS
+EFIAPI
+DxeRuntimeVariableWriteLibConstructor (
+ IN EFI_HANDLE ImageHandle,
+ IN EFI_SYSTEM_TABLE *SystemTable
+ )
+{
+ EFI_STATUS Status;
+ EFI_EVENT ExitBootServiceEvent;
+ EFI_EVENT LegacyBootEvent;
+
+ //
+ // Locate VariableLockProtocol.
+ //
+ Status = gBS->LocateProtocol (&gEdkiiVariableLockProtocolGuid, NULL, (VOID **)&mVariableWriteLibVariableLock);
+ ASSERT_EFI_ERROR (Status);
+
+ //
+ // Register the event to inform SMM variable that it is at runtime.
+ //
+ Status = gBS->CreateEventEx (
+ EVT_NOTIFY_SIGNAL,
+ TPL_NOTIFY,
+ DxeRuntimeVariableWriteLibOnExitBootServices,
+ NULL,
+ &gEfiEventExitBootServicesGuid,
+ &ExitBootServiceEvent
+ );
+ ASSERT_EFI_ERROR (Status);
+
+ //
+ // Register the event to inform SMM variable that it is at runtime for legacy boot.
+ // Reuse OnExitBootServices() here.
+ //
+ Status = EfiCreateEventLegacyBootEx (
+ TPL_NOTIFY,
+ DxeRuntimeVariableWriteLibOnExitBootServices,
+ NULL,
+ &LegacyBootEvent
+ );
+ ASSERT_EFI_ERROR (Status);
+
+ return Status;
+}
diff --git a/Platform/Intel/MinPlatformPkg/Library/DxeRuntimeVariableWriteLib/DxeRuntimeVariableWriteLib.inf b/Platform/Intel/MinPlatformPkg/Library/DxeRuntimeVariableWriteLib/DxeRuntimeVariableWriteLib.inf
new file mode 100644
index 0000000000..704a8ac7cc
--- /dev/null
+++ b/Platform/Intel/MinPlatformPkg/Library/DxeRuntimeVariableWriteLib/DxeRuntimeVariableWriteLib.inf
@@ -0,0 +1,49 @@
+## @file
+# Component description file for DXE Variable Write Lib
+#
+# This library provides phase agnostic access to the UEFI Variable Services.
+# This is done by implementing a wrapper on top of the phase specific mechanism
+# for writing to UEFI variables. For example, the DXE implementation accesses
+# the UEFI Runtime Services Table, and the SMM implementation uses
+# EFI_SMM_VARIABLE_PROTOCOL.
+#
+# Using this library allows code to be written in a generic manner that can be
+# used in DXE or SMM without modification.
+#
+# Copyright (c) 2021, Intel Corporation. All rights reserved.<BR>
+#
+# SPDX-License-Identifier: BSD-2-Clause-Patent
+#
+##
+
+[Defines]
+ INF_VERSION = 0x00010005
+ BASE_NAME = DxeRuntimeVariableWriteLib
+ FILE_GUID = 9681E383-5FD4-47A4-B4F8-6651EE603E4E
+ VERSION_STRING = 1.0
+ MODULE_TYPE = DXE_RUNTIME_DRIVER
+ LIBRARY_CLASS = VariableWriteLib|DXE_CORE DXE_DRIVER DXE_RUNTIME_DRIVER UEFI_APPLICATION UEFI_DRIVER
+ CONSTRUCTOR = DxeRuntimeVariableWriteLibConstructor
+
+[Packages]
+ MdePkg/MdePkg.dec
+ MdeModulePkg/MdeModulePkg.dec
+
+[Sources]
+ DxeRuntimeVariableWriteLib.c
+
+[LibraryClasses]
+ DebugLib
+ UefiLib
+ UefiBootServicesTableLib
+ UefiRuntimeServicesTableLib
+
+[Guids]
+ gEfiEventExitBootServicesGuid ## CONSUMES ## Event
+
+[Protocols]
+ gEfiVariableWriteArchProtocolGuid ## CONSUMES
+ gEdkiiVariableLockProtocolGuid ## CONSUMES
+
+[Depex]
+ gEfiVariableWriteArchProtocolGuid AND gEdkiiVariableLockProtocolGuid
diff --git a/Platform/Intel/MinPlatformPkg/Library/SmmVariableWriteLib/SmmVariableWriteCommon.c b/Platform/Intel/MinPlatformPkg/Library/SmmVariableWriteLib/SmmVariableWriteCommon.c
new file mode 100644
index 0000000000..e8d7d19ed1
--- /dev/null
+++ b/Platform/Intel/MinPlatformPkg/Library/SmmVariableWriteLib/SmmVariableWriteCommon.c
@@ -0,0 +1,167 @@
+/** @file
+ SMM Variable Write Lib
+
+ This library provides phase agnostic access to the UEFI Variable Services.
+ This is done by implementing a wrapper on top of the phase specific mechanism
+ for writing to UEFI variables.
+
+ This is the common implementation pieces that are shared between
+ traditional SMM and standalone MM.
+
+ Copyright (c) 2021, Intel Corporation. All rights reserved.<BR>
+ SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <Uefi/UefiBaseType.h>
+
+#include <Protocol/SmmVariable.h>
+
+EFI_SMM_VARIABLE_PROTOCOL *mVariableWriteLibSmmVariable = NULL;
+
+/**
+ Sets the value of a variable.
+
+ @param[in] VariableName A Null-terminated string that is the name of the vendor's variable.
+ Each VariableName is unique for each VendorGuid. VariableName must
+ contain 1 or more characters. If VariableName is an empty string,
+ then EFI_INVALID_PARAMETER is returned.
+ @param[in] VendorGuid A unique identifier for the vendor.
+ @param[in] Attributes Attributes bitmask to set for the variable.
+ @param[in] DataSize The size in bytes of the Data buffer. Unless the EFI_VARIABLE_APPEND_WRITE or
+ EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS attribute is set, a size of zero
+ causes the variable to be deleted. When the EFI_VARIABLE_APPEND_WRITE attribute is
+ set, then a SetVariable() call with a DataSize of zero will not cause any change to
+ the variable value (the timestamp associated with the variable may be updated however
+ even if no new data value is provided,see the description of the
+ EFI_VARIABLE_AUTHENTICATION_2 descriptor below. In this case the DataSize will not
+ be zero since the EFI_VARIABLE_AUTHENTICATION_2 descriptor will be populated).
+ @param[in] Data The contents for the variable.
+
+ @retval EFI_SUCCESS The firmware has successfully stored the variable and its data as
+ defined by the Attributes.
+ @retval EFI_INVALID_PARAMETER An invalid combination of attribute bits, name, and GUID was supplied, or the
+ DataSize exceeds the maximum allowed.
+ @retval EFI_INVALID_PARAMETER VariableName is an empty string.
+ @retval EFI_OUT_OF_RESOURCES Not enough storage is available to hold the variable and its data.
+ @retval EFI_DEVICE_ERROR The variable could not be retrieved due to a hardware error.
+ @retval EFI_WRITE_PROTECTED The variable in question is read-only.
+ @retval EFI_WRITE_PROTECTED The variable in question cannot be deleted.
+ @retval EFI_SECURITY_VIOLATION The variable could not be written due to EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACESS being set,
+ but the AuthInfo does NOT pass the validation check carried out by the firmware.
+
+ @retval EFI_NOT_FOUND The variable trying to be updated or deleted was not found.
+
+**/
+EFI_STATUS
+EFIAPI
+VarLibSetVariable (
+ IN CHAR16 *VariableName,
+ IN EFI_GUID *VendorGuid,
+ IN UINT32 Attributes,
+ IN UINTN DataSize,
+ IN VOID *Data
+ )
+{
+ EFI_STATUS Status = EFI_UNSUPPORTED;
+
+ if (mVariableWriteLibSmmVariable != NULL) {
+ Status = mVariableWriteLibSmmVariable->SmmSetVariable (
+ VariableName,
+ VendorGuid,
+ Attributes,
+ DataSize,
+ Data
+ );
+ }
+ return Status;
+}
+
+/**
+ Returns information about the EFI variables.
+
+ @param[in] Attributes Attributes bitmask to specify the type of variables on
+ which to return information.
+ @param[out] MaximumVariableStorageSize On output the maximum size of the storage space
+ available for the EFI variables associated with the
+ attributes specified.
+ @param[out] RemainingVariableStorageSize Returns the remaining size of the storage space
+ available for the EFI variables associated with the
+ attributes specified.
+ @param[out] MaximumVariableSize Returns the maximum size of the individual EFI
+ variables associated with the attributes specified.
+
+ @retval EFI_SUCCESS Valid answer returned.
+ @retval EFI_INVALID_PARAMETER An invalid combination of attribute bits was supplied
+ @retval EFI_UNSUPPORTED The attribute is not supported on this platform, and the
+ MaximumVariableStorageSize,
+ RemainingVariableStorageSize, MaximumVariableSize
+ are undefined.
+**/
+EFI_STATUS
+EFIAPI
+VarLibQueryVariableInfo (
+ IN UINT32 Attributes,
+ OUT UINT64 *MaximumVariableStorageSize,
+ OUT UINT64 *RemainingVariableStorageSize,
+ OUT UINT64 *MaximumVariableSize
+ )
+{
+ EFI_STATUS Status = EFI_UNSUPPORTED;
+
+ if (mVariableWriteLibSmmVariable != NULL) {
+ Status = mVariableWriteLibSmmVariable->SmmQueryVariableInfo (
+ Attributes,
+ MaximumVariableStorageSize,
+ RemainingVariableStorageSize,
+ MaximumVariableSize
+ );
+ }
+ return Status;
+}
+
+/**
+ Indicates if the VarLibVariableRequestToLock() API is supported by the current
+ VariableWriteLib implementation. At time of writting, this API is not
+ available in SMM or after ExitBootServices.
+
+ @retval TRUE The VarLibVariableRequestToLock() API is supported
+ @retval FALSE The VarLibVariableRequestToLock() API is not supported
+**/
+BOOLEAN
+EFIAPI
+VarLibIsVariableRequestToLockSupported (
+ VOID
+ )
+{
+ return FALSE;
+}
+
+/**
+ Mark a variable that will become read-only after leaving the DXE phase of execution.
+ Write request coming from SMM environment through EFI_SMM_VARIABLE_PROTOCOL is allowed.
+
+ @param[in] This The EDKII_VARIABLE_LOCK_PROTOCOL instance.
+ @param[in] VariableName A pointer to the variable name that will be made read-only subsequently.
+ @param[in] VendorGuid A pointer to the vendor GUID that will be made read-only subsequently.
+
+ @retval EFI_SUCCESS The variable specified by the VariableName and the VendorGuid was marked
+ as pending to be read-only.
+ @retval EFI_INVALID_PARAMETER VariableName or VendorGuid is NULL.
+ Or VariableName is an empty string.
+ @retval EFI_ACCESS_DENIED EFI_END_OF_DXE_EVENT_GROUP_GUID or EFI_EVENT_GROUP_READY_TO_BOOT has
+ already been signaled.
+ @retval EFI_OUT_OF_RESOURCES There is not enough resource to hold the lock request.
+**/
+EFI_STATUS
+EFIAPI
+VarLibVariableRequestToLock (
+ IN CHAR16 *VariableName,
+ IN EFI_GUID *VendorGuid
+ )
+{
+ //
+ // Variable lock protocol is not accessible from SMM
+ //
+ return EFI_UNSUPPORTED;
+}
diff --git a/Platform/Intel/MinPlatformPkg/Library/SmmVariableWriteLib/StandaloneMmVariableWriteLib.inf b/Platform/Intel/MinPlatformPkg/Library/SmmVariableWriteLib/StandaloneMmVariableWriteLib.inf
new file mode 100644
index 0000000000..4cafc421c4
--- /dev/null
+++ b/Platform/Intel/MinPlatformPkg/Library/SmmVariableWriteLib/StandaloneMmVariableWriteLib.inf
@@ -0,0 +1,45 @@
+## @file
+# Component description file for Standalone MM Variable Write Lib
+#
+# This library provides phase agnostic access to the UEFI Variable Services.
+# This is done by implementing a wrapper on top of the phase specific mechanism
+# for writing to UEFI variables. For example, the DXE implementation accesses
+# the UEFI Runtime Services Table, and the SMM implementation uses
+# EFI_SMM_VARIABLE_PROTOCOL.
+#
+# Using this library allows code to be written in a generic manner that can be
+# used in DXE or SMM without modification.
+#
+# Copyright (c) 2021, Intel Corporation. All rights reserved.<BR>
+#
+# SPDX-License-Identifier: BSD-2-Clause-Patent
+#
+##
+
+[Defines]
+ INF_VERSION = 0x0001001B
+ BASE_NAME = SmmVariableWriteLib
+ FILE_GUID = 62A023A6-DEBA-4407-A617-18963090DAFD
+ VERSION_STRING = 1.0
+ MODULE_TYPE = MM_STANDALONE
+ PI_SPECIFICATION_VERSION = 0x00010032
+ LIBRARY_CLASS = VariableWriteLib|MM_STANDALONE
+ CONSTRUCTOR = StandaloneMmVariableWriteLibConstructor
+
+[Packages]
+ MdePkg/MdePkg.dec
+ MdeModulePkg/MdeModulePkg.dec
+
+[Sources]
+ SmmVariableWriteCommon.c
+ StandaloneMmVariableWriteLibConstructor.c
+
+[LibraryClasses]
+ DebugLib
+ MmServicesTableLib
+
+[Protocols]
+ gEfiSmmVariableProtocolGuid ## CONSUMES
+
+[Depex]
+ gEfiSmmVariableProtocolGuid
diff --git a/Platform/Intel/MinPlatformPkg/Library/SmmVariableWriteLib/StandaloneMmVariableWriteLibConstructor.c b/Platform/Intel/MinPlatformPkg/Library/SmmVariableWriteLib/StandaloneMmVariableWriteLibConstructor.c
new file mode 100644
index 0000000000..4493929328
--- /dev/null
+++ b/Platform/Intel/MinPlatformPkg/Library/SmmVariableWriteLib/StandaloneMmVariableWriteLibConstructor.c
@@ -0,0 +1,48 @@
+/** @file
+ Standalone MM Variable Write Lib
+
+ This library provides phase agnostic access to the UEFI Variable Services.
+ This is done by implementing a wrapper on top of the phase specific mechanism
+ for reading from UEFI variables.
+
+ This is the standalone MM specific LibraryClass constructor.
+
+ Copyright (c) 2021, Intel Corporation. All rights reserved.<BR>
+ SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <Uefi/UefiBaseType.h>
+
+#include <Protocol/SmmVariable.h>
+
+#include <Library/DebugLib.h>
+#include <Library/MmServicesTableLib.h>
+
+extern EFI_SMM_VARIABLE_PROTOCOL *mVariableWriteLibSmmVariable;
+
+/**
+ The constructor function acquires the EFI SMM Variable Services
+
+ @param ImageHandle The firmware allocated handle for the EFI image.
+ @param SystemTable A pointer to the MM System Table.
+
+ @retval EFI_SUCCESS The constructor always returns RETURN_SUCCESS.
+
+**/
+EFI_STATUS
+EFIAPI
+StandaloneMmVariableWriteLibConstructor (
+ IN EFI_HANDLE ImageHandle,
+ IN EFI_MM_SYSTEM_TABLE *SystemTable
+ )
+{
+ EFI_STATUS Status;
+
+ //
+ // Locate SmmVariableProtocol.
+ //
+ Status = gMmst->MmLocateProtocol (&gEfiSmmVariableProtocolGuid, NULL, (VOID **) &mVariableWriteLibSmmVariable);
+ ASSERT_EFI_ERROR (Status);
+ return Status;
+}
diff --git a/Platform/Intel/MinPlatformPkg/Library/SmmVariableWriteLib/TraditionalMmVariableWriteLib.inf b/Platform/Intel/MinPlatformPkg/Library/SmmVariableWriteLib/TraditionalMmVariableWriteLib.inf
new file mode 100644
index 0000000000..5d833b7e0f
--- /dev/null
+++ b/Platform/Intel/MinPlatformPkg/Library/SmmVariableWriteLib/TraditionalMmVariableWriteLib.inf
@@ -0,0 +1,44 @@
+## @file
+# Component description file for Traditional MM Variable Write Lib
+#
+# This library provides phase agnostic access to the UEFI Variable Services.
+# This is done by implementing a wrapper on top of the phase specific mechanism
+# for writing to UEFI variables. For example, the DXE implementation accesses
+# the UEFI Runtime Services Table, and the SMM implementation uses
+# EFI_SMM_VARIABLE_PROTOCOL.
+#
+# Using this library allows code to be written in a generic manner that can be
+# used in DXE or SMM without modification.
+#
+# Copyright (c) 2021, Intel Corporation. All rights reserved.<BR>
+#
+# SPDX-License-Identifier: BSD-2-Clause-Patent
+#
+##
+
+[Defines]
+ INF_VERSION = 0x00010005
+ BASE_NAME = TraditionalMmVariableWriteLib
+ FILE_GUID = 8C385E9B-C260-466C-91D2-43D839712680
+ VERSION_STRING = 1.0
+ MODULE_TYPE = DXE_SMM_DRIVER
+ LIBRARY_CLASS = VariableWriteLib|DXE_SMM_DRIVER SMM_CORE
+ CONSTRUCTOR = TraditionalMmVariableWriteLibConstructor
+
+[Packages]
+ MdePkg/MdePkg.dec
+ MdeModulePkg/MdeModulePkg.dec
+
+[Sources]
+ SmmVariableWriteCommon.c
+ TraditionalMmVariableWriteLibConstructor.c
+
+[LibraryClasses]
+ DebugLib
+ SmmServicesTableLib
+
+[Protocols]
+ gEfiSmmVariableProtocolGuid ## CONSUMES
+
+[Depex]
+ gEfiSmmVariableProtocolGuid
diff --git a/Platform/Intel/MinPlatformPkg/Library/SmmVariableWriteLib/TraditionalMmVariableWriteLibConstructor.c b/Platform/Intel/MinPlatformPkg/Library/SmmVariableWriteLib/TraditionalMmVariableWriteLibConstructor.c
new file mode 100644
index 0000000000..472ccc5aad
--- /dev/null
+++ b/Platform/Intel/MinPlatformPkg/Library/SmmVariableWriteLib/TraditionalMmVariableWriteLibConstructor.c
@@ -0,0 +1,48 @@
+/** @file
+ Traditional MM Variable Write Lib
+
+ This library provides phase agnostic access to the UEFI Variable Services.
+ This is done by implementing a wrapper on top of the phase specific mechanism
+ for reading from UEFI variables.
+
+ This is the traditional SMM specific LibraryClass constructor.
+
+ Copyright (c) 2021, Intel Corporation. All rights reserved.<BR>
+ SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <Uefi.h>
+
+#include <Protocol/SmmVariable.h>
+
+#include <Library/DebugLib.h>
+#include <Library/SmmServicesTableLib.h>
+
+extern EFI_SMM_VARIABLE_PROTOCOL *mVariableWriteLibSmmVariable;
+
+/**
+ The constructor function acquires the EFI SMM Variable Services
+
+ @param ImageHandle The firmware allocated handle for the EFI image.
+ @param SystemTable A pointer to the EFI System Table.
+
+ @retval EFI_SUCCESS The constructor always returns RETURN_SUCCESS.
+
+**/
+EFI_STATUS
+EFIAPI
+TraditionalMmVariableWriteLibConstructor (
+ IN EFI_HANDLE ImageHandle,
+ IN EFI_SYSTEM_TABLE *SystemTable
+ )
+{
+ EFI_STATUS Status;
+
+ //
+ // Locate SmmVariableProtocol.
+ //
+ Status = gSmst->SmmLocateProtocol (&gEfiSmmVariableProtocolGuid, NULL, (VOID **) &mVariableWriteLibSmmVariable);
+ ASSERT_EFI_ERROR (Status);
+ return Status;
+}
diff --git a/Platform/Intel/MinPlatformPkg/MinPlatformPkg.dsc b/Platform/Intel/MinPlatformPkg/MinPlatformPkg.dsc
index 18b5c6f5b1..e968ec4cb2 100644
--- a/Platform/Intel/MinPlatformPkg/MinPlatformPkg.dsc
+++ b/Platform/Intel/MinPlatformPkg/MinPlatformPkg.dsc
@@ -121,6 +121,7 @@
SpiFlashCommonLib|MinPlatformPkg/Flash/Library/SpiFlashCommonLibNull/SpiFlashCommonLibNull.inf
StandaloneMmDriverEntryPoint|MdePkg/Library/StandaloneMmDriverEntryPoint/StandaloneMmDriverEntryPoint.inf
VariableReadLib|MinPlatformPkg/Library/SmmVariableReadLib/StandaloneMmVariableReadLib.inf
+ VariableWriteLib|MinPlatformPkg/Library/SmmVariableWriteLib/StandaloneMmVariableWriteLib.inf
###################################################################################################
#
--
2.27.0.windows.1
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