Hi Michael,

I have a minor suggestion marked inline as [SAMI].

Otherwise this patch looks good to me.

Reviewed-by: Sami Mujawar <sami.mujawar@...>

Regards,

Sami Mujawar

On 12/04/2022 05:29 pm, Michael Kubacki via groups.io wrote:

From: Michael Kubacki <michael.kubacki@...>

REF:https://bugzilla.tianocore.org/show_bug.cgi?id=3479

Adds a new library class VariableFlashInfoLib that abstracts access
to variable flash information. The instance provided first attempts
to retrieve information from the Variable Flash Info HOB. If that
HOB is not present, it falls back to the PCDs defined in
MdeModulePkg.

This fall back behavior provides backward compatibility for platforms
that only provide PCDs but also allows platforms that need to
dynamically provide the information using the Variable Flash Info HOB
to do so at runtime.

Cc: Jian J Wang <jian.j.wang@...>
Cc: Hao A Wu <hao.a.wu@...>
Cc: Liming Gao <gaoliming@...>
Signed-off-by: Michael Kubacki <michael.kubacki@...>
---
MdeModulePkg/Library/BaseVariableFlashInfoLib/BaseVariableFlashInfoLib.c | 178 ++++++++++++++++++++
MdeModulePkg/Include/Library/VariableFlashInfoLib.h | 68 ++++++++
MdeModulePkg/Library/BaseVariableFlashInfoLib/BaseVariableFlashInfoLib.inf | 48 ++++++
MdeModulePkg/Library/BaseVariableFlashInfoLib/BaseVariableFlashInfoLib.uni | 12 ++
MdeModulePkg/MdeModulePkg.dec | 4 +
MdeModulePkg/MdeModulePkg.dsc | 2 +
6 files changed, 312 insertions(+)

diff --git a/MdeModulePkg/Library/BaseVariableFlashInfoLib/BaseVariableFlashInfoLib.c b/MdeModulePkg/Library/BaseVariableFlashInfoLib/BaseVariableFlashInfoLib.c
new file mode 100644
index 000000000000..a1db97bdf218
--- /dev/null
+++ b/MdeModulePkg/Library/BaseVariableFlashInfoLib/BaseVariableFlashInfoLib.c
@@ -0,0 +1,178 @@
+/** @file
+ Variable Flash Information Library
+
+ Copyright (c) Microsoft Corporation<BR>
+
+ SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <Uefi.h>
+#include <Pi/PiMultiPhase.h>
+#include <Guid/VariableFlashInfo.h>
+#include <Library/DebugLib.h>
+#include <Library/HobLib.h>
+#include <Library/VariableFlashInfoLib.h>
+
+/**
+ Get the HOB that contains variable flash information.
+
+ @param[out] VariableFlashInfo Pointer to a pointer to set to the variable flash information structure.
+
+ @retval EFI_SUCCESS Variable flash information was found successfully.
+ @retval EFI_INVALID_PARAMETER The VariableFlashInfo pointer given is NULL.
+ @retval EFI_NOT_FOUND Variable flash information could not be found.
+
+**/
+EFI_STATUS
+GetVariableFlashInfoFromHob (
+ OUT VARIABLE_FLASH_INFO **VariableFlashInfo
+ )

[SAMI] Can this function be made STATIC, please?

+{
+ EFI_HOB_GUID_TYPE *GuidHob;
+
+ if (VariableFlashInfo == NULL) {
+ return EFI_INVALID_PARAMETER;
+ }
+
+ GuidHob = GetFirstGuidHob (&gVariableFlashInfoHobGuid);
+ if (GuidHob == NULL) {
+ return EFI_NOT_FOUND;
+ }
+
+ *VariableFlashInfo = GET_GUID_HOB_DATA (GuidHob);
+
+ //
+ // Assert if more than one variable flash information HOB is present.
+ //
+ DEBUG_CODE (
+ if ((GetNextGuidHob (&gVariableFlashInfoHobGuid, GET_NEXT_HOB (GuidHob)) != NULL)) {
+ DEBUG ((DEBUG_ERROR, "ERROR: Found two variable flash information HOBs\n"));
+ ASSERT (FALSE);
+ }
+
+ );
+
+ return EFI_SUCCESS;
+}
+
+/**
+ Get the base address and size for the NV storage area used for UEFI variable storage.
+
+ @param[out] BaseAddress The NV storage base address.
+ @param[out] Length The NV storage length in bytes.
+
+ @retval EFI_SUCCESS NV storage information was found successfully.
+ @retval EFI_INVALID_PARAMETER A required pointer parameter is NULL.
+
+**/
+EFI_STATUS
+EFIAPI
+GetVariableFlashNvStorageInfo (
+ OUT EFI_PHYSICAL_ADDRESS *BaseAddress,
+ OUT UINT64 *Length
+ )
+{
+ EFI_STATUS Status;
+ VARIABLE_FLASH_INFO *VariableFlashInfo;
+
+ if ((BaseAddress == NULL) || (Length == NULL)) {
+ return EFI_INVALID_PARAMETER;
+ }
+
+ Status = GetVariableFlashInfoFromHob (&VariableFlashInfo);
+ if (!EFI_ERROR (Status)) {
+ *BaseAddress = VariableFlashInfo->NvVariableBaseAddress;
+ *Length = VariableFlashInfo->NvVariableLength;
+ } else {
+ *BaseAddress = (EFI_PHYSICAL_ADDRESS)(PcdGet64 (PcdFlashNvStorageVariableBase64) != 0 ?
+ PcdGet64 (PcdFlashNvStorageVariableBase64) :
+ PcdGet32 (PcdFlashNvStorageVariableBase)
+ );
+ *Length = (UINT64)PcdGet32 (PcdFlashNvStorageVariableSize);
+ }
+
+ return EFI_SUCCESS;
+}
+
+/**
+ Get the base address and size for the fault tolerant write (FTW) spare
+ area used for UEFI variable storage.
+
+ @param[out] BaseAddress The FTW spare base address.
+ @param[out] Length The FTW spare length in bytes.
+
+ @retval EFI_SUCCESS FTW spare information was found successfully.
+ @retval EFI_INVALID_PARAMETER A required pointer parameter is NULL.
+ @retval EFI_NOT_FOUND FTW spare information could not be found.
+
+**/
+EFI_STATUS
+EFIAPI
+GetVariableFlashFtwSpareInfo (
+ OUT EFI_PHYSICAL_ADDRESS *BaseAddress,
+ OUT UINT64 *Length
+ )
+{
+ EFI_STATUS Status;
+ VARIABLE_FLASH_INFO *VariableFlashInfo;
+
+ if ((BaseAddress == NULL) || (Length == NULL)) {
+ return EFI_INVALID_PARAMETER;
+ }
+
+ Status = GetVariableFlashInfoFromHob (&VariableFlashInfo);
+ if (!EFI_ERROR (Status)) {
+ *BaseAddress = VariableFlashInfo->FtwSpareBaseAddress;
+ *Length = VariableFlashInfo->FtwSpareLength;
+ } else {
+ *BaseAddress = (EFI_PHYSICAL_ADDRESS)(PcdGet64 (PcdFlashNvStorageFtwSpareBase64) != 0 ?
+ PcdGet64 (PcdFlashNvStorageFtwSpareBase64) :
+ PcdGet32 (PcdFlashNvStorageFtwSpareBase)
+ );
+ *Length = (UINT64)PcdGet32 (PcdFlashNvStorageFtwSpareSize);
+ }
+
+ return EFI_SUCCESS;
+}
+
+/**
+ Get the base address and size for the fault tolerant write (FTW) working
+ area used for UEFI variable storage.
+
+ @param[out] BaseAddress The FTW working area base address.
+ @param[out] Length The FTW working area length in bytes.
+
+ @retval EFI_SUCCESS FTW working information was found successfully.
+ @retval EFI_INVALID_PARAMETER A required pointer parameter is NULL.
+ @retval EFI_NOT_FOUND FTW working information could not be found.
+
+**/
+EFI_STATUS
+EFIAPI
+GetVariableFlashFtwWorkingInfo (
+ OUT EFI_PHYSICAL_ADDRESS *BaseAddress,
+ OUT UINT64 *Length
+ )
+{
+ EFI_STATUS Status;
+ VARIABLE_FLASH_INFO *VariableFlashInfo;
+
+ if ((BaseAddress == NULL) || (Length == NULL)) {
+ return EFI_INVALID_PARAMETER;
+ }
+
+ Status = GetVariableFlashInfoFromHob (&VariableFlashInfo);
+ if (!EFI_ERROR (Status)) {
+ *BaseAddress = VariableFlashInfo->FtwWorkingBaseAddress;
+ *Length = VariableFlashInfo->FtwWorkingLength;
+ } else {
+ *BaseAddress = (EFI_PHYSICAL_ADDRESS)(PcdGet64 (PcdFlashNvStorageFtwWorkingBase64) != 0 ?
+ PcdGet64 (PcdFlashNvStorageFtwWorkingBase64) :
+ PcdGet32 (PcdFlashNvStorageFtwWorkingBase)
+ );
+ *Length = (UINT64)PcdGet32 (PcdFlashNvStorageFtwWorkingSize);
+ }
+
+ return EFI_SUCCESS;
+}
diff --git a/MdeModulePkg/Include/Library/VariableFlashInfoLib.h b/MdeModulePkg/Include/Library/VariableFlashInfoLib.h
new file mode 100644
index 000000000000..1367be9376ea
--- /dev/null
+++ b/MdeModulePkg/Include/Library/VariableFlashInfoLib.h
@@ -0,0 +1,68 @@
+/** @file
+ Variable Flash Information Library
+
+Copyright (c) Microsoft Corporation<BR>
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#ifndef VARIABLE_FLASH_INFO_LIB_H_
+#define VARIABLE_FLASH_INFO_LIB_H_
+
+/**
+ Get the base address and size for the NV storage area used for UEFI variable storage.
+
+ @param[out] BaseAddress The NV storage base address.
+ @param[out] Length The NV storage length in bytes.
+
+ @retval EFI_SUCCESS NV storage information was found successfully.
+ @retval EFI_INVALID_PARAMETER A required pointer parameter is NULL.
+ @retval EFI_NOT_FOUND NV storage information could not be found.
+
+**/
+EFI_STATUS
+EFIAPI
+GetVariableFlashNvStorageInfo (
+ OUT EFI_PHYSICAL_ADDRESS *BaseAddress,
+ OUT UINT64 *Length
+ );
+
+/**
+ Get the base address and size for the fault tolerant write (FTW) spare
+ area used for UEFI variable storage.
+
+ @param[out] BaseAddress The FTW spare base address.
+ @param[out] Length The FTW spare length in bytes.
+
+ @retval EFI_SUCCESS FTW spare information was found successfully.
+ @retval EFI_INVALID_PARAMETER A required pointer parameter is NULL.
+ @retval EFI_NOT_FOUND FTW spare information could not be found.
+
+**/
+EFI_STATUS
+EFIAPI
+GetVariableFlashFtwSpareInfo (
+ OUT EFI_PHYSICAL_ADDRESS *BaseAddress,
+ OUT UINT64 *Length
+ );
+
+/**
+ Get the base address and size for the fault tolerant write (FTW) working
+ area used for UEFI variable storage.
+
+ @param[out] BaseAddress The FTW working area base address.
+ @param[out] Length The FTW working area length in bytes.
+
+ @retval EFI_SUCCESS FTW working information was found successfully.
+ @retval EFI_INVALID_PARAMETER A required pointer parameter is NULL.
+ @retval EFI_NOT_FOUND FTW working information could not be found.
+
+**/
+EFI_STATUS
+EFIAPI
+GetVariableFlashFtwWorkingInfo (
+ OUT EFI_PHYSICAL_ADDRESS *BaseAddress,
+ OUT UINT64 *Length
+ );
+
+#endif
diff --git a/MdeModulePkg/Library/BaseVariableFlashInfoLib/BaseVariableFlashInfoLib.inf b/MdeModulePkg/Library/BaseVariableFlashInfoLib/BaseVariableFlashInfoLib.inf
new file mode 100644
index 000000000000..70175e75f9b1
--- /dev/null
+++ b/MdeModulePkg/Library/BaseVariableFlashInfoLib/BaseVariableFlashInfoLib.inf
@@ -0,0 +1,48 @@
+## @file
+# Variable Flash Information Library
+#
+# Provides services to access UEFI variable flash information.
+#
+# Copyright (c) Microsoft Corporation<BR>
+# SPDX-License-Identifier: BSD-2-Clause-Patent
+##
+
+[Defines]
+ INF_VERSION = 0x00010005
+ BASE_NAME = BaseVariableFlashInfoLib
+ MODULE_UNI_FILE = BaseVariableFlashInfoLib.uni
+ FILE_GUID = DEC426C9-C92E-4BAD-8E93-3F61C261118B
+ MODULE_TYPE = BASE
+ VERSION_STRING = 1.0
+ LIBRARY_CLASS = VariableFlashInfoLib
+
+#
+# The following information is for reference only and not required by the build tools.
+#
+# VALID_ARCHITECTURES = ANY
+#
+
+[Sources]
+ BaseVariableFlashInfoLib.c
+
+[Packages]
+ MdePkg/MdePkg.dec
+ MdeModulePkg/MdeModulePkg.dec
+
+[LibraryClasses]
+ DebugLib
+ HobLib
+
+[Guids]
+ gVariableFlashInfoHobGuid ## CONSUMES ## HOB
+
+[Pcd]
+ gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageVariableBase ## SOMETIMES_CONSUMES
+ gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageVariableBase64 ## SOMETIMES_CONSUMES
+ gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageVariableSize ## SOMETIMES_CONSUMES
+ gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageFtwSpareBase ## SOMETIMES_CONSUMES
+ gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageFtwSpareBase64 ## SOMETIMES_CONSUMES
+ gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageFtwSpareSize ## SOMETIMES_CONSUMES
+ gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageFtwWorkingBase ## SOMETIMES_CONSUMES
+ gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageFtwWorkingBase64 ## SOMETIMES_CONSUMES
+ gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageFtwWorkingSize ## SOMETIMES_CONSUMES
diff --git a/MdeModulePkg/Library/BaseVariableFlashInfoLib/BaseVariableFlashInfoLib.uni b/MdeModulePkg/Library/BaseVariableFlashInfoLib/BaseVariableFlashInfoLib.uni
new file mode 100644
index 000000000000..9a5348fa02a0
--- /dev/null
+++ b/MdeModulePkg/Library/BaseVariableFlashInfoLib/BaseVariableFlashInfoLib.uni
@@ -0,0 +1,12 @@
+// /** @file
+// Variable Flash Information Library
+//
+// Copyright (c) Microsoft Corporation<BR>
+//
+// SPDX-License-Identifier: BSD-2-Clause-Patent
+//
+// **/
+
+#string STR_MODULE_ABSTRACT #language en-US "UEFI variable flash information library"
+
+#string STR_MODULE_DESCRIPTION #language en-US "Provides services to access UEFI variable flash information."
diff --git a/MdeModulePkg/MdeModulePkg.dec b/MdeModulePkg/MdeModulePkg.dec
index 4e82f5836096..2bcb9f9453af 100644
--- a/MdeModulePkg/MdeModulePkg.dec
+++ b/MdeModulePkg/MdeModulePkg.dec
@@ -154,6 +154,10 @@ [LibraryClasses]
#
VariablePolicyHelperLib|Include/Library/VariablePolicyHelperLib.h
+ ## @libraryclass Provides services to access UEFI variable flash information.
+ #
+ VariableFlashInfoLib|Include/Library/VariableFlashInfoLib.h
+
[Guids]
## MdeModule package token space guid
# Include/Guid/MdeModulePkgTokenSpace.h
diff --git a/MdeModulePkg/MdeModulePkg.dsc b/MdeModulePkg/MdeModulePkg.dsc
index b1d83461865e..90a0a7ec4a7c 100644
--- a/MdeModulePkg/MdeModulePkg.dsc
+++ b/MdeModulePkg/MdeModulePkg.dsc
@@ -103,6 +103,7 @@ [LibraryClasses]
DisplayUpdateProgressLib|MdeModulePkg/Library/DisplayUpdateProgressLibGraphics/DisplayUpdateProgressLibGraphics.inf
VariablePolicyHelperLib|MdeModulePkg/Library/VariablePolicyHelperLib/VariablePolicyHelperLib.inf
MmUnblockMemoryLib|MdePkg/Library/MmUnblockMemoryLib/MmUnblockMemoryLibNull.inf
+ VariableFlashInfoLib|MdeModulePkg/Library/BaseVariableFlashInfoLib/BaseVariableFlashInfoLib.inf
[LibraryClasses.EBC.PEIM]
IoLib|MdePkg/Library/PeiIoLibCpuIo/PeiIoLibCpuIo.inf
@@ -440,6 +441,7 @@ [Components]
MdeModulePkg/Library/FmpAuthenticationLibNull/FmpAuthenticationLibNull.inf
MdeModulePkg/Library/DxeCapsuleLibFmp/DxeCapsuleLib.inf
MdeModulePkg/Library/DxeCapsuleLibFmp/DxeRuntimeCapsuleLib.inf
+ MdeModulePkg/Library/BaseVariableFlashInfoLib/BaseVariableFlashInfoLib.inf
[Components.IA32, Components.X64, Components.AARCH64]
MdeModulePkg/Universal/EbcDxe/EbcDxe.inf