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Message-ID: <7a458180-d131-fb33-12f9-03362df72a14@linux.microsoft.com>
Date: Mon, 25 Apr 2022 18:21:52 -0400
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Subject: Re: [edk2-devel] [PATCH v4 2/8] MdeModulePkg/VariableFlashInfoLib: Add initial library
To: devel@edk2.groups.io, sami.mujawar@arm.com
Cc: Jian J Wang <jian.j.wang@intel.com>, Hao A Wu <hao.a.wu@intel.com>,
 Liming Gao <gaoliming@byosoft.com.cn>, nd@arm.com
References: <20220412162940.4978-1-mikuback@linux.microsoft.com>
 <20220412162940.4978-3-mikuback@linux.microsoft.com>
 <45a37a8e-0fd7-45a4-5eec-dbbc0d42ba33@arm.com>
From: "Michael Kubacki" <mikuback@linux.microsoft.com>
In-Reply-To: <45a37a8e-0fd7-45a4-5eec-dbbc0d42ba33@arm.com>
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Thanks for your review. I will make that change.

Regards,
Michael

On 4/25/2022 12:05 PM, Sami Mujawar wrote:
> Hi Michael,
>=20
> I have a minor suggestion marked inline as [SAMI].
>=20
> Otherwise this patch looks good to me.
>=20
> Reviewed-by: Sami Mujawar <sami.mujawar@arm.com>
>=20
> Regards,
>=20
> Sami Mujawar
>=20
> On 12/04/2022 05:29 pm, Michael Kubacki via groups.io wrote:
>> From: Michael Kubacki <michael.kubacki@microsoft.com>
>>
>> REF:https://bugzilla.tianocore.org/show_bug.cgi?id=3D3479
>>
>> 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@intel.com>
>> Cc: Hao A Wu <hao.a.wu@intel.com>
>> Cc: Liming Gao <gaoliming@byosoft.com.cn>
>> Signed-off-by: Michael Kubacki <michael.kubacki@microsoft.com>
>> ---
>>  =20
>> MdeModulePkg/Library/BaseVariableFlashInfoLib/BaseVariableFlashInfoLib.c=
  =20
>> | 178 ++++++++++++++++++++
>>  =20
>> MdeModulePkg/Include/Library/VariableFlashInfoLib.h                     =
  =20
>> |=C2=A0 68 ++++++++
>>  =20
>> MdeModulePkg/Library/BaseVariableFlashInfoLib/BaseVariableFlashInfoLib.i=
nf=20
>> |=C2=A0 48 ++++++
>>  =20
>> MdeModulePkg/Library/BaseVariableFlashInfoLib/BaseVariableFlashInfoLib.u=
ni=20
>> |=C2=A0 12 ++
>>  =20
>> MdeModulePkg/MdeModulePkg.dec                                           =
  =20
>> |=C2=A0=C2=A0 4 +
>>  =20
>> MdeModulePkg/MdeModulePkg.dsc                                           =
  =20
>> |=C2=A0=C2=A0 2 +
>> =C2=A0 6 files changed, 312 insertions(+)
>>
>> diff --git=20
>> a/MdeModulePkg/Library/BaseVariableFlashInfoLib/BaseVariableFlashInfoLib=
.c=20
>> b/MdeModulePkg/Library/BaseVariableFlashInfoLib/BaseVariableFlashInfoLib=
.c=20
>>
>> new file mode 100644
>> index 000000000000..a1db97bdf218
>> --- /dev/null
>> +++=20
>> b/MdeModulePkg/Library/BaseVariableFlashInfoLib/BaseVariableFlashInfoLib=
.c=20
>>
>> @@ -0,0 +1,178 @@
>> +/** @file
>> +=C2=A0 Variable Flash Information Library
>> +
>> +=C2=A0 Copyright (c) Microsoft Corporation<BR>
>> +
>> +=C2=A0 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>
>> +
>> +/**
>> +=C2=A0 Get the HOB that contains variable flash information.
>> +
>> +=C2=A0 @param[out] VariableFlashInfo=C2=A0=C2=A0 Pointer to a pointer t=
o set to the=20
>> variable flash information structure.
>> +
>> +=C2=A0 @retval EFI_SUCCESS=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=
=A0=C2=A0=C2=A0=C2=A0=C2=A0 Variable flash information was=20
>> found successfully.
>> +=C2=A0 @retval EFI_INVALID_PARAMETER=C2=A0=C2=A0 The VariableFlashInfo =
pointer given=20
>> is NULL.
>> +=C2=A0 @retval EFI_NOT_FOUND=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=
=C2=A0=C2=A0=C2=A0 Variable flash information could=20
>> not be found.
>> +
>> +**/
>> +EFI_STATUS
>> +GetVariableFlashInfoFromHob (
>> +=C2=A0 OUT VARIABLE_FLASH_INFO=C2=A0 **VariableFlashInfo
>> +=C2=A0 )
> [SAMI] Can this function be made STATIC, please?
>> +{
>> +=C2=A0 EFI_HOB_GUID_TYPE=C2=A0 *GuidHob;
>> +
>> +=C2=A0 if (VariableFlashInfo =3D=3D NULL) {
>> +=C2=A0=C2=A0=C2=A0 return EFI_INVALID_PARAMETER;
>> +=C2=A0 }
>> +
>> +=C2=A0 GuidHob =3D GetFirstGuidHob (&gVariableFlashInfoHobGuid);
>> +=C2=A0 if (GuidHob =3D=3D NULL) {
>> +=C2=A0=C2=A0=C2=A0 return EFI_NOT_FOUND;
>> +=C2=A0 }
>> +
>> +=C2=A0 *VariableFlashInfo =3D GET_GUID_HOB_DATA (GuidHob);
>> +
>> +=C2=A0 //
>> +=C2=A0 // Assert if more than one variable flash information HOB is pre=
sent.
>> +=C2=A0 //
>> +=C2=A0 DEBUG_CODE (
>> +=C2=A0=C2=A0=C2=A0 if ((GetNextGuidHob (&gVariableFlashInfoHobGuid, GET=
_NEXT_HOB=20
>> (GuidHob)) !=3D NULL)) {
>> +=C2=A0=C2=A0=C2=A0 DEBUG ((DEBUG_ERROR, "ERROR: Found two variable flas=
h information=20
>> HOBs\n"));
>> +=C2=A0=C2=A0=C2=A0 ASSERT (FALSE);
>> +=C2=A0 }
>> +
>> +=C2=A0=C2=A0=C2=A0 );
>> +
>> +=C2=A0 return EFI_SUCCESS;
>> +}
>> +
>> +/**
>> +=C2=A0 Get the base address and size for the NV storage area used for U=
EFI=20
>> variable storage.
>> +
>> +=C2=A0 @param[out] BaseAddress=C2=A0=C2=A0=C2=A0 The NV storage base ad=
dress.
>> +=C2=A0 @param[out] Length=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=
=A0 The NV storage length in bytes.
>> +
>> +=C2=A0 @retval EFI_SUCCESS=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=
=A0=C2=A0=C2=A0=C2=A0=C2=A0 NV storage information was found=20
>> successfully.
>> +=C2=A0 @retval EFI_INVALID_PARAMETER=C2=A0=C2=A0 A required pointer par=
ameter is NULL.
>> +
>> +**/
>> +EFI_STATUS
>> +EFIAPI
>> +GetVariableFlashNvStorageInfo (
>> +=C2=A0 OUT EFI_PHYSICAL_ADDRESS=C2=A0 *BaseAddress,
>> +=C2=A0 OUT UINT64=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=
=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 *Length
>> +=C2=A0 )
>> +{
>> +=C2=A0 EFI_STATUS=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=
=C2=A0 Status;
>> +=C2=A0 VARIABLE_FLASH_INFO=C2=A0 *VariableFlashInfo;
>> +
>> +=C2=A0 if ((BaseAddress =3D=3D NULL) || (Length =3D=3D NULL)) {
>> +=C2=A0=C2=A0=C2=A0 return EFI_INVALID_PARAMETER;
>> +=C2=A0 }
>> +
>> +=C2=A0 Status =3D GetVariableFlashInfoFromHob (&VariableFlashInfo);
>> +=C2=A0 if (!EFI_ERROR (Status)) {
>> +=C2=A0=C2=A0=C2=A0 *BaseAddress =3D VariableFlashInfo->NvVariableBaseAd=
dress;
>> +=C2=A0=C2=A0=C2=A0 *Length=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 =3D VariableFl=
ashInfo->NvVariableLength;
>> +=C2=A0 } else {
>> +=C2=A0=C2=A0=C2=A0 *BaseAddress =3D (EFI_PHYSICAL_ADDRESS)(PcdGet64=20
>> (PcdFlashNvStorageVariableBase64) !=3D 0 ?
>> +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=
=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=
=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=
=A0=C2=A0=C2=A0=C2=A0=C2=A0 PcdGet64=20
>> (PcdFlashNvStorageVariableBase64) :
>> +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=
=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=
=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=
=A0=C2=A0=C2=A0=C2=A0=C2=A0 PcdGet32=20
>> (PcdFlashNvStorageVariableBase)
>> +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=
=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=
=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=
=A0=C2=A0=C2=A0=C2=A0=C2=A0 );
>> +=C2=A0=C2=A0=C2=A0 *Length =3D (UINT64)PcdGet32 (PcdFlashNvStorageVaria=
bleSize);
>> +=C2=A0 }
>> +
>> +=C2=A0 return EFI_SUCCESS;
>> +}
>> +
>> +/**
>> +=C2=A0 Get the base address and size for the fault tolerant write (FTW)=
 spare
>> +=C2=A0 area used for UEFI variable storage.
>> +
>> +=C2=A0 @param[out] BaseAddress=C2=A0=C2=A0=C2=A0 The FTW spare base add=
ress.
>> +=C2=A0 @param[out] Length=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=
=A0 The FTW spare length in bytes.
>> +
>> +=C2=A0 @retval EFI_SUCCESS=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=
=A0=C2=A0=C2=A0=C2=A0=C2=A0 FTW spare information was found=20
>> successfully.
>> +=C2=A0 @retval EFI_INVALID_PARAMETER=C2=A0=C2=A0 A required pointer par=
ameter is NULL.
>> +=C2=A0 @retval EFI_NOT_FOUND=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=
=C2=A0=C2=A0=C2=A0 FTW spare information could not be=20
>> found.
>> +
>> +**/
>> +EFI_STATUS
>> +EFIAPI
>> +GetVariableFlashFtwSpareInfo (
>> +=C2=A0 OUT EFI_PHYSICAL_ADDRESS=C2=A0 *BaseAddress,
>> +=C2=A0 OUT UINT64=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=
=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 *Length
>> +=C2=A0 )
>> +{
>> +=C2=A0 EFI_STATUS=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=
=C2=A0 Status;
>> +=C2=A0 VARIABLE_FLASH_INFO=C2=A0 *VariableFlashInfo;
>> +
>> +=C2=A0 if ((BaseAddress =3D=3D NULL) || (Length =3D=3D NULL)) {
>> +=C2=A0=C2=A0=C2=A0 return EFI_INVALID_PARAMETER;
>> +=C2=A0 }
>> +
>> +=C2=A0 Status =3D GetVariableFlashInfoFromHob (&VariableFlashInfo);
>> +=C2=A0 if (!EFI_ERROR (Status)) {
>> +=C2=A0=C2=A0=C2=A0 *BaseAddress =3D VariableFlashInfo->FtwSpareBaseAddr=
ess;
>> +=C2=A0=C2=A0=C2=A0 *Length=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 =3D VariableFl=
ashInfo->FtwSpareLength;
>> +=C2=A0 } else {
>> +=C2=A0=C2=A0=C2=A0 *BaseAddress =3D (EFI_PHYSICAL_ADDRESS)(PcdGet64=20
>> (PcdFlashNvStorageFtwSpareBase64) !=3D 0 ?
>> +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=
=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=
=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=
=A0=C2=A0=C2=A0=C2=A0=C2=A0 PcdGet64=20
>> (PcdFlashNvStorageFtwSpareBase64) :
>> +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=
=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=
=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=
=A0=C2=A0=C2=A0=C2=A0=C2=A0 PcdGet32=20
>> (PcdFlashNvStorageFtwSpareBase)
>> +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=
=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=
=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=
=A0=C2=A0=C2=A0=C2=A0=C2=A0 );
>> +=C2=A0=C2=A0=C2=A0 *Length =3D (UINT64)PcdGet32 (PcdFlashNvStorageFtwSp=
areSize);
>> +=C2=A0 }
>> +
>> +=C2=A0 return EFI_SUCCESS;
>> +}
>> +
>> +/**
>> +=C2=A0 Get the base address and size for the fault tolerant write (FTW)=
=20
>> working
>> +=C2=A0 area used for UEFI variable storage.
>> +
>> +=C2=A0 @param[out] BaseAddress=C2=A0=C2=A0=C2=A0 The FTW working area b=
ase address.
>> +=C2=A0 @param[out] Length=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=
=A0 The FTW working area length in bytes.
>> +
>> +=C2=A0 @retval EFI_SUCCESS=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=
=A0=C2=A0=C2=A0=C2=A0=C2=A0 FTW working information was found=20
>> successfully.
>> +=C2=A0 @retval EFI_INVALID_PARAMETER=C2=A0=C2=A0 A required pointer par=
ameter is NULL.
>> +=C2=A0 @retval EFI_NOT_FOUND=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=
=C2=A0=C2=A0=C2=A0 FTW working information could not=20
>> be found.
>> +
>> +**/
>> +EFI_STATUS
>> +EFIAPI
>> +GetVariableFlashFtwWorkingInfo (
>> +=C2=A0 OUT EFI_PHYSICAL_ADDRESS=C2=A0 *BaseAddress,
>> +=C2=A0 OUT UINT64=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=
=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 *Length
>> +=C2=A0 )
>> +{
>> +=C2=A0 EFI_STATUS=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=
=C2=A0 Status;
>> +=C2=A0 VARIABLE_FLASH_INFO=C2=A0 *VariableFlashInfo;
>> +
>> +=C2=A0 if ((BaseAddress =3D=3D NULL) || (Length =3D=3D NULL)) {
>> +=C2=A0=C2=A0=C2=A0 return EFI_INVALID_PARAMETER;
>> +=C2=A0 }
>> +
>> +=C2=A0 Status =3D GetVariableFlashInfoFromHob (&VariableFlashInfo);
>> +=C2=A0 if (!EFI_ERROR (Status)) {
>> +=C2=A0=C2=A0=C2=A0 *BaseAddress =3D VariableFlashInfo->FtwWorkingBaseAd=
dress;
>> +=C2=A0=C2=A0=C2=A0 *Length=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 =3D VariableFl=
ashInfo->FtwWorkingLength;
>> +=C2=A0 } else {
>> +=C2=A0=C2=A0=C2=A0 *BaseAddress =3D (EFI_PHYSICAL_ADDRESS)(PcdGet64=20
>> (PcdFlashNvStorageFtwWorkingBase64) !=3D 0 ?
>> +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=
=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=
=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=
=A0=C2=A0=C2=A0=C2=A0=C2=A0 PcdGet64=20
>> (PcdFlashNvStorageFtwWorkingBase64) :
>> +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=
=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=
=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=
=A0=C2=A0=C2=A0=C2=A0=C2=A0 PcdGet32=20
>> (PcdFlashNvStorageFtwWorkingBase)
>> +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=
=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=
=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=
=A0=C2=A0=C2=A0=C2=A0=C2=A0 );
>> +=C2=A0=C2=A0=C2=A0 *Length =3D (UINT64)PcdGet32 (PcdFlashNvStorageFtwWo=
rkingSize);
>> +=C2=A0 }
>> +
>> +=C2=A0 return EFI_SUCCESS;
>> +}
>> diff --git a/MdeModulePkg/Include/Library/VariableFlashInfoLib.h=20
>> 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
>> +=C2=A0 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_
>> +
>> +/**
>> +=C2=A0 Get the base address and size for the NV storage area used for U=
EFI=20
>> variable storage.
>> +
>> +=C2=A0 @param[out] BaseAddress=C2=A0=C2=A0=C2=A0 The NV storage base ad=
dress.
>> +=C2=A0 @param[out] Length=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=
=A0 The NV storage length in bytes.
>> +
>> +=C2=A0 @retval EFI_SUCCESS=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=
=A0=C2=A0=C2=A0=C2=A0=C2=A0 NV storage information was found=20
>> successfully.
>> +=C2=A0 @retval EFI_INVALID_PARAMETER=C2=A0=C2=A0 A required pointer par=
ameter is NULL.
>> +=C2=A0 @retval EFI_NOT_FOUND=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=
=C2=A0=C2=A0=C2=A0 NV storage information could not be=20
>> found.
>> +
>> +**/
>> +EFI_STATUS
>> +EFIAPI
>> +GetVariableFlashNvStorageInfo (
>> +=C2=A0 OUT EFI_PHYSICAL_ADDRESS=C2=A0 *BaseAddress,
>> +=C2=A0 OUT UINT64=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=
=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 *Length
>> +=C2=A0 );
>> +
>> +/**
>> +=C2=A0 Get the base address and size for the fault tolerant write (FTW)=
 spare
>> +=C2=A0 area used for UEFI variable storage.
>> +
>> +=C2=A0 @param[out] BaseAddress=C2=A0=C2=A0=C2=A0 The FTW spare base add=
ress.
>> +=C2=A0 @param[out] Length=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=
=A0 The FTW spare length in bytes.
>> +
>> +=C2=A0 @retval EFI_SUCCESS=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=
=A0=C2=A0=C2=A0=C2=A0=C2=A0 FTW spare information was found=20
>> successfully.
>> +=C2=A0 @retval EFI_INVALID_PARAMETER=C2=A0=C2=A0 A required pointer par=
ameter is NULL.
>> +=C2=A0 @retval EFI_NOT_FOUND=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=
=C2=A0=C2=A0=C2=A0 FTW spare information could not be=20
>> found.
>> +
>> +**/
>> +EFI_STATUS
>> +EFIAPI
>> +GetVariableFlashFtwSpareInfo (
>> +=C2=A0 OUT EFI_PHYSICAL_ADDRESS=C2=A0 *BaseAddress,
>> +=C2=A0 OUT UINT64=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=
=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 *Length
>> +=C2=A0 );
>> +
>> +/**
>> +=C2=A0 Get the base address and size for the fault tolerant write (FTW)=
=20
>> working
>> +=C2=A0 area used for UEFI variable storage.
>> +
>> +=C2=A0 @param[out] BaseAddress=C2=A0=C2=A0=C2=A0 The FTW working area b=
ase address.
>> +=C2=A0 @param[out] Length=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=
=A0 The FTW working area length in bytes.
>> +
>> +=C2=A0 @retval EFI_SUCCESS=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=
=A0=C2=A0=C2=A0=C2=A0=C2=A0 FTW working information was found=20
>> successfully.
>> +=C2=A0 @retval EFI_INVALID_PARAMETER=C2=A0=C2=A0 A required pointer par=
ameter is NULL.
>> +=C2=A0 @retval EFI_NOT_FOUND=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=
=C2=A0=C2=A0=C2=A0 FTW working information could not=20
>> be found.
>> +
>> +**/
>> +EFI_STATUS
>> +EFIAPI
>> +GetVariableFlashFtwWorkingInfo (
>> +=C2=A0 OUT EFI_PHYSICAL_ADDRESS=C2=A0 *BaseAddress,
>> +=C2=A0 OUT UINT64=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=
=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 *Length
>> +=C2=A0 );
>> +
>> +#endif
>> diff --git=20
>> a/MdeModulePkg/Library/BaseVariableFlashInfoLib/BaseVariableFlashInfoLib=
.inf=20
>> b/MdeModulePkg/Library/BaseVariableFlashInfoLib/BaseVariableFlashInfoLib=
.inf=20
>>
>> new file mode 100644
>> index 000000000000..70175e75f9b1
>> --- /dev/null
>> +++=20
>> b/MdeModulePkg/Library/BaseVariableFlashInfoLib/BaseVariableFlashInfoLib=
.inf=20
>>
>> @@ -0,0 +1,48 @@
>> +## @file
>> +#=C2=A0 Variable Flash Information Library
>> +#
>> +#=C2=A0 Provides services to access UEFI variable flash information.
>> +#
>> +#=C2=A0 Copyright (c) Microsoft Corporation<BR>
>> +#=C2=A0 SPDX-License-Identifier: BSD-2-Clause-Patent
>> +##
>> +
>> +[Defines]
>> +=C2=A0 INF_VERSION=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 =3D 0x00010005
>> +=C2=A0 BASE_NAME=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 =3D Ba=
seVariableFlashInfoLib
>> +=C2=A0 MODULE_UNI_FILE=C2=A0=C2=A0 =3D BaseVariableFlashInfoLib.uni
>> +=C2=A0 FILE_GUID=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 =3D DE=
C426C9-C92E-4BAD-8E93-3F61C261118B
>> +=C2=A0 MODULE_TYPE=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 =3D BASE
>> +=C2=A0 VERSION_STRING=C2=A0=C2=A0=C2=A0 =3D 1.0
>> +=C2=A0 LIBRARY_CLASS=C2=A0=C2=A0=C2=A0=C2=A0 =3D VariableFlashInfoLib
>> +
>> +#
>> +# The following information is for reference only and not required by=
=20
>> the build tools.
>> +#
>> +#=C2=A0 VALID_ARCHITECTURES=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=
=C2=A0=C2=A0=C2=A0 =3D ANY
>> +#
>> +
>> +[Sources]
>> +=C2=A0 BaseVariableFlashInfoLib.c
>> +
>> +[Packages]
>> +=C2=A0 MdePkg/MdePkg.dec
>> +=C2=A0 MdeModulePkg/MdeModulePkg.dec
>> +
>> +[LibraryClasses]
>> +=C2=A0 DebugLib
>> +=C2=A0 HobLib
>> +
>> +[Guids]
>> +=C2=A0 gVariableFlashInfoHobGuid=C2=A0=C2=A0=C2=A0=C2=A0 ## CONSUMES=C2=
=A0=C2=A0=C2=A0=C2=A0 ## HOB
>> +
>> +[Pcd]
>> +=C2=A0 gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageVariableBase    =
 =20
>> ## SOMETIMES_CONSUMES
>> +=C2=A0 gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageVariableBase64  =
 =20
>> ## SOMETIMES_CONSUMES
>> +=C2=A0 gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageVariableSize    =
 =20
>> ## SOMETIMES_CONSUMES
>> +=C2=A0 gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageFtwSpareBase    =
 =20
>> ## SOMETIMES_CONSUMES
>> +=C2=A0 gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageFtwSpareBase64  =
 =20
>> ## SOMETIMES_CONSUMES
>> +=C2=A0 gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageFtwSpareSize    =
 =20
>> ## SOMETIMES_CONSUMES
>> +=C2=A0 gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageFtwWorkingBase  =
 =20
>> ## SOMETIMES_CONSUMES
>> +=C2=A0 gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageFtwWorkingBase64=
 =20
>> ## SOMETIMES_CONSUMES
>> +=C2=A0 gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageFtwWorkingSize  =
 =20
>> ## SOMETIMES_CONSUMES
>> diff --git=20
>> a/MdeModulePkg/Library/BaseVariableFlashInfoLib/BaseVariableFlashInfoLib=
.uni=20
>> b/MdeModulePkg/Library/BaseVariableFlashInfoLib/BaseVariableFlashInfoLib=
.uni=20
>>
>> new file mode 100644
>> index 000000000000..9a5348fa02a0
>> --- /dev/null
>> +++=20
>> b/MdeModulePkg/Library/BaseVariableFlashInfoLib/BaseVariableFlashInfoLib=
.uni=20
>>
>> @@ -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=C2=A0=C2=A0=C2=A0=C2=A0 #language en-US "UE=
FI variable flash=20
>> information library"
>> +
>> +#string STR_MODULE_DESCRIPTION=C2=A0 #language en-US "Provides services=
 to=20
>> access UEFI variable flash information."
>> diff --git a/MdeModulePkg/MdeModulePkg.dec=20
>> b/MdeModulePkg/MdeModulePkg.dec
>> index 4e82f5836096..2bcb9f9453af 100644
>> --- a/MdeModulePkg/MdeModulePkg.dec
>> +++ b/MdeModulePkg/MdeModulePkg.dec
>> @@ -154,6 +154,10 @@ [LibraryClasses]
>> =C2=A0=C2=A0=C2=A0 #
>> =C2=A0=C2=A0=C2=A0 VariablePolicyHelperLib|Include/Library/VariablePolic=
yHelperLib.h
>> +=C2=A0 ##=C2=A0 @libraryclass=C2=A0 Provides services to access UEFI va=
riable flash=20
>> information.
>> +=C2=A0 #
>> +=C2=A0 VariableFlashInfoLib|Include/Library/VariableFlashInfoLib.h
>> +
>> =C2=A0 [Guids]
>> =C2=A0=C2=A0=C2=A0 ## MdeModule package token space guid
>> =C2=A0=C2=A0=C2=A0 # Include/Guid/MdeModulePkgTokenSpace.h
>> diff --git a/MdeModulePkg/MdeModulePkg.dsc=20
>> b/MdeModulePkg/MdeModulePkg.dsc
>> index b1d83461865e..90a0a7ec4a7c 100644
>> --- a/MdeModulePkg/MdeModulePkg.dsc
>> +++ b/MdeModulePkg/MdeModulePkg.dsc
>> @@ -103,6 +103,7 @@ [LibraryClasses]
>>    =20
>> DisplayUpdateProgressLib|MdeModulePkg/Library/DisplayUpdateProgressLibGr=
aphics/DisplayUpdateProgressLibGraphics.inf=20
>>
>>    =20
>> VariablePolicyHelperLib|MdeModulePkg/Library/VariablePolicyHelperLib/Var=
iablePolicyHelperLib.inf=20
>>
>>    =20
>> MmUnblockMemoryLib|MdePkg/Library/MmUnblockMemoryLib/MmUnblockMemoryLibN=
ull.inf=20
>>
>> + =20
>> VariableFlashInfoLib|MdeModulePkg/Library/BaseVariableFlashInfoLib/BaseV=
ariableFlashInfoLib.inf=20
>>
>> =C2=A0 [LibraryClasses.EBC.PEIM]
>> =C2=A0=C2=A0=C2=A0 IoLib|MdePkg/Library/PeiIoLibCpuIo/PeiIoLibCpuIo.inf
>> @@ -440,6 +441,7 @@ [Components]
>>    =20
>> MdeModulePkg/Library/FmpAuthenticationLibNull/FmpAuthenticationLibNull.i=
nf=20
>>
>> =C2=A0=C2=A0=C2=A0 MdeModulePkg/Library/DxeCapsuleLibFmp/DxeCapsuleLib.i=
nf
>> =C2=A0=C2=A0=C2=A0 MdeModulePkg/Library/DxeCapsuleLibFmp/DxeRuntimeCapsu=
leLib.inf
>> + =20
>> MdeModulePkg/Library/BaseVariableFlashInfoLib/BaseVariableFlashInfoLib.i=
nf=20
>>
>> =C2=A0 [Components.IA32, Components.X64, Components.AARCH64]
>> =C2=A0=C2=A0=C2=A0 MdeModulePkg/Universal/EbcDxe/EbcDxe.inf
>=20
>=20
>=20
>=20