Re: [PATCH 3/6] MdeModulePkg/FaultTolerantWriteDxe: factor out boot service accesses

["Wang, Jian J" <jian.j.wang@intel.com>]

Reviewed-by: Jian J Wang <jian.j.wang@intel.com>

> -----Original Message-----
> From: Ard Biesheuvel [mailto:ard.biesheuvel@linaro.org]
> Sent: Friday, January 04, 2019 2:28 AM
> To: edk2-devel@lists.01.org
> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>; Laszlo Ersek
> <lersek@redhat.com>; Leif Lindholm <leif.lindholm@linaro.org>; Kinney,
> Michael D <michael.d.kinney@intel.com>; Gao, Liming <liming.gao@intel.com>;
> Wang, Jian J <jian.j.wang@intel.com>; Wu, Hao A <hao.a.wu@intel.com>;
> Jagadeesh Ujja <jagadeesh.ujja@arm.com>; Achin Gupta
> <Achin.Gupta@arm.com>; Thomas Panakamattam Abraham
> <thomas.abraham@arm.com>; Sami Mujawar <Sami.Mujawar@arm.com>
> Subject: [PATCH 3/6] MdeModulePkg/FaultTolerantWriteDxe: factor out boot
> service accesses
> 
> In preparation of providing a standalone MM based FTW driver, move
> the existing SMM driver to the new MM services table, and factor out
> some pieces that are specific to the traditional driver, mainly
> related to the use of UEFI boot services, which are not accessible
> to standalone MM drivers.
> 
> Contributed-under: TianoCore Contribution Agreement 1.1
> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
> ---
>  MdeModulePkg/MdeModulePkg.dsc                                                  |  1 +
>  MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWrite.h
> | 22 ++++-
>  MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteDxe.c
> | 31 +++++++
>  MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteSmm.c
> | 54 +++++------
>  MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteSmm.inf
> |  5 +-
> 
> MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteSmmCom
> mon.h     | 31 +++++++
> 
> MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteSmmDxe.c
> |  1 +
> 
> MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteTraditiona
> lMm.c | 94 ++++++++++++++++++++
>  MdeModulePkg/Universal/FaultTolerantWriteDxe/UpdateWorkingBlock.c
> | 10 +--
>  9 files changed, 205 insertions(+), 44 deletions(-)
> 
> diff --git a/MdeModulePkg/MdeModulePkg.dsc
> b/MdeModulePkg/MdeModulePkg.dsc
> index 5d042be3a862..ef3c144ed524 100644
> --- a/MdeModulePkg/MdeModulePkg.dsc
> +++ b/MdeModulePkg/MdeModulePkg.dsc
> @@ -153,6 +153,7 @@ [LibraryClasses.common.DXE_SMM_DRIVER]
>    DebugLib|MdePkg/Library/UefiDebugLibConOut/UefiDebugLibConOut.inf
> 
> MemoryAllocationLib|MdePkg/Library/SmmMemoryAllocationLib/SmmMemory
> AllocationLib.inf
> 
> SmmServicesTableLib|MdePkg/Library/SmmServicesTableLib/SmmServicesTable
> Lib.inf
> +
> MmServicesTableLib|MdePkg/Library/MmServicesTableLib/MmServicesTableLib
> .inf
>    LockBoxLib|MdeModulePkg/Library/SmmLockBoxLib/SmmLockBoxSmmLib.inf
>    SmmMemLib|MdePkg/Library/SmmMemLib/SmmMemLib.inf
> 
> diff --git
> a/MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWrite.h
> b/MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWrite.h
> index 844cf3bee04d..8d146264b129 100644
> --- a/MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWrite.h
> +++ b/MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWrite.h
> @@ -31,7 +31,6 @@ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY
> KIND, EITHER EXPRESS OR IMPLIED.
>  #include <Library/UefiDriverEntryPoint.h>
>  #include <Library/BaseMemoryLib.h>
>  #include <Library/MemoryAllocationLib.h>
> -#include <Library/UefiBootServicesTableLib.h>
>  #include <Library/ReportStatusCodeLib.h>
> 
>  //
> @@ -766,4 +765,25 @@ WriteWorkSpaceData (
>    IN UINT8                              *Buffer
>    );
> 
> +/**
> +  Internal implementation of CRC32. Depending on the execution context
> +  (traditional SMM or DXE vs standalone MM), this function is implemented
> +  via a call to the CalculateCrc32 () boot service, or via a library
> +  call.
> +
> +  If Buffer is NULL, then ASSERT().
> +  If Length is greater than (MAX_ADDRESS - Buffer + 1), then ASSERT().
> +
> +  @param[in]  Buffer       A pointer to the buffer on which the 32-bit CRC is to be
> computed.
> +  @param[in]  Length       The number of bytes in the buffer Data.
> +
> +  @retval Crc32            The 32-bit CRC was computed for the data buffer.
> +
> +**/
> +UINT32
> +FtwCalculateCrc32 (
> +  IN  VOID                         *Buffer,
> +  IN  UINTN                        Length
> +  );
> +
>  #endif
> diff --git
> a/MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteDxe.c
> b/MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteDxe.c
> index 094e40f9d86c..24e507104bbe 100644
> ---
> a/MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteDxe.c
> +++
> b/MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteDxe.c
> @@ -51,6 +51,7 @@ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY
> KIND, EITHER EXPRESS OR IMPLIED.
> 
>  **/
> 
> +#include <Library/UefiBootServicesTableLib.h>
>  #include "FaultTolerantWrite.h"
>  EFI_EVENT                                 mFvbRegistration = NULL;
> 
> @@ -250,3 +251,33 @@ FaultTolerantWriteInitialize (
> 
>    return EFI_SUCCESS;
>  }
> +
> +/**
> +  Internal implementation of CRC32. Depending on the execution context
> +  (traditional SMM or DXE vs standalone MM), this function is implemented
> +  via a call to the CalculateCrc32 () boot service, or via a library
> +  call.
> +
> +  If Buffer is NULL, then ASSERT().
> +  If Length is greater than (MAX_ADDRESS - Buffer + 1), then ASSERT().
> +
> +  @param[in]  Buffer       A pointer to the buffer on which the 32-bit CRC is to be
> computed.
> +  @param[in]  Length       The number of bytes in the buffer Data.
> +
> +  @retval Crc32            The 32-bit CRC was computed for the data buffer.
> +
> +**/
> +UINT32
> +FtwCalculateCrc32 (
> +  IN  VOID                         *Buffer,
> +  IN  UINTN                        Length
> +  )
> +{
> +  EFI_STATUS    Status;
> +  UINT32        ReturnValue;
> +
> +  Status = gBS->CalculateCrc32 (Buffer, Length, &ReturnValue);
> +  ASSERT_EFI_ERROR (Status);
> +
> +  return ReturnValue;
> +}
> diff --git
> a/MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteSmm.c
> b/MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteSmm.c
> index 481fea3f1fdf..e91d04e56d7c 100644
> ---
> a/MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteSmm.c
> +++
> b/MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteSmm.c
> @@ -54,14 +54,13 @@ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY
> KIND, EITHER EXPRESS OR IMPLIED.
> 
>  **/
> 
> -#include <PiSmm.h>
> -#include <Library/SmmServicesTableLib.h>
> -#include <Library/SmmMemLib.h>
> +#include <PiMm.h>
> +#include <Library/MmServicesTableLib.h>
>  #include <Library/BaseLib.h>
>  #include <Protocol/SmmSwapAddressRange.h>
>  #include "FaultTolerantWrite.h"
>  #include "FaultTolerantWriteSmmCommon.h"
> -#include <Protocol/SmmEndOfDxe.h>
> +#include <Protocol/MmEndOfDxe.h>
> 
>  EFI_EVENT                                 mFvbRegistration = NULL;
>  EFI_FTW_DEVICE                            *mFtwDevice      = NULL;
> @@ -92,7 +91,7 @@ FtwGetFvbByHandle (
>    //
>    // To get the SMM FVB protocol interface on the handle
>    //
> -  return gSmst->SmmHandleProtocol (
> +  return gMmst->MmHandleProtocol (
>                    FvBlockHandle,
>                    &gEfiSmmFirmwareVolumeBlockProtocolGuid,
>                    (VOID **) FvBlock
> @@ -119,7 +118,7 @@ FtwGetSarProtocol (
>    //
>    // Locate Smm Swap Address Range protocol
>    //
> -  Status = gSmst->SmmLocateProtocol (
> +  Status = gMmst->MmLocateProtocol (
>                      &gEfiSmmSwapAddressRangeProtocolGuid,
>                      NULL,
>                      SarProtocol
> @@ -158,7 +157,7 @@ GetFvbCountAndBuffer (
>    BufferSize     = 0;
>    *NumberHandles = 0;
>    *Buffer        = NULL;
> -  Status = gSmst->SmmLocateHandle (
> +  Status = gMmst->MmLocateHandle (
>                      ByProtocol,
>                      &gEfiSmmFirmwareVolumeBlockProtocolGuid,
>                      NULL,
> @@ -174,7 +173,7 @@ GetFvbCountAndBuffer (
>      return EFI_OUT_OF_RESOURCES;
>    }
> 
> -  Status = gSmst->SmmLocateHandle (
> +  Status = gMmst->MmLocateHandle (
>                      ByProtocol,
>                      &gEfiSmmFirmwareVolumeBlockProtocolGuid,
>                      NULL,
> @@ -336,8 +335,7 @@ SmmFaultTolerantWriteHandler (
>    }
>    CommBufferPayloadSize = TempCommBufferSize -
> SMM_FTW_COMMUNICATE_HEADER_SIZE;
> 
> -  if (!SmmIsBufferOutsideSmmValid ((UINTN)CommBuffer,
> TempCommBufferSize)) {
> -    DEBUG ((EFI_D_ERROR, "SmmFtwHandler: SMM communication buffer in
> SMRAM or overflow!\n"));
> +  if (!FtwSmmIsBufferOutsideSmmValid ((UINTN)CommBuffer,
> TempCommBufferSize)) {
>      return EFI_SUCCESS;
>    }
> 
> @@ -525,13 +523,12 @@ FvbNotificationEvent (
>    EFI_STATUS                              Status;
>    EFI_SMM_FAULT_TOLERANT_WRITE_PROTOCOL   *FtwProtocol;
>    EFI_HANDLE                              SmmFtwHandle;
> -  EFI_HANDLE                              FtwHandle;
> 
>    //
>    // Just return to avoid install SMM FaultTolerantWriteProtocol again
>    // if SMM Fault Tolerant Write protocol had been installed.
>    //
> -  Status = gSmst->SmmLocateProtocol (
> +  Status = gMmst->MmLocateProtocol (
>                      &gEfiSmmFaultTolerantWriteProtocolGuid,
>                      NULL,
>                      (VOID **) &FtwProtocol
> @@ -551,7 +548,7 @@ FvbNotificationEvent (
>    //
>    // Install protocol interface
>    //
> -  Status = gSmst->SmmInstallProtocolInterface (
> +  Status = gMmst->MmInstallProtocolInterface (
>                      &mFtwDevice->Handle,
>                      &gEfiSmmFaultTolerantWriteProtocolGuid,
>                      EFI_NATIVE_INTERFACE,
> @@ -562,20 +559,13 @@ FvbNotificationEvent (
>    ///
>    /// Register SMM FTW SMI handler
>    ///
> -  Status = gSmst->SmiHandlerRegister (SmmFaultTolerantWriteHandler,
> &gEfiSmmFaultTolerantWriteProtocolGuid, &SmmFtwHandle);
> +  Status = gMmst->MmiHandlerRegister (SmmFaultTolerantWriteHandler,
> &gEfiSmmFaultTolerantWriteProtocolGuid, &SmmFtwHandle);
>    ASSERT_EFI_ERROR (Status);
> 
>    //
>    // Notify the Ftw wrapper driver SMM Ftw is ready
>    //
> -  FtwHandle = NULL;
> -  Status = gBS->InstallProtocolInterface (
> -                  &FtwHandle,
> -                  &gEfiSmmFaultTolerantWriteProtocolGuid,
> -                  EFI_NATIVE_INTERFACE,
> -                  NULL
> -                  );
> -  ASSERT_EFI_ERROR (Status);
> +  FtwNotifySmmReady ();
> 
>    return EFI_SUCCESS;
>  }
> @@ -592,7 +582,7 @@ FvbNotificationEvent (
>  **/
>  EFI_STATUS
>  EFIAPI
> -SmmEndOfDxeCallback (
> +MmEndOfDxeCallback (
>    IN CONST EFI_GUID                       *Protocol,
>    IN VOID                                 *Interface,
>    IN EFI_HANDLE                           Handle
> @@ -614,14 +604,12 @@ SmmEndOfDxeCallback (
> 
>  **/
>  EFI_STATUS
> -EFIAPI
> -SmmFaultTolerantWriteInitialize (
> -  IN EFI_HANDLE                           ImageHandle,
> -  IN EFI_SYSTEM_TABLE                     *SystemTable
> +MmFaultTolerantWriteInitialize (
> +  VOID
>    )
>  {
>    EFI_STATUS                              Status;
> -  VOID                                    *SmmEndOfDxeRegistration;
> +  VOID                                    *MmEndOfDxeRegistration;
> 
>    //
>    // Allocate private data structure for SMM FTW protocol and do some
> initialization
> @@ -634,17 +622,17 @@ SmmFaultTolerantWriteInitialize (
>    //
>    // Register EFI_SMM_END_OF_DXE_PROTOCOL_GUID notify function.
>    //
> -  Status = gSmst->SmmRegisterProtocolNotify (
> -                    &gEfiSmmEndOfDxeProtocolGuid,
> -                    SmmEndOfDxeCallback,
> -                    &SmmEndOfDxeRegistration
> +  Status = gMmst->MmRegisterProtocolNotify (
> +                    &gEfiMmEndOfDxeProtocolGuid,
> +                    MmEndOfDxeCallback,
> +                    &MmEndOfDxeRegistration
>                      );
>    ASSERT_EFI_ERROR (Status);
> 
>    //
>    // Register FvbNotificationEvent () notify function.
>    //
> -  Status = gSmst->SmmRegisterProtocolNotify (
> +  Status = gMmst->MmRegisterProtocolNotify (
>                      &gEfiSmmFirmwareVolumeBlockProtocolGuid,
>                      FvbNotificationEvent,
>                      &mFvbRegistration
> diff --git
> a/MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteSmm.inf
> b/MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteSmm.inf
> index 606cc2266bda..1653365bc247 100644
> ---
> a/MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteSmm.inf
> +++
> b/MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteSmm.inf
> @@ -37,6 +37,7 @@ [Sources]
>    FtwMisc.c
>    UpdateWorkingBlock.c
>    FaultTolerantWrite.c
> +  FaultTolerantWriteTraditionalMm.c
>    FaultTolerantWriteSmm.c
>    FaultTolerantWrite.h
>    FaultTolerantWriteSmmCommon.h
> @@ -46,7 +47,7 @@ [Packages]
>    MdeModulePkg/MdeModulePkg.dec
> 
>  [LibraryClasses]
> -  SmmServicesTableLib
> +  MmServicesTableLib
>    MemoryAllocationLib
>    BaseMemoryLib
>    UefiDriverEntryPoint
> @@ -73,7 +74,7 @@ [Protocols]
>    ## PRODUCES
>    ## UNDEFINED # SmiHandlerRegister
>    gEfiSmmFaultTolerantWriteProtocolGuid
> -  gEfiSmmEndOfDxeProtocolGuid                      ## CONSUMES
> +  gEfiMmEndOfDxeProtocolGuid                      ## CONSUMES
> 
>  [FeaturePcd]
>    gEfiMdeModulePkgTokenSpaceGuid.PcdFullFtwServiceEnable    ## CONSUMES
> diff --git
> a/MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteSmmCo
> mmon.h
> b/MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteSmmCo
> mmon.h
> index 8ad0015f3c9e..25b5f7c87326 100644
> ---
> a/MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteSmmCo
> mmon.h
> +++
> b/MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteSmmCo
> mmon.h
> @@ -77,4 +77,35 @@ typedef struct {
>    UINT8                                 Data[1];
>  } SMM_FTW_GET_LAST_WRITE_HEADER;
> 
> +/**
> +  Entry point of the module
> +**/
> +EFI_STATUS
> +MmFaultTolerantWriteInitialize (
> +  VOID
> +  );
> +
> +/**
> +  This function check if the buffer is valid per processor architecture and not
> overlap with SMRAM.
> +
> +  @param Buffer  The buffer start address to be checked.
> +  @param Length  The buffer length to be checked.
> +
> +  @retval TRUE  This buffer is valid per processor architecture and not overlap
> with SMRAM.
> +  @retval FALSE This buffer is not valid per processor architecture or overlap
> with SMRAM.
> +**/
> +BOOLEAN
> +FtwSmmIsBufferOutsideSmmValid (
> +  IN EFI_PHYSICAL_ADDRESS  Buffer,
> +  IN UINT64                Length
> +  );
> +
> +/**
> +  Notify the system that the SMM driver is ready
> +**/
> +VOID
> +FtwNotifySmmReady (
> +  VOID
> +  );
> +
>  #endif
> diff --git
> a/MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteSmmDx
> e.c
> b/MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteSmmDx
> e.c
> index 259e9365f483..8694b9254cde 100644
> ---
> a/MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteSmmDx
> e.c
> +++
> b/MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteSmmDx
> e.c
> @@ -14,6 +14,7 @@ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY
> KIND, EITHER EXPRESS OR IMPLIED.
> 
>  **/
> 
> +#include <Library/UefiBootServicesTableLib.h>
>  #include "FaultTolerantWriteSmmDxe.h"
> 
>  EFI_HANDLE                         mHandle                   = NULL;
> diff --git
> a/MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteTraditio
> nalMm.c
> b/MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteTraditio
> nalMm.c
> new file mode 100644
> index 000000000000..440dced37bf8
> --- /dev/null
> +++
> b/MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteTraditio
> nalMm.c
> @@ -0,0 +1,94 @@
> +/** @file
> +
> +  Parts of the SMM/MM implementation that are specific to traditional MM
> +
> +Copyright (c) 2011 - 2018, Intel Corporation. All rights reserved. <BR>
> +Copyright (c) 2018, Linaro, Ltd. All rights reserved. <BR>
> +This program and the accompanying materials
> +are licensed and made available under the terms and conditions of the BSD
> License
> +which accompanies this distribution.  The full text of the license may be found
> at
> +http://opensource.org/licenses/bsd-license.php
> +
> +THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
> +WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS
> OR IMPLIED.
> +
> +**/
> +
> +#include <Library/SmmMemLib.h>
> +#include <Library/UefiBootServicesTableLib.h>
> +#include "FaultTolerantWrite.h"
> +#include "FaultTolerantWriteSmmCommon.h"
> +
> +BOOLEAN
> +FtwSmmIsBufferOutsideSmmValid (
> +  IN EFI_PHYSICAL_ADDRESS  Buffer,
> +  IN UINT64                Length
> +  )
> +{
> +  if (!SmmIsBufferOutsideSmmValid (Buffer, Length)) {
> +    DEBUG ((EFI_D_ERROR, "SmmFtwHandler: SMM communication buffer in
> SMRAM or overflow!\n"));
> +    return FALSE;
> +  }
> +  return TRUE;
> +}
> +
> +/**
> +  Internal implementation of CRC32. Depending on the execution context
> +  (traditional SMM or DXE vs standalone MM), this function is implemented
> +  via a call to the CalculateCrc32 () boot service, or via a library
> +  call.
> +
> +  If Buffer is NULL, then ASSERT().
> +  If Length is greater than (MAX_ADDRESS - Buffer + 1), then ASSERT().
> +
> +  @param[in]  Buffer       A pointer to the buffer on which the 32-bit CRC is to be
> computed.
> +  @param[in]  Length       The number of bytes in the buffer Data.
> +
> +  @retval Crc32            The 32-bit CRC was computed for the data buffer.
> +
> +**/
> +UINT32
> +FtwCalculateCrc32 (
> +  IN  VOID                         *Buffer,
> +  IN  UINTN                        Length
> +  )
> +{
> +  EFI_STATUS    Status;
> +  UINT32        ReturnValue;
> +
> +  Status = gBS->CalculateCrc32 (Buffer, Length, &ReturnValue);
> +  ASSERT_EFI_ERROR (Status);
> +
> +  return ReturnValue;
> +}
> +
> +/**
> +  Notify the system that the SMM driver is ready
> +**/
> +VOID
> +FtwNotifySmmReady (
> +  VOID
> +  )
> +{
> +  EFI_HANDLE          FtwHandle;
> +  EFI_STATUS          Status;
> +
> +  FtwHandle = NULL;
> +  Status = gBS->InstallProtocolInterface (
> +                  &FtwHandle,
> +                  &gEfiSmmFaultTolerantWriteProtocolGuid,
> +                  EFI_NATIVE_INTERFACE,
> +                  NULL
> +                  );
> +  ASSERT_EFI_ERROR (Status);
> +}
> +
> +EFI_STATUS
> +EFIAPI
> +SmmFaultTolerantWriteInitialize (
> +  IN EFI_HANDLE            ImageHandle,
> +  IN EFI_SYSTEM_TABLE      *SystemTable
> +  )
> +{
> +  return MmFaultTolerantWriteInitialize ();
> +}
> diff --git
> a/MdeModulePkg/Universal/FaultTolerantWriteDxe/UpdateWorkingBlock.c
> b/MdeModulePkg/Universal/FaultTolerantWriteDxe/UpdateWorkingBlock.c
> index 50d3421b88bb..d09e9719cf05 100644
> --- a/MdeModulePkg/Universal/FaultTolerantWriteDxe/UpdateWorkingBlock.c
> +++ b/MdeModulePkg/Universal/FaultTolerantWriteDxe/UpdateWorkingBlock.c
> @@ -29,8 +29,6 @@ InitializeLocalWorkSpaceHeader (
>    VOID
>    )
>  {
> -  EFI_STATUS                              Status;
> -
>    //
>    // Check signature with gEdkiiWorkingBlockSignatureGuid.
>    //
> @@ -64,12 +62,8 @@ InitializeLocalWorkSpaceHeader (
>    //
>    // Calculate the Crc of woking block header
>    //
> -  Status = gBS->CalculateCrc32 (
> -                  &mWorkingBlockHeader,
> -                  sizeof (EFI_FAULT_TOLERANT_WORKING_BLOCK_HEADER),
> -                  &mWorkingBlockHeader.Crc
> -                  );
> -  ASSERT_EFI_ERROR (Status);
> +  mWorkingBlockHeader.Crc = FtwCalculateCrc32 (&mWorkingBlockHeader,
> +                              sizeof (EFI_FAULT_TOLERANT_WORKING_BLOCK_HEADER));
> 
>    mWorkingBlockHeader.WorkingBlockValid    = FTW_VALID_STATE;
>    mWorkingBlockHeader.WorkingBlockInvalid  = FTW_INVALID_STATE;
> --
> 2.17.1