[edk2,v2,05/17] MdeModulePkg/FaultTolerantWriteDxe: factor out boot service accesses

Message ID 20190114132758.24054-6-ard.biesheuvel@linaro.org
State New
Headers show
Series
  • implement standalone MM versions of the variable runtime drivers
Related show

Commit Message

Ard Biesheuvel Jan. 14, 2019, 1:27 p.m.
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>

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

Regression-tested-by: Laszlo Ersek <lersek@redhat.com>
---
 MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteSmm.inf         |   5 +-
 MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWrite.h              |  23 ++++-
 MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteSmmCommon.h     |  34 +++++++
 MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteDxe.c           |  31 ++++++
 MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteSmm.c           |  53 ++++------
 MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteTraditionalMm.c | 106 ++++++++++++++++++++
 MdeModulePkg/Universal/FaultTolerantWriteDxe/UpdateWorkingBlock.c              |  10 +-
 7 files changed, 219 insertions(+), 43 deletions(-)

-- 
2.20.1

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Comments

Zeng, Star Jan. 16, 2019, 3:29 a.m. | #1
Some minor comments.

With them handled, Reviewed-by: Star Zeng <star.zeng@intel.com>

Thanks,
Star

On 2019/1/14 21:27, Ard Biesheuvel wrote:
> 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>

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

> Regression-tested-by: Laszlo Ersek <lersek@redhat.com>

> ---

>   MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteSmm.inf         |   5 +-

>   MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWrite.h              |  23 ++++-

>   MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteSmmCommon.h     |  34 +++++++

>   MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteDxe.c           |  31 ++++++

>   MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteSmm.c           |  53 ++++------

>   MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteTraditionalMm.c | 106 ++++++++++++++++++++

>   MdeModulePkg/Universal/FaultTolerantWriteDxe/UpdateWorkingBlock.c              |  10 +-

>   7 files changed, 219 insertions(+), 43 deletions(-)

> 


[Trimmed]

>   

> +/**

> +  Entry point of the module

> +**/


The block should be matched with the MmFaultTolerantWriteInitialize 
implementation in FaultTolerantWriteSmm.c. But not 
SmmFaultTolerantWriteInitialize implementation in 
FaultTolerantWriteTraditionalMm.c

> +EFI_STATUS

> +MmFaultTolerantWriteInitialize (

> +  VOID

> +  );

> +

> +/**

> +  This function checks if the buffer is valid per processor architecture and

> +  does 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 does not

> +                overlap with SMRAM.

> +  @retval FALSE This buffer is not valid per processor architecture or overlaps

> +                with SMRAM.

> +**/

> +BOOLEAN

> +FtwSmmIsBufferOutsideSmmValid (

> +  IN EFI_PHYSICAL_ADDRESS  Buffer,

> +  IN UINT64                Length

> +  );

> +

> +/**

> +  Notify the system that the SMM FTW driver is ready

> +**/

> +VOID

> +FtwNotifySmmReady (

> +  VOID

> +  );

> +

>   #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.


[Trimmed]

>   

>   **/

>   EFI_STATUS

> -EFIAPI

> -SmmFaultTolerantWriteInitialize (

> -  IN EFI_HANDLE                           ImageHandle,

> -  IN EFI_SYSTEM_TABLE                     *SystemTable


The comments block should be also removed for these two parameters.

> +MmFaultTolerantWriteInitialize (

> +  VOID

>     )

>   {

>     EFI_STATUS                              Status;

> -  VOID                                    *SmmEndOfDxeRegistration;

> +  VOID                                    *MmEndOfDxeRegistration;

>   

>     //

>     // Allocate private data structure for SMM FTW protocol and do some initialization

> @@ -634,17 +623,17 @@ 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/FaultTolerantWriteTraditionalMm.c b/MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteTraditionalMm.c

> new file mode 100644

> index 000000000000..78351199d3f1

> --- /dev/null

> +++ b/MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteTraditionalMm.c

> @@ -0,0 +1,106 @@


[Trimmed]

> +

> +/**

> +  Entry point of the module


The comments block should have description for the two parameters.


Thanks,
Star

> +**/

> +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;

> 


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Patch

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/FaultTolerantWrite.h b/MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWrite.h
index 844cf3bee04d..a23cb620e2f2 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 +765,26 @@  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/FaultTolerantWriteSmmCommon.h b/MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteSmmCommon.h
index 8ad0015f3c9e..23d9a49e8bcf 100644
--- a/MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteSmmCommon.h
+++ b/MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteSmmCommon.h
@@ -77,4 +77,38 @@  typedef struct {
   UINT8                                 Data[1];
 } SMM_FTW_GET_LAST_WRITE_HEADER;
 
+/**
+  Entry point of the module
+**/
+EFI_STATUS
+MmFaultTolerantWriteInitialize (
+  VOID
+  );
+
+/**
+  This function checks if the buffer is valid per processor architecture and
+  does 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 does not
+                overlap with SMRAM.
+  @retval FALSE This buffer is not valid per processor architecture or overlaps
+                with SMRAM.
+**/
+BOOLEAN
+FtwSmmIsBufferOutsideSmmValid (
+  IN EFI_PHYSICAL_ADDRESS  Buffer,
+  IN UINT64                Length
+  );
+
+/**
+  Notify the system that the SMM FTW driver is ready
+**/
+VOID
+FtwNotifySmmReady (
+  VOID
+  );
+
 #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..148eedc71a0c 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,
@@ -336,7 +335,7 @@  SmmFaultTolerantWriteHandler (
   }
   CommBufferPayloadSize = TempCommBufferSize - SMM_FTW_COMMUNICATE_HEADER_SIZE;
 
-  if (!SmmIsBufferOutsideSmmValid ((UINTN)CommBuffer, TempCommBufferSize)) {
+  if (!FtwSmmIsBufferOutsideSmmValid ((UINTN)CommBuffer, TempCommBufferSize)) {
     DEBUG ((EFI_D_ERROR, "SmmFtwHandler: SMM communication buffer in SMRAM or overflow!\n"));
     return EFI_SUCCESS;
   }
@@ -525,13 +524,12 @@  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 +549,7 @@  FvbNotificationEvent (
   //
   // Install protocol interface
   //
-  Status = gSmst->SmmInstallProtocolInterface (
+  Status = gMmst->MmInstallProtocolInterface (
                     &mFtwDevice->Handle,
                     &gEfiSmmFaultTolerantWriteProtocolGuid,
                     EFI_NATIVE_INTERFACE,
@@ -562,20 +560,13 @@  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 +583,7 @@  FvbNotificationEvent (
 **/
 EFI_STATUS
 EFIAPI
-SmmEndOfDxeCallback (
+MmEndOfDxeCallback (
   IN CONST EFI_GUID                       *Protocol,
   IN VOID                                 *Interface,
   IN EFI_HANDLE                           Handle
@@ -614,14 +605,12 @@  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 +623,17 @@  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/FaultTolerantWriteTraditionalMm.c b/MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteTraditionalMm.c
new file mode 100644
index 000000000000..78351199d3f1
--- /dev/null
+++ b/MdeModulePkg/Universal/FaultTolerantWriteDxe/FaultTolerantWriteTraditionalMm.c
@@ -0,0 +1,106 @@ 
+/** @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"
+
+/**
+  This function checks if the buffer is valid per processor architecture and
+  does 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 does not
+                overlap with SMRAM.
+  @retval FALSE This buffer is not valid per processor architecture or overlaps
+                with SMRAM.
+**/
+BOOLEAN
+FtwSmmIsBufferOutsideSmmValid (
+  IN EFI_PHYSICAL_ADDRESS  Buffer,
+  IN UINT64                Length
+  )
+{
+  return SmmIsBufferOutsideSmmValid (Buffer, Length);
+}
+
+/**
+  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 FTW 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);
+}
+
+/**
+  Entry point of the module
+**/
+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;