path: root/MdeModulePkg/Universal/FirmwareVolume/FaultTolerantWriteLite/Dxe/FtwLite.c

/*++

Copyright (c) 2006 - 2007, Intel Corporation                                                         
All rights reserved. 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.  


Module Name:

  FtwLite.c

Abstract:

  This is a simple fault tolerant write driver, based on PlatformFd library.
  And it only supports write BufferSize <= SpareAreaLength.

  This boot service only protocol provides fault tolerant write capability for 
  block devices.  The protocol has internal non-volatile intermediate storage 
  of the data and private information. It should be able to recover 
  automatically from a critical fault, such as power failure. 

Notes:

  The implementation uses an FTW Lite (Fault Tolerant Write) Work Space. 
  This work space is a memory copy of the work space on the Woring Block,
  the size of the work space is the FTW_WORK_SPACE_SIZE bytes.

--*/

#include <FtwLite.h>

//
// In write function, we should check the target range to prevent the user
// from writing Spare block and Working space directly.
//
//
// Fault Tolerant Write Protocol API
//
EFI_STATUS
EFIAPI
FtwLiteWrite (
  IN EFI_FTW_LITE_PROTOCOL                 *This,
  IN EFI_HANDLE                            FvbHandle,
  IN EFI_LBA                               Lba,
  IN UINTN                                 Offset,
  IN OUT UINTN                             *NumBytes,
  IN VOID                                  *Buffer
  )
/*++

Routine Description:
    Starts a target block update. This function will record data about write 
    in fault tolerant storage and will complete the write in a recoverable 
    manner, ensuring at all times that either the original contents or 
    the modified contents are available.

Arguments:
    This             - Calling context
    FvbHandle        - The handle of FVB protocol that provides services for 
                       reading, writing, and erasing the target block.
    Lba              - The logical block address of the target block.  
    Offset           - The offset within the target block to place the data.
    NumBytes         - The number of bytes to write to the target block.
    Buffer           - The data to write.

Returns:
    EFI_SUCCESS          - The function completed successfully
    EFI_BAD_BUFFER_SIZE  - The write would span a target block, which is not 
                           a valid action.
    EFI_ACCESS_DENIED    - No writes have been allocated.
    EFI_NOT_FOUND        - Cannot find FVB by handle.
    EFI_OUT_OF_RESOURCES - Cannot allocate memory.
    EFI_ABORTED          - The function could not complete successfully.

--*/
{
  EFI_STATUS                          Status;
  EFI_FTW_LITE_DEVICE                 *FtwLiteDevice;
  EFI_FTW_LITE_RECORD                 *Record;
  EFI_FIRMWARE_VOLUME_BLOCK_PROTOCOL  *Fvb;
  EFI_PHYSICAL_ADDRESS                FvbPhysicalAddress;
  UINTN                               MyLength;
  UINTN                               MyOffset;
  UINTN                               MyBufferSize;
  UINT8                               *MyBuffer;
  UINTN                               SpareBufferSize;
  UINT8                               *SpareBuffer;
  UINTN                               Index;
  UINT8                               *Ptr;
  EFI_DEV_PATH_PTR                    DevPtr;

  //
  // Refresh work space and get last record
  //
  FtwLiteDevice = FTW_LITE_CONTEXT_FROM_THIS (This);
  Status        = WorkSpaceRefresh (FtwLiteDevice);
  if (EFI_ERROR (Status)) {
    return EFI_ABORTED;
  }

  Record = FtwLiteDevice->FtwLastRecord;

  //
  // Check the flags of last write record
  //
  if ((Record->WriteAllocated == FTW_VALID_STATE) || (Record->SpareCompleted == FTW_VALID_STATE)) {
    return EFI_ACCESS_DENIED;
  }
  //
  // IF former record has completed, THEN use next record
  //
  if (Record->WriteCompleted == FTW_VALID_STATE) {
    Record++;
    FtwLiteDevice->FtwLastRecord = Record;
  }

  MyOffset = (UINT8 *) Record - FtwLiteDevice->FtwWorkSpace;

  //
  // Check if the input data can fit within the target block
  //
  if ((Offset +*NumBytes) > FtwLiteDevice->SpareAreaLength) {
    return EFI_BAD_BUFFER_SIZE;
  }
  //
  // Check if there is enough free space for allocate a record
  //
  if ((MyOffset + WRITE_TOTAL_SIZE) > FtwLiteDevice->FtwWorkSpaceSize) {
    Status = FtwReclaimWorkSpace (FtwLiteDevice);
    if (EFI_ERROR (Status)) {
      DEBUG ((EFI_D_ERROR, "FtwLite: Reclaim work space - %r", Status));
      return EFI_ABORTED;
    }
  }
  //
  // Get the FVB protocol by handle
  //
  Status = FtwGetFvbByHandle (FvbHandle, &Fvb);
  if (EFI_ERROR (Status)) {
    return EFI_NOT_FOUND;
  }
  //
  // Allocate a write record in workspace.
  // Update Header->WriteAllocated as VALID
  //
  Status = FtwUpdateFvState (
            FtwLiteDevice->FtwFvBlock,
            FtwLiteDevice->FtwWorkSpaceLba,
            FtwLiteDevice->FtwWorkSpaceBase + MyOffset,
            WRITE_ALLOCATED
            );

  if (EFI_ERROR (Status)) {
    DEBUG ((EFI_D_FTW_LITE, "FtwLite: Allocate record - %r\n", Status));
    return EFI_ABORTED;
  }

  Record->WriteAllocated = FTW_VALID_STATE;

  //
  // Prepare data of write record, filling DevPath with memory mapped address.
  //
  DevPtr.MemMap                 = (MEMMAP_DEVICE_PATH *) &Record->DevPath;
  DevPtr.MemMap->Header.Type    = HARDWARE_DEVICE_PATH;
  DevPtr.MemMap->Header.SubType = HW_MEMMAP_DP;
  SetDevicePathNodeLength (&DevPtr.MemMap->Header, sizeof (MEMMAP_DEVICE_PATH));

  Status = Fvb->GetPhysicalAddress (Fvb, &FvbPhysicalAddress);
  if (EFI_ERROR (Status)) {
    DEBUG ((EFI_D_FTW_LITE, "FtwLite: Get FVB physical address - %r\n", Status));
    return EFI_ABORTED;
  }

  DevPtr.MemMap->MemoryType       = EfiMemoryMappedIO;
  DevPtr.MemMap->StartingAddress  = FvbPhysicalAddress;
  DevPtr.MemMap->EndingAddress    = FvbPhysicalAddress +*NumBytes;
  //
  // ignored!
  //
  Record->Lba       = Lba;
  Record->Offset    = Offset;
  Record->NumBytes  = *NumBytes;

  //
  // Write the record to the work space.
  //
  MyOffset  = (UINT8 *) Record - FtwLiteDevice->FtwWorkSpace;
  MyLength  = FTW_LITE_RECORD_SIZE;

  Status = FtwLiteDevice->FtwFvBlock->Write (
                                        FtwLiteDevice->FtwFvBlock,
                                        FtwLiteDevice->FtwWorkSpaceLba,
                                        FtwLiteDevice->FtwWorkSpaceBase + MyOffset,
                                        &MyLength,
                                        (UINT8 *) Record
                                        );
  if (EFI_ERROR (Status)) {
    return EFI_ABORTED;
  }
  //
  // Record has been written to working block, then write data.
  //
  //
  // Allocate a memory buffer
  //
  MyBufferSize  = FtwLiteDevice->SpareAreaLength;
  MyBuffer      = AllocatePool (MyBufferSize);
  if (MyBuffer == NULL) {
    return EFI_OUT_OF_RESOURCES;
  }
  //
  // Starting at Lba, if the number of the rest blocks on Fvb is less
  // than NumberOfSpareBlock.
  //
  //
  // Read all original data from target block to memory buffer
  //
  if (IsInWorkingBlock (FtwLiteDevice, Fvb, Lba)) {
    //
    // If target block falls into working block, we must follow the process of
    // updating working block.
    //
    Ptr = MyBuffer;
    for (Index = 0; Index < FtwLiteDevice->NumberOfSpareBlock; Index += 1) {
      MyLength = FtwLiteDevice->SizeOfSpareBlock;
      Status = FtwLiteDevice->FtwFvBlock->Read (
                                            FtwLiteDevice->FtwFvBlock,
                                            FtwLiteDevice->FtwWorkBlockLba + Index,
                                            0,
                                            &MyLength,
                                            Ptr
                                            );
      if (EFI_ERROR (Status)) {
        FreePool (MyBuffer);
        return EFI_ABORTED;
      }

      Ptr += MyLength;
    }
    //
    // Update Offset by adding the offset from the start LBA of working block to
    // the target LBA. The target block can not span working block!
    //
    Offset = (((UINTN) (Lba - FtwLiteDevice->FtwWorkBlockLba)) * FtwLiteDevice->SizeOfSpareBlock + Offset);
    ASSERT ((Offset +*NumBytes) <= FtwLiteDevice->SpareAreaLength);

  } else {

    Ptr = MyBuffer;
    for (Index = 0; Index < FtwLiteDevice->NumberOfSpareBlock; Index += 1) {
      MyLength  = FtwLiteDevice->SizeOfSpareBlock;
      Status    = Fvb->Read (Fvb, Lba + Index, 0, &MyLength, Ptr);
      if (EFI_ERROR (Status)) {
        FreePool (MyBuffer);
        return EFI_ABORTED;
      }

      Ptr += MyLength;
    }
  }
  //
  // Overwrite the updating range data with
  // the input buffer content
  //
  CopyMem (MyBuffer + Offset, Buffer, *NumBytes);

  //
  // Try to keep the content of spare block
  // Save spare block into a spare backup memory buffer (Sparebuffer)
  //
  SpareBufferSize = FtwLiteDevice->SpareAreaLength;
  SpareBuffer     = AllocatePool (SpareBufferSize);
  if (SpareBuffer == NULL) {
    FreePool (MyBuffer);
    return EFI_OUT_OF_RESOURCES;
  }

  Ptr = SpareBuffer;
  for (Index = 0; Index < FtwLiteDevice->NumberOfSpareBlock; Index += 1) {
    MyLength = FtwLiteDevice->SizeOfSpareBlock;
    Status = FtwLiteDevice->FtwBackupFvb->Read (
                                            FtwLiteDevice->FtwBackupFvb,
                                            FtwLiteDevice->FtwSpareLba + Index,
                                            0,
                                            &MyLength,
                                            Ptr
                                            );
    if (EFI_ERROR (Status)) {
      FreePool (MyBuffer);
      FreePool (SpareBuffer);
      return EFI_ABORTED;
    }

    Ptr += MyLength;
  }
  //
  // Write the memory buffer to spare block
  // Don't forget to erase Flash first.
  //
  Status  = FtwEraseSpareBlock (FtwLiteDevice);
  Ptr     = MyBuffer;
  for (Index = 0; Index < FtwLiteDevice->NumberOfSpareBlock; Index += 1) {
    MyLength = FtwLiteDevice->SizeOfSpareBlock;
    Status = FtwLiteDevice->FtwBackupFvb->Write (
                                            FtwLiteDevice->FtwBackupFvb,
                                            FtwLiteDevice->FtwSpareLba + Index,
                                            0,
                                            &MyLength,
                                            Ptr
                                            );
    if (EFI_ERROR (Status)) {
      FreePool (MyBuffer);
      FreePool (SpareBuffer);
      return EFI_ABORTED;
    }

    Ptr += MyLength;
  }
  //
  // Free MyBuffer
  //
  FreePool (MyBuffer);

  //
  // Set the SpareCompleteD in the FTW record,
  //
  MyOffset = (UINT8 *) Record - FtwLiteDevice->FtwWorkSpace;
  Status = FtwUpdateFvState (
            FtwLiteDevice->FtwFvBlock,
            FtwLiteDevice->FtwWorkSpaceLba,
            FtwLiteDevice->FtwWorkSpaceBase + MyOffset,
            SPARE_COMPLETED
            );
  if (EFI_ERROR (Status)) {
    FreePool (SpareBuffer);
    return EFI_ABORTED;
  }

  Record->SpareCompleted = FTW_VALID_STATE;

  //
  //  Since the content has already backuped in spare block, the write is
  //  guaranteed to be completed with fault tolerant manner.
  //
  Status = FtwWriteRecord (FtwLiteDevice, Fvb);
  if (EFI_ERROR (Status)) {
    FreePool (SpareBuffer);
    return EFI_ABORTED;
  }

  Record++;
  FtwLiteDevice->FtwLastRecord = Record;

  //
  // Restore spare backup buffer into spare block , if no failure happened during FtwWrite.
  //
  Status  = FtwEraseSpareBlock (FtwLiteDevice);
  Ptr     = SpareBuffer;
  for (Index = 0; Index < FtwLiteDevice->NumberOfSpareBlock; Index += 1) {
    MyLength = FtwLiteDevice->SizeOfSpareBlock;
    Status = FtwLiteDevice->FtwBackupFvb->Write (
                                            FtwLiteDevice->FtwBackupFvb,
                                            FtwLiteDevice->FtwSpareLba + Index,
                                            0,
                                            &MyLength,
                                            Ptr
                                            );
    if (EFI_ERROR (Status)) {
      FreePool (SpareBuffer);
      return EFI_ABORTED;
    }

    Ptr += MyLength;
  }
  //
  // All success.
  //
  FreePool (SpareBuffer);

  DEBUG (
    (EFI_D_FTW_LITE,
    "FtwLite: Write() success, (Lba:Offset)=(%lx:0x%x), NumBytes: 0x%x\n",
    Lba,
    Offset,
    *NumBytes)
    );

  return EFI_SUCCESS;
}


EFI_STATUS
FtwWriteRecord (
  IN EFI_FTW_LITE_DEVICE                   *FtwLiteDevice,
  IN EFI_FIRMWARE_VOLUME_BLOCK_PROTOCOL    *Fvb
  )
/*++

Routine Description:
    Write a record with fault tolerant mannaer.
    Since the content has already backuped in spare block, the write is 
    guaranteed to be completed with fault tolerant manner.
    
Arguments:
    FtwLiteDevice       - The private data of FTW_LITE driver
    Fvb                 - The FVB protocol that provides services for 
                          reading, writing, and erasing the target block.

Returns:
    EFI_SUCCESS         - The function completed successfully
    EFI_ABORTED         - The function could not complete successfully

--*/
{
  EFI_STATUS          Status;
  EFI_FTW_LITE_RECORD *Record;
  EFI_LBA             WorkSpaceLbaOffset;  
  UINTN               Offset;

  //
  // Spare Complete but Destination not complete,
  // Recover the targt block with the spare block.
  //
  Record = FtwLiteDevice->FtwLastRecord;

  //
  // IF target block is working block, THEN Flush Spare Block To Working Block;
  // ELSE IF target block is boot block, THEN Flush Spare Block To boot Block;
  // ELSE flush spare block to normal target block.ENDIF
  //
  if (IsInWorkingBlock (FtwLiteDevice, Fvb, Record->Lba)) {
    //
    // If target block is working block, Attention:
    // it's required to set SPARE_COMPLETED to spare block.
    //
    WorkSpaceLbaOffset = FtwLiteDevice->FtwWorkSpaceLba - FtwLiteDevice->FtwWorkBlockLba;
    Offset = (UINT8 *) Record - FtwLiteDevice->FtwWorkSpace;
    Status = FtwUpdateFvState (
              FtwLiteDevice->FtwBackupFvb,
              FtwLiteDevice->FtwSpareLba + WorkSpaceLbaOffset,
              FtwLiteDevice->FtwWorkSpaceBase + Offset,
              SPARE_COMPLETED
              );
    ASSERT_EFI_ERROR (Status);

    Status = FlushSpareBlockToWorkingBlock (FtwLiteDevice);
  } else if (IsBootBlock (FtwLiteDevice, Fvb, Record->Lba)) {
    //
    // Update boot block
    //
    Status = FlushSpareBlockToBootBlock (FtwLiteDevice);
  } else {
    //
    // Update blocks other than working block or boot block
    //
    Status = FlushSpareBlockToTargetBlock (FtwLiteDevice, Fvb, Record->Lba);
  }

  ASSERT_EFI_ERROR (Status);

  //
  // Set WriteCompleted flag in record
  //
  Offset = (UINT8 *) Record - FtwLiteDevice->FtwWorkSpace;
  Status = FtwUpdateFvState (
            FtwLiteDevice->FtwFvBlock,
            FtwLiteDevice->FtwWorkSpaceLba,
            FtwLiteDevice->FtwWorkSpaceBase + Offset,
            WRITE_COMPLETED
            );
  ASSERT_EFI_ERROR (Status);

  Record->WriteCompleted = FTW_VALID_STATE;
  return EFI_SUCCESS;
}


EFI_STATUS
FtwRestart (
  IN EFI_FTW_LITE_DEVICE    *FtwLiteDevice
  )
/*++

Routine Description:
    Restarts a previously interrupted write. The caller must provide the 
    block protocol needed to complete the interrupted write.
    
Arguments:
    FtwLiteDevice       - The private data of FTW_LITE driver
    FvbHandle           - The handle of FVB protocol that provides services for 
                          reading, writing, and erasing the target block.

Returns:
    EFI_SUCCESS         - The function completed successfully
    EFI_ACCESS_DENIED   - No pending writes exist
    EFI_NOT_FOUND       - FVB protocol not found by the handle
    EFI_ABORTED         - The function could not complete successfully

--*/
{
  EFI_STATUS                          Status;
  EFI_FTW_LITE_RECORD                 *Record;
  EFI_FIRMWARE_VOLUME_BLOCK_PROTOCOL  *Fvb;
  EFI_DEV_PATH_PTR                    DevPathPtr;

  //
  // Spare Completed but Destination not complete,
  // Recover the targt block with the spare block.
  //
  Record = FtwLiteDevice->FtwLastRecord;

  //
  // Only support memory mapped FVB device path by now.
  //
  DevPathPtr.MemMap = (MEMMAP_DEVICE_PATH *) &Record->DevPath;
  if (!((DevPathPtr.MemMap->Header.Type == HARDWARE_DEVICE_PATH) && (DevPathPtr.MemMap->Header.SubType == HW_MEMMAP_DP))
      ) {
    DEBUG ((EFI_D_FTW_LITE, "FtwLite: FVB Device Path is not memory mapped\n"));
    return EFI_ABORTED;
  }

  Status = GetFvbByAddress (DevPathPtr.MemMap->StartingAddress, &Fvb);
  if (EFI_ERROR (Status)) {
    return EFI_NOT_FOUND;
  }
  //
  //  Since the content has already backuped in spare block, the write is
  //  guaranteed to be completed with fault tolerant manner.
  //
  Status = FtwWriteRecord (FtwLiteDevice, Fvb);
  DEBUG ((EFI_D_FTW_INFO, "FtwLite: Restart() - %r\n", Status));

  Record++;
  FtwLiteDevice->FtwLastRecord = Record;

  //
  // Erase Spare block
  // This is restart, no need to keep spareblock content.
  //
  FtwEraseSpareBlock (FtwLiteDevice);

  return Status;
}


EFI_STATUS
FtwAbort (
  IN EFI_FTW_LITE_DEVICE    *FtwLiteDevice
  )
/*++

Routine Description:
    Aborts all previous allocated writes.

Arguments:
    FtwLiteDevice    - The private data of FTW_LITE driver

Returns:
    EFI_SUCCESS      - The function completed successfully
    EFI_ABORTED      - The function could not complete successfully.
    EFI_NOT_FOUND    - No allocated writes exist.

--*/
{
  EFI_STATUS  Status;
  UINTN       Offset;

  if (FtwLiteDevice->FtwLastRecord->WriteCompleted == FTW_VALID_STATE) {
    return EFI_NOT_FOUND;
  }
  //
  // Update the complete state of the header as VALID and abort.
  //
  Offset = (UINT8 *) FtwLiteDevice->FtwLastRecord - FtwLiteDevice->FtwWorkSpace;
  Status = FtwUpdateFvState (
            FtwLiteDevice->FtwFvBlock,
            FtwLiteDevice->FtwWorkSpaceLba,
            FtwLiteDevice->FtwWorkSpaceBase + Offset,
            WRITE_COMPLETED
            );
  if (EFI_ERROR (Status)) {
    return EFI_ABORTED;
  }

  FtwLiteDevice->FtwLastRecord->WriteCompleted  = FTW_VALID_STATE;

  Status = FtwGetLastRecord (FtwLiteDevice, &FtwLiteDevice->FtwLastRecord);

  //
  // Erase the spare block
  //
  Status = FtwEraseSpareBlock (FtwLiteDevice);

  DEBUG ((EFI_D_FTW_INFO, "FtwLite: Abort() success \n"));
  return EFI_SUCCESS;
}

EFI_STATUS
EFIAPI
InitializeFtwLite (
  IN EFI_HANDLE         ImageHandle,
  IN EFI_SYSTEM_TABLE   *SystemTable
  )
/*++
  Routine Description: 
    This function is the entry point of the Fault Tolerant Write driver.
  
  Arguments: 
    ImageHandle   - EFI_HANDLE: A handle for the image that is initializing 
                    this driver
    SystemTable   - EFI_SYSTEM_TABLE: A pointer to the EFI system table
        
  Returns:  
    EFI_SUCCESS           - FTW has finished the initialization
    EFI_ABORTED           - FTW initialization error

--*/
{
  EFI_FIRMWARE_VOLUME_BLOCK_PROTOCOL  *Fvb;
  UINTN                               Index;
  EFI_HANDLE                          *HandleBuffer;
  UINTN                               HandleCount;
  EFI_FIRMWARE_VOLUME_HEADER          *FwVolHeader;
  EFI_PHYSICAL_ADDRESS                BaseAddress;
  EFI_FTW_LITE_DEVICE                 *FtwLiteDevice;
  EFI_FTW_LITE_RECORD                 *Record;
  UINTN                               Length;
  EFI_STATUS                          Status;
  UINTN                               Offset;
  EFI_FV_BLOCK_MAP_ENTRY              *FvbMapEntry;
  UINT32                              LbaIndex;
  EFI_PEI_HOB_POINTERS                FvHob;
  EFI_FLASH_MAP_ENTRY_DATA            *FlashMapEntry;
  //
  // Allocate Private data of this driver,
  // INCLUDING THE FtwWorkSpace[FTW_WORK_SPACE_SIZE].
  //
  FtwLiteDevice = NULL;
  FtwLiteDevice = AllocatePool (sizeof (EFI_FTW_LITE_DEVICE) + FTW_WORK_SPACE_SIZE);
  if (FtwLiteDevice != NULL) {
    Status = EFI_SUCCESS;
  } else {
    Status = EFI_OUT_OF_RESOURCES;
  }

  ASSERT_EFI_ERROR (Status);

  ZeroMem (FtwLiteDevice, sizeof (EFI_FTW_LITE_DEVICE));
  FtwLiteDevice->Signature = FTW_LITE_DEVICE_SIGNATURE;

  //
  // Initialize other parameters, and set WorkSpace as FTW_ERASED_BYTE.
  //
  FtwLiteDevice->FtwWorkSpace     = (UINT8 *) (FtwLiteDevice + 1);
  FtwLiteDevice->FtwWorkSpaceSize = FTW_WORK_SPACE_SIZE;
  SetMem (
    FtwLiteDevice->FtwWorkSpace,
    FtwLiteDevice->FtwWorkSpaceSize,
    FTW_ERASED_BYTE
    );
  FtwLiteDevice->FtwWorkSpaceHeader = (EFI_FAULT_TOLERANT_WORKING_BLOCK_HEADER *) FtwLiteDevice->FtwWorkSpace;

  FtwLiteDevice->FtwLastRecord      = NULL;
        
  //
  // BUGBUG: Here should use Pcd after build tool support dynamic PCD
  //        
  FtwLiteDevice->SpareAreaLength  = 0;
  FtwLiteDevice->WorkSpaceLength  = 0;
  FvHob.Raw = GetHobList ();
  while ((FvHob.Raw = GetNextGuidHob (&gEfiFlashMapHobGuid, FvHob.Raw)) != NULL) {

    FlashMapEntry = (EFI_FLASH_MAP_ENTRY_DATA *) GET_GUID_HOB_DATA (FvHob.Guid);
      
    //
    // Get the FTW work space Flash Map SUB area
    //
    if ((FlashMapEntry->AreaType == EFI_FLASH_AREA_FTW_STATE) && (FlashMapEntry->NumEntries == 1)) {
      FtwLiteDevice->WorkSpaceAddress = FlashMapEntry->Entries[0].Base;
      FtwLiteDevice->WorkSpaceLength  = (UINTN) FlashMapEntry->Entries[0].Length;
    }
    //
    // Get the FTW backup SUB area
    //
    if ((FlashMapEntry->AreaType == EFI_FLASH_AREA_FTW_BACKUP) && (FlashMapEntry->NumEntries == 1)) {
      FtwLiteDevice->SpareAreaAddress = FlashMapEntry->Entries[0].Base;
      FtwLiteDevice->SpareAreaLength  = (UINTN) FlashMapEntry->Entries[0].Length;
    }
    
    FvHob.Raw = GET_NEXT_HOB (FvHob);
  }

  ASSERT ((FtwLiteDevice->WorkSpaceLength != 0) && (FtwLiteDevice->SpareAreaLength != 0));

  //
  // Locate FVB protocol
  //
  Status = gBS->LocateHandleBuffer (
                  ByProtocol,
                  &gEfiFirmwareVolumeBlockProtocolGuid,
                  NULL,
                  &HandleCount,
                  &HandleBuffer
                  );
  ASSERT_EFI_ERROR (Status);

  ASSERT (HandleCount > 0);

  FtwLiteDevice->FtwFvBlock       = NULL;
  FtwLiteDevice->FtwBackupFvb     = NULL;
  FtwLiteDevice->FtwWorkSpaceLba  = (EFI_LBA) (-1);
  FtwLiteDevice->FtwSpareLba      = (EFI_LBA) (-1);
  for (Index = 0; Index < HandleCount; Index += 1) {
    Status = gBS->HandleProtocol (
                    HandleBuffer[Index],
                    &gEfiFirmwareVolumeBlockProtocolGuid,
                    (VOID **) &Fvb
                    );
    ASSERT_EFI_ERROR (Status);

    Status = Fvb->GetPhysicalAddress (Fvb, &BaseAddress);
    if (EFI_ERROR (Status)) {
      continue;
    }

    FwVolHeader = (EFI_FIRMWARE_VOLUME_HEADER *) ((UINTN) BaseAddress);

    if ((FtwLiteDevice->WorkSpaceAddress >= BaseAddress) &&
        (FtwLiteDevice->WorkSpaceAddress <= (BaseAddress + FwVolHeader->FvLength))
        ) {
      FtwLiteDevice->FtwFvBlock = Fvb;
      //
      // To get the LBA of work space
      //
      if ((FwVolHeader->FvLength) > (FwVolHeader->HeaderLength)) {
        //
        // FV may have multiple types of BlockLength
        //
        FvbMapEntry = &FwVolHeader->BlockMap[0];
        while (!((FvbMapEntry->NumBlocks == 0) && (FvbMapEntry->Length == 0))) {
          for (LbaIndex = 1; LbaIndex <= FvbMapEntry->NumBlocks; LbaIndex += 1) {
            if (FtwLiteDevice->WorkSpaceAddress < (BaseAddress + FvbMapEntry->Length * LbaIndex)) {
              FtwLiteDevice->FtwWorkSpaceLba = LbaIndex - 1;
              //
              // Get the Work space size and Base(Offset)
              //
              FtwLiteDevice->FtwWorkSpaceSize = FtwLiteDevice->WorkSpaceLength;
              FtwLiteDevice->FtwWorkSpaceBase = (UINTN) (FtwLiteDevice->WorkSpaceAddress - (BaseAddress + FvbMapEntry->Length * (LbaIndex - 1)));
              break;
            }
          }
          //
          // end for
          //
          FvbMapEntry++;
        }
        //
        // end while
        //
      }
    }

    if ((FtwLiteDevice->SpareAreaAddress >= BaseAddress) &&
        (FtwLiteDevice->SpareAreaAddress <= (BaseAddress + FwVolHeader->FvLength))
        ) {
      FtwLiteDevice->FtwBackupFvb = Fvb;
      //
      // To get the LBA of spare
      //
      if ((FwVolHeader->FvLength) > (FwVolHeader->HeaderLength)) {
        //
        // FV may have multiple types of BlockLength
        //
        FvbMapEntry = &FwVolHeader->BlockMap[0];
        while (!((FvbMapEntry->NumBlocks == 0) && (FvbMapEntry->Length == 0))) {
          for (LbaIndex = 1; LbaIndex <= FvbMapEntry->NumBlocks; LbaIndex += 1) {
            if (FtwLiteDevice->SpareAreaAddress < (BaseAddress + FvbMapEntry->Length * LbaIndex)) {
              //
              // Get the NumberOfSpareBlock and SizeOfSpareBlock
              //
              FtwLiteDevice->FtwSpareLba        = LbaIndex - 1;
              FtwLiteDevice->SizeOfSpareBlock   = FvbMapEntry->Length;
              FtwLiteDevice->NumberOfSpareBlock = FtwLiteDevice->SpareAreaLength / FtwLiteDevice->SizeOfSpareBlock;
              //
              // Check the range of spare area to make sure that it's in FV range
              //
              ASSERT ((FtwLiteDevice->FtwSpareLba + FtwLiteDevice->NumberOfSpareBlock) <= FvbMapEntry->NumBlocks);
              break;
            }
          }

          FvbMapEntry++;
        }
        //
        // end while
        //
      }
    }
  }
  //
  // Calculate the start LBA of working block. Working block is an area which
  // contains working space in its last block and has the same size as spare
  // block, unless there are not enough blocks before the block that contains
  // working space.
  //
  FtwLiteDevice->FtwWorkBlockLba = FtwLiteDevice->FtwWorkSpaceLba - FtwLiteDevice->NumberOfSpareBlock + 1;
  if ((INT64) (FtwLiteDevice->FtwWorkBlockLba) < 0) {
    FtwLiteDevice->FtwWorkBlockLba = 0;
  }

  if ((FtwLiteDevice->FtwFvBlock == NULL) ||
      (FtwLiteDevice->FtwBackupFvb == NULL) ||
      (FtwLiteDevice->FtwWorkSpaceLba == (EFI_LBA) (-1)) ||
      (FtwLiteDevice->FtwSpareLba == (EFI_LBA) (-1))
      ) {
    DEBUG ((EFI_D_ERROR, "FtwLite: Working or spare FVB not ready\n"));
    ASSERT_EFI_ERROR (Status);
  }
  //
  // Refresh workspace data from working block
  //
  Status = WorkSpaceRefresh (FtwLiteDevice);
  ASSERT_EFI_ERROR (Status);

  //
  // If the working block workspace is not valid, try the spare block
  //
  if (!IsValidWorkSpace (FtwLiteDevice->FtwWorkSpaceHeader)) {
    DEBUG ((EFI_D_FTW_LITE, "FtwLite: Workspace invalid, read from backup\n"));
    //
    // Read from spare block
    //
    Length = FtwLiteDevice->FtwWorkSpaceSize;
    Status = FtwLiteDevice->FtwBackupFvb->Read (
                                            FtwLiteDevice->FtwBackupFvb,
                                            FtwLiteDevice->FtwSpareLba,
                                            FtwLiteDevice->FtwWorkSpaceBase,
                                            &Length,
                                            FtwLiteDevice->FtwWorkSpace
                                            );
    ASSERT_EFI_ERROR (Status);

    //
    // If spare block is valid, then replace working block content.
    //
    if (IsValidWorkSpace (FtwLiteDevice->FtwWorkSpaceHeader)) {
      Status = FlushSpareBlockToWorkingBlock (FtwLiteDevice);
      DEBUG ((EFI_D_FTW_LITE, "FtwLite: Restart working block in Init() - %r\n", Status));
      ASSERT_EFI_ERROR (Status);

      FtwAbort (FtwLiteDevice);
      //
      // Refresh work space.
      //
      Status = WorkSpaceRefresh (FtwLiteDevice);
      if (EFI_ERROR (Status)) {
        return EFI_ABORTED;
      }
    } else {
      DEBUG ((EFI_D_FTW_LITE, "FtwLite: Both are invalid, init workspace\n"));
      //
      // If both are invalid, then initialize work space.
      //
      SetMem (
        FtwLiteDevice->FtwWorkSpace,
        FtwLiteDevice->FtwWorkSpaceSize,
        FTW_ERASED_BYTE
        );
      InitWorkSpaceHeader (FtwLiteDevice->FtwWorkSpaceHeader);
      //
      // Write to work space on the working block
      //
      Length = FtwLiteDevice->FtwWorkSpaceSize;
      Status = FtwLiteDevice->FtwFvBlock->Write (
                                            FtwLiteDevice->FtwFvBlock,
                                            FtwLiteDevice->FtwWorkSpaceLba,
                                            FtwLiteDevice->FtwWorkSpaceBase,
                                            &Length,
                                            FtwLiteDevice->FtwWorkSpace
                                            );
      if (EFI_ERROR (Status)) {
        return EFI_ABORTED;
      }
    }
  }
  //
  // Hook the protocol API
  //
  FtwLiteDevice->FtwLiteInstance.Write = FtwLiteWrite;

  //
  // Install protocol interface
  //
  Status = gBS->InstallProtocolInterface (
                  &FtwLiteDevice->Handle,
                  &gEfiFaultTolerantWriteLiteProtocolGuid,
                  EFI_NATIVE_INTERFACE,
                  &FtwLiteDevice->FtwLiteInstance
                  );
  if (EFI_ERROR (Status)) {
    return EFI_ABORTED;
  }
  //
  // If (!SpareCompleted)  THEN  Abort to rollback.
  //
  if ((FtwLiteDevice->FtwLastRecord->WriteAllocated == FTW_VALID_STATE) &&
      (FtwLiteDevice->FtwLastRecord->SpareCompleted != FTW_VALID_STATE)
      ) {
    DEBUG ((EFI_D_FTW_LITE, "FtwLite: Init.. record not SpareCompleted, abort()\n"));
    FtwAbort (FtwLiteDevice);
  }
  //
  // if (SpareCompleted) THEN  Restart to fault tolerant write.
  //
  if ((FtwLiteDevice->FtwLastRecord->SpareCompleted == FTW_VALID_STATE) &&
      (FtwLiteDevice->FtwLastRecord->WriteCompleted != FTW_VALID_STATE)
      ) {

    Status = FtwRestart (FtwLiteDevice);
    DEBUG ((EFI_D_FTW_LITE, "FtwLite: Restart last write - %r\n", Status));
    if (EFI_ERROR (Status)) {
      return Status;
    }
  }
  //
  // To check the workspace buffer behind last records is EMPTY or not.
  // If it's not EMPTY, FTW_LITE also need to call reclaim().
  //
  Record  = FtwLiteDevice->FtwLastRecord;
  Offset  = (UINT8 *) Record - FtwLiteDevice->FtwWorkSpace;
  if (FtwLiteDevice->FtwWorkSpace[Offset] != FTW_ERASED_BYTE) {
    Offset += WRITE_TOTAL_SIZE;
  }

  if (!IsErasedFlashBuffer (
        FTW_ERASE_POLARITY,
        FtwLiteDevice->FtwWorkSpace + Offset,
        FtwLiteDevice->FtwWorkSpaceSize - Offset
        )) {
    DEBUG ((EFI_D_FTW_LITE, "FtwLite: Workspace is dirty, call reclaim...\n"));
    Status = FtwReclaimWorkSpace (FtwLiteDevice);
    if (EFI_ERROR (Status)) {
      DEBUG ((EFI_D_FTW_LITE, "FtwLite: Workspace reclaim - %r\n", Status));
      return EFI_ABORTED;
    }
  }

  return EFI_SUCCESS;
}