FtwMisc.c

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#include "FaultTolerantWrite.h"
 
BOOLEAN
IsErasedFlashBuffer (
  IN UINT8  *Buffer,
  IN UINTN  BufferSize
  )
{
  BOOLEAN  IsEmpty;
  UINT8    *Ptr;
  UINTN    Index;
 
  Ptr     = Buffer;
  IsEmpty = TRUE;
  for (Index = 0; Index < BufferSize; Index += 1) {
    if (*Ptr++ != FTW_ERASED_BYTE) {
      IsEmpty = FALSE;
      break;
    }
  }
 
  return IsEmpty;
}
 
EFI_STATUS
FtwEraseBlock (
  IN EFI_FTW_DEVICE                   *FtwDevice,
  EFI_FIRMWARE_VOLUME_BLOCK_PROTOCOL  *FvBlock,
  EFI_LBA                             Lba,
  UINTN                               NumberOfBlocks
  )
{
  return FvBlock->EraseBlocks (
                    FvBlock,
                    Lba,
                    NumberOfBlocks,
                    EFI_LBA_LIST_TERMINATOR
                    );
}
 
EFI_STATUS
FtwEraseSpareBlock (
  IN EFI_FTW_DEVICE  *FtwDevice
  )
{
  return FtwDevice->FtwBackupFvb->EraseBlocks (
                                    FtwDevice->FtwBackupFvb,
                                    FtwDevice->FtwSpareLba,
                                    FtwDevice->NumberOfSpareBlock,
                                    EFI_LBA_LIST_TERMINATOR
                                    );
}
 
BOOLEAN
IsWorkingBlock (
  EFI_FTW_DEVICE                      *FtwDevice,
  EFI_FIRMWARE_VOLUME_BLOCK_PROTOCOL  *FvBlock,
  EFI_LBA                             Lba
  )
{
  //
  // If matching the following condition, the target block is in working block.
  // 1. Target block is on the FV of working block (Using the same FVB protocol instance).
  // 2. Lba falls into the range of working block.
  //
  return (BOOLEAN)
         (
          (FvBlock == FtwDevice->FtwFvBlock) &&
          (Lba >= FtwDevice->FtwWorkBlockLba) &&
          (Lba <= FtwDevice->FtwWorkSpaceLba)
         );
}
 
EFI_HANDLE
GetFvbByAddress (
  IN  EFI_PHYSICAL_ADDRESS                Address,
  OUT EFI_FIRMWARE_VOLUME_BLOCK_PROTOCOL  **FvBlock
  )
{
  EFI_STATUS                          Status;
  EFI_HANDLE                          *HandleBuffer;
  UINTN                               HandleCount;
  UINTN                               Index;
  EFI_PHYSICAL_ADDRESS                FvbBaseAddress;
  EFI_FIRMWARE_VOLUME_BLOCK_PROTOCOL  *Fvb;
  EFI_HANDLE                          FvbHandle;
  UINTN                               BlockSize;
  UINTN                               NumberOfBlocks;
 
  *FvBlock     = NULL;
  FvbHandle    = NULL;
  HandleBuffer = NULL;
  //
  // Locate all handles of Fvb protocol
  //
  Status = GetFvbCountAndBuffer (&HandleCount, &HandleBuffer);
  if (EFI_ERROR (Status)) {
    return NULL;
  }
 
  //
  // Get the FVB to access variable store
  //
  for (Index = 0; Index < HandleCount; Index += 1) {
    Status = FtwGetFvbByHandle (HandleBuffer[Index], &Fvb);
    if (EFI_ERROR (Status)) {
      break;
    }
 
    //
    // Compare the address and select the right one
    //
    Status = Fvb->GetPhysicalAddress (Fvb, &FvbBaseAddress);
    if (EFI_ERROR (Status)) {
      continue;
    }
 
    //
    // Now, one FVB has one type of BlockSize
    //
    Status = Fvb->GetBlockSize (Fvb, 0, &BlockSize, &NumberOfBlocks);
    if (EFI_ERROR (Status)) {
      continue;
    }
 
    if ((Address >= FvbBaseAddress) && (Address < (FvbBaseAddress + BlockSize * NumberOfBlocks))) {
      *FvBlock  = Fvb;
      FvbHandle = HandleBuffer[Index];
      break;
    }
  }
 
  FreePool (HandleBuffer);
  return FvbHandle;
}
 
BOOLEAN
IsBootBlock (
  EFI_FTW_DEVICE                      *FtwDevice,
  EFI_FIRMWARE_VOLUME_BLOCK_PROTOCOL  *FvBlock
  )
{
  EFI_STATUS                          Status;
  EFI_SWAP_ADDRESS_RANGE_PROTOCOL     *SarProtocol;
  EFI_PHYSICAL_ADDRESS                BootBlockBase;
  UINTN                               BootBlockSize;
  EFI_PHYSICAL_ADDRESS                BackupBlockBase;
  UINTN                               BackupBlockSize;
  EFI_FIRMWARE_VOLUME_BLOCK_PROTOCOL  *BootFvb;
  BOOLEAN                             IsSwapped;
  EFI_HANDLE                          FvbHandle;
 
  if (!FeaturePcdGet (PcdFullFtwServiceEnable)) {
    return FALSE;
  }
 
  Status = FtwGetSarProtocol ((VOID **)&SarProtocol);
  if (EFI_ERROR (Status)) {
    return FALSE;
  }
 
  //
  // Get the boot block range
  //
  Status = SarProtocol->GetRangeLocation (
                          SarProtocol,
                          &BootBlockBase,
                          &BootBlockSize,
                          &BackupBlockBase,
                          &BackupBlockSize
                          );
  if (EFI_ERROR (Status)) {
    return FALSE;
  }
 
  Status = SarProtocol->GetSwapState (SarProtocol, &IsSwapped);
  if (EFI_ERROR (Status)) {
    return FALSE;
  }
 
  //
  // Get FVB by address
  //
  if (!IsSwapped) {
    FvbHandle = GetFvbByAddress (BootBlockBase, &BootFvb);
  } else {
    FvbHandle = GetFvbByAddress (BackupBlockBase, &BootFvb);
  }
 
  if (FvbHandle == NULL) {
    return FALSE;
  }
 
  //
  // Compare the Fvb
  //
  return (BOOLEAN)(FvBlock == BootFvb);
}
 
EFI_STATUS
FlushSpareBlockToBootBlock (
  EFI_FTW_DEVICE  *FtwDevice
  )
{
  EFI_STATUS                          Status;
  UINTN                               Length;
  UINT8                               *Buffer;
  UINTN                               Count;
  UINT8                               *Ptr;
  UINTN                               Index;
  BOOLEAN                             TopSwap;
  EFI_SWAP_ADDRESS_RANGE_PROTOCOL     *SarProtocol;
  EFI_FIRMWARE_VOLUME_BLOCK_PROTOCOL  *BootFvb;
  EFI_LBA                             BootLba;
 
  if (!FeaturePcdGet (PcdFullFtwServiceEnable)) {
    return EFI_UNSUPPORTED;
  }
 
  //
  // Locate swap address range protocol
  //
  Status = FtwGetSarProtocol ((VOID **)&SarProtocol);
  if (EFI_ERROR (Status)) {
    return Status;
  }
 
  //
  // Allocate a memory buffer
  //
  Length = FtwDevice->SpareAreaLength;
  Buffer = AllocatePool (Length);
  if (Buffer == NULL) {
    return EFI_OUT_OF_RESOURCES;
  }
 
  //
  // Get TopSwap bit state
  //
  Status = SarProtocol->GetSwapState (SarProtocol, &TopSwap);
  if (EFI_ERROR (Status)) {
    DEBUG ((DEBUG_ERROR, "Ftw: Get Top Swapped status - %r\n", Status));
    FreePool (Buffer);
    return EFI_ABORTED;
  }
 
  if (TopSwap) {
    //
    // Get FVB of current boot block
    //
    if (GetFvbByAddress (FtwDevice->SpareAreaAddress + FtwDevice->SpareAreaLength, &BootFvb) == NULL) {
      FreePool (Buffer);
      return EFI_ABORTED;
    }
 
    //
    // Read data from current boot block
    //
    BootLba = 0;
    Ptr     = Buffer;
    for (Index = 0; Index < FtwDevice->NumberOfSpareBlock; Index += 1) {
      Count  = FtwDevice->SpareBlockSize;
      Status = BootFvb->Read (
                          BootFvb,
                          BootLba + Index,
                          0,
                          &Count,
                          Ptr
                          );
      if (EFI_ERROR (Status)) {
        FreePool (Buffer);
        return Status;
      }
 
      Ptr += Count;
    }
  } else {
    //
    // Read data from spare block
    //
    Ptr = Buffer;
    for (Index = 0; Index < FtwDevice->NumberOfSpareBlock; Index += 1) {
      Count  = FtwDevice->SpareBlockSize;
      Status = FtwDevice->FtwBackupFvb->Read (
                                          FtwDevice->FtwBackupFvb,
                                          FtwDevice->FtwSpareLba + Index,
                                          0,
                                          &Count,
                                          Ptr
                                          );
      if (EFI_ERROR (Status)) {
        FreePool (Buffer);
        return Status;
      }
 
      Ptr += Count;
    }
 
    //
    // Set TopSwap bit
    //
    Status = SarProtocol->SetSwapState (SarProtocol, TRUE);
    if (EFI_ERROR (Status)) {
      FreePool (Buffer);
      return Status;
    }
  }
 
  //
  // Erase current spare block
  // Because TopSwap is set, this actually erase the top block (boot block)!
  //
  Status = FtwEraseSpareBlock (FtwDevice);
  if (EFI_ERROR (Status)) {
    FreePool (Buffer);
    return EFI_ABORTED;
  }
 
  //
  // Write memory buffer to current spare block. Still top block.
  //
  Ptr = Buffer;
  for (Index = 0; Index < FtwDevice->NumberOfSpareBlock; Index += 1) {
    Count  = FtwDevice->SpareBlockSize;
    Status = FtwDevice->FtwBackupFvb->Write (
                                        FtwDevice->FtwBackupFvb,
                                        FtwDevice->FtwSpareLba + Index,
                                        0,
                                        &Count,
                                        Ptr
                                        );
    if (EFI_ERROR (Status)) {
      DEBUG ((DEBUG_ERROR, "Ftw: FVB Write boot block - %r\n", Status));
      FreePool (Buffer);
      return Status;
    }
 
    Ptr += Count;
  }
 
  FreePool (Buffer);
 
  //
  // Clear TopSwap bit
  //
  Status = SarProtocol->SetSwapState (SarProtocol, FALSE);
 
  return Status;
}
 
EFI_STATUS
FlushSpareBlockToTargetBlock (
  EFI_FTW_DEVICE                      *FtwDevice,
  EFI_FIRMWARE_VOLUME_BLOCK_PROTOCOL  *FvBlock,
  EFI_LBA                             Lba,
  UINTN                               BlockSize,
  UINTN                               NumberOfBlocks
  )
{
  EFI_STATUS  Status;
  UINTN       Length;
  UINT8       *Buffer;
  UINTN       Count;
  UINT8       *Ptr;
  UINTN       Index;
 
  if ((FtwDevice == NULL) || (FvBlock == NULL)) {
    return EFI_INVALID_PARAMETER;
  }
 
  //
  // Allocate a memory buffer
  //
  Length = FtwDevice->SpareAreaLength;
  Buffer = AllocatePool (Length);
  if (Buffer == NULL) {
    return EFI_OUT_OF_RESOURCES;
  }
 
  //
  // Read all content of spare block to memory buffer
  //
  Ptr = Buffer;
  for (Index = 0; Index < FtwDevice->NumberOfSpareBlock; Index += 1) {
    Count  = FtwDevice->SpareBlockSize;
    Status = FtwDevice->FtwBackupFvb->Read (
                                        FtwDevice->FtwBackupFvb,
                                        FtwDevice->FtwSpareLba + Index,
                                        0,
                                        &Count,
                                        Ptr
                                        );
    if (EFI_ERROR (Status)) {
      FreePool (Buffer);
      return Status;
    }
 
    Ptr += Count;
  }
 
  //
  // Erase the target block
  //
  Status = FtwEraseBlock (FtwDevice, FvBlock, Lba, NumberOfBlocks);
  if (EFI_ERROR (Status)) {
    FreePool (Buffer);
    return EFI_ABORTED;
  }
 
  //
  // Write memory buffer to block, using the FvBlock protocol interface
  //
  Ptr = Buffer;
  for (Index = 0; Index < NumberOfBlocks; Index += 1) {
    Count  = BlockSize;
    Status = FvBlock->Write (FvBlock, Lba + Index, 0, &Count, Ptr);
    if (EFI_ERROR (Status)) {
      DEBUG ((DEBUG_ERROR, "Ftw: FVB Write block - %r\n", Status));
      FreePool (Buffer);
      return Status;
    }
 
    Ptr += Count;
  }
 
  FreePool (Buffer);
 
  return Status;
}
 
EFI_STATUS
FlushSpareBlockToWorkingBlock (
  EFI_FTW_DEVICE  *FtwDevice
  )
{
  EFI_STATUS                               Status;
  UINTN                                    Length;
  UINT8                                    *Buffer;
  EFI_FAULT_TOLERANT_WORKING_BLOCK_HEADER  *WorkingBlockHeader;
  UINTN                                    Count;
  UINT8                                    *Ptr;
  UINTN                                    Index;
 
  //
  // Allocate a memory buffer
  //
  Length = FtwDevice->SpareAreaLength;
  Buffer = AllocatePool (Length);
  if (Buffer == NULL) {
    return EFI_OUT_OF_RESOURCES;
  }
 
  //
  // To guarantee that the WorkingBlockValid is set on spare block
  //
  //  Offset = OFFSET_OF(EFI_FAULT_TOLERANT_WORKING_BLOCK_HEADER,
  //                            WorkingBlockValid);
  // To skip Signature and Crc: sizeof(EFI_GUID)+sizeof(UINT32).
  //
  FtwUpdateFvState (
    FtwDevice->FtwBackupFvb,
    FtwDevice->SpareBlockSize,
    FtwDevice->FtwSpareLba + FtwDevice->FtwWorkSpaceLbaInSpare,
    FtwDevice->FtwWorkSpaceBaseInSpare + sizeof (EFI_GUID) + sizeof (UINT32),
    WORKING_BLOCK_VALID
    );
  //
  // Read from spare block to memory buffer
  //
  Ptr = Buffer;
  for (Index = 0; Index < FtwDevice->NumberOfSpareBlock; Index += 1) {
    Count  = FtwDevice->SpareBlockSize;
    Status = FtwDevice->FtwBackupFvb->Read (
                                        FtwDevice->FtwBackupFvb,
                                        FtwDevice->FtwSpareLba + Index,
                                        0,
                                        &Count,
                                        Ptr
                                        );
    if (EFI_ERROR (Status)) {
      FreePool (Buffer);
      return Status;
    }
 
    Ptr += Count;
  }
 
  //
  // Clear the CRC and STATE, copy data from spare to working block.
  //
  WorkingBlockHeader = (EFI_FAULT_TOLERANT_WORKING_BLOCK_HEADER *)(Buffer + (UINTN)FtwDevice->FtwWorkSpaceLbaInSpare * FtwDevice->SpareBlockSize + FtwDevice->FtwWorkSpaceBaseInSpare);
  InitWorkSpaceHeader (WorkingBlockHeader);
  WorkingBlockHeader->WorkingBlockValid   = FTW_ERASE_POLARITY;
  WorkingBlockHeader->WorkingBlockInvalid = FTW_ERASE_POLARITY;
 
  //
  // target block is working block, then
  //   Set WorkingBlockInvalid in EFI_FAULT_TOLERANT_WORKING_BLOCK_HEADER
  //   before erase the working block.
  //
  //  Offset = OFFSET_OF(EFI_FAULT_TOLERANT_WORKING_BLOCK_HEADER,
  //                            WorkingBlockInvalid);
  // So hardcode offset as sizeof(EFI_GUID)+sizeof(UINT32) to
  // skip Signature and Crc.
  //
  Status = FtwUpdateFvState (
             FtwDevice->FtwFvBlock,
             FtwDevice->WorkBlockSize,
             FtwDevice->FtwWorkSpaceLba,
             FtwDevice->FtwWorkSpaceBase + sizeof (EFI_GUID) + sizeof (UINT32),
             WORKING_BLOCK_INVALID
             );
  if (EFI_ERROR (Status)) {
    FreePool (Buffer);
    return EFI_ABORTED;
  }
 
  FtwDevice->FtwWorkSpaceHeader->WorkingBlockInvalid = FTW_VALID_STATE;
 
  //
  // Erase the working block
  //
  Status = FtwEraseBlock (FtwDevice, FtwDevice->FtwFvBlock, FtwDevice->FtwWorkBlockLba, FtwDevice->NumberOfWorkBlock);
  if (EFI_ERROR (Status)) {
    FreePool (Buffer);
    return EFI_ABORTED;
  }
 
  //
  // Write memory buffer to working block, using the FvBlock protocol interface
  //
  Ptr = Buffer;
  for (Index = 0; Index < FtwDevice->NumberOfWorkBlock; Index += 1) {
    Count  = FtwDevice->WorkBlockSize;
    Status = FtwDevice->FtwFvBlock->Write (
                                      FtwDevice->FtwFvBlock,
                                      FtwDevice->FtwWorkBlockLba + Index,
                                      0,
                                      &Count,
                                      Ptr
                                      );
    if (EFI_ERROR (Status)) {
      DEBUG ((DEBUG_ERROR, "Ftw: FVB Write block - %r\n", Status));
      FreePool (Buffer);
      return Status;
    }
 
    Ptr += Count;
  }
 
  //
  // Since the memory buffer will not be used, free memory Buffer.
  //
  FreePool (Buffer);
 
  //
  // Update the VALID of the working block
  //
  // Offset = OFFSET_OF(EFI_FAULT_TOLERANT_WORKING_BLOCK_HEADER, WorkingBlockValid);
  // So hardcode offset as sizeof(EFI_GUID)+sizeof(UINT32) to skip Signature and Crc.
  //
  Status = FtwUpdateFvState (
             FtwDevice->FtwFvBlock,
             FtwDevice->WorkBlockSize,
             FtwDevice->FtwWorkSpaceLba,
             FtwDevice->FtwWorkSpaceBase + sizeof (EFI_GUID) + sizeof (UINT32),
             WORKING_BLOCK_VALID
             );
  if (EFI_ERROR (Status)) {
    return EFI_ABORTED;
  }
 
  FtwDevice->FtwWorkSpaceHeader->WorkingBlockInvalid = FTW_INVALID_STATE;
  FtwDevice->FtwWorkSpaceHeader->WorkingBlockValid   = FTW_VALID_STATE;
 
  return EFI_SUCCESS;
}
 
EFI_STATUS
FtwUpdateFvState (
  IN EFI_FIRMWARE_VOLUME_BLOCK_PROTOCOL  *FvBlock,
  IN UINTN                               BlockSize,
  IN EFI_LBA                             Lba,
  IN UINTN                               Offset,
  IN UINT8                               NewBit
  )
{
  EFI_STATUS  Status;
  UINT8       State;
  UINTN       Length;
 
  //
  // Calculate the real Offset and Lba to write.
  //
  while (Offset >= BlockSize) {
    Offset -= BlockSize;
    Lba++;
  }
 
  //
  // Read state from device, assume State is only one byte.
  //
  Length = sizeof (UINT8);
  Status = FvBlock->Read (FvBlock, Lba, Offset, &Length, &State);
  if (EFI_ERROR (Status)) {
    return EFI_ABORTED;
  }
 
  State ^= FTW_POLARITY_REVERT;
  State  = (UINT8)(State | NewBit);
  State ^= FTW_POLARITY_REVERT;
 
  //
  // Write state back to device
  //
  Length = sizeof (UINT8);
  Status = FvBlock->Write (FvBlock, Lba, Offset, &Length, &State);
 
  return Status;
}
 
EFI_STATUS
FtwGetLastWriteHeader (
  IN EFI_FAULT_TOLERANT_WORKING_BLOCK_HEADER  *FtwWorkSpaceHeader,
  IN UINTN                                    FtwWorkSpaceSize,
  OUT EFI_FAULT_TOLERANT_WRITE_HEADER         **FtwWriteHeader
  )
{
  UINTN                            Offset;
  EFI_FAULT_TOLERANT_WRITE_HEADER  *FtwHeader;
 
  *FtwWriteHeader = NULL;
  FtwHeader       = (EFI_FAULT_TOLERANT_WRITE_HEADER *)(FtwWorkSpaceHeader + 1);
  Offset          = sizeof (EFI_FAULT_TOLERANT_WORKING_BLOCK_HEADER);
 
  if (!CompareGuid (&FtwWorkSpaceHeader->Signature, &gEdkiiWorkingBlockSignatureGuid)) {
    *FtwWriteHeader = FtwHeader;
    return EFI_ABORTED;
  }
 
  while (FtwHeader->Complete == FTW_VALID_STATE) {
    Offset += FTW_WRITE_TOTAL_SIZE (FtwHeader->NumberOfWrites, FtwHeader->PrivateDataSize);
    //
    // If Offset exceed the FTW work space boudary, return error.
    //
 
    if ((Offset + sizeof (EFI_FAULT_TOLERANT_WRITE_HEADER)) >= FtwWorkSpaceSize) {
      *FtwWriteHeader = FtwHeader;
      return EFI_ABORTED;
    }
 
    FtwHeader = (EFI_FAULT_TOLERANT_WRITE_HEADER *)((UINT8 *)FtwWorkSpaceHeader + Offset);
  }
 
  //
  // Last write header is found
  //
  *FtwWriteHeader = FtwHeader;
 
  return EFI_SUCCESS;
}
 
EFI_STATUS
FtwGetLastWriteRecord (
  IN EFI_FAULT_TOLERANT_WRITE_HEADER   *FtwWriteHeader,
  OUT EFI_FAULT_TOLERANT_WRITE_RECORD  **FtwWriteRecord
  )
{
  UINTN                            Index;
  EFI_FAULT_TOLERANT_WRITE_RECORD  *FtwRecord;
 
  *FtwWriteRecord = NULL;
  FtwRecord       = (EFI_FAULT_TOLERANT_WRITE_RECORD *)(FtwWriteHeader + 1);
 
  //
  // Try to find the last write record "that has not completed"
  //
  for (Index = 0; Index < FtwWriteHeader->NumberOfWrites; Index += 1) {
    if (FtwRecord->DestinationComplete != FTW_VALID_STATE) {
      //
      // The last write record is found
      //
      *FtwWriteRecord = FtwRecord;
      return EFI_SUCCESS;
    }
 
    FtwRecord++;
 
    if (FtwWriteHeader->PrivateDataSize != 0) {
      FtwRecord = (EFI_FAULT_TOLERANT_WRITE_RECORD *)((UINTN)FtwRecord + (UINTN)FtwWriteHeader->PrivateDataSize);
    }
  }
 
  //
  //  if Index == NumberOfWrites, then
  //  the last record has been written successfully,
  //  but the Header->Complete Flag has not been set.
  //  also return the last record.
  //
  if (Index == FtwWriteHeader->NumberOfWrites) {
    *FtwWriteRecord = (EFI_FAULT_TOLERANT_WRITE_RECORD *)((UINTN)FtwRecord - FTW_RECORD_SIZE (FtwWriteHeader->PrivateDataSize));
    return EFI_SUCCESS;
  }
 
  return EFI_ABORTED;
}
 
BOOLEAN
IsFirstRecordOfWrites (
  IN EFI_FAULT_TOLERANT_WRITE_HEADER  *FtwHeader,
  IN EFI_FAULT_TOLERANT_WRITE_RECORD  *FtwRecord
  )
{
  UINT8  *Head;
  UINT8  *Ptr;
 
  Head = (UINT8 *)FtwHeader;
  Ptr  = (UINT8 *)FtwRecord;
 
  Head += sizeof (EFI_FAULT_TOLERANT_WRITE_HEADER);
  return (BOOLEAN)(Head == Ptr);
}
 
BOOLEAN
IsLastRecordOfWrites (
  IN EFI_FAULT_TOLERANT_WRITE_HEADER  *FtwHeader,
  IN EFI_FAULT_TOLERANT_WRITE_RECORD  *FtwRecord
  )
{
  UINT8  *Head;
  UINT8  *Ptr;
 
  Head = (UINT8 *)FtwHeader;
  Ptr  = (UINT8 *)FtwRecord;
 
  Head += FTW_WRITE_TOTAL_SIZE (FtwHeader->NumberOfWrites - 1, FtwHeader->PrivateDataSize);
  return (BOOLEAN)(Head == Ptr);
}
 
EFI_STATUS
GetPreviousRecordOfWrites (
  IN     EFI_FAULT_TOLERANT_WRITE_HEADER  *FtwHeader,
  IN OUT EFI_FAULT_TOLERANT_WRITE_RECORD  **FtwRecord
  )
{
  UINT8  *Ptr;
 
  if (IsFirstRecordOfWrites (FtwHeader, *FtwRecord)) {
    *FtwRecord = NULL;
    return EFI_ACCESS_DENIED;
  }
 
  Ptr        = (UINT8 *)(*FtwRecord);
  Ptr       -= FTW_RECORD_SIZE (FtwHeader->PrivateDataSize);
  *FtwRecord = (EFI_FAULT_TOLERANT_WRITE_RECORD *)Ptr;
  return EFI_SUCCESS;
}
 
EFI_STATUS
InitFtwDevice (
  OUT EFI_FTW_DEVICE  **FtwData
  )
{
  EFI_STATUS            Status;
  EFI_PHYSICAL_ADDRESS  WorkSpaceAddress;
  UINT64                Size;
  UINTN                 FtwWorkingSize;
  EFI_FTW_DEVICE        *FtwDevice;
 
  FtwWorkingSize = 0;
 
  Status = GetVariableFlashFtwWorkingInfo (&WorkSpaceAddress, &Size);
  ASSERT_EFI_ERROR (Status);
 
  Status = SafeUint64ToUintn (Size, &FtwWorkingSize);
  // This driver currently assumes the size will be UINTN so assert the value is safe for now.
  ASSERT_EFI_ERROR (Status);
 
  //
  // Allocate private data of this driver,
  // Including the FtwWorkSpace[FTW_WORK_SPACE_SIZE].
  //
  FtwDevice = AllocateZeroPool (sizeof (EFI_FTW_DEVICE) + FtwWorkingSize);
  if (FtwDevice == NULL) {
    return EFI_OUT_OF_RESOURCES;
  }
 
  FtwDevice->WorkSpaceAddress = WorkSpaceAddress;
  FtwDevice->WorkSpaceLength  = FtwWorkingSize;
 
  Status = GetVariableFlashFtwSpareInfo (&FtwDevice->SpareAreaAddress, &Size);
  ASSERT_EFI_ERROR (Status);
 
  Status = SafeUint64ToUintn (Size, &FtwDevice->SpareAreaLength);
  // This driver currently assumes the size will be UINTN so assert the value is safe for now.
  ASSERT_EFI_ERROR (Status);
 
  //
  // Initialize other parameters, and set WorkSpace as FTW_ERASED_BYTE.
  //
  if ((FtwDevice->WorkSpaceLength == 0) || (FtwDevice->SpareAreaLength == 0)) {
    DEBUG ((DEBUG_ERROR, "Ftw: Workspace or Spare block does not exist!\n"));
    FreePool (FtwDevice);
    return EFI_INVALID_PARAMETER;
  }
 
  FtwDevice->Signature       = FTW_DEVICE_SIGNATURE;
  FtwDevice->FtwFvBlock      = NULL;
  FtwDevice->FtwBackupFvb    = NULL;
  FtwDevice->FtwWorkSpaceLba = (EFI_LBA)(-1);
  FtwDevice->FtwSpareLba     = (EFI_LBA)(-1);
 
  *FtwData = FtwDevice;
  return EFI_SUCCESS;
}
 
EFI_STATUS
FindFvbForFtw (
  IN OUT EFI_FTW_DEVICE  *FtwDevice
  )
{
  EFI_STATUS                          Status;
  EFI_HANDLE                          *HandleBuffer;
  UINTN                               HandleCount;
  UINTN                               Index;
  EFI_PHYSICAL_ADDRESS                FvbBaseAddress;
  EFI_FIRMWARE_VOLUME_BLOCK_PROTOCOL  *Fvb;
  EFI_FVB_ATTRIBUTES_2                Attributes;
  UINT32                              LbaIndex;
  UINTN                               BlockSize;
  UINTN                               NumberOfBlocks;
 
  HandleBuffer = NULL;
 
  //
  // Get all FVB handle.
  //
  Status = GetFvbCountAndBuffer (&HandleCount, &HandleBuffer);
  if (EFI_ERROR (Status)) {
    return EFI_NOT_FOUND;
  }
 
  //
  // Get the FVB to access variable store
  //
  Fvb = NULL;
  for (Index = 0; Index < HandleCount; Index += 1) {
    Status = FtwGetFvbByHandle (HandleBuffer[Index], &Fvb);
    if (EFI_ERROR (Status)) {
      Status = EFI_NOT_FOUND;
      break;
    }
 
    //
    // Ensure this FVB protocol support Write operation.
    //
    Status = Fvb->GetAttributes (Fvb, &Attributes);
    if (EFI_ERROR (Status) || ((Attributes & EFI_FVB2_WRITE_STATUS) == 0)) {
      continue;
    }
 
    //
    // Compare the address and select the right one
    //
    Status = Fvb->GetPhysicalAddress (Fvb, &FvbBaseAddress);
    if (EFI_ERROR (Status)) {
      continue;
    }
 
    //
    // Now, one FVB has one type of BlockSize.
    //
    Status = Fvb->GetBlockSize (Fvb, 0, &BlockSize, &NumberOfBlocks);
    if (EFI_ERROR (Status)) {
      continue;
    }
 
    if ((FtwDevice->FtwFvBlock == NULL) && (FtwDevice->WorkSpaceAddress >= FvbBaseAddress) &&
        ((FtwDevice->WorkSpaceAddress + FtwDevice->WorkSpaceLength) <= (FvbBaseAddress + BlockSize * NumberOfBlocks)))
    {
      FtwDevice->FtwFvBlock = Fvb;
      //
      // To get the LBA of work space
      //
      for (LbaIndex = 1; LbaIndex <= NumberOfBlocks; LbaIndex += 1) {
        if (  (FtwDevice->WorkSpaceAddress >= (FvbBaseAddress + BlockSize * (LbaIndex - 1)))
           && (FtwDevice->WorkSpaceAddress < (FvbBaseAddress + BlockSize * LbaIndex)))
        {
          FtwDevice->FtwWorkSpaceLba = LbaIndex - 1;
          //
          // Get the Work space size and Base(Offset)
          //
          FtwDevice->FtwWorkSpaceSize       = FtwDevice->WorkSpaceLength;
          FtwDevice->WorkBlockSize          = BlockSize;
          FtwDevice->FtwWorkSpaceBase       = (UINTN)(FtwDevice->WorkSpaceAddress - (FvbBaseAddress + FtwDevice->WorkBlockSize * (LbaIndex - 1)));
          FtwDevice->NumberOfWorkSpaceBlock = FTW_BLOCKS (FtwDevice->FtwWorkSpaceBase + FtwDevice->FtwWorkSpaceSize, FtwDevice->WorkBlockSize);
          if (FtwDevice->FtwWorkSpaceSize >= FtwDevice->WorkBlockSize) {
            //
            // Check the alignment of work space address and length, they should be block size aligned when work space size is larger than one block size.
            //
            if (((FtwDevice->WorkSpaceAddress & (FtwDevice->WorkBlockSize - 1)) != 0) ||
                ((FtwDevice->WorkSpaceLength & (FtwDevice->WorkBlockSize - 1)) != 0))
            {
              DEBUG ((DEBUG_ERROR, "Ftw: Work space address or length is not block size aligned when work space size is larger than one block size\n"));
              FreePool (HandleBuffer);
              ASSERT (FALSE);
              return EFI_ABORTED;
            }
          } else if ((FtwDevice->FtwWorkSpaceBase + FtwDevice->FtwWorkSpaceSize) > FtwDevice->WorkBlockSize) {
            DEBUG ((DEBUG_ERROR, "Ftw: The work space range should not span blocks when work space size is less than one block size\n"));
            FreePool (HandleBuffer);
            ASSERT (FALSE);
            return EFI_ABORTED;
          }
 
          break;
        }
      }
    }
 
    if ((FtwDevice->FtwBackupFvb == NULL) && (FtwDevice->SpareAreaAddress >= FvbBaseAddress) &&
        ((FtwDevice->SpareAreaAddress + FtwDevice->SpareAreaLength) <= (FvbBaseAddress + BlockSize * NumberOfBlocks)))
    {
      FtwDevice->FtwBackupFvb = Fvb;
      //
      // To get the LBA of spare
      //
      for (LbaIndex = 1; LbaIndex <= NumberOfBlocks; LbaIndex += 1) {
        if (  (FtwDevice->SpareAreaAddress >= (FvbBaseAddress + BlockSize * (LbaIndex - 1)))
           && (FtwDevice->SpareAreaAddress < (FvbBaseAddress + BlockSize * LbaIndex)))
        {
          //
          // Get the NumberOfSpareBlock and BlockSize
          //
          FtwDevice->FtwSpareLba        = LbaIndex - 1;
          FtwDevice->SpareBlockSize     = BlockSize;
          FtwDevice->NumberOfSpareBlock = FtwDevice->SpareAreaLength / FtwDevice->SpareBlockSize;
          //
          // Check the range of spare area to make sure that it's in FV range
          //
          if ((FtwDevice->FtwSpareLba + FtwDevice->NumberOfSpareBlock) > NumberOfBlocks) {
            DEBUG ((DEBUG_ERROR, "Ftw: Spare area is out of FV range\n"));
            FreePool (HandleBuffer);
            ASSERT (FALSE);
            return EFI_ABORTED;
          }
 
          //
          // Check the alignment of spare area address and length, they should be block size aligned
          //
          if (((FtwDevice->SpareAreaAddress & (FtwDevice->SpareBlockSize - 1)) != 0) ||
              ((FtwDevice->SpareAreaLength & (FtwDevice->SpareBlockSize - 1)) != 0))
          {
            DEBUG ((DEBUG_ERROR, "Ftw: Spare area address or length is not block size aligned\n"));
            FreePool (HandleBuffer);
            //
            // Report Status Code EFI_SW_EC_ABORTED.
            //
            REPORT_STATUS_CODE ((EFI_ERROR_CODE | EFI_ERROR_UNRECOVERED), (EFI_SOFTWARE_DXE_BS_DRIVER | EFI_SW_EC_ABORTED));
            ASSERT (FALSE);
            CpuDeadLoop ();
          }
 
          break;
        }
      }
    }
  }
 
  FreePool (HandleBuffer);
 
  if ((FtwDevice->FtwBackupFvb == NULL) || (FtwDevice->FtwFvBlock == NULL) ||
      (FtwDevice->FtwWorkSpaceLba == (EFI_LBA)(-1)) || (FtwDevice->FtwSpareLba == (EFI_LBA)(-1)))
  {
    return EFI_ABORTED;
  }
 
  DEBUG ((DEBUG_INFO, "Ftw: FtwWorkSpaceLba - 0x%lx, WorkBlockSize  - 0x%x, FtwWorkSpaceBase - 0x%x\n", FtwDevice->FtwWorkSpaceLba, FtwDevice->WorkBlockSize, FtwDevice->FtwWorkSpaceBase));
  DEBUG ((DEBUG_INFO, "Ftw: FtwSpareLba     - 0x%lx, SpareBlockSize - 0x%x\n", FtwDevice->FtwSpareLba, FtwDevice->SpareBlockSize));
 
  return EFI_SUCCESS;
}
 
EFI_STATUS
InitFtwProtocol (
  IN OUT EFI_FTW_DEVICE  *FtwDevice
  )
{
  EFI_STATUS                          Status;
  EFI_FIRMWARE_VOLUME_BLOCK_PROTOCOL  *Fvb;
  EFI_FAULT_TOLERANT_WRITE_HEADER     *FtwHeader;
  UINTN                               Offset;
  EFI_HANDLE                          FvbHandle;
  EFI_LBA                             WorkSpaceLbaOffset;
 
  //
  // Find the right SMM Fvb protocol instance for FTW.
  //
  Status = FindFvbForFtw (FtwDevice);
  if (EFI_ERROR (Status)) {
    return EFI_NOT_FOUND;
  }
 
  //
  // Calculate the start LBA of working block.
  //
  if (FtwDevice->FtwWorkSpaceSize >= FtwDevice->WorkBlockSize) {
    //
    // Working block is a standalone area which only contains working space.
    //
    FtwDevice->NumberOfWorkBlock = FtwDevice->NumberOfWorkSpaceBlock;
  } else {
    //
    // 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.
    //
    FtwDevice->NumberOfWorkBlock = (UINTN)(FtwDevice->FtwWorkSpaceLba + FtwDevice->NumberOfWorkSpaceBlock);
    while (FtwDevice->NumberOfWorkBlock * FtwDevice->WorkBlockSize > FtwDevice->SpareAreaLength) {
      FtwDevice->NumberOfWorkBlock--;
    }
  }
 
  FtwDevice->FtwWorkBlockLba = FtwDevice->FtwWorkSpaceLba + FtwDevice->NumberOfWorkSpaceBlock - FtwDevice->NumberOfWorkBlock;
  DEBUG ((DEBUG_INFO, "Ftw: NumberOfWorkBlock - 0x%x, FtwWorkBlockLba - 0x%lx\n", FtwDevice->NumberOfWorkBlock, FtwDevice->FtwWorkBlockLba));
 
  //
  // Calcualte the LBA and base of work space in spare block.
  // Note: Do not assume Spare Block and Work Block have same block size.
  //
  WorkSpaceLbaOffset                 = FtwDevice->FtwWorkSpaceLba - FtwDevice->FtwWorkBlockLba;
  FtwDevice->FtwWorkSpaceLbaInSpare  = (EFI_LBA)(((UINTN)WorkSpaceLbaOffset * FtwDevice->WorkBlockSize + FtwDevice->FtwWorkSpaceBase) / FtwDevice->SpareBlockSize);
  FtwDevice->FtwWorkSpaceBaseInSpare = ((UINTN)WorkSpaceLbaOffset * FtwDevice->WorkBlockSize + FtwDevice->FtwWorkSpaceBase) % FtwDevice->SpareBlockSize;
  DEBUG ((DEBUG_INFO, "Ftw: WorkSpaceLbaInSpare - 0x%lx, WorkSpaceBaseInSpare - 0x%x\n", FtwDevice->FtwWorkSpaceLbaInSpare, FtwDevice->FtwWorkSpaceBaseInSpare));
 
  //
  // Initialize other parameters, and set WorkSpace as FTW_ERASED_BYTE.
  //
  FtwDevice->FtwWorkSpace       = (UINT8 *)(FtwDevice + 1);
  FtwDevice->FtwWorkSpaceHeader = (EFI_FAULT_TOLERANT_WORKING_BLOCK_HEADER *)FtwDevice->FtwWorkSpace;
 
  FtwDevice->FtwLastWriteHeader = NULL;
  FtwDevice->FtwLastWriteRecord = NULL;
 
  InitializeLocalWorkSpaceHeader (FtwDevice->WorkSpaceLength);
 
  //
  // Refresh the working space data from working block
  //
  Status = WorkSpaceRefresh (FtwDevice);
  ASSERT_EFI_ERROR (Status);
  //
  // If the working block workspace is not valid, try the spare block
  //
  if (!IsValidWorkSpace (FtwDevice->FtwWorkSpaceHeader)) {
    //
    // Read from spare block
    //
    Status = ReadWorkSpaceData (
               FtwDevice->FtwBackupFvb,
               FtwDevice->SpareBlockSize,
               FtwDevice->FtwSpareLba + FtwDevice->FtwWorkSpaceLbaInSpare,
               FtwDevice->FtwWorkSpaceBaseInSpare,
               FtwDevice->FtwWorkSpaceSize,
               FtwDevice->FtwWorkSpace
               );
    ASSERT_EFI_ERROR (Status);
 
    //
    // If spare block is valid, then replace working block content.
    //
    if (IsValidWorkSpace (FtwDevice->FtwWorkSpaceHeader)) {
      Status = FlushSpareBlockToWorkingBlock (FtwDevice);
      DEBUG ((
        DEBUG_INFO,
        "Ftw: Restart working block update in %a() - %r\n",
        __func__,
        Status
        ));
      FtwAbort (&FtwDevice->FtwInstance);
      //
      // Refresh work space.
      //
      Status = WorkSpaceRefresh (FtwDevice);
      ASSERT_EFI_ERROR (Status);
    } else {
      DEBUG ((
        DEBUG_INFO,
        "Ftw: Both working and spare blocks are invalid, init workspace\n"
        ));
      //
      // If both are invalid, then initialize work space.
      //
      SetMem (
        FtwDevice->FtwWorkSpace,
        FtwDevice->FtwWorkSpaceSize,
        FTW_ERASED_BYTE
        );
      InitWorkSpaceHeader (FtwDevice->FtwWorkSpaceHeader);
      //
      // Initialize the work space
      //
      Status = FtwReclaimWorkSpace (FtwDevice, FALSE);
      ASSERT_EFI_ERROR (Status);
    }
  }
 
  //
  // If the FtwDevice->FtwLastWriteRecord is 1st record of write header &&
  // (! SpareComplete) THEN call Abort().
  //
  if ((FtwDevice->FtwLastWriteHeader->HeaderAllocated == FTW_VALID_STATE) &&
      (FtwDevice->FtwLastWriteRecord->SpareComplete != FTW_VALID_STATE) &&
      IsFirstRecordOfWrites (FtwDevice->FtwLastWriteHeader, FtwDevice->FtwLastWriteRecord)
      )
  {
    DEBUG ((DEBUG_ERROR, "Ftw: Init.. find first record not SpareCompleted, abort()\n"));
    FtwAbort (&FtwDevice->FtwInstance);
  }
 
  //
  // If Header is incompleted and the last record has completed, then
  // call Abort() to set the Header->Complete FLAG.
  //
  if ((FtwDevice->FtwLastWriteHeader->Complete != FTW_VALID_STATE) &&
      (FtwDevice->FtwLastWriteRecord->DestinationComplete == FTW_VALID_STATE) &&
      IsLastRecordOfWrites (FtwDevice->FtwLastWriteHeader, FtwDevice->FtwLastWriteRecord)
      )
  {
    DEBUG ((DEBUG_ERROR, "Ftw: Init.. find last record completed but header not, abort()\n"));
    FtwAbort (&FtwDevice->FtwInstance);
  }
 
  //
  // To check the workspace buffer following last Write header/records is EMPTY or not.
  // If it's not EMPTY, FTW also need to call reclaim().
  //
  FtwHeader = FtwDevice->FtwLastWriteHeader;
  Offset    = (UINT8 *)FtwHeader - FtwDevice->FtwWorkSpace;
  if (FtwDevice->FtwWorkSpace[Offset] != FTW_ERASED_BYTE) {
    Offset += FTW_WRITE_TOTAL_SIZE (FtwHeader->NumberOfWrites, FtwHeader->PrivateDataSize);
  }
 
  if (!IsErasedFlashBuffer (FtwDevice->FtwWorkSpace + Offset, FtwDevice->FtwWorkSpaceSize - Offset)) {
    Status = FtwReclaimWorkSpace (FtwDevice, TRUE);
    ASSERT_EFI_ERROR (Status);
  }
 
  //
  // Restart if it's boot block
  //
  if ((FtwDevice->FtwLastWriteHeader->Complete != FTW_VALID_STATE) &&
      (FtwDevice->FtwLastWriteRecord->SpareComplete == FTW_VALID_STATE)
      )
  {
    if (FtwDevice->FtwLastWriteRecord->BootBlockUpdate == FTW_VALID_STATE) {
      Status = FlushSpareBlockToBootBlock (FtwDevice);
      DEBUG ((DEBUG_ERROR, "Ftw: Restart boot block update - %r\n", Status));
      ASSERT_EFI_ERROR (Status);
      FtwAbort (&FtwDevice->FtwInstance);
    } else {
      //
      // if (SpareCompleted) THEN  Restart to fault tolerant write.
      //
      FvbHandle = NULL;
      FvbHandle = GetFvbByAddress ((EFI_PHYSICAL_ADDRESS)(UINTN)((INT64)FtwDevice->SpareAreaAddress + FtwDevice->FtwLastWriteRecord->RelativeOffset), &Fvb);
      if (FvbHandle != NULL) {
        Status = FtwRestart (&FtwDevice->FtwInstance, FvbHandle);
        DEBUG ((DEBUG_ERROR, "Ftw: Restart last write - %r\n", Status));
        ASSERT_EFI_ERROR (Status);
      }
 
      FtwAbort (&FtwDevice->FtwInstance);
    }
  }
 
  //
  // Hook the protocol API
  //
  FtwDevice->FtwInstance.GetMaxBlockSize = FtwGetMaxBlockSize;
  FtwDevice->FtwInstance.Allocate        = FtwAllocate;
  FtwDevice->FtwInstance.Write           = FtwWrite;
  FtwDevice->FtwInstance.Restart         = FtwRestart;
  FtwDevice->FtwInstance.Abort           = FtwAbort;
  FtwDevice->FtwInstance.GetLastWrite    = FtwGetLastWrite;
 
  return EFI_SUCCESS;
}