decompress.c

来自「EFI BIOS是Intel提出的下一代的BIOS标准。这里上传的Edk源代码是」· C语言 代码 · 共 996 行 · 第 1/2 页

      if (CharC == 0) {
        CharC = 1;
      } else if (CharC == 1) {
        CharC = (UINT16) (GetBits (Sd, 4) + 3);
      } else if (CharC == 2) {
        CharC = (UINT16) (GetBits (Sd, CBIT) + 20);
      }

      while ((INT16) (--CharC) >= 0) {
        Sd->mCLen[Index++] = 0;
      }

    } else {

      Sd->mCLen[Index++] = (UINT8) (CharC - 2);

    }
  }

  while (Index < NC) {
    Sd->mCLen[Index++] = 0;
  }

  MakeTable (Sd, NC, Sd->mCLen, 12, Sd->mCTable);

  return ;
}

STATIC
UINT16
DecodeC (
  SCRATCH_DATA  *Sd
  )
/*++

Routine Description:

  Decode a character/length value.

Arguments:

  Sd    - The global scratch data.

Returns:

  The value decoded.

--*/
{
  UINT16  Index2;
  UINT32  Mask;

  if (Sd->mBlockSize == 0) {
    //
    // Starting a new block
    //
    Sd->mBlockSize    = (UINT16) GetBits (Sd, 16);
    Sd->mBadTableFlag = ReadPTLen (Sd, NT, TBIT, 3);
    if (Sd->mBadTableFlag != 0) {
      return 0;
    }

    ReadCLen (Sd);

    Sd->mBadTableFlag = ReadPTLen (Sd, MAXNP, Sd->mPBit, (UINT16) (-1));
    if (Sd->mBadTableFlag != 0) {
      return 0;
    }
  }

  Sd->mBlockSize--;
  Index2 = Sd->mCTable[Sd->mBitBuf >> (BITBUFSIZ - 12)];

  if (Index2 >= NC) {
    Mask = 1U << (BITBUFSIZ - 1 - 12);

    do {
      if (Sd->mBitBuf & Mask) {
        Index2 = Sd->mRight[Index2];
      } else {
        Index2 = Sd->mLeft[Index2];
      }

      Mask >>= 1;
    } while (Index2 >= NC);
  }
  //
  // Advance what we have read
  //
  FillBuf (Sd, Sd->mCLen[Index2]);

  return Index2;
}

STATIC
VOID
Decode (
  SCRATCH_DATA  *Sd
  )
/*++

Routine Description:

  Decode the source data and put the resulting data into the destination buffer.

Arguments:

  Sd            - The global scratch data

Returns: (VOID)

 --*/
{
  UINT16  BytesRemain;
  UINT32  DataIdx;
  UINT16  CharC;

  BytesRemain = (UINT16) (-1);

  DataIdx     = 0;

  for (;;) {
    CharC = DecodeC (Sd);
    if (Sd->mBadTableFlag != 0) {
      return ;
    }

    if (CharC < 256) {
      //
      // Process an Original character
      //
      if (Sd->mOutBuf >= Sd->mOrigSize) {
        return ;
      } else {
        Sd->mDstBase[Sd->mOutBuf++] = (UINT8) CharC;
      }

    } else {
      //
      // Process a Pointer
      //
      CharC       = (UINT16) (CharC - (UINT8_MAX + 1 - THRESHOLD));

      BytesRemain = CharC;

      DataIdx     = Sd->mOutBuf - DecodeP (Sd) - 1;

      BytesRemain--;
      while ((INT16) (BytesRemain) >= 0) {
        Sd->mDstBase[Sd->mOutBuf++] = Sd->mDstBase[DataIdx++];
        if (Sd->mOutBuf >= Sd->mOrigSize) {
          return ;
        }

        BytesRemain--;
      }
    }
  }

  return ;
}

EFI_STATUS
GetInfo (
  IN      VOID    *Source,
  IN      UINT32  SrcSize,
  OUT     UINT32  *DstSize,
  OUT     UINT32  *ScratchSize
  )
/*++

Routine Description:

  The internal implementation of *_DECOMPRESS_PROTOCOL.GetInfo().

Arguments:

  Source      - The source buffer containing the compressed data.
  SrcSize     - The size of source buffer
  DstSize     - The size of destination buffer.
  ScratchSize - The size of scratch buffer.

Returns:

  EFI_SUCCESS           - The size of destination buffer and the size of scratch buffer are successull retrieved.
  EFI_INVALID_PARAMETER - The source data is corrupted

--*/
{
  UINT8 *Src;

  *ScratchSize  = sizeof (SCRATCH_DATA);

  Src           = Source;
  if (SrcSize < 8) {
    return EFI_INVALID_PARAMETER;
  }

  *DstSize = Src[4] + (Src[5] << 8) + (Src[6] << 16) + (Src[7] << 24);
  return EFI_SUCCESS;
}

EFI_STATUS
Decompress (
  IN      VOID    *Source,
  IN      UINT32  SrcSize,
  IN OUT  VOID    *Destination,
  IN      UINT32  DstSize,
  IN OUT  VOID    *Scratch,
  IN      UINT32  ScratchSize,
  IN      UINT8   Version
  )
/*++

Routine Description:

  The internal implementation of *_DECOMPRESS_PROTOCOL.Decompress().

Arguments:

  Source      - The source buffer containing the compressed data.
  SrcSize     - The size of source buffer
  Destination - The destination buffer to store the decompressed data
  DstSize     - The size of destination buffer.
  Scratch     - The buffer used internally by the decompress routine. This  buffer is needed to store intermediate data.
  ScratchSize - The size of scratch buffer.
  Version     - The version of de/compression algorithm.
                Version 1 for EFI 1.1 de/compression algorithm.
                Version 2 for Tiano de/compression algorithm.

Returns:

  EFI_SUCCESS           - Decompression is successfull
  EFI_INVALID_PARAMETER - The source data is corrupted

--*/
{
  UINT32        Index;
  UINT32        CompSize;
  UINT32        OrigSize;
  EFI_STATUS    Status;
  SCRATCH_DATA  *Sd;
  UINT8         *Src;
  UINT8         *Dst;

  Status  = EFI_SUCCESS;
  Src     = Source;
  Dst     = Destination;

  if (ScratchSize < sizeof (SCRATCH_DATA)) {
    return EFI_INVALID_PARAMETER;
  }

  Sd = (SCRATCH_DATA *) Scratch;

  if (SrcSize < 8) {
    return EFI_INVALID_PARAMETER;
  }

  CompSize  = Src[0] + (Src[1] << 8) + (Src[2] << 16) + (Src[3] << 24);
  OrigSize  = Src[4] + (Src[5] << 8) + (Src[6] << 16) + (Src[7] << 24);

  //
  // If compressed file size is 0, return
  //
  if (OrigSize == 0) {
    return Status;
  }

  if (SrcSize < CompSize + 8) {
    return EFI_INVALID_PARAMETER;
  }

  if (DstSize != OrigSize) {
    return EFI_INVALID_PARAMETER;
  }

  Src = Src + 8;

  for (Index = 0; Index < sizeof (SCRATCH_DATA); Index++) {
    ((UINT8 *) Sd)[Index] = 0;
  }
  //
  // The length of the field 'Position Set Code Length Array Size' in Block Header.
  // For EFI 1.1 de/compression algorithm(Version 1), mPBit = 4
  // For Tiano de/compression algorithm(Version 2), mPBit = 5
  //
  switch (Version) {
  case 1:
    Sd->mPBit = 4;
    break;

  case 2:
    Sd->mPBit = 5;
    break;

  default:
    //
    // Currently, only have 2 versions
    //
    return EFI_INVALID_PARAMETER;
  }

  Sd->mSrcBase  = Src;
  Sd->mDstBase  = Dst;
  Sd->mCompSize = CompSize;
  Sd->mOrigSize = OrigSize;

  //
  // Fill the first BITBUFSIZ bits
  //
  FillBuf (Sd, BITBUFSIZ);

  //
  // Decompress it
  //
  Decode (Sd);

  if (Sd->mBadTableFlag != 0) {
    //
    // Something wrong with the source
    //
    Status = EFI_INVALID_PARAMETER;
  }

  return Status;
}

EFI_STATUS
EFIAPI
EfiGetInfo (
  IN      VOID                    *Source,
  IN      UINT32                  SrcSize,
  OUT     UINT32                  *DstSize,
  OUT     UINT32                  *ScratchSize
  )
/*++

Routine Description:

  The implementation is same as that  of EFI_DECOMPRESS_PROTOCOL.GetInfo().

Arguments:

  This        - The protocol instance pointer
  Source      - The source buffer containing the compressed data.
  SrcSize     - The size of source buffer
  DstSize     - The size of destination buffer.
  ScratchSize - The size of scratch buffer.

Returns:

  EFI_SUCCESS           - The size of destination buffer and the size of scratch buffer are successull retrieved.
  EFI_INVALID_PARAMETER - The source data is corrupted

--*/
{
  return GetInfo (
          Source,
          SrcSize,
          DstSize,
          ScratchSize
          );
}

EFI_STATUS
EFIAPI
EfiDecompress (
  IN      VOID                    *Source,
  IN      UINT32                  SrcSize,
  IN OUT  VOID                    *Destination,
  IN      UINT32                  DstSize,
  IN OUT  VOID                    *Scratch,
  IN      UINT32                  ScratchSize
  )
/*++

Routine Description:

  The implementation is same as that of EFI_DECOMPRESS_PROTOCOL.Decompress().

Arguments:

  This        - The protocol instance pointer
  Source      - The source buffer containing the compressed data.
  SrcSize     - The size of source buffer
  Destination - The destination buffer to store the decompressed data
  DstSize     - The size of destination buffer.
  Scratch     - The buffer used internally by the decompress routine. This  buffer is needed to store intermediate data.
  ScratchSize - The size of scratch buffer.

Returns:

  EFI_SUCCESS           - Decompression is successfull
  EFI_INVALID_PARAMETER - The source data is corrupted

--*/
{
  //
  // For EFI 1.1 de/compression algorithm, the version is 1.
  //
  return Decompress (
          Source,
          SrcSize,
          Destination,
          DstSize,
          Scratch,
          ScratchSize,
          1
          );
}

EFI_STATUS
EFIAPI
TianoGetInfo (
  IN      VOID                          *Source,
  IN      UINT32                        SrcSize,
  OUT     UINT32                        *DstSize,
  OUT     UINT32                        *ScratchSize
  )
/*++

Routine Description:

  The implementation is same as that of EFI_TIANO_DECOMPRESS_PROTOCOL.GetInfo().

Arguments:

  This        - The protocol instance pointer
  Source      - The source buffer containing the compressed data.
  SrcSize     - The size of source buffer
  DstSize     - The size of destination buffer.
  ScratchSize - The size of scratch buffer.

Returns:

  EFI_SUCCESS           - The size of destination buffer and the size of scratch buffer are successull retrieved.
  EFI_INVALID_PARAMETER - The source data is corrupted

--*/
{
  return GetInfo (
          Source,
          SrcSize,
          DstSize,
          ScratchSize
          );
}

EFI_STATUS
EFIAPI
TianoDecompress (
  IN      VOID                          *Source,
  IN      UINT32                        SrcSize,
  IN OUT  VOID                          *Destination,
  IN      UINT32                        DstSize,
  IN OUT  VOID                          *Scratch,
  IN      UINT32                        ScratchSize
  )
/*++

Routine Description:

  The implementation is same as that  of EFI_TIANO_DECOMPRESS_PROTOCOL.Decompress().

Arguments:

  This        - The protocol instance pointer
  Source      - The source buffer containing the compressed data.
  SrcSize     - The size of source buffer
  Destination - The destination buffer to store the decompressed data
  DstSize     - The size of destination buffer.
  Scratch     - The buffer used internally by the decompress routine. This  buffer is needed to store intermediate data.
  ScratchSize - The size of scratch buffer.

Returns:

  EFI_SUCCESS           - Decompression is successfull
  EFI_INVALID_PARAMETER - The source data is corrupted

--*/
{
  //
  // For Tiano de/compression algorithm, the version is 2.
  //
  return Decompress (
          Source,
          SrcSize,
          Destination,
          DstSize,
          Scratch,
          ScratchSize,
          2
          );
}