MdePkg/Library/BaseUefiDecompressLib/BaseUefiDecompressLib.c File Reference


Functions

VOID FillBuf (IN SCRATCH_DATA *Sd, IN UINT16 NumOfBits)
UINT32 GetBits (IN SCRATCH_DATA *Sd, IN UINT16 NumOfBits)
UINT16 MakeTable (IN SCRATCH_DATA *Sd, IN UINT16 NumOfChar, IN UINT8 *BitLen, IN UINT16 TableBits, OUT UINT16 *Table)
UINT32 DecodeP (IN SCRATCH_DATA *Sd)
UINT16 ReadPTLen (IN SCRATCH_DATA *Sd, IN UINT16 nn, IN UINT16 nbit, IN UINT16 Special)
VOID ReadCLen (SCRATCH_DATA *Sd)
UINT16 DecodeC (SCRATCH_DATA *Sd)
VOID Decode (SCRATCH_DATA *Sd)
RETURN_STATUS EFIAPI UefiDecompressGetInfo (IN CONST VOID *Source, IN UINT32 SourceSize, OUT UINT32 *DestinationSize, OUT UINT32 *ScratchSize)
RETURN_STATUS EFIAPI UefiDecompress (IN CONST VOID *Source, IN OUT VOID *Destination, IN OUT VOID *Scratch)

Detailed Description

UEFI Decompress Library implementation refer to UEFI specification.

Copyright (c) 2006 - 2015, Intel Corporation. All rights reserved.
Portions copyright (c) 2008 - 2009, Apple Inc. 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.


Function Documentation

VOID Decode ( SCRATCH_DATA Sd  ) 

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

Parameters:
Sd The global scratch data.

References BIT8, DecodeC(), DecodeP(), SCRATCH_DATA::mBadTableFlag, SCRATCH_DATA::mDstBase, SCRATCH_DATA::mOrigSize, SCRATCH_DATA::mOutBuf, and THRESHOLD.

Referenced by UefiDecompress().

UINT16 DecodeC ( SCRATCH_DATA Sd  ) 

Decode a character/length value.

Read one value from mBitBuf, Get one code from mBitBuf. If it is at block boundary, generates Huffman code mapping table for Extra Set, Code&Len Set and Position Set.

Parameters:
Sd The global scratch data.
Returns:
The value decoded.

References BITBUFSIZ, FillBuf(), GetBits(), Mask, MAXNP, SCRATCH_DATA::mBadTableFlag, SCRATCH_DATA::mBitBuf, SCRATCH_DATA::mBlockSize, SCRATCH_DATA::mCLen, SCRATCH_DATA::mCTable, SCRATCH_DATA::mLeft, SCRATCH_DATA::mPBit, SCRATCH_DATA::mRight, NC, NT, ReadCLen(), ReadPTLen(), and TBIT.

Referenced by Decode().

UINT32 DecodeP ( IN SCRATCH_DATA Sd  ) 

Decodes a position value.

Get a position value according to Position Huffman Table.

Parameters:
Sd The global scratch data.
Returns:
The position value decoded.

References BITBUFSIZ, FillBuf(), GetBits(), Mask, and MAXNP.

Referenced by Decode().

VOID FillBuf ( IN SCRATCH_DATA Sd,
IN UINT16  NumOfBits 
)

Read NumOfBit of bits from source into mBitBuf.

Shift mBitBuf NumOfBits left. Read in NumOfBits of bits from source.

Parameters:
Sd The global scratch data.
NumOfBits The number of bits to shift and read.

Referenced by DecodeC(), DecodeP(), GetBits(), ReadCLen(), ReadPTLen(), and UefiDecompress().

UINT32 GetBits ( IN SCRATCH_DATA Sd,
IN UINT16  NumOfBits 
)

Get NumOfBits of bits out from mBitBuf.

Get NumOfBits of bits out from mBitBuf. Fill mBitBuf with subsequent NumOfBits of bits from source. Returns NumOfBits of bits that are popped out.

Parameters:
Sd The global scratch data.
NumOfBits The number of bits to pop and read.
Returns:
The bits that are popped out.

References BITBUFSIZ, and FillBuf().

Referenced by DecodeC(), DecodeP(), ReadCLen(), and ReadPTLen().

UINT16 MakeTable ( IN SCRATCH_DATA Sd,
IN UINT16  NumOfChar,
IN UINT8 BitLen,
IN UINT16  TableBits,
OUT UINT16 Table 
)

Creates Huffman Code mapping table according to code length array.

Creates Huffman Code mapping table for Extra Set, Char&Len Set and Position Set according to code length array. If TableBits > 16, then ASSERT ().

Parameters:
Sd The global scratch data.
NumOfChar The number of symbols in the symbol set.
BitLen Code length array.
TableBits The width of the mapping table.
Table The table to be created.
Return values:
0 OK.
BAD_TABLE The table is corrupted.

References ASSERT, BAD_TABLE, Len, Mask, NC, and SetMem16().

Referenced by ReadCLen(), and ReadPTLen().

VOID ReadCLen ( SCRATCH_DATA Sd  ) 

Reads code lengths for Char&Len Set.

Read in and decode the Char&Len Set Code Length Array, then generate the Huffman Code mapping table for the Char&Len Set.

Parameters:
Sd The global scratch data.

References BITBUFSIZ, CBIT, FillBuf(), GetBits(), MakeTable(), Mask, SCRATCH_DATA::mBitBuf, SCRATCH_DATA::mCLen, SCRATCH_DATA::mCTable, SCRATCH_DATA::mLeft, SCRATCH_DATA::mPTLen, SCRATCH_DATA::mPTTable, SCRATCH_DATA::mRight, NC, NT, SetMem(), and SetMem16().

Referenced by DecodeC().

UINT16 ReadPTLen ( IN SCRATCH_DATA Sd,
IN UINT16  nn,
IN UINT16  nbit,
IN UINT16  Special 
)

Reads code lengths for the Extra Set or the Position Set.

Read in the Extra Set or Pointion Set Length Arrary, then generate the Huffman code mapping for them.

Parameters:
Sd The global scratch data.
nn The number of symbols.
nbit The number of bits needed to represent nn.
Special The special symbol that needs to be taken care of.
Return values:
0 OK.
BAD_TABLE Table is corrupted.

References ASSERT, BITBUFSIZ, FillBuf(), GetBits(), MakeTable(), Mask, NPT, SetMem(), and SetMem16().

Referenced by DecodeC().

RETURN_STATUS EFIAPI UefiDecompress ( IN CONST VOID *  Source,
IN OUT VOID *  Destination,
IN OUT VOID *  Scratch 
)

Decompresses a compressed source buffer.

Extracts decompressed data to its original form. This function is designed so that the decompression algorithm can be implemented without using any memory services. As a result, this function is not allowed to call any memory allocation services in its implementation. It is the caller's responsibility to allocate and free the Destination and Scratch buffers. If the compressed source data specified by Source is successfully decompressed into Destination, then RETURN_SUCCESS is returned. If the compressed source data specified by Source is not in a valid compressed data format, then RETURN_INVALID_PARAMETER is returned.

If Source is NULL, then ASSERT(). If Destination is NULL, then ASSERT(). If the required scratch buffer size > 0 and Scratch is NULL, then ASSERT().

Parameters:
Source The source buffer containing the compressed data.
Destination The destination buffer to store the decompressed data.
Scratch A temporary scratch buffer that is used to perform the decompression. This is an optional parameter that may be NULL if the required scratch buffer size is 0.
Return values:
RETURN_SUCCESS Decompression completed successfully, and the uncompressed buffer is returned in Destination.
RETURN_INVALID_PARAMETER The source buffer specified by Source is corrupted (not in a valid compressed format).

References ASSERT, BITBUFSIZ, CONST, Decode(), FillBuf(), SCRATCH_DATA::mBadTableFlag, SCRATCH_DATA::mCompSize, SCRATCH_DATA::mDstBase, SCRATCH_DATA::mOrigSize, SCRATCH_DATA::mPBit, SCRATCH_DATA::mSrcBase, NULL, RETURN_INVALID_PARAMETER, RETURN_SUCCESS, and SetMem().

RETURN_STATUS EFIAPI UefiDecompressGetInfo ( IN CONST VOID *  Source,
IN UINT32  SourceSize,
OUT UINT32 DestinationSize,
OUT UINT32 ScratchSize 
)

Given a compressed source buffer, this function retrieves the size of the uncompressed buffer and the size of the scratch buffer required to decompress the compressed source buffer.

Retrieves the size of the uncompressed buffer and the temporary scratch buffer required to decompress the buffer specified by Source and SourceSize. If the size of the uncompressed buffer or the size of the scratch buffer cannot be determined from the compressed data specified by Source and SourceData, then RETURN_INVALID_PARAMETER is returned. Otherwise, the size of the uncompressed buffer is returned in DestinationSize, the size of the scratch buffer is returned in ScratchSize, and RETURN_SUCCESS is returned. This function does not have scratch buffer available to perform a thorough checking of the validity of the source data. It just retrieves the "Original Size" field from the beginning bytes of the source data and output it as DestinationSize. And ScratchSize is specific to the decompression implementation.

If Source is NULL, then ASSERT(). If DestinationSize is NULL, then ASSERT(). If ScratchSize is NULL, then ASSERT().

Parameters:
Source The source buffer containing the compressed data.
SourceSize The size, in bytes, of the source buffer.
DestinationSize A pointer to the size, in bytes, of the uncompressed buffer that will be generated when the compressed buffer specified by Source and SourceSize is decompressed.
ScratchSize A pointer to the size, in bytes, of the scratch buffer that is required to decompress the compressed buffer specified by Source and SourceSize.
Return values:
RETURN_SUCCESS The size of the uncompressed data was returned in DestinationSize, and the size of the scratch buffer was returned in ScratchSize.
RETURN_INVALID_PARAMETER The size of the uncompressed data or the size of the scratch buffer cannot be determined from the compressed data specified by Source and SourceSize.

References ASSERT, NULL, ReadUnaligned32(), RETURN_INVALID_PARAMETER, and RETURN_SUCCESS.


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