source: vbox/trunk/src/VBox/Devices/EFI/Firmware/MdePkg/Library/BaseUefiDecompressLib/BaseUefiDecompressLibInternals.h

/** @file
  Internal data structure defintions for Base UEFI Decompress Library.

  Copyright (c) 2006 - 2019, Intel Corporation. All rights reserved.<BR>
  SPDX-License-Identifier: BSD-2-Clause-Patent

**/

#ifndef __BASE_UEFI_DECOMPRESS_LIB_INTERNALS_H__
#define __BASE_UEFI_DECOMPRESS_LIB_INTERNALS_H__

#include <Base.h>
#include <Library/BaseLib.h>
#include <Library/DebugLib.h>
#include <Library/BaseMemoryLib.h>
#include <Library/UefiDecompressLib.h>
//
// Decompression algorithm begins here
//
#define BITBUFSIZ  32
#define MAXMATCH   256
#define THRESHOLD  3
#define CODE_BIT   16
#define BAD_TABLE  - 1

//
// C: Char&Len Set; P: Position Set; T: exTra Set
//
#define NC       (0xff + MAXMATCH + 2 - THRESHOLD)
#define CBIT     9
#define MAXPBIT  5
#define TBIT     5
#define MAXNP    ((1U << MAXPBIT) - 1)
#define NT       (CODE_BIT + 3)
#if NT > MAXNP
#define NPT  NT
#else
#define NPT  MAXNP
#endif

typedef struct {
  UINT8     *mSrcBase; // The starting address of compressed data
  UINT8     *mDstBase; // The starting address of decompressed data
  UINT32    mOutBuf;
  UINT32    mInBuf;

  UINT16    mBitCount;
  UINT32    mBitBuf;
  UINT32    mSubBitBuf;
  UINT16    mBlockSize;
  UINT32    mCompSize;
  UINT32    mOrigSize;

  UINT16    mBadTableFlag;

  UINT16    mLeft[2 * NC - 1];
  UINT16    mRight[2 * NC - 1];
  UINT8     mCLen[NC];
  UINT8     mPTLen[NPT];
  UINT16    mCTable[4096];
  UINT16    mPTTable[256];

  ///
  /// The length of the field 'Position Set Code Length Array Size' in Block Header.
  /// For UEFI 2.0 de/compression algorithm, mPBit = 4.
  /// For Tiano de/compression algorithm, mPBit = 5.
  ///
  UINT8     mPBit;
} SCRATCH_DATA;

/**
  Read NumOfBit of bits from source into mBitBuf.

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

  @param  Sd        The global scratch data.
  @param  NumOfBits The number of bits to shift and read.

**/
VOID
FillBuf (
  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.

  @param  Sd        The global scratch data.
  @param  NumOfBits The number of bits to pop and read.

  @return The bits that are popped out.

**/
UINT32
GetBits (
  IN  SCRATCH_DATA  *Sd,
  IN  UINT16        NumOfBits
  );

/**
  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 ().

  @param  Sd        The global scratch data.
  @param  NumOfChar The number of symbols in the symbol set.
  @param  BitLen    Code length array.
  @param  TableBits The width of the mapping table.
  @param  Table     The table to be created.

  @retval  0 OK.
  @retval  BAD_TABLE The table is corrupted.

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

/**
  Decodes a position value.

  Get a position value according to Position Huffman Table.

  @param  Sd The global scratch data.

  @return The position value decoded.

**/
UINT32
DecodeP (
  IN  SCRATCH_DATA  *Sd
  );

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

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

  @param  Sd      The global scratch data.
  @param  nn      The number of symbols.
  @param  nbit    The number of bits needed to represent nn.
  @param  Special The special symbol that needs to be taken care of.

  @retval  0 OK.
  @retval  BAD_TABLE Table is corrupted.

**/
UINT16
ReadPTLen (
  IN  SCRATCH_DATA  *Sd,
  IN  UINT16        nn,
  IN  UINT16        nbit,
  IN  UINT16        Special
  );

/**
  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.

  @param  Sd The global scratch data.

**/
VOID
ReadCLen (
  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.

  @param  Sd The global scratch data.

  @return The value decoded.

**/
UINT16
DecodeC (
  SCRATCH_DATA  *Sd
  );

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

  @param  Sd The global scratch data.

**/
VOID
Decode (
  SCRATCH_DATA  *Sd
  );

/**
  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().

  @param  Source      The source buffer containing the compressed data.
  @param  Destination The destination buffer to store the decompressed data.
  @param  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.
  @param  Version     1 for UEFI Decompress algoruthm, 2 for Tiano Decompess algorithm.

  @retval  RETURN_SUCCESS Decompression completed successfully, and
                          the uncompressed buffer is returned in Destination.
  @retval  RETURN_INVALID_PARAMETER
                          The source buffer specified by Source is corrupted
                          (not in a valid compressed format).
**/
RETURN_STATUS
UefiTianoDecompress (
  IN CONST VOID  *Source,
  IN OUT VOID    *Destination,
  IN OUT VOID    *Scratch,
  IN UINT32      Version
  );

#endif