MdePkg/Library/BaseUefiDecompressLib/BaseUefiDecompressLibInternals.h

   1 /** @file
   2   Internal include file for Base UEFI Decompress Libary.
   3
   4   Copyright (c) 2006, Intel Corporation
   5   All rights reserved. This program and the accompanying materials
   6   are licensed and made available under the terms and conditions of the BSD License
   7   which accompanies this distribution.  The full text of the license may be found at
   8   http://opensource.org/licenses/bsd-license.php
   9
  10   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  11   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  12
  13   Module Name:  BaseUefiDecompressLibInternals.h
  14
  15 **/
  16
  17 #ifndef __BASE_UEFI_DECOMPRESS_LIB_INTERNALS_H__
  18 #define __BASE_UEFI_DECOMPRESS_LIB_INTERNALS_H__
  19
  20 //
  21 // Decompression algorithm begins here
  22 //
  23 #define BITBUFSIZ 32
  24 #define MAXMATCH  256
  25 #define THRESHOLD 3
  26 #define CODE_BIT  16
  27 #define BAD_TABLE - 1
  28
  29 //
  30 // C: Char&Len Set; P: Position Set; T: exTra Set
  31 //
  32 #define NC      (0xff + MAXMATCH + 2 - THRESHOLD)
  33 #define CBIT    9
  34 #define MAXPBIT 5
  35 #define TBIT    5
  36 #define MAXNP   ((1U << MAXPBIT) - 1)
  37 #define NT      (CODE_BIT + 3)
  38 #if NT > MAXNP
  39 #define NPT NT
  40 #else
  41 #define NPT MAXNP
  42 #endif
  43
  44 typedef struct {
  45   UINT8   *mSrcBase;  ///< Starting address of compressed data
  46   UINT8   *mDstBase;  ///< Starting address of decompressed data
  47   UINT32  mOutBuf;
  48   UINT32  mInBuf;
  49
  50   UINT16  mBitCount;
  51   UINT32  mBitBuf;
  52   UINT32  mSubBitBuf;
  53   UINT16  mBlockSize;
  54   UINT32  mCompSize;
  55   UINT32  mOrigSize;
  56
  57   UINT16  mBadTableFlag;
  58
  59   UINT16  mLeft[2 * NC - 1];
  60   UINT16  mRight[2 * NC - 1];
  61   UINT8   mCLen[NC];
  62   UINT8   mPTLen[NPT];
  63   UINT16  mCTable[4096];
  64   UINT16  mPTTable[256];
  65
  66   ///
  67   /// The length of the field 'Position Set Code Length Array Size' in Block Header.
  68   /// For EFI 1.1 de/compression algorithm, mPBit = 4
  69   /// For Tiano de/compression algorithm, mPBit = 5
  70   ///
  71   UINT8   mPBit;
  72 } SCRATCH_DATA;
  73
  74 /**
  75   Read NumOfBit of bits from source into mBitBuf
  76
  77   Shift mBitBuf NumOfBits left. Read in NumOfBits of bits from source.
  78
  79   @param  Sd        The global scratch data
  80   @param  NumOfBits The number of bits to shift and read.
  81
  82 **/
  83 VOID
  84 FillBuf (
  85   IN  SCRATCH_DATA  *Sd,
  86   IN  UINT16        NumOfBits
  87   );
  88
  89 /**
  90   Get NumOfBits of bits out from mBitBuf
  91
  92   Get NumOfBits of bits out from mBitBuf. Fill mBitBuf with subsequent
  93   NumOfBits of bits from source. Returns NumOfBits of bits that are
  94   popped out.
  95
  96   @param  Sd        The global scratch data.
  97   @param  NumOfBits The number of bits to pop and read.
  98
  99   @return The bits that are popped out.
 100
 101 **/
 102 UINT32
 103 GetBits (
 104   IN  SCRATCH_DATA  *Sd,
 105   IN  UINT16        NumOfBits
 106   );
 107
 108 /**
 109   Creates Huffman Code mapping table according to code length array.
 110
 111   Creates Huffman Code mapping table for Extra Set, Char&Len Set
 112   and Position Set according to code length array.
 113
 114   @param  Sd        The global scratch data
 115   @param  NumOfChar Number of symbols in the symbol set
 116   @param  BitLen    Code length array
 117   @param  TableBits The width of the mapping table
 118   @param  Table     The table
 119
 120   @retval  0 OK.
 121   @retval  BAD_TABLE The table is corrupted.
 122
 123 **/
 124 UINT16
 125 MakeTable (
 126   IN  SCRATCH_DATA  *Sd,
 127   IN  UINT16        NumOfChar,
 128   IN  UINT8         *BitLen,
 129   IN  UINT16        TableBits,
 130   OUT UINT16        *Table
 131   );
 132
 133 /**
 134   Decodes a position value.
 135
 136   Get a position value according to Position Huffman Table.
 137
 138   @param  Sd the global scratch data
 139
 140   @return The position value decoded.
 141
 142 **/
 143 UINT32
 144 DecodeP (
 145   IN  SCRATCH_DATA  *Sd
 146   );
 147
 148 /**
 149   Reads code lengths for the Extra Set or the Position Set.
 150
 151   Read in the Extra Set or Pointion Set Length Arrary, then
 152   generate the Huffman code mapping for them.
 153
 154   @param  Sd      The global scratch data.
 155   @param  nn      Number of symbols.
 156   @param  nbit    Number of bits needed to represent nn.
 157   @param  Special The special symbol that needs to be taken care of.
 158
 159   @retval  0 OK.
 160   @retval  BAD_TABLE Table is corrupted.
 161
 162 **/
 163 UINT16
 164 ReadPTLen (
 165   IN  SCRATCH_DATA  *Sd,
 166   IN  UINT16        nn,
 167   IN  UINT16        nbit,
 168   IN  UINT16        Special
 169   );
 170
 171 /**
 172   Reads code lengths for Char&Len Set.
 173
 174   Read in and decode the Char&Len Set Code Length Array, then
 175   generate the Huffman Code mapping table for the Char&Len Set.
 176
 177   @param  Sd the global scratch data
 178
 179 **/
 180 VOID
 181 ReadCLen (
 182   SCRATCH_DATA  *Sd
 183   );
 184
 185 /**
 186   Decode a character/length value.
 187
 188   Read one value from mBitBuf, Get one code from mBitBuf. If it is at block boundary, generates
 189   Huffman code mapping table for Extra Set, Code&Len Set and
 190   Position Set.
 191
 192   @param  Sd The global scratch data.
 193
 194   @return The value decoded.
 195
 196 **/
 197 UINT16
 198 DecodeC (
 199   SCRATCH_DATA  *Sd
 200   );
 201
 202 /**
 203   Decode the source data and put the resulting data into the destination buffer.
 204
 205   Decode the source data and put the resulting data into the destination buffer.
 206
 207   @param  Sd The global scratch data
 208
 209 **/
 210 VOID
 211 Decode (
 212   SCRATCH_DATA  *Sd
 213   );
 214
 215 #endif