MdePkg/Library/BaseUefiDecompressLib/BaseUefiDecompressLibInternals.h

   1 /** @file
   2   Internal data structure defintions for Base UEFI Decompress Libary.
   3
   4   Copyright (c) 2006 - 2008, Intel Corporation. All rights reserved.<BR>
   5   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 **/
  14
  15 #ifndef __BASE_UEFI_DECOMPRESS_LIB_INTERNALS_H__
  16 #define __BASE_UEFI_DECOMPRESS_LIB_INTERNALS_H__
  17
  18 //
  19 // Decompression algorithm begins here
  20 //
  21 #define BITBUFSIZ 32
  22 #define MAXMATCH  256
  23 #define THRESHOLD 3
  24 #define CODE_BIT  16
  25 #define BAD_TABLE - 1
  26
  27 //
  28 // C: Char&Len Set; P: Position Set; T: exTra Set
  29 //
  30 #define NC      (0xff + MAXMATCH + 2 - THRESHOLD)
  31 #define CBIT    9
  32 #define MAXPBIT 5
  33 #define TBIT    5
  34 #define MAXNP   ((1U << MAXPBIT) - 1)
  35 #define NT      (CODE_BIT + 3)
  36 #if NT > MAXNP
  37 #define NPT NT
  38 #else
  39 #define NPT MAXNP
  40 #endif
  41
  42 typedef struct {
  43   UINT8   *mSrcBase;  // Starting address of compressed data
  44   UINT8   *mDstBase;  // Starting address of decompressed data
  45   UINT32  mOutBuf;
  46   UINT32  mInBuf;
  47
  48   UINT16  mBitCount;
  49   UINT32  mBitBuf;
  50   UINT32  mSubBitBuf;
  51   UINT16  mBlockSize;
  52   UINT32  mCompSize;
  53   UINT32  mOrigSize;
  54
  55   UINT16  mBadTableFlag;
  56
  57   UINT16  mLeft[2 * NC - 1];
  58   UINT16  mRight[2 * NC - 1];
  59   UINT8   mCLen[NC];
  60   UINT8   mPTLen[NPT];
  61   UINT16  mCTable[4096];
  62   UINT16  mPTTable[256];
  63
  64   ///
  65   /// The length of the field 'Position Set Code Length Array Size' in Block Header.
  66   /// For UEFI 2.0 de/compression algorithm, mPBit = 4
  67   ///
  68   UINT8   mPBit;
  69 } SCRATCH_DATA;
  70
  71 /**
  72   Read NumOfBit of bits from source into mBitBuf.
  73
  74   Shift mBitBuf NumOfBits left. Read in NumOfBits of bits from source.
  75
  76   @param  Sd        The global scratch data
  77   @param  NumOfBits The number of bits to shift and read.
  78
  79 **/
  80 VOID
  81 FillBuf (
  82   IN  SCRATCH_DATA  *Sd,
  83   IN  UINT16        NumOfBits
  84   );
  85
  86 /**
  87   Get NumOfBits of bits out from mBitBuf.
  88
  89   Get NumOfBits of bits out from mBitBuf. Fill mBitBuf with subsequent
  90   NumOfBits of bits from source. Returns NumOfBits of bits that are
  91   popped out.
  92
  93   @param  Sd        The global scratch data.
  94   @param  NumOfBits The number of bits to pop and read.
  95
  96   @return The bits that are popped out.
  97
  98 **/
  99 UINT32
 100 GetBits (
 101   IN  SCRATCH_DATA  *Sd,
 102   IN  UINT16        NumOfBits
 103   );
 104
 105 /**
 106   Creates Huffman Code mapping table according to code length array.
 107
 108   Creates Huffman Code mapping table for Extra Set, Char&Len Set
 109   and Position Set according to code length array.
 110
 111   @param  Sd        The global scratch data
 112   @param  NumOfChar Number of symbols in the symbol set
 113   @param  BitLen    Code length array
 114   @param  TableBits The width of the mapping table
 115   @param  Table     The table to be created.
 116
 117   @retval  0 OK.
 118   @retval  BAD_TABLE The table is corrupted.
 119
 120 **/
 121 UINT16
 122 MakeTable (
 123   IN  SCRATCH_DATA  *Sd,
 124   IN  UINT16        NumOfChar,
 125   IN  UINT8         *BitLen,
 126   IN  UINT16        TableBits,
 127   OUT UINT16        *Table
 128   );
 129
 130 /**
 131   Decodes a position value.
 132
 133   Get a position value according to Position Huffman Table.
 134
 135   @param  Sd the global scratch data
 136
 137   @return The position value decoded.
 138
 139 **/
 140 UINT32
 141 DecodeP (
 142   IN  SCRATCH_DATA  *Sd
 143   );
 144
 145 /**
 146   Reads code lengths for the Extra Set or the Position Set.
 147
 148   Read in the Extra Set or Pointion Set Length Arrary, then
 149   generate the Huffman code mapping for them.
 150
 151   @param  Sd      The global scratch data.
 152   @param  nn      Number of symbols.
 153   @param  nbit    Number of bits needed to represent nn.
 154   @param  Special The special symbol that needs to be taken care of.
 155
 156   @retval  0 OK.
 157   @retval  BAD_TABLE Table is corrupted.
 158
 159 **/
 160 UINT16
 161 ReadPTLen (
 162   IN  SCRATCH_DATA  *Sd,
 163   IN  UINT16        nn,
 164   IN  UINT16        nbit,
 165   IN  UINT16        Special
 166   );
 167
 168 /**
 169   Reads code lengths for Char&Len Set.
 170
 171   Read in and decode the Char&Len Set Code Length Array, then
 172   generate the Huffman Code mapping table for the Char&Len Set.
 173
 174   @param  Sd the global scratch data
 175
 176 **/
 177 VOID
 178 ReadCLen (
 179   SCRATCH_DATA  *Sd
 180   );
 181
 182 /**
 183   Decode a character/length value.
 184
 185   Read one value from mBitBuf, Get one code from mBitBuf. If it is at block boundary, generates
 186   Huffman code mapping table for Extra Set, Code&Len Set and
 187   Position Set.
 188
 189   @param  Sd The global scratch data.
 190
 191   @return The value decoded.
 192
 193 **/
 194 UINT16
 195 DecodeC (
 196   SCRATCH_DATA  *Sd
 197   );
 198
 199 /**
 200   Decode the source data and put the resulting data into the destination buffer.
 201
 202   @param  Sd The global scratch data
 203
 204 **/
 205 VOID
 206 Decode (
 207   SCRATCH_DATA  *Sd
 208   );
 209
 210 #endif