MdePkg/Library/BaseUefiDecompressLib/BaseUefiDecompressLibInternals.h

   1 /** @file
   2   Internal data structure defintions for Base UEFI Decompress Library.
   3
   4   Copyright (c) 2006 - 2010, Intel Corporation. All rights reserved.<BR>
   5   SPDX-License-Identifier: BSD-2-Clause-Patent
   6
   7 **/
   8
   9 #ifndef __BASE_UEFI_DECOMPRESS_LIB_INTERNALS_H__
  10 #define __BASE_UEFI_DECOMPRESS_LIB_INTERNALS_H__
  11
  12 //
  13 // Decompression algorithm begins here
  14 //
  15 #define BITBUFSIZ 32
  16 #define MAXMATCH  256
  17 #define THRESHOLD 3
  18 #define CODE_BIT  16
  19 #define BAD_TABLE - 1
  20
  21 //
  22 // C: Char&Len Set; P: Position Set; T: exTra Set
  23 //
  24 #define NC      (0xff + MAXMATCH + 2 - THRESHOLD)
  25 #define CBIT    9
  26 #define MAXPBIT 5
  27 #define TBIT    5
  28 #define MAXNP   ((1U << MAXPBIT) - 1)
  29 #define NT      (CODE_BIT + 3)
  30 #if NT > MAXNP
  31 #define NPT NT
  32 #else
  33 #define NPT MAXNP
  34 #endif
  35
  36 typedef struct {
  37   UINT8   *mSrcBase;  // The starting address of compressed data
  38   UINT8   *mDstBase;  // The starting address of decompressed data
  39   UINT32  mOutBuf;
  40   UINT32  mInBuf;
  41
  42   UINT16  mBitCount;
  43   UINT32  mBitBuf;
  44   UINT32  mSubBitBuf;
  45   UINT16  mBlockSize;
  46   UINT32  mCompSize;
  47   UINT32  mOrigSize;
  48
  49   UINT16  mBadTableFlag;
  50
  51   UINT16  mLeft[2 * NC - 1];
  52   UINT16  mRight[2 * NC - 1];
  53   UINT8   mCLen[NC];
  54   UINT8   mPTLen[NPT];
  55   UINT16  mCTable[4096];
  56   UINT16  mPTTable[256];
  57
  58   ///
  59   /// The length of the field 'Position Set Code Length Array Size' in Block Header.
  60   /// For UEFI 2.0 de/compression algorithm, mPBit = 4.
  61   ///
  62   UINT8   mPBit;
  63 } SCRATCH_DATA;
  64
  65 /**
  66   Read NumOfBit of bits from source into mBitBuf.
  67
  68   Shift mBitBuf NumOfBits left. Read in NumOfBits of bits from source.
  69
  70   @param  Sd        The global scratch data.
  71   @param  NumOfBits The number of bits to shift and read.
  72
  73 **/
  74 VOID
  75 FillBuf (
  76   IN  SCRATCH_DATA  *Sd,
  77   IN  UINT16        NumOfBits
  78   );
  79
  80 /**
  81   Get NumOfBits of bits out from mBitBuf.
  82
  83   Get NumOfBits of bits out from mBitBuf. Fill mBitBuf with subsequent
  84   NumOfBits of bits from source. Returns NumOfBits of bits that are
  85   popped out.
  86
  87   @param  Sd        The global scratch data.
  88   @param  NumOfBits The number of bits to pop and read.
  89
  90   @return The bits that are popped out.
  91
  92 **/
  93 UINT32
  94 GetBits (
  95   IN  SCRATCH_DATA  *Sd,
  96   IN  UINT16        NumOfBits
  97   );
  98
  99 /**
 100   Creates Huffman Code mapping table according to code length array.
 101
 102   Creates Huffman Code mapping table for Extra Set, Char&Len Set
 103   and Position Set according to code length array.
 104   If TableBits > 16, then ASSERT ().
 105
 106   @param  Sd        The global scratch data.
 107   @param  NumOfChar The number of symbols in the symbol set.
 108   @param  BitLen    Code length array.
 109   @param  TableBits The width of the mapping table.
 110   @param  Table     The table to be created.
 111
 112   @retval  0 OK.
 113   @retval  BAD_TABLE The table is corrupted.
 114
 115 **/
 116 UINT16
 117 MakeTable (
 118   IN  SCRATCH_DATA  *Sd,
 119   IN  UINT16        NumOfChar,
 120   IN  UINT8         *BitLen,
 121   IN  UINT16        TableBits,
 122   OUT UINT16        *Table
 123   );
 124
 125 /**
 126   Decodes a position value.
 127
 128   Get a position value according to Position Huffman Table.
 129
 130   @param  Sd The global scratch data.
 131
 132   @return The position value decoded.
 133
 134 **/
 135 UINT32
 136 DecodeP (
 137   IN  SCRATCH_DATA  *Sd
 138   );
 139
 140 /**
 141   Reads code lengths for the Extra Set or the Position Set.
 142
 143   Read in the Extra Set or Position Set Length Array, then
 144   generate the Huffman code mapping for them.
 145
 146   @param  Sd      The global scratch data.
 147   @param  nn      The number of symbols.
 148   @param  nbit    The number of bits needed to represent nn.
 149   @param  Special The special symbol that needs to be taken care of.
 150
 151   @retval  0 OK.
 152   @retval  BAD_TABLE Table is corrupted.
 153
 154 **/
 155 UINT16
 156 ReadPTLen (
 157   IN  SCRATCH_DATA  *Sd,
 158   IN  UINT16        nn,
 159   IN  UINT16        nbit,
 160   IN  UINT16        Special
 161   );
 162
 163 /**
 164   Reads code lengths for Char&Len Set.
 165
 166   Read in and decode the Char&Len Set Code Length Array, then
 167   generate the Huffman Code mapping table for the Char&Len Set.
 168
 169   @param  Sd The global scratch data.
 170
 171 **/
 172 VOID
 173 ReadCLen (
 174   SCRATCH_DATA  *Sd
 175   );
 176
 177 /**
 178   Decode a character/length value.
 179
 180   Read one value from mBitBuf, Get one code from mBitBuf. If it is at block boundary, generates
 181   Huffman code mapping table for Extra Set, Code&Len Set and
 182   Position Set.
 183
 184   @param  Sd The global scratch data.
 185
 186   @return The value decoded.
 187
 188 **/
 189 UINT16
 190 DecodeC (
 191   SCRATCH_DATA  *Sd
 192   );
 193
 194 /**
 195   Decode the source data and put the resulting data into the destination buffer.
 196
 197   @param  Sd The global scratch data.
 198
 199 **/
 200 VOID
 201 Decode (
 202   SCRATCH_DATA  *Sd
 203   );
 204
 205 #endif