MdePkg/Library/BaseUefiDecompressLib/BaseUefiDecompressLibInternals.h

   1 /** @file
   2   Internal data structure defintions for Base UEFI Decompress Libary.
   3
   4   Copyright (c) 2006 - 2010, 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;  // The starting address of compressed data
  44   UINT8   *mDstBase;  // The 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   If TableBits > 16, then ASSERT ().
 111
 112   @param  Sd        The global scratch data
 113   @param  NumOfChar The number of symbols in the symbol set
 114   @param  BitLen    Code length array
 115   @param  TableBits The width of the mapping table
 116   @param  Table     The table to be created.
 117
 118   @retval  0 OK.
 119   @retval  BAD_TABLE The table is corrupted.
 120
 121 **/
 122 UINT16
 123 MakeTable (
 124   IN  SCRATCH_DATA  *Sd,
 125   IN  UINT16        NumOfChar,
 126   IN  UINT8         *BitLen,
 127   IN  UINT16        TableBits,
 128   OUT UINT16        *Table
 129   );
 130
 131 /**
 132   Decodes a position value.
 133
 134   Get a position value according to Position Huffman Table.
 135
 136   @param  Sd the global scratch data
 137
 138   @return The position value decoded.
 139
 140 **/
 141 UINT32
 142 DecodeP (
 143   IN  SCRATCH_DATA  *Sd
 144   );
 145
 146 /**
 147   Reads code lengths for the Extra Set or the Position Set.
 148
 149   Read in the Extra Set or Pointion Set Length Arrary, then
 150   generate the Huffman code mapping for them.
 151
 152   @param  Sd      The global scratch data.
 153   @param  nn      The number of symbols.
 154   @param  nbit    The number of bits needed to represent nn.
 155   @param  Special The special symbol that needs to be taken care of.
 156
 157   @retval  0 OK.
 158   @retval  BAD_TABLE Table is corrupted.
 159
 160 **/
 161 UINT16
 162 ReadPTLen (
 163   IN  SCRATCH_DATA  *Sd,
 164   IN  UINT16        nn,
 165   IN  UINT16        nbit,
 166   IN  UINT16        Special
 167   );
 168
 169 /**
 170   Reads code lengths for Char&Len Set.
 171
 172   Read in and decode the Char&Len Set Code Length Array, then
 173   generate the Huffman Code mapping table for the Char&Len Set.
 174
 175   @param  Sd the global scratch data
 176
 177 **/
 178 VOID
 179 ReadCLen (
 180   SCRATCH_DATA  *Sd
 181   );
 182
 183 /**
 184   Decode a character/length value.
 185
 186   Read one value from mBitBuf, Get one code from mBitBuf. If it is at block boundary, generates
 187   Huffman code mapping table for Extra Set, Code&Len Set and
 188   Position Set.
 189
 190   @param  Sd The global scratch data.
 191
 192   @return The value decoded.
 193
 194 **/
 195 UINT16
 196 DecodeC (
 197   SCRATCH_DATA  *Sd
 198   );
 199
 200 /**
 201   Decode the source data and put the resulting data into the destination buffer.
 202
 203   @param  Sd The global scratch data
 204
 205 **/
 206 VOID
 207 Decode (
 208   SCRATCH_DATA  *Sd
 209   );
 210
 211 #endif