summaryrefslogtreecommitdiff
path: root/MdePkg/Library/BaseUefiDecompressLib/BaseUefiDecompressLibInternals.h
blob: 856c1f7b017b27a16e32acb1a61ec7bbba63edb2 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
/** @file
  Internal data structure defintions for Base UEFI Decompress Libary.

  Copyright (c) 2006 - 2010, Intel Corporation. All rights reserved.<BR>
  This program and the accompanying materials
  are licensed and made available under the terms and conditions of the BSD License
  which accompanies this distribution.  The full text of the license may be found at
  http://opensource.org/licenses/bsd-license.php

  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.

**/

#ifndef __BASE_UEFI_DECOMPRESS_LIB_INTERNALS_H__
#define __BASE_UEFI_DECOMPRESS_LIB_INTERNALS_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;  // Starting address of compressed data
  UINT8   *mDstBase;  // 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
  ///
  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 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 Pointion Set Length Arrary, then
  generate the Huffman code mapping for them.

  @param  Sd      The global scratch data.
  @param  nn      Number of symbols.
  @param  nbit    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
  );

#endif