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Kyungsik Leee76e1fd2013-07-08 16:01:46 -07001/*
2 * Wrapper for decompressing LZ4-compressed kernel, initramfs, and initrd
3 *
4 * Copyright (C) 2013, LG Electronics, Kyungsik Lee <kyungsik.lee@lge.com>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 */
10
11#ifdef STATIC
12#define PREBOOT
13#include "lz4/lz4_decompress.c"
14#else
15#include <linux/decompress/unlz4.h>
16#endif
17#include <linux/types.h>
18#include <linux/lz4.h>
19#include <linux/decompress/mm.h>
20#include <linux/compiler.h>
21
22#include <asm/unaligned.h>
23
24/*
25 * Note: Uncompressed chunk size is used in the compressor side
26 * (userspace side for compression).
27 * It is hardcoded because there is not proper way to extract it
28 * from the binary stream which is generated by the preliminary
29 * version of LZ4 tool so far.
30 */
31#define LZ4_DEFAULT_UNCOMPRESSED_CHUNK_SIZE (8 << 20)
32#define ARCHIVE_MAGICNUMBER 0x184C2102
33
34STATIC inline int INIT unlz4(u8 *input, int in_len,
35 int (*fill) (void *, unsigned int),
36 int (*flush) (void *, unsigned int),
37 u8 *output, int *posp,
38 void (*error) (char *x))
39{
40 int ret = -1;
41 size_t chunksize = 0;
42 size_t uncomp_chunksize = LZ4_DEFAULT_UNCOMPRESSED_CHUNK_SIZE;
43 u8 *inp;
44 u8 *inp_start;
45 u8 *outp;
46 int size = in_len;
47#ifdef PREBOOT
48 size_t out_len = get_unaligned_le32(input + in_len);
49#endif
50 size_t dest_len;
51
52
53 if (output) {
54 outp = output;
55 } else if (!flush) {
56 error("NULL output pointer and no flush function provided");
57 goto exit_0;
58 } else {
59 outp = large_malloc(uncomp_chunksize);
60 if (!outp) {
61 error("Could not allocate output buffer");
62 goto exit_0;
63 }
64 }
65
66 if (input && fill) {
67 error("Both input pointer and fill function provided,");
68 goto exit_1;
69 } else if (input) {
70 inp = input;
71 } else if (!fill) {
72 error("NULL input pointer and missing fill function");
73 goto exit_1;
74 } else {
75 inp = large_malloc(lz4_compressbound(uncomp_chunksize));
76 if (!inp) {
77 error("Could not allocate input buffer");
78 goto exit_1;
79 }
80 }
81 inp_start = inp;
82
83 if (posp)
84 *posp = 0;
85
86 if (fill)
87 fill(inp, 4);
88
89 chunksize = get_unaligned_le32(inp);
90 if (chunksize == ARCHIVE_MAGICNUMBER) {
91 inp += 4;
92 size -= 4;
93 } else {
94 error("invalid header");
95 goto exit_2;
96 }
97
98 if (posp)
99 *posp += 4;
100
101 for (;;) {
102
103 if (fill)
104 fill(inp, 4);
105
106 chunksize = get_unaligned_le32(inp);
107 if (chunksize == ARCHIVE_MAGICNUMBER) {
108 inp += 4;
109 size -= 4;
110 if (posp)
111 *posp += 4;
112 continue;
113 }
114 inp += 4;
115 size -= 4;
116
117 if (posp)
118 *posp += 4;
119
120 if (fill) {
121 if (chunksize > lz4_compressbound(uncomp_chunksize)) {
122 error("chunk length is longer than allocated");
123 goto exit_2;
124 }
125 fill(inp, chunksize);
126 }
127#ifdef PREBOOT
128 if (out_len >= uncomp_chunksize) {
129 dest_len = uncomp_chunksize;
130 out_len -= dest_len;
131 } else
132 dest_len = out_len;
133 ret = lz4_decompress(inp, &chunksize, outp, dest_len);
134#else
135 dest_len = uncomp_chunksize;
136 ret = lz4_decompress_unknownoutputsize(inp, chunksize, outp,
137 &dest_len);
138#endif
139 if (ret < 0) {
140 error("Decoding failed");
141 goto exit_2;
142 }
143
Jan Beulich2a1d6892014-01-23 15:56:20 -0800144 ret = -1;
Kyungsik Leee76e1fd2013-07-08 16:01:46 -0700145 if (flush && flush(outp, dest_len) != dest_len)
146 goto exit_2;
147 if (output)
148 outp += dest_len;
149 if (posp)
150 *posp += chunksize;
151
152 size -= chunksize;
153
154 if (size == 0)
155 break;
156 else if (size < 0) {
157 error("data corrupted");
158 goto exit_2;
159 }
160
161 inp += chunksize;
162 if (fill)
163 inp = inp_start;
164 }
165
166 ret = 0;
167exit_2:
168 if (!input)
169 large_free(inp_start);
170exit_1:
171 if (!output)
172 large_free(outp);
173exit_0:
174 return ret;
175}
176
177#ifdef PREBOOT
178STATIC int INIT decompress(unsigned char *buf, int in_len,
179 int(*fill)(void*, unsigned int),
180 int(*flush)(void*, unsigned int),
181 unsigned char *output,
182 int *posp,
183 void(*error)(char *x)
184 )
185{
186 return unlz4(buf, in_len - 4, fill, flush, output, posp, error);
187}
188#endif