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e76e1fdf KL |
1 | /* |
2 | * Wrapper for decompressing LZ4-compressed kernel, initramfs, and initrd | |
3 | * | |
4 | * Copyright (C) 2013, LG Electronics, Kyungsik Lee <[email protected]> | |
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 | ||
34 | STATIC 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 | ||
2a1d689c | 144 | ret = -1; |
e76e1fdf KL |
145 | 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; | |
167 | exit_2: | |
168 | if (!input) | |
169 | large_free(inp_start); | |
170 | exit_1: | |
171 | if (!output) | |
172 | large_free(outp); | |
173 | exit_0: | |
174 | return ret; | |
175 | } | |
176 | ||
177 | #ifdef PREBOOT | |
178 | STATIC 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 |