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| 1 | +/* |
| 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 | + |
| 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 | + |
| 144 | + if (flush && flush(outp, dest_len) != dest_len) |
| 145 | + goto exit_2; |
| 146 | + if (output) |
| 147 | + outp += dest_len; |
| 148 | + if (posp) |
| 149 | + *posp += chunksize; |
| 150 | + |
| 151 | + size -= chunksize; |
| 152 | + |
| 153 | + if (size == 0) |
| 154 | + break; |
| 155 | + else if (size < 0) { |
| 156 | + error("data corrupted"); |
| 157 | + goto exit_2; |
| 158 | + } |
| 159 | + |
| 160 | + inp += chunksize; |
| 161 | + if (fill) |
| 162 | + inp = inp_start; |
| 163 | + } |
| 164 | + |
| 165 | + ret = 0; |
| 166 | +exit_2: |
| 167 | + if (!input) |
| 168 | + large_free(inp_start); |
| 169 | +exit_1: |
| 170 | + if (!output) |
| 171 | + large_free(outp); |
| 172 | +exit_0: |
| 173 | + return ret; |
| 174 | +} |
| 175 | + |
| 176 | +#ifdef PREBOOT |
| 177 | +STATIC int INIT decompress(unsigned char *buf, int in_len, |
| 178 | + int(*fill)(void*, unsigned int), |
| 179 | + int(*flush)(void*, unsigned int), |
| 180 | + unsigned char *output, |
| 181 | + int *posp, |
| 182 | + void(*error)(char *x) |
| 183 | + ) |
| 184 | +{ |
| 185 | + return unlz4(buf, in_len - 4, fill, flush, output, posp, error); |
| 186 | +} |
| 187 | +#endif |
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