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Diffstat (limited to '')
| -rw-r--r-- | lib/decompress_unlz4.c | 220 |
1 files changed, 220 insertions, 0 deletions
diff --git a/lib/decompress_unlz4.c b/lib/decompress_unlz4.c new file mode 100644 index 000000000..b202aa864 --- /dev/null +++ b/lib/decompress_unlz4.c @@ -0,0 +1,220 @@ +/* + * Wrapper for decompressing LZ4-compressed kernel, initramfs, and initrd + * + * Copyright (C) 2013, LG Electronics, Kyungsik Lee <kyungsik.lee@lge.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#ifdef STATIC +#define PREBOOT +#include "lz4/lz4_decompress.c" +#else +#include <linux/decompress/unlz4.h> +#endif +#include <linux/types.h> +#include <linux/lz4.h> +#include <linux/decompress/mm.h> +#include <linux/compiler.h> + +#include <asm/unaligned.h> + +/* + * Note: Uncompressed chunk size is used in the compressor side + * (userspace side for compression). + * It is hardcoded because there is not proper way to extract it + * from the binary stream which is generated by the preliminary + * version of LZ4 tool so far. + */ +#define LZ4_DEFAULT_UNCOMPRESSED_CHUNK_SIZE (8 << 20) +#define ARCHIVE_MAGICNUMBER 0x184C2102 + +STATIC inline int INIT unlz4(u8 *input, long in_len, + long (*fill)(void *, unsigned long), + long (*flush)(void *, unsigned long), + u8 *output, long *posp, + void (*error) (char *x)) +{ + int ret = -1; + size_t chunksize = 0; + size_t uncomp_chunksize = LZ4_DEFAULT_UNCOMPRESSED_CHUNK_SIZE; + u8 *inp; + u8 *inp_start; + u8 *outp; + long size = in_len; +#ifdef PREBOOT + size_t out_len = get_unaligned_le32(input + in_len); +#endif + size_t dest_len; + + + if (output) { + outp = output; + } else if (!flush) { + error("NULL output pointer and no flush function provided"); + goto exit_0; + } else { + outp = large_malloc(uncomp_chunksize); + if (!outp) { + error("Could not allocate output buffer"); + goto exit_0; + } + } + + if (input && fill) { + error("Both input pointer and fill function provided,"); + goto exit_1; + } else if (input) { + inp = input; + } else if (!fill) { + error("NULL input pointer and missing fill function"); + goto exit_1; + } else { + inp = large_malloc(LZ4_compressBound(uncomp_chunksize)); + if (!inp) { + error("Could not allocate input buffer"); + goto exit_1; + } + } + inp_start = inp; + + if (posp) + *posp = 0; + + if (fill) { + size = fill(inp, 4); + if (size < 4) { + error("data corrupted"); + goto exit_2; + } + } + + chunksize = get_unaligned_le32(inp); + if (chunksize == ARCHIVE_MAGICNUMBER) { + if (!fill) { + inp += 4; + size -= 4; + } + } else { + error("invalid header"); + goto exit_2; + } + + if (posp) + *posp += 4; + + for (;;) { + + if (fill) { + size = fill(inp, 4); + if (size == 0) + break; + if (size < 4) { + error("data corrupted"); + goto exit_2; + } + } else if (size < 4) { + /* empty or end-of-file */ + goto exit_3; + } + + chunksize = get_unaligned_le32(inp); + if (chunksize == ARCHIVE_MAGICNUMBER) { + if (!fill) { + inp += 4; + size -= 4; + } + if (posp) + *posp += 4; + continue; + } + + if (!fill && chunksize == 0) { + /* empty or end-of-file */ + goto exit_3; + } + + if (posp) + *posp += 4; + + if (!fill) { + inp += 4; + size -= 4; + } else { + if (chunksize > LZ4_compressBound(uncomp_chunksize)) { + error("chunk length is longer than allocated"); + goto exit_2; + } + size = fill(inp, chunksize); + if (size < chunksize) { + error("data corrupted"); + goto exit_2; + } + } +#ifdef PREBOOT + if (out_len >= uncomp_chunksize) { + dest_len = uncomp_chunksize; + out_len -= dest_len; + } else + dest_len = out_len; + + ret = LZ4_decompress_fast(inp, outp, dest_len); + chunksize = ret; +#else + dest_len = uncomp_chunksize; + + ret = LZ4_decompress_safe(inp, outp, chunksize, dest_len); + dest_len = ret; +#endif + if (ret < 0) { + error("Decoding failed"); + goto exit_2; + } + + ret = -1; + if (flush && flush(outp, dest_len) != dest_len) + goto exit_2; + if (output) + outp += dest_len; + if (posp) + *posp += chunksize; + + if (!fill) { + size -= chunksize; + + if (size == 0) + break; + else if (size < 0) { + error("data corrupted"); + goto exit_2; + } + inp += chunksize; + } + } + +exit_3: + ret = 0; +exit_2: + if (!input) + large_free(inp_start); +exit_1: + if (!output) + large_free(outp); +exit_0: + return ret; +} + +#ifdef PREBOOT +STATIC int INIT __decompress(unsigned char *buf, long in_len, + long (*fill)(void*, unsigned long), + long (*flush)(void*, unsigned long), + unsigned char *output, long out_len, + long *posp, + void (*error)(char *x) + ) +{ + return unlz4(buf, in_len - 4, fill, flush, output, posp, error); +} +#endif |