2 * Wrapper for decompressing LZ4-compressed kernel, initramfs, and initrd
4 * Copyright (C) 2013, LG Electronics, Kyungsik Lee <kyungsik.lee@lge.com>
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.
13 #include "lz4/lz4_decompress.c"
15 #include <linux/decompress/unlz4.h>
17 #include <linux/types.h>
18 #include <linux/lz4.h>
19 #include <linux/decompress/mm.h>
20 #include <linux/compiler.h>
22 #include <asm/unaligned.h>
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.
31 #define LZ4_DEFAULT_UNCOMPRESSED_CHUNK_SIZE (8 << 20)
32 #define ARCHIVE_MAGICNUMBER 0x184C2102
34 STATIC inline int INIT unlz4(u8 *input, long in_len,
35 long (*fill)(void *, unsigned long),
36 long (*flush)(void *, unsigned long),
37 u8 *output, long *posp,
38 void (*error) (char *x))
42 size_t uncomp_chunksize = LZ4_DEFAULT_UNCOMPRESSED_CHUNK_SIZE;
48 size_t out_len = get_unaligned_le32(input + in_len);
56 error("NULL output pointer and no flush function provided");
59 outp = large_malloc(uncomp_chunksize);
61 error("Could not allocate output buffer");
67 error("Both input pointer and fill function provided,");
72 error("NULL input pointer and missing fill function");
75 inp = large_malloc(LZ4_compressBound(uncomp_chunksize));
77 error("Could not allocate input buffer");
89 error("data corrupted");
94 chunksize = get_unaligned_le32(inp);
95 if (chunksize == ARCHIVE_MAGICNUMBER) {
101 error("invalid header");
115 error("data corrupted");
120 chunksize = get_unaligned_le32(inp);
121 if (chunksize == ARCHIVE_MAGICNUMBER) {
139 if (chunksize > LZ4_compressBound(uncomp_chunksize)) {
140 error("chunk length is longer than allocated");
143 size = fill(inp, chunksize);
144 if (size < chunksize) {
145 error("data corrupted");
150 if (out_len >= uncomp_chunksize) {
151 dest_len = uncomp_chunksize;
156 ret = LZ4_decompress_fast(inp, outp, dest_len);
159 dest_len = uncomp_chunksize;
161 ret = LZ4_decompress_safe(inp, outp, chunksize, dest_len);
165 error("Decoding failed");
170 if (flush && flush(outp, dest_len) != dest_len)
183 error("data corrupted");
193 large_free(inp_start);
202 STATIC int INIT __decompress(unsigned char *buf, long in_len,
203 long (*fill)(void*, unsigned long),
204 long (*flush)(void*, unsigned long),
205 unsigned char *output, long out_len,
207 void (*error)(char *x)
210 return unlz4(buf, in_len - 4, fill, flush, output, posp, error);