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-rw-r--r--lib/decompress_unlz4.c187
1 files changed, 187 insertions, 0 deletions
diff --git a/lib/decompress_unlz4.c b/lib/decompress_unlz4.c
new file mode 100644
index 0000000..3e67cfad1
--- /dev/null
+++ b/lib/decompress_unlz4.c
@@ -0,0 +1,187 @@
+/*
+ * 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, int in_len,
+ int (*fill) (void *, unsigned int),
+ int (*flush) (void *, unsigned int),
+ u8 *output, int *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;
+ int 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)
+ fill(inp, 4);
+
+ chunksize = get_unaligned_le32(inp);
+ if (chunksize == ARCHIVE_MAGICNUMBER) {
+ inp += 4;
+ size -= 4;
+ } else {
+ error("invalid header");
+ goto exit_2;
+ }
+
+ if (posp)
+ *posp += 4;
+
+ for (;;) {
+
+ if (fill)
+ fill(inp, 4);
+
+ chunksize = get_unaligned_le32(inp);
+ if (chunksize == ARCHIVE_MAGICNUMBER) {
+ inp += 4;
+ size -= 4;
+ if (posp)
+ *posp += 4;
+ continue;
+ }
+ inp += 4;
+ size -= 4;
+
+ if (posp)
+ *posp += 4;
+
+ if (fill) {
+ if (chunksize > lz4_compressbound(uncomp_chunksize)) {
+ error("chunk length is longer than allocated");
+ goto exit_2;
+ }
+ fill(inp, chunksize);
+ }
+#ifdef PREBOOT
+ if (out_len >= uncomp_chunksize) {
+ dest_len = uncomp_chunksize;
+ out_len -= dest_len;
+ } else
+ dest_len = out_len;
+ ret = lz4_decompress(inp, &chunksize, outp, dest_len);
+#else
+ dest_len = uncomp_chunksize;
+ ret = lz4_decompress_unknownoutputsize(inp, chunksize, outp,
+ &dest_len);
+#endif
+ if (ret < 0) {
+ error("Decoding failed");
+ goto exit_2;
+ }
+
+ if (flush && flush(outp, dest_len) != dest_len)
+ goto exit_2;
+ if (output)
+ outp += dest_len;
+ if (posp)
+ *posp += chunksize;
+
+ size -= chunksize;
+
+ if (size == 0)
+ break;
+ else if (size < 0) {
+ error("data corrupted");
+ goto exit_2;
+ }
+
+ inp += chunksize;
+ if (fill)
+ inp = inp_start;
+ }
+
+ 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, int in_len,
+ int(*fill)(void*, unsigned int),
+ int(*flush)(void*, unsigned int),
+ unsigned char *output,
+ int *posp,
+ void(*error)(char *x)
+ )
+{
+ return unlz4(buf, in_len - 4, fill, flush, output, posp, error);
+}
+#endif