add lzop decompression support
Add lzop decompression support to the existing lzo bitstream handling
(think gzip versus zlib), and support it for uImage decompression if
CONFIG_LZO is enabled.
Lzop doesn't compress as good as gzip (~10% worse), but decompression
is very fast (~0.7s faster here on a slow ppc). The lzop decompression
code is based on Albin Tonnerre's recent ARM Linux lzo support patch.
Cc: albin.tonnerre@free-electrons.com
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
diff --git a/lib_generic/lzo/lzo1x_decompress.c b/lib_generic/lzo/lzo1x_decompress.c
index 2780e11..09bdc8f 100644
--- a/lib_generic/lzo/lzo1x_decompress.c
+++ b/lib_generic/lzo/lzo1x_decompress.c
@@ -24,6 +24,93 @@
#define COPY4(dst, src) \
put_unaligned(get_unaligned((const u32 *)(src)), (u32 *)(dst))
+static const unsigned char lzop_magic[] = {
+ 0x89, 0x4c, 0x5a, 0x4f, 0x00, 0x0d, 0x0a, 0x1a, 0x0a
+};
+
+#define HEADER_HAS_FILTER 0x00000800L
+
+static inline const unsigned char *parse_header(const unsigned char *src)
+{
+ u8 level = 0;
+ u16 version;
+ int i;
+
+ /* read magic: 9 first bytes */
+ for (i = 0; i < ARRAY_SIZE(lzop_magic); i++) {
+ if (*src++ != lzop_magic[i])
+ return NULL;
+ }
+ /* get version (2bytes), skip library version (2),
+ * 'need to be extracted' version (2) and
+ * method (1) */
+ version = get_unaligned_be16(src);
+ src += 7;
+ if (version >= 0x0940)
+ level = *src++;
+ if (get_unaligned_be32(src) & HEADER_HAS_FILTER)
+ src += 4; /* filter info */
+
+ /* skip flags, mode and mtime_low */
+ src += 12;
+ if (version >= 0x0940)
+ src += 4; /* skip mtime_high */
+
+ i = *src++;
+ /* don't care about the file name, and skip checksum */
+ src += i + 4;
+
+ return src;
+}
+
+int lzop_decompress(const unsigned char *src, size_t src_len,
+ unsigned char *dst, size_t *dst_len)
+{
+ unsigned char *start = dst;
+ const unsigned char *send = src + src_len;
+ u32 slen, dlen;
+ size_t tmp;
+ int r;
+
+ src = parse_header(src);
+ if (!src)
+ return LZO_E_ERROR;
+
+ while (src < send) {
+ /* read uncompressed block size */
+ dlen = get_unaligned_be32(src);
+ src += 4;
+
+ /* exit if last block */
+ if (dlen == 0) {
+ *dst_len = dst - start;
+ return LZO_E_OK;
+ }
+
+ /* read compressed block size, and skip block checksum info */
+ slen = get_unaligned_be32(src);
+ src += 8;
+
+ if (slen <= 0 || slen > dlen)
+ return LZO_E_ERROR;
+
+ /* decompress */
+ tmp = dlen;
+ r = lzo1x_decompress_safe((u8 *) src, slen, dst, &tmp);
+
+ if (r != LZO_E_OK)
+ return r;
+
+ if (dlen != tmp)
+ return LZO_E_ERROR;
+
+ src += slen;
+ dst += dlen;
+ }
+
+ return LZO_E_INPUT_OVERRUN;
+}
+
int lzo1x_decompress_safe(const unsigned char *in, size_t in_len,
unsigned char *out, size_t *out_len)
{