add gunzip

2 files changed, 86 insertions, 1 deletions

diff --git a/lib/Makefile b/lib/Makefile
index 13aa1ce8d9..0aaf53f69a 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -11,7 +11,7 @@ obj-y			+= xfuncs.o
 obj-y			+= getopt.o
 obj-y 			+= readkey.o
 obj-$(CONFIG_BZLIB)	+= bzlib.o bzlib_crctable.o bzlib_decompress.o bzlib_huffman.o bzlib_randtable.o
-obj-$(CONFIG_ZLIB)	+= zlib.o
+obj-$(CONFIG_ZLIB)	+= zlib.o gunzip.o
 obj-$(CONFIG_CRC32)	+= crc32.o
 obj-$(CONFIG_CMDLINE_EDITING)	+= readline.o
 obj-$(CONFIG_SIMPLE_READLINE)	+= readline_simple.o
diff --git a/lib/gunzip.c b/lib/gunzip.c
new file mode 100644
index 0000000000..c41568afd6
--- /dev/null
+++ b/lib/gunzip.c
@@ -0,0 +1,85 @@
+#include <common.h>
+#include <zlib.h>
+#include <malloc.h>
+
+#define	ZALLOC_ALIGNMENT	16
+
+static void *zalloc(void *x, unsigned items, unsigned size)
+{
+	void *p;
+
+	size *= items;
+	size = (size + ZALLOC_ALIGNMENT - 1) & ~(ZALLOC_ALIGNMENT - 1);
+
+	p = malloc (size);
+
+	return (p);
+}
+
+static void zfree(void *x, void *addr, unsigned nb)
+{
+	free (addr);
+}
+
+#define HEAD_CRC	2
+#define EXTRA_FIELD	4
+#define ORIG_NAME	8
+#define COMMENT		0x10
+#define RESERVED	0xe0
+
+#define DEFLATED	8
+
+int gunzip(void *dst, int dstlen, unsigned char *src, unsigned long *lenp)
+{
+	z_stream s;
+	int r, i, flags;
+
+	/* skip header */
+	i = 10;
+	flags = src[3];
+	if (src[2] != DEFLATED || (flags & RESERVED) != 0) {
+		puts ("Error: Bad gzipped data\n");
+		return (-1);
+	}
+	if ((flags & EXTRA_FIELD) != 0)
+		i = 12 + src[10] + (src[11] << 8);
+	if ((flags & ORIG_NAME) != 0)
+		while (src[i++] != 0)
+			;
+	if ((flags & COMMENT) != 0)
+		while (src[i++] != 0)
+			;
+	if ((flags & HEAD_CRC) != 0)
+		i += 2;
+	if (i >= *lenp) {
+		puts ("Error: gunzip out of data in header\n");
+		return (-1);
+	}
+
+	s.zalloc = zalloc;
+	s.zfree = zfree;
+#if defined(CONFIG_HW_WATCHDOG) || defined(CONFIG_WATCHDOG)
+	s.outcb = (cb_func)WATCHDOG_RESET;
+#else
+	s.outcb = Z_NULL;
+#endif	/* CONFIG_HW_WATCHDOG */
+
+	r = inflateInit2(&s, -MAX_WBITS);
+	if (r != Z_OK) {
+		printf ("Error: inflateInit2() returned %d\n", r);
+		return (-1);
+	}
+	s.next_in = src + i;
+	s.avail_in = *lenp - i;
+	s.next_out = dst;
+	s.avail_out = dstlen;
+	r = inflate(&s, Z_FINISH);
+	if (r != Z_OK && r != Z_STREAM_END) {
+		printf ("Error: inflate() returned %d\n", r);
+		return (-1);
+	}
+	*lenp = s.next_out - (unsigned char *) dst;
+	inflateEnd(&s);
+
+	return (0);
+}