[U-Boot,1/2] gunzip: add gzwrite routine for extracting compresed images to block device

diff --git a/include/common.h b/include/common.h
index 9129454..f96baea 100644
--- a/include/common.h
+++ b/include/common.h
@@ -713,6 +713,45 @@  int gunzip(void *, int, unsigned char *, unsigned long *);
 int zunzip(void *dst, int dstlen, unsigned char *src, unsigned long *lenp,
 						int stoponerr, int offset);
 
+/**
+ * gzwrite progress indicators: defined weak to allow board-specific
+ * overrides:
+ *
+ *	gzwrite_progress_init called on startup
+ *	gzwrite_progress called during decompress/write loop
+ *	gzwrite_progress_finish called at end of loop to
+ *		indicate success (retcode=0) or failure
+ */
+void gzwrite_progress_init(u64 expected_size);
+
+void gzwrite_progress(int iteration,
+		     u64 bytes_written,
+		     u64 total_bytes);
+
+void gzwrite_progress_finish(int retcode,
+			     u64 totalwritten,
+			     u64 totalsize,
+			     u32 expected_crc,
+			     u32 calculated_crc);
+
+/**
+ * decompress and write gzipped image from memory to block device
+ *
+ * @param	src		compressed image address
+ * @param	len		compressed image length in bytes
+ * @param	dev		block device descriptor
+ * @param	szwritebuf	bytes per write (pad to erase size)
+ * @param	startoffs	offset in bytes of first write
+ * @param	szexpected	expected uncompressed length
+ *				may be zero to use gzip trailer
+ *				for files under 4GiB
+ */
+int gzwrite(unsigned char *src, int len,
+	    struct block_dev_desc *dev,
+	    unsigned long szwritebuf,
+	    u64 startoffs,
+	    u64 szexpected);
+
 /* lib/qsort.c */
 void qsort(void *base, size_t nmemb, size_t size,
 	   int(*compar)(const void *, const void *));
diff --git a/lib/gunzip.c b/lib/gunzip.c
index f469fcb..d28fda8 100644
--- a/lib/gunzip.c
+++ b/lib/gunzip.c
@@ -12,6 +12,8 @@ 
 #include <malloc.h>
 #include <u-boot/zlib.h>
 
+#define HEADER0			'\x1f'
+#define HEADER1			'\x8b'
 #define	ZALLOC_ALIGNMENT	16
 #define HEAD_CRC		2
 #define EXTRA_FIELD		4
@@ -66,6 +68,196 @@  int gunzip(void *dst, int dstlen, unsigned char *src, unsigned long *lenp)
 	return zunzip(dst, dstlen, src, lenp, 1, i);
 }
 
+__weak
+void gzwrite_progress_init(u64 expectedsize)
+{
+	putc('\n');
+}
+
+__weak
+void gzwrite_progress(int iteration,
+		     u64 bytes_written,
+		     u64 total_bytes)
+{
+	if (0 == (iteration & 3))
+		printf("%llu/%llu\r", bytes_written, total_bytes);
+}
+
+__weak
+void gzwrite_progress_finish(int returnval,
+			     u64 bytes_written,
+			     u64 total_bytes,
+			     u32 expected_crc,
+			     u32 calculated_crc)
+{
+	if (0 == returnval) {
+		printf("\n\t%llu bytes, crc 0x%08x\n",
+		       total_bytes, calculated_crc);
+	} else {
+		printf("\n\tuncompressed %llu of %llu\n"
+		       "\tcrcs == 0x%08x/0x%08x\n",
+		       bytes_written, total_bytes,
+		       expected_crc, calculated_crc);
+	}
+}
+
+int gzwrite(unsigned char *src, int len,
+	    struct block_dev_desc *dev,
+	    unsigned long szwritebuf,
+	    u64 startoffs,
+	    u64 szexpected)
+{
+	int i, flags;
+	z_stream s;
+	int r = 0;
+	unsigned char *writebuf;
+	unsigned crc = 0;
+	u64 totalfilled = 0;
+	lbaint_t blksperbuf, outblock;
+	u32 expected_crc;
+	u32 payload_size;
+	int iteration = 0;
+
+	if (!szwritebuf ||
+	    (szwritebuf % dev->blksz) ||
+	    (szwritebuf < dev->blksz)) {
+		printf("%s: size %lu not a multiple of %lu\n",
+		       __func__, szwritebuf, dev->blksz);
+		return -1;
+	}
+
+	if (startoffs % dev->blksz) {
+		printf("%s: start offset %llu not a multiple of %lu\n",
+		       __func__, startoffs, dev->blksz);
+		return -1;
+	}
+
+	blksperbuf = szwritebuf / dev->blksz;
+	outblock = startoffs / dev->blksz;
+
+	/* 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 >= len-8) {
+		puts("Error: gunzip out of data in header");
+		return -1;
+	}
+
+	payload_size = len - i - 8;
+
+	memcpy(&expected_crc, src + len - 8, sizeof(expected_crc));
+	expected_crc = le32_to_cpu(expected_crc);
+	u32 szuncompressed;
+	memcpy(&szuncompressed, src + len - 4, sizeof(szuncompressed));
+	if (szexpected == 0) {
+		szexpected = le32_to_cpu(szuncompressed);
+	} else if (szuncompressed != (u32)szexpected) {
+		printf("size of %llx doesn't match trailer low bits %x\n",
+		       szexpected, szuncompressed);
+		return -1;
+	}
+	if (szexpected / dev->blksz > (dev->lba - outblock)) {
+		printf("%s: uncompressed size %llu exceeds device size\n",
+		       __func__, szexpected);
+		return -1;
+	}
+
+	gzwrite_progress_init(szexpected);
+
+	s.zalloc = gzalloc;
+	s.zfree = gzfree;
+
+	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 = payload_size+8;
+	writebuf = (unsigned char *)malloc(szwritebuf);
+
+	/* decompress until deflate stream ends or end of file */
+	do {
+		if (s.avail_in == 0) {
+			printf("%s: weird termination with result %d\n",
+			       __func__, r);
+			break;
+		}
+
+		/* run inflate() on input until output buffer not full */
+		do {
+			unsigned long blocks_written;
+			int numfilled;
+			lbaint_t writeblocks;
+
+			s.avail_out = szwritebuf;
+			s.next_out = writebuf;
+			r = inflate(&s, Z_SYNC_FLUSH);
+			if ((r != Z_OK) &&
+			    (r != Z_STREAM_END)) {
+				printf("Error: inflate() returned %d\n", r);
+				goto out;
+			}
+			numfilled = szwritebuf - s.avail_out;
+			crc = crc32(crc, writebuf, numfilled);
+			totalfilled += numfilled;
+			if (numfilled < szwritebuf) {
+				writeblocks = (numfilled+dev->blksz-1)
+						/ dev->blksz;
+				memset(writebuf+numfilled, 0,
+				       dev->blksz-(numfilled%dev->blksz));
+			} else {
+				writeblocks = blksperbuf;
+			}
+
+			gzwrite_progress(iteration++,
+					 totalfilled,
+					 szexpected);
+			blocks_written = dev->block_write(dev->dev,
+							  outblock,
+							  writeblocks,
+							  writebuf);
+			outblock += blocks_written;
+			if (ctrlc()) {
+				puts("abort\n");
+				goto out;
+			}
+			WATCHDOG_RESET();
+		} while (s.avail_out == 0);
+		/* done when inflate() says it's done */
+	} while (r != Z_STREAM_END);
+
+	if ((szexpected != totalfilled) ||
+	    (crc != expected_crc))
+		r = -1;
+	else
+		r = 0;
+
+out:
+	gzwrite_progress_finish(r, totalfilled, szexpected,
+				expected_crc, crc);
+	free(writebuf);
+	inflateEnd(&s);
+
+	return r;
+}
+
 /*
  * Uncompress blocks compressed with zlib without headers
  */
@@ -81,7 +273,7 @@  int zunzip(void *dst, int dstlen, unsigned char *src, unsigned long *lenp,
 
 	r = inflateInit2(&s, -MAX_WBITS);
 	if (r != Z_OK) {
-		printf ("Error: inflateInit2() returned %d\n", r);
+		printf("Error: inflateInit2() returned %d\n", r);
 		return -1;
 	}
 	s.next_in = src + offset;