unzip: add gzwrite command to write compressed image to block device

Add gzwrite command to write gzip-compressed images to block devices.

Input must be gzip-compressed according to RFC1952, since the crc
and file size in the trailer will be confirmed during operation.
The decompressed file size must be specified on the command line
for images with decompressed sizes >= 4GiB because the trailer
only contains the low 32 bits of the original file size.

Signed-off-by: Eric Nelson <eric.nelson@boundarydevices.com>

common/cmd_unzip.c

@@ -39,3 +39,50 @@ U_BOOT_CMD(
 	"unzip a memory region",
 	"srcaddr dstaddr [dstsize]"
 );
+
+static int do_gzwrite(cmd_tbl_t *cmdtp, int flag,
+		      int argc, char * const argv[])
+{
+	block_dev_desc_t *bdev;
+	int ret;
+	unsigned char *addr;
+	unsigned long length;
+	unsigned long writebuf = 1<<20;
+	u64 startoffs = 0;
+	u64 szexpected = 0;
+
+	if (argc < 5)
+		return CMD_RET_USAGE;
+	ret = get_device(argv[1], argv[2], &bdev);
+	if (ret < 0)
+		return CMD_RET_FAILURE;
+
+	addr = (unsigned char *)simple_strtoul(argv[3], NULL, 16);
+	length = simple_strtoul(argv[4], NULL, 16);
+
+	if (5 < argc) {
+		writebuf = simple_strtoul(argv[5], NULL, 16);
+		if (6 < argc) {
+			startoffs = simple_strtoull(argv[6], NULL, 16);
+			if (7 < argc)
+				szexpected = simple_strtoull(argv[7],
+							     NULL, 16);
+		}
+	}
+
+	ret = gzwrite(addr, length, bdev, writebuf, startoffs, szexpected);
+
+	return ret ? CMD_RET_FAILURE : CMD_RET_SUCCESS;
+}
+
+U_BOOT_CMD(
+	gzwrite, 8, 0, do_gzwrite,
+	"unzip and write memory to block device",
+	"<interface> <dev> <addr> length [wbuf=1M [offs=0 [outsize=0]]]\n"
+	"\twbuf is the size in bytes (hex) of write buffer\n"
+	"\t\tand should be padded to erase size for SSDs\n"
+	"\toffs is the output start offset in bytes (hex)\n"
+	"\toutsize is the size of the expected output (hex bytes)\n"
+	"\t\tand is required for files with uncompressed lengths\n"
+	"\t\t4 GiB or larger\n"
+);