ar71xx: Unifi AP Pro sysupgrade patch

The current implementation of mtd will not append the backup
file created by sysupgrade to the correct partition, as mtd will append
the data to first jffs2 partition it finds. As the kernel is also
stored on a jffs2 partition (which resides before the overlay
partition), the data will be appended to this partition.

To fix this problem, a new option

-s <number>             skip the first n bytes when appending data to the jffs2 partiton, defaults to "0"

is added to mtd.

Signed-off-by: Peter Wagner <tripolar@gmx.at>

SVN-Revision: 38807

1 files changed, 12 insertions, 3 deletions

diff --git a/package/system/mtd/src/mtd.c b/package/system/mtd/src/mtd.c
index a660486..2ec02a8 100644
--- a/package/system/mtd/src/mtd.c
+++ b/package/system/mtd/src/mtd.c
@@ -55,6 +55,7 @@ int quiet;
 int no_erase;
 int mtdsize = 0;
 int erasesize = 0;
+int jffs2_skip_bytes=0;
 
 int mtd_open(const char *mtd, bool block)
 {
@@ -339,7 +340,6 @@ resume:
 		fprintf(stderr, "Could not open mtd device: %s\n", mtd);
 		exit(1);
 	}
-
 	if (part_offset > 0) {
 		fprintf(stderr, "Seeking on mtd device '%s' to: %u\n", mtd, part_offset);
 		lseek(fd, part_offset, SEEK_SET);
@@ -379,7 +379,7 @@ resume:
 			continue;
 		}
 
-		if (jffs2file) {
+		if (jffs2file && w >= jffs2_skip_bytes) {
 			if (memcmp(buf, JFFS2_EOF, sizeof(JFFS2_EOF) - 1) == 0) {
 				if (!quiet)
 					fprintf(stderr, "\b\b\b   ");
@@ -503,6 +503,7 @@ static void usage(void)
 	"        -e <device>             erase <device> before executing the command\n"
 	"        -d <name>               directory for jffs2write, defaults to \"tmp\"\n"
 	"        -j <name>               integrate <file> into jffs2 data when writing an image\n"
+	"        -s <number>             skip the first n bytes when appending data to the jffs2 partiton, defaults to \"0\"\n"
 	"        -p                      write beginning at partition offset\n");
 	if (mtd_fixtrx) {
 	    fprintf(stderr,
@@ -560,7 +561,7 @@ int main (int argc, char **argv)
 #ifdef FIS_SUPPORT
 			"F:"
 #endif
-			"frnqe:d:j:p:o:")) != -1)
+			"frnqe:d:s:j:p:o:")) != -1)
 		switch (ch) {
 			case 'f':
 				force = 1;
@@ -574,6 +575,14 @@ int main (int argc, char **argv)
 			case 'j':
 				jffs2file = optarg;
 				break;
+			case 's':
+				errno = 0;
+				jffs2_skip_bytes = strtoul(optarg, 0, 0);
+				if (errno) {
+						fprintf(stderr, "-s: illegal numeric string\n");
+						usage();
+				}
+				break;
 			case 'q':
 				quiet++;
 				break;