procd: more nand takeover fixes

if the initramfs kernel and payload were flashed in one block, the payload might not be at the start of the ubi partition due to bad blocks inside the kernel partition.

Signed-off-by: John Crispin <blogic@openwrt.org>

SVN-Revision: 43513

package/system/procd/files/nand-preinit.sh

@@ -4,14 +4,18 @@
 nand_takeover() {
 	. /lib/upgrade/nand.sh
 	mtd=$(find_mtd_index "$CI_UBIPART")
-	local file_type="$(identify $2)"
-	mtd -l 400 dump /dev/mtd$mtd > /tmp/takeover.hdr
-	MAGIC=$(dd if=/tmp/takeover.hdr bs=1 skip=261 count=5 2> /dev/null)
-	SIZE=$(printf "%d" 0x$(dd if=/tmp/takeover.hdr bs=4 count=1 2> /dev/null | hexdump -v -n 4 -e '1/1 "%02x"'))
-	[ "$MAGIC" = "ustar" ] && {
-		mtd -l $((SIZE + 4))  dump /dev/mtd$mtd | dd bs=1 skip=4 of=/tmp/sysupgrade.tar
-		nand_do_upgrade_stage2 /tmp/sysupgrade.tar
-	}
+	esize=$(cat /proc/mtd | grep mtd$mtd |cut -d" " -f 3)
+	[ -z "$esize" ] && return 1
+	esize=$(printf "%d" 0x$esize)
+	for a in `seq 0 64`; do
+		mtd -o $((a * esize)) -l 400 dump /dev/mtd$mtd > /tmp/takeover.hdr
+		MAGIC=$(dd if=/tmp/takeover.hdr bs=1 skip=261 count=5 2> /dev/null)
+		SIZE=$(printf "%d" 0x$(dd if=/tmp/takeover.hdr bs=4 count=1 2> /dev/null | hexdump -v -n 4 -e '1/1 "%02x"'))
+		[ "$MAGIC" = "ustar" ] && {
+			mtd -o $((a * esize)) -l $((SIZE + 4)) dump /dev/mtd$mtd | dd bs=1 skip=4 of=/tmp/sysupgrade.tar
+			nand_do_upgrade_stage2 /tmp/sysupgrade.tar
+		}
+	done
 }
 
 boot_hook_add initramfs nand_takeover