procd: add helper for starting NAND sysupgrade

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>

SVN-Revision: 45339

package/system/procd/files/nand.sh

@@ -353,3 +353,12 @@ nand_do_platform_check() {
 
 	return 0
 }
+
+# Start NAND upgrade process
+#
+# $(1): file to be used for upgrade
+nand_do_upgrade() {
+	echo -n $1 > /tmp/sysupgrade-nand-path
+	cp /sbin/upgraded /tmp/
+	nand_upgrade_stage1
+}