diff --git a/package/base-files/files/sbin/sysupgrade b/package/base-files/files/sbin/sysupgrade
index 3a5087a0c8..935d08048e 100755
--- a/package/base-files/files/sbin/sysupgrade
+++ b/package/base-files/files/sbin/sysupgrade
@@ -2,8 +2,10 @@
 
 . /lib/functions.sh
 . /lib/functions/system.sh
+. /usr/share/libubox/jshn.sh
 
 # initialize defaults
+export MTD_ARGS=""
 export MTD_CONFIG_ARGS=""
 export INTERACTIVE=0
 export VERBOSE=1
@@ -190,9 +192,6 @@ add_overlayfiles() {
 	return 0
 }
 
-# hooks
-sysupgrade_image_check="fwtool_check_signature fwtool_check_image platform_check_image"
-
 if [ $SAVE_OVERLAY = 1 ]; then
 	[ ! -d /overlay/upper/etc ] && {
 		echo "Cannot find '/overlay/upper/etc', required for '-c'" >&2
@@ -249,7 +248,7 @@ do_save_conffiles() {
 
 	v "Saving config files..."
 	[ "$VERBOSE" -gt 1 ] && TAR_V="v" || TAR_V=""
-	tar c${TAR_V}zpf "$conf_tar" -T "$CONFFILES" 2>/dev/null
+	tar c${TAR_V}zf "$conf_tar" -T "$CONFFILES" 2>/dev/null
 	if [ "$?" -ne 0 ]; then
 		echo "Failed to create the configuration backup."
 		rm -f "$conf_tar"
@@ -315,20 +314,19 @@ case "$IMAGE" in
 		;;
 esac
 
-export ARGV="$IMAGE"
-export ARGC=1
-
-for check in $sysupgrade_image_check; do
-	( $check "$IMAGE" ) || {
-		if [ $FORCE -eq 1 ]; then
-			echo "Image check '$check' failed but --force given - will update anyway!" >&2
-			break
-		else
-			echo "Image check '$check' failed." >&2
-			exit 1
-		fi
-	}
-done
+json_load "$(/usr/libexec/validate_firmware_image "$IMAGE")" || {
+	echo "Failed to check image"
+	exit 1
+}
+json_get_var valid "valid"
+[ "$valid" -eq 0 ] && {
+	if [ $FORCE -eq 1 ]; then
+		echo "Image check failed but --force given - will update anyway!" >&2
+	else
+		echo "Image check failed." >&2
+		exit 1
+	fi
+}
 
 if [ -n "$CONF_IMAGE" ]; then
 	case "$(get_magic_word $CONF_IMAGE cat)" in
@@ -353,24 +351,27 @@ if [ $TEST -eq 1 ]; then
 	exit 0
 fi
 
-if [ $SAVE_PARTITIONS -eq 0 ]; then
-	touch /tmp/sysupgrade.always.overwrite.bootdisk.partmap
-else
-	rm -f /tmp/sysupgrade.always.overwrite.bootdisk.partmap
-fi
-
 install_bin /sbin/upgraded
 v "Commencing upgrade. Closing all shell sessions."
 
-COMMAND='. /lib/functions.sh; include /lib/upgrade; do_upgrade_stage2'
+COMMAND='/lib/upgrade/do_stage2'
 
 if [ -n "$FAILSAFE" ]; then
 	printf '%s\x00%s\x00%s' "$RAM_ROOT" "$IMAGE" "$COMMAND" >/tmp/sysupgrade
 	lock -u /tmp/.failsafe
 else
+	force_attr=""
+	[ $FORCE -eq 1 ] && force_attr="\"force\": true,"
+	backup_attr=""
+	[ $SAVE_CONFIG -eq 1 ] && backup_attr="\"backup\": $(json_string $CONF_TAR),"
 	ubus call system sysupgrade "{
 		\"prefix\": $(json_string "$RAM_ROOT"),
 		\"path\": $(json_string "$IMAGE"),
-		\"command\": $(json_string "$COMMAND")
+		$force_attr
+		$backup_attr
+		\"command\": $(json_string "$COMMAND"),
+		\"options\": {
+			\"save_partitions\": $SAVE_PARTITIONS
+		}
 	}"
 fi