diff --git a/target/linux/rockchip/armv8/base-files/lib/preinit/79_move_config b/target/linux/rockchip/armv8/base-files/lib/preinit/79_move_config
deleted file mode 100644
index 96e636ee81..0000000000
--- a/target/linux/rockchip/armv8/base-files/lib/preinit/79_move_config
+++ /dev/null
@@ -1,16 +0,0 @@
-move_config() {
-	local partdev
-
-	. /lib/upgrade/common.sh
-
-	if export_bootdevice && export_partdevice partdev 1; then
-		if mount -o rw,noatime "/dev/$partdev" /mnt; then
-			if [ -f "/mnt/$BACKUP_FILE" ]; then
-				mv -f "/mnt/$BACKUP_FILE" /
-			fi
-			umount /mnt
-		fi
-	fi
-}
-
-boot_hook_add preinit_mount_root move_config
diff --git a/target/linux/rockchip/armv8/base-files/lib/upgrade/platform.sh b/target/linux/rockchip/armv8/base-files/lib/upgrade/platform.sh
index 49a969f410..003ff4d1bf 100644
--- a/target/linux/rockchip/armv8/base-files/lib/upgrade/platform.sh
+++ b/target/linux/rockchip/armv8/base-files/lib/upgrade/platform.sh
@@ -1,12 +1,17 @@
+# modified by jjm2473
+# 1. keep overlay partition when upgrade
+# 2. reset rom uuid in ext_overlay (aka sandbox mode) when upgrade (stage2:istoreos_pre_upgrade)
+
 REQUIRE_IMAGE_METADATA=1
 
 platform_check_image() {
 	local diskdev partdev diff
 
 	export_bootdevice && export_partdevice diskdev 0 || {
-		echo "Unable to determine upgrade device"
+		v "Unable to determine upgrade device"
 		return 1
 	}
+	[ "$SAVE_CONFIG" -eq 1 ] && return 0
 
 	get_partitions "/dev/$diskdev" bootdisk
 
@@ -21,47 +26,47 @@ platform_check_image() {
 	rm -f /tmp/image.bs /tmp/partmap.bootdisk /tmp/partmap.image
 
 	if [ -n "$diff" ]; then
-		echo "Partition layout has changed. Full image will be written."
+		v "Partition layout has changed. Full image will be written."
 		ask_bool 0 "Abort" && exit 1
 		return 0
 	fi
 }
 
-platform_copy_config() {
-	local partdev
-
-	if export_partdevice partdev 1; then
-		mount -o rw,noatime "/dev/$partdev" /mnt
-		cp -af "$UPGRADE_BACKUP" "/mnt/$BACKUP_FILE"
-		umount /mnt
-	fi
-}
-
 platform_do_upgrade() {
 	local diskdev partdev diff
 
 	export_bootdevice && export_partdevice diskdev 0 || {
-		echo "Unable to determine upgrade device"
+		v "Unable to determine upgrade device"
 		return 1
 	}
 
 	sync
 
-	if [ "$UPGRADE_OPT_SAVE_PARTITIONS" = "1" ]; then
-		get_partitions "/dev/$diskdev" bootdisk
+	if [ "$UPGRADE_OPT_SAVE_PARTITIONS" = "1" -o -n "$UPGRADE_BACKUP" ]; then
+		[ -n "$UPGRADE_BACKUP" ] || get_partitions "/dev/$diskdev" bootdisk
 
 		#extract the boot sector from the image
 		get_image "$@" | dd of=/tmp/image.bs count=1 bs=512b
 
 		get_partitions /tmp/image.bs image
 
-		#compare tables
-		diff="$(grep -F -x -v -f /tmp/partmap.bootdisk /tmp/partmap.image)"
+		if [ -n "$UPGRADE_BACKUP" ]; then
+			#keep overlay partition when upgrade
+			diff=
+		else
+			#compare tables
+			diff="$(grep -F -x -v -f /tmp/partmap.bootdisk /tmp/partmap.image)"
+		fi
 	else
 		diff=1
 	fi
 
 	if [ -n "$diff" ]; then
+		grep /overlay /proc/mounts > /dev/null && {
+			/bin/mount -o noatime,remount,ro /overlay
+			/usr/bin/umount -R -d -l /overlay 2>/dev/null || /bin/umount -l /overlay
+		}
+
 		get_image "$@" | dd of="/dev/$diskdev" bs=4096 conv=fsync
 
 		# Separate removal and addtion is necessary; otherwise, partition 1
@@ -74,15 +79,23 @@ platform_do_upgrade() {
 
 	#iterate over each partition from the image and write it to the boot disk
 	while read part start size; do
+		if [ -n "$UPGRADE_BACKUP" -a "$part" -ge 3 ]; then
+			v "Skip partition $part >= 3 when upgrading"
+			continue
+		fi
 		if export_partdevice partdev $part; then
-			echo "Writing image to /dev/$partdev..."
-			get_image "$@" | dd of="/dev/$partdev" ibs="512" obs=1M skip="$start" count="$size" conv=fsync
+			v "Writing image to /dev/$partdev..."
+			if [ "$part" -eq 3 ]; then
+				echo "RESET000" | dd of="/dev/$partdev" bs=512 count=1 conv=sync,fsync 2>/dev/null
+			else
+				get_image "$@" | dd of="/dev/$partdev" ibs="512" obs=1M skip="$start" count="$size" conv=fsync
+			fi
 		else
-			echo "Unable to find partition $part device, skipped."
+			v "Unable to find partition $part device, skipped."
 		fi
 	done < /tmp/partmap.image
 
 	#copy partition uuid
-	echo "Writing new UUID to /dev/$diskdev..."
+	v "Writing new UUID to /dev/$diskdev..."
 	get_image "$@" | dd of="/dev/$diskdev" bs=1 skip=440 count=4 seek=440 conv=fsync
 }
diff --git a/target/linux/rockchip/image/Makefile b/target/linux/rockchip/image/Makefile
index 5d90ef8cf8..3141adb1fa 100644
--- a/target/linux/rockchip/image/Makefile
+++ b/target/linux/rockchip/image/Makefile
@@ -33,7 +33,7 @@ define Build/pine64-img
 	# http://opensource.rock-chips.com/wiki_Boot_option#Boot_flow
 	#
 	# U-Boot SPL expects the U-Boot ITB to be located at sector 0x4000 (8 MiB) on the MMC storage
-	PADDING=1 $(SCRIPT_DIR)/gen_image_generic.sh \
+	$(SCRIPT_DIR)/gen_image_generic.sh \
 		$@ \
 		$(CONFIG_TARGET_KERNEL_PARTSIZE) $@.boot \
 		$(CONFIG_TARGET_ROOTFS_PARTSIZE) $(IMAGE_ROOTFS) \