diff --git a/package/boot/grub2/Makefile b/package/boot/grub2/Makefile
index 8df4eb6e39..c8d6db2524 100644
--- a/package/boot/grub2/Makefile
+++ b/package/boot/grub2/Makefile
@@ -181,7 +181,7 @@ define Package/grub2-efi-arm/install
 		-c $(PKG_BUILD_DIR)/grub-early.cfg \
 		-o $(STAGING_DIR_IMAGE)/grub2/boot$(if $(CONFIG_aarch64),aa64,arm).efi \
 		boot chain configfile fat linux ls part_gpt part_msdos reboot search \
-		search_fs_uuid search_label serial efi_gop lsefi minicmd ext2
+		search_fs_uuid search_label serial test efi_gop lsefi minicmd ext2
 	$(STAGING_DIR_HOST)/bin/grub-mkimage \
 		-d $(PKG_BUILD_DIR)/grub-core \
 		-p /boot/grub \
diff --git a/target/linux/armsr/base-files/etc/board.d/99-default_network b/target/linux/armsr/base-files/etc/board.d/99-default_network
new file mode 100755
index 0000000000..830d1d998b
--- /dev/null
+++ b/target/linux/armsr/base-files/etc/board.d/99-default_network
@@ -0,0 +1,29 @@
+#!/bin/sh
+#
+# Copyright (C) 2013-2015 OpenWrt.org
+#
+
+. /lib/functions/uci-defaults.sh
+
+board_config_update
+
+json_is_a network object && exit 0
+
+ETHNUM=$(ls /sys/class/net/ | grep eth | wc -l)
+[ $ETHNUM == 0 ] && exit 0
+
+if [ $ETHNUM == 1 ]; then
+    ucidef_set_interface_lan 'eth0' 'dhcp'
+else
+    [ -d /sys/class/net/eth0 ] && ucidef_set_interface_wan 'eth0'
+    interface=""
+    for eth_interface in /sys/class/net/eth*
+    do
+        [ "$eth_interface" != "/sys/class/net/eth0" ] && interface=$interface" "${eth_interface##*/}
+    done
+    [ -n "$interface" ] && ucidef_set_interface_lan "$interface"
+fi
+
+board_config_flush
+
+exit 0
diff --git a/target/linux/armsr/base-files/lib/upgrade/platform.sh b/target/linux/armsr/base-files/lib/upgrade/platform.sh
index e72c6955e5..4c940e399c 100644
--- a/target/linux/armsr/base-files/lib/upgrade/platform.sh
+++ b/target/linux/armsr/base-files/lib/upgrade/platform.sh
@@ -1,6 +1,6 @@
 # SPDX-License-Identifier: GPL-2.0-or-later
 
-RAMFS_COPY_BIN="/usr/sbin/blkid"
+RAMFS_COPY_BIN="/usr/sbin/blkid readlink"
 
 platform_check_image() {
 	local board=$(board_name)
@@ -33,21 +33,6 @@ platform_check_image() {
 	fi
 }
 
-platform_copy_config() {
-	local partdev parttype=ext4
-
-	if export_partdevice partdev 1; then
-		part_magic_fat "/dev/$partdev" && parttype=vfat
-		mount -t $parttype -o rw,noatime "/dev/$partdev" /mnt
-		cp -af "$UPGRADE_BACKUP" "/mnt/$BACKUP_FILE"
-		umount /mnt
-	else
-		v "ERROR: Unable to find partition to copy config data to"
-	fi
-
-	sleep 5
-}
-
 # To avoid writing over any firmware
 # files (e.g ubootefi.var or firmware/X/ aka EBBR)
 # Copy efi/openwrt and efi/boot from the new image
@@ -97,16 +82,20 @@ platform_do_upgrade() {
 
 	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
 
 		v "Extract boot sector from the image"
 		get_image_dd "$1" of=/tmp/image.bs count=63 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
@@ -131,11 +120,17 @@ 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 $part; then
 			v "Writing image to /dev/$partdev..."
 			if [ "$part" = "1" ]; then
 				platform_do_upgrade_efi_system_partition \
 					$1 $partdev $start $size || return 1
+			elif [ "$part" -eq 3 ]; then
+				echo "RESET000" | dd of="/dev/$partdev" bs=512 count=1 conv=sync,fsync 2>/dev/null
 			else
 				v "Normal partition, doing DD"
 				get_image_dd "$1" of="/dev/$partdev" ibs=512 obs=1M skip="$start" \
diff --git a/target/linux/armsr/image/Makefile b/target/linux/armsr/image/Makefile
index b34c1f16e7..11201de13a 100644
--- a/target/linux/armsr/image/Makefile
+++ b/target/linux/armsr/image/Makefile
@@ -18,10 +18,10 @@ endif
 
 GRUB_SERIAL:=$(call qstrip,$(CONFIG_TARGET_SERIAL))
 
+GRUB_CONSOLE_CMDLINE += console=$(GRUB_SERIAL),$(CONFIG_GRUB_BAUDRATE)n8$(if $(CONFIG_GRUB_FLOWCONTROL),r,)
 GRUB_SERIAL_CONFIG := serial --unit=0 --speed=$(CONFIG_GRUB_BAUDRATE) --word=8 --parity=no --stop=1 --rtscts=$(if $(CONFIG_GRUB_FLOWCONTROL),on,off)
-GRUB_TERMINALS += serial
 
-GRUB_TERMINAL_CONFIG := terminal_input $(GRUB_TERMINALS); terminal_output $(GRUB_TERMINALS)
+GRUB_TERMINAL_CONFIG := terminal_input $(GRUB_TERMINALS); terminal_output $(GRUB_TERMINALS) $(if $(GRUB_SERIAL),serial,)
 
 ROOTPART:=$(call qstrip,$(CONFIG_TARGET_ROOTFS_PARTNAME))
 ROOTPART:=$(if $(ROOTPART),$(ROOTPART),PARTUUID=$(IMG_PART_SIGNATURE)-02)
@@ -58,6 +58,7 @@ define Build/grub-config
 		-e 's#@TERMINAL_CONFIG@#$(strip $(GRUB_TERMINAL_CONFIG))#g' \
 		-e 's#@ROOTPART@#root=$(ROOTPART) rootwait#g' \
 		-e 's#@GPT_ROOTPART@#root=$(GPT_ROOTPART) rootwait#g' \
+		-e 's#@BOOTOPTS@#$(BOOTOPTS)#g' \
 		-e 's#@CMDLINE@#$(BOOTOPTS) $(GRUB_CONSOLE_CMDLINE)#g' \
 		-e 's#@TIMEOUT@#$(GRUB_TIMEOUT)#g' \
 		-e 's#@TITLE@#$(GRUB_TITLE)#g' \
diff --git a/target/linux/armsr/image/grub-efi.cfg b/target/linux/armsr/image/grub-efi.cfg
index fd329e41e0..7e3b53221b 100644
--- a/target/linux/armsr/image/grub-efi.cfg
+++ b/target/linux/armsr/image/grub-efi.cfg
@@ -3,12 +3,25 @@
 
 set default="0"
 set timeout="@TIMEOUT@"
+set rompart="@GPT_ROOTPART@"
+set kernel="/efi/openwrt/@KERNEL_NAME@"
+
+if [ ! -e $kernel ]; then
+	search --set=root --label kernel
+fi
 
 menuentry "@TITLE@" {
-	search --set=root --label kernel
-	linux /efi/openwrt/@KERNEL_NAME@ @GPT_ROOTPART@ @CMDLINE@ noinitrd
+	linux $kernel $rompart @BOOTOPTS@ noinitrd
 }
 menuentry "@TITLE@ (failsafe)" {
-	search --set=root --label kernel
-	linux /efi/openwrt/@KERNEL_NAME@ failsafe=true @GPT_ROOTPART@ @CMDLINE@ noinitrd
+	linux $kernel failsafe=true $rompart @BOOTOPTS@ noinitrd
+}
+menuentry "@TITLE@ (ttyS0)" {
+	linux $kernel $rompart @CMDLINE@ noinitrd
+}
+menuentry "@TITLE@ (ttyAMA0)" {
+	linux $kernel $rompart @BOOTOPTS@ console=ttyAMA0,115200n8 noinitrd $cmdline_ext
+}
+menuentry "@TITLE@ (ttyUSB0)" {
+	linux $kernel $rompart @BOOTOPTS@ console=ttyUSB0,115200n8 noinitrd $cmdline_ext
 }