diff --git a/target/linux/bcm27xx/base-files/lib/preinit/79_move_config b/target/linux/bcm27xx/base-files/lib/preinit/79_move_config
index c9fb59a64f..db5bf93b62 100644
--- a/target/linux/bcm27xx/base-files/lib/preinit/79_move_config
+++ b/target/linux/bcm27xx/base-files/lib/preinit/79_move_config
@@ -2,16 +2,20 @@
 
 . /lib/upgrade/common.sh
 
-BOOTPART=/dev/mmcblk0p1
-
 move_config() {
-	if [ -b $BOOTPART ]; then
+	local partdev
+
+	export_bootdevice && export_partdevice partdev 1 || {
+		partdev=mmcblk0p1
+	}
+
+	if [ -b "/dev/$partdev" ]; then
 		insmod nls_cp437
 		insmod nls_iso8859-1
 		insmod fat
 		insmod vfat
 		mkdir -p /boot
-		mount -t vfat -o rw,noatime $BOOTPART /boot
+		mount -t vfat -o rw,noatime /dev/$partdev /boot
 		[ -f "/boot/$BACKUP_FILE" ] && mv -f "/boot/$BACKUP_FILE" /
 	fi
 }
diff --git a/target/linux/bcm27xx/base-files/lib/upgrade/platform.sh b/target/linux/bcm27xx/base-files/lib/upgrade/platform.sh
index a48b7cc08a..956bc1c788 100644
--- a/target/linux/bcm27xx/base-files/lib/upgrade/platform.sh
+++ b/target/linux/bcm27xx/base-files/lib/upgrade/platform.sh
@@ -90,7 +90,7 @@ platform_copy_config() {
 
 	if export_partdevice partdev 1; then
 		mkdir -p /boot
-		[ -f /boot/kernel.img ] || mount -t vfat -o rw,noatime "/dev/$partdev" /boot
+		[ -f "/boot/kernel*.img" ] || mount -t vfat -o rw,noatime "/dev/$partdev" /boot
 		cp -af "$UPGRADE_BACKUP" "/boot/$BACKUP_FILE"
 		tar -C / -zxvf "$UPGRADE_BACKUP" boot/cmdline.txt boot/config.txt
 		sync
diff --git a/target/linux/bcm27xx/image/gen_rpi_sdcard_img.sh b/target/linux/bcm27xx/image/gen_rpi_sdcard_img.sh
index 5e8fb2769c..488a3517c7 100755
--- a/target/linux/bcm27xx/image/gen_rpi_sdcard_img.sh
+++ b/target/linux/bcm27xx/image/gen_rpi_sdcard_img.sh
@@ -1,10 +1,11 @@
 #!/bin/sh
 
-set -x
-[ $# -eq 5 ] || {
+set -e -x
+
+if [ $# -ne 5 ]; then
     echo "SYNTAX: $0 <file> <bootfs image> <rootfs image> <bootfs size> <rootfs size>"
     exit 1
-}
+fi
 
 OUTPUT="$1"
 BOOTFS="$2"
@@ -12,18 +13,16 @@ ROOTFS="$3"
 BOOTFSSIZE="$4"
 ROOTFSSIZE="$5"
 
+align=4096
 head=4
+kernel_type=c
+rootfs_type=83
 sect=63
 
-set $(ptgen -o $OUTPUT -h $head -s $sect -l 4096 -t c -p ${BOOTFSSIZE}M -t 83 -p ${ROOTFSSIZE}M)
+set $(ptgen -o $OUTPUT -h $head -s $sect -l $align -t $kernel_type -p ${BOOTFSSIZE}M -t $rootfs_type -p ${ROOTFSSIZE}M)
 
 BOOTOFFSET="$(($1 / 512))"
-BOOTSIZE="$(($2 / 512))"
 ROOTFSOFFSET="$(($3 / 512))"
-ROOTFSSIZE="$(($4 / 512))"
 
 dd bs=512 if="$BOOTFS" of="$OUTPUT" seek="$BOOTOFFSET" conv=notrunc
 dd bs=512 if="$ROOTFS" of="$OUTPUT" seek="$ROOTFSOFFSET" conv=notrunc
-
-
-