+platform_nand_pre_upgrade() {
+ local board=$(board_name)
+
+ case "$board" in
+ rb*)
+ CI_KERNPART=none
+ local fw_mtd=$(find_mtd_part kernel)
+ fw_mtd="${fw_mtd/block/}"
+ [ -n "$fw_mtd" ] || return
+ mtd erase kernel
+ tar xf "$1" sysupgrade-routerboard/kernel -O | nandwrite -o "$fw_mtd" -
+ ;;
+ wi2a-ac200i)
+ case "$(fw_printenv -n dualPartition)" in
+ imgA)
+ fw_setenv dualPartition imgB
+ fw_setenv ActImg NokiaImageB
+ ;;
+ imgB)
+ fw_setenv dualPartition imgA
+ fw_setenv ActImg NokiaImageA
+ ;;
+ esac
+ ubiblock -r /dev/ubiblock0_0 2>/dev/null >/dev/null
+ rm -f /dev/ubiblock0_0
+ ubidetach -d 0 2>/dev/null >/dev/null
+ CI_UBIPART=ubi_alt
+ CI_KERNPART=kernel_alt
+ ;;
+ esac
+}
+