openwrt/target/linux/layerscape/base-files/lib/preinit/02_sysinfo_fixup

do_sysinfo_layerscape_fixup() {
	[ -e /tmp/sysinfo/board_name ] || return
	[ -e /proc/cmdline ] || return
	cmdline=$(strings /proc/cmdline)
	case "${cmdline}" in
		*root=/dev/mmcblk*)
			board="$(strings /tmp/sysinfo/board_name)-sdboot"
			echo ${board} > /tmp/sysinfo/board_name
		;;
	esac
}

boot_hook_add preinit_main do_sysinfo_layerscape_fixup