openwrt/package/hotplug2/files/hotplug2.rules

$include /etc/hotplug2-init.rules

SUBSYSTEM ~~ (net|button|usb) {
	exec /sbin/hotplug-call %SUBSYSTEM%;
}

DEVICENAME ~~ (watchdog) {
	exec /sbin/watchdog -t 10 /dev/watchdog;
	next
}