FreeBSD and Thinkpad-specific keys and indicators

Thinkpad laptops, e.g. mine Thinkpad X220, has a lot of functional keys. Some of them work without any problems — they are passed by the underlying kernel to the X server and it recognizes them as a usual key symbols: XF86AudioMute, XF86AudioRaiseVolume, XF86AudioNext, etc. But some special keys are not passed to the X server from the underlying OS layers. Screenshot with functional keys from Thinkpad X220 manual For example, there are: ThinkVantage key. Fn+F2 key — it should lock the computer. Fn+F3 key — it should enable energy preservation mode by default. Fn+F5 — toggles state of wireless devices in the system. Fn+Space — enables screen magnifier. Round key at the left of the ThinkVantage key — it should toggle the microphone state. But these keys are still visible by the OS (thanks to the acpi_ibm kernel module!) and the devd daemon receives the corresponding events when user presses the mentioned functional key. So, it is possible to use this daemon to map these keys for…