I would like to keep my kernel at a minimum, and thus I'd like to know
which parts of it should be built in order for bluetooth to work.
ng_ubt(4) - driver for usb bluetooth devices
ng_bluetooth(4) - generic code
ng_hci(4) - bluetooth host controller interface (hci)
ng_l2cap(4) - bluetooth link layer control and adaptation protocol (l2cap)
ng_btsocket(4) - bluetooth sockets/rfcomm
all of this of course depends on netgraph(4) framework