I partialy finished porting of Bluetooth stack from (Open/Net)BSD.
Port include ubt driver, netbt (BT stack), bthub pseudo-dev, and userspace
libs and progs such as libbluetooth(3), libsdp(3) and btconfig(8).
I have some troubles related with unloading module and sometime detaching.
I can't catch this bug. :( But, stack working for my dongle. 
Now I working on porting of another drivers, such as bthid(4), btsco(4),
btuart and etc. with some userspace utils such as btdevctl(8) and
btuartd(4).

If someone want look at, please grab it from
http://griffinslair.by.ru/dfly_bt_kmod.tar.bz2

Port is now very ugly and need more and more work.

And can someone direct me to docs, how develop modules, which can serve as
bus for other drivers?