LinuxCNC to fpga over spi driver for Beagleboneblack and RaspberryPi for the Pluto-P Board
(http://www.knjn.com/FPGA-Parallel.html).
Further Docs:
http://wiki.linuxcnc.org/cgi-bin/wiki.pl?RaspbianXenomaiBuild
http://www.raspberrypi.org/forums/viewtopic.php?f=37&t=33809
In the meantime parts of the raspi code flows to
"Driver for the Raspberry Pi and the Mesa 7i90HD Anything IO Card over SPI"