For anyone interested here are some more apple docs on porting drivers...

developer.apple.com/documentation/Porting/Conceptual/PortingDrivers/intro/chapter_1_section_1.html

developer.apple.com/documentation/Darwin/Conceptual/KEXTConcept/KEXTConceptIOKit/hello_iokit.html#//apple_ref/doc/uid/20002366


Sounds like fun, I've been wanting to play around in Xcode. Although I would probably go into intellisense withdrawal.