There is an ARM Linux version of AROS completed by Michael Schulz. I even donated 5 quid to it myself. Maybe that would be a source of drivers.
https://power2people.org/projects/arm/ indicates that it's only Phase 1 of the bounty if somebody wanted to drum up another bounty, much of the work of a native port to the RasPi is already done.
Update:
AROS Broadway commercial distribution of ARM Aeros hosted on Linux is at
http://www.ares-shop.de/product_info.php?products_id=66 .
