Hi Nathan,

> Plenty of PCI devices aren't going to have OF entries, and don't
> really need them. As long as the system knows the mapping from system
> memory to PCI address and IO space, all of the necessary information
> can be derived from the BARs of the PCI device themselves.

Yes, but OF is responsible for doing initial configuration transactions
with the devices and assigning them address space on boot up. The
purpose of bus_space_write_* and mapiodev is to shield the higher levels
from having to be concerned about the details of the memory layout, but
isn't it still useful to have access to OF to make sure the device is
optimized for the architecture, especially when using devices that are
native to the architecture?

tim