- Remove redundant softc members for RIDs.
- Change some softc members to be unsigned where more appropriate.
- Add some missing const.
- Remove support for mmap(2)'ing VGA I/O as it was broken [1] and
not required by X.Org anyway.
- Fix some confusion between bus, physical and virtual addresses
which mostly consisted in using members of struct video_adapter
inappropriately but wasn't fatal except for the regular framebuffer
mmap(2)'ing.
- Remove redundant bzero(9)'ing of the softc.
- Don't map the framebuffer twice in case the firmware has already
mapped it as besides wasting resources this isn't possible with
all MMUs. This is a bit tricky as a) just because the firmware
provides a property with a virtual address doesn't mean it's
actually mapped (but typically is when the framebuffer is the
console) and b) the firmware doesn't necessarily map the it with
the same byteorder as we do. This make machfb(4) work on machines
with cheetah-class MMUs (including X.Org).
Reported by: Michael Plass [1]
MFC after: 3 days
f880062633