> From: Simon Burge <simonb@netbsd.org>
> Ross Harvey wrote:
>
> > Yes, to run XFree86 you choose one of:
> > 
> > [[ ... deleted ... ]]
> > 
> > 	(2) Do a horrible, disgusting kludge to fake up inb(), outb(),
> > 	    (gee, what do they mean when you have more than one bus?)
> > 	    and device mapping in order to generally rape our otherwise
> > 	    nice device abstractions and flatten them out.
> > 
> > [[ ... deleted ... ]]
> > 
> > Option (2) was avoided previously because of purism (at least in part, I
> > think) but for the record: I've made the decision that it is now OK for
> > NetBSD/alpha to go this way. (Hehe.)
>
> The portmeister speaks :-)
>
> > FreeBSD chose (2), which doesn't even look very hard given the rather small
> > size of their diff. It's certainly even easier to do again, given that the
> > diff is public. I'm thinking that we could have a separate configuration
> > program (maybe options to wsconsctl(8)) that would identify which bus and
> > which device would be the target of the inb/outb/devmap compatibility
> > interface.
>
> Do you have a handy pointer to the FreeBSD diffs?

See: http://www.freebsd.org/~dfr/

> > At this point, I think we really must go with (2). (BTW, note that a
> > partial-(2) has become easier recently, as BWX-capable alphas are a larger
> > fraction of our user base these days.)
>
> This is 21164 and up, right?

No, bwx came in at the halfway point at the ev5 -> ev56 step, aka as the
21164 -> 21164a step.

> > Hope this helps. I'll volunteer to help with the kernel work and with any
> > needed alpha assembly or xf86-assembly-conversion.
>
> I've not looked at alpha much, but if anything I'm more of a MIPS person
> so I'll probably find alpha easier to understand that x86 :-)

Having worked with both alpha and mips, all I can say is "at least alpha
is nicely documented".  Developers should get the Alpha Architecture Reference
Manual. (Not the handbook.)  See:

	ftp://ftp.netbsd.org/pub/NetBSD/misc/dec-docs/index.html#alpha-arch+sw

You might try to get the brown/red third edition, though, and not the green
second edition, but they aren't too different.

	ross.harvey@computer.org