PERFORCE change 28827 for review

[Robert Drehmel]

[Moving to mips at FreeBSD]

Hello Juli,

> $PLATFORM is best spelled $MACHINE or $TARGET_MACHINE depending on
> the context (in this one it's $MACHINE), wouldn't you say?

I just took the next best name grep revealed to me
(from sys/conf/Makefile.mips); you are right, I will
change the name of the variable to MACHINE.

At this stage, I just want to get it working.  I think the two
ARC libraries (in sys/dev and sys/boot) we currently have should
be merged later, at least the ARC data structure definitions
which currently reside in dev/arcbios/arcbios.h and
boot/arc/include/arc(types|funcs).h.
(They need to be changed anyway - some of the structures have a
wrong layout for the SGI Octane I am testing on, and that requires
tedious trail-and-error sequences.  I did not find any documentation
about the specialties of the SGI ARC.)
My plan was to start using (and modifying) the structures and
constants imported from NetBSD, in new ARC code, mainly to enable
code-sharing.  This is ugly as long as the `other' headers
(the original boot/arc/include files) are used in the same library,
but should turn out to be cleaner after every piece of ARC code
uses dev/arcbios/arcbios.h.  Of couse, this is only theoretical
and I need to ask the alpha people for their opinion first.

What do you think?

Let me reply to your other mail because of the knotted topics:

> Unfortunately, 'sgimips' is not fine-grained enough here.  Need to
> have a tunable to build it for other SGI machines, where that
> location may not be right at all.  Do you have any particular
> stylistic feelings on how to do that?

I guess we should stay compatible with NetBSD.  If they are not
distinguishing SGI machines on that level, we could use 'sgimips'
and e.g.  'sgimips_ip32' for more granularity (or just 'ip32'?).

ciao,
-robert