RFC: mips target support for Juniper Apollo

[Jim Wilson <wilson at specifixinc dot com>]

Here is a patch which adds the Juniper Apollo processor to the mips
toolchain.

The Juniper Apollo is a bit of an oddball target.  It is based on the
r4000, but is a 32-bit part, so the only thing that really looks like
the r4000 is the coprocessor 0 support.  It adds a few instructions
which are handled by this patch.  It removed a few instructions which I
haven't tried to handle here.  I didn't see a mechanism for this.

It is also missing branch delay slots.  This is a serious
incompatibility which requires having separate magic numbers for Apollo,
as it won't be compatible with anything else.

I'm concerned about the choice of the magic numbers.  I don't want to
conflict with number that Red Hat is using, but only a Red Hat employee
can check that.  This primarily means E_MIPS_MACH_APOLLO in the
include/elf/mips.h file.

I have an initial as yet unsubmitted gcc port for the processor, but I
do not have a simulator port yet, so this is still a bit of a work in
progress.  I think the binutils port is simple enough that it reasonable
to submit it at this time even though I can't fully test it against gcc
yet.

I am looking for comments, particularly from MIPS maintainers, as to
whether the patch is reasonable, whether anything should be changed,
etc.
-- 
Jim Wilson, GNU Tools Support, http://www.SpecifixInc.com

Attachment: patch.apollo
Description: Text document