Debian ports for RiscPC, ARM710, etc.

[Jim Pick <jim@jimpick.com>]

Philip Blundell <pb@nexus.co.uk> writes:

> >Most of the things should work - but on a StrongARM RiscPC only. Since 
> >I've got an ARM710 there'll be no chance using the binary packages on my 
> >system.
> 
> Once everything is working on StrongARM it will be a no-brainer operation to 
> recompile everything with the right CFLAGS for ARM710.  In fact the NetWinder 
> packages won't even work on a StrongARM RiscPC because of the halfword 
> problem.  They should be OK out of the box on an EBSA or similar.

I'm wondering what we should do for the Debian port to support more
machines than just the NetWinder.

Right now, we've built gcc with the --with-cpu=strongarm option, and
we are compiling all the packages with the normal CFLAGS options.
We're using the Corel patched gcc right now, but plan on moving to
Philip's egcs.

So I suppose we are building binaries that use the halfword
instructions.  Is that correct?

In the interests of portability, what would be the performance cost if
we somehow compiled things without the halfword instructions?  Do all
apps benefit, or just some specific ones?  Corel is using them for
their RPM-based distribution, so I have assumed that there is a
significant performance difference.

As Philip says, it would be a no-brainer to create additional
debian-arm distributions which have been compiled to use different
instruction sets, since they can share the same source (actually, all
Debian architectures use the same source).  ie. We could have an
"arm-riscpc" distribution, and maybe even an "arm-710" (??)
distribution for older machines.  Of course, this is only going to
happen if there is enough interest.

This isn't without precedence - there is a sparc and a sparc64
distribution, and there has been much talk about how to build a
Pentium-optimized distribution, where just some packages are
optimized, and the rest would be symlinked to the i386 distribution.

If anybody wants me to, I could build a chroot image and a set of
packages that have been compiled to use a different instruction set
and put them on my FTP site.

Is anybody interested in such a thing?  There isn't much point in me
doing it if nobody is going to try it, since I don't have the hardware
to test it on.

I suppose I can lookup what flags to use from the source for the
Linux/ARM distribution.  Or maybe somebody could tell me?

Cheers,

 - Jim