[Debian-coldfire-devel] Linux on coldfire

[Adam Conrad]

Wouter Verhelst wrote:
> 
> BTW, speaking of assemblers: my changes to binutils have been completed
> a while back, so should be ready. I haven't tested them yet (there seems
> to be a problem with shipping...), but I don't think there's much I
> could've done wrong (it's basically just checking a huge table of
> opcodes and marking those that appear on both architectures as "ok").
> For those who care, you can pull binutils out of svn, compile it (be
> sure to use "--target=m68k-linux" if you're not compiling on an m68k
> box), and then use the '-mcf68' flag. If you want or need to use gcc to
> get there, use -Wa,-mcf68 (exactly as written, i.e., no spaces). Testers
> are welcome :-)

Speaking of opcode shuffling and other fun stuff, I spoke with Jeff
Bailey recently about ColdFire/m68k biarch, and after much discussion,
we realised that if we want to get the most of this hardware, we should
perhaps do the following:

1) Get a kernel patch the will emulate missing m68k opcodes on ColdFire
(so that our current archive works as-is on CF machines)
2) Fix up binutils and gcc to have a "neutral" target (as Wouter as has
done) and compile all Debian packages from now on using that as our
default target.
3) Get glibc capability stuff going on m68k, so we can take advantage of
the ColdFire (and CF sub-model) crypto accel in stuff like libssl, with
optimised libraries in /usr/lib/[whatever]

> That means we're now ready to go modifying gcc. Which I don't feel as
> confident about as binutils; anyone else feel up to the challenge?

I just got my board a few days ago and am swamped with work, but I'd be
happy to look into glibc hwcap changes and some of the GCC mangling when
I find the spare time to power it up and play.  I suspect someone else
(Stephen, Michael?) may be a better fit to look at kernel patches for
opcode emulation.

... Adam