fedora for ARM

[Lennert Buytenhek]

On Wed, Jun 06, 2007 at 02:28:25PM -0700, Ed Swierk wrote:

> > There is something to be said for target emulation or
> > run-parts-of-the-build-on-hardware solutions, but I think the
> > best answer is one where any available host can compile Fedora
> > for any target.
> 
> Isn't that exactly what we'd get with target emulation? Any available
> host that can run an emulator could then build all of fedora Fedora
> for ARM or PowerPC or whatever.

I think that something like qemu-system-arm is probably one of the
very few ways of speeding up package builds while still being able
to guarantee that the result is 100% identical.  (Although my
fastest ARM boxes are probably faster than doing it via qemu.)

For the Debian armeb port, what we did for a while is to run all
package builds natively, but to have the actual compiling be done
on a fast x86 box, by making the ARM board use distcc, and having
the x86 box run distccd with an ARM cross-compiler.  I don't think
this generates 100% identical binary code, but it should still be
functionally equivalent.


> Supporting cross-compiling would be great, but having spent a several
> weeks fighting with Python and its libraries last year and losing, I
> suspect scouring the other nine zillion Fedora packages for
> cross-correctness is no small exercise, not to mention battling new
> bugs as they crop up.

I would fully agree with the sentiment that cross-compiling the entire
distro as _the_ standard way of maintaining the arch package repository
is not a realistic scenario and will likely never be.  Preferably, I
would like to just keep doing this entirely natively.

It appears a lot less effort to maintain a set of patches to make some
limited subset of packages (say, 300 packages) cross-compilable,
though.  In some cases, we'll have to do this anyway.


> That said, there is certainly room for both approaches, and getting
> even a small number of packages to cross-compile might be enough for
> many embedded applications.

ACK.