[fedora-arm] Support for ARMv7, hardware math

[Andy Green]

On 11/30/10 19:49, Somebody in the thread at some point said:

Hi -

> I understand we probably will have logistic issues releasing v7 arch
> for F14 since it has already been released (for x86), I assume it
> isn't trivial to add compiler flags for the 13k packages in both F14
> and rawhide(F15. That sounds like a lot work. It is easier to put them
> directly into rawhide rather then in both places so they are there
> moving forward (still a lot of work but it only needs to be done once
> and you probably can easily script it.)

Compiler flags and so on are mainly handled by rpmbuild based on the 
macros for the architecture it's building on.  So it's not like patching 
thousands of packages.

> We could branch out a cortex or a v7 release, but that is more
> logistic issues, and honestly by dropping arm5tel support. I dont
> think we are dropping much hardware that people are actually
> interested in running Fedora on and especially by the F15 release.

I am very interested in running Fedora on armv5tel as we can today.

> Tablets, laptops, embedded servers would be more realistic, and

There is a quite wide spread of arm hardware about, it is not going to 
be the case that suddenly everything is Cortex.  For example these last 
days I have been using Arm Fedora on NXP LPC3250 which is a new, cheap 
chip based on the ARM926EJ core which is armv5; Fedora is working great 
on SD Card.  The last thing I worked on uses Fedora on an iMX31 CPU 
which is ARM1136 / armv6.

If it makes a big difference to build for high end cortex specifically, 
then I hope we're able to keep armv5 while the chips are still current 
and being designed into things along the lines of i386 / x86_64.

> As far as actually moving forward...
>
> If it is possible to cross-compile RPMS, and get sane results, it

I think trying to make Fedora build cross is a whole other issue.

Building stuff cross is a trickier business than you might think.  Many 
packages with recent autotools can build cross OK, plus or minus some 
magic needed to work with rpmbuild like that, but there is no point 
doing all that work if there are fast ARM high-end machines available 
that can build them native.  Surely it's clear that high end arm 
machines are clearly going to approach x86 kinds of speed anyway in the 
next years reducing any pay back from the effort of going cross.

-Andy