[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Re: Restricting architectures

+++ Robert Schwebel [2010-09-03 09:20 +0200]:

[sorry - got the emdebian email wrong on previous mail - reply to
this, not that]

[Emdebian people: this is useful thread from linaro-dev I am now
cross-posting. Start here to read it:

> I would like to test what the Debian guys have available. Can you point
> me to the right entry point? There seem to be too much Debian cross
> efforts out there and it is dificult for people from the outside to find
> the right things. 

Right now things are in a state of flux as the linaro stuff gets into
Ubuntu and the Emdebian tools are being updated.

> All I find in my apt-cache is this:
> thebe:~# apt-cache policy gcc-4.3-arm-linux-gnu
> gcc-4.3-arm-linux-gnu:
>   Installed: (none)
>   Candidate: 4.3.2-1.1
>   Version table:
>      4.3.2-1.1 0
>         500 http://www.emdebian.org lenny/main Packages
> This is
> a) not in debian (not even in unstable)

The problem is that cross-toolchain builds have cross-arch
dependencies and autobuilders don't understand dependencies outside
their architecture, so a scheme was needed to allow autobuilders to
cope (one day multiarch will help here). That was worked out over a
year ago () but gcc4.4 breakage and real life got in the way of getting
it into Debian. A similar (but not identical) scheme has now been
implmented by Marcin for the armel/linaro/ubuntu toolchains.

> b) gcc-4.3.2 + binutils-2.18.1 + glibc-2.7.

newer toolchains for armel are available, but much of the rest broke:

4.4 has been stalled for over a year because the biarch/triarch
multilib builds ((?)) broke.
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=504487 Al viro has
just appeared and applied his genius to fix it all so a pile of
patches went in last week/this week.

There has also been much anguish about paths and tools re the various
possibilities of existing dpkg-cross style triplet paths, sysrooted
builds/paths, and multiarch paths and what should be done in default
toolchains, and how to manage transitions. That seems to be shaking
out now, as as far as we can tell the sysroot and existing paths are
orthogonal and both still work in the linaro cross-tools, and
multiarch isn't going to be properly with us until next cycle so we
can leave the associated breakage a little longer. 

> The gcc upstream development (this is where you have to push your
> patches into and where it makes sense to do development on toolchains)
> is gcc-4.6, and for production systems I'd like to have gcc-4.5.1,
> binutils-2.20.1 and glibc-2.12.1. So I assume I have not the right
> paths in my sources.list?

The reason newer stuff is not available is mostly one of resources.
Hector Oron has been looking after the build-process, but keeping all
the Debian arches cross-building and up-to-date with Debian has proved
to be more than he had time for. (It's OK until something mysterious
breaks, so it went well until 4.4 came out with much breakage). The
combination of Marcin's and Al's (and Zumbi's and Doko's) recent work
with a general desire to make this stuff happen directly in the
distributions, rather than outside, is rapidly improving matters
(although there reamins plenty to do).

However there is still a shortage of attention on anything other than
arm cross-toolchains. And I'm not sure with where we are at in terms
of getting all this stuff into Debian, as oppposed to Ubuntu. I assume
it just missed squeeze so will remain in the emdebian repos for a
little longer.

Anyone who wanted to help make sure the various arches stay building
and help get the cross-builds happening in the main archive is
_extremely_ welcome. Talk to Hector for details of how to help.

Current status is here:

Principal hats:  Linaro, Emdebian, Wookware, Balloonboard, ARM

Reply to: