Cross compilers for non-x86 hosts

[Alex Bennée <alex.bennee@linaro.org>]

Hi,

I've been making good progress at restoring QEMU's TCG tests thanks to
the availability of docker and Debian's excellent cross toolchains as of
stretch:

  https://lists.gnu.org/archive/html/qemu-devel/2018-04/msg03906.html

For some of our more esoteric architectures (hppa, m68k, alpha, sh4) I
used a sid based image as the toolchains exist to support the "ports".
This has proved much easier than re-implementing yet another set of
build scripts so I'm very grateful to the work you guys have done in the
last release ;-)

As I've now got one of the new AArch64 dev boxes I thought I'd better
check my series out on a non-x86 system.

I was pleasantly surprised to find the docker-ce in stretch was already
multi-arch aware so all the base Debian images where pulled down in
their aarch64 forms. However the images failed to build because the
compilers where not available in the aarch64 archive. For example:

  https://packages.debian.org/sid/gcc-alpha-linux-gnu

Only has binaries for amd64, i386 and an unofficial x32 build.

So aside from the usual time and inclination is there anything in
particular stopping the cross compilers being built for the other
supported architectures?

I did download the gcc-defaults source package but I'm unsure what the
correct invocation is to build an individual set of packages for one
target. What would the correct dpkg-buildpkg invocation be to build the
alpha toolchain for example?

Thanks,


--
Alex Bennée