Re: Alternate toolchain for armhf (e.g. linaro) under schroot sbuild

+++ nice sw123 [2015-09-14 22:45 +0200]:
> Hi there!
> 
> Can I use sbuild-createchroot... (Jessie)
> 
> sudo sbuild-createchroot
> --make-sbuild-tarball=/srv/chroots/jessie-sbuild.tgz jessie
> /srv/chroots/jessie http://httpredir.debian.org/debian/
> 
> 
> ... BUT THEN opt to *not* use a packaged armhf toolchain.
> https://wiki.debian.org/CrossToolchains#Installation
 
> 
> ...AND INSTEAD opt to *use* a different toolchain, such as the Linaro
> Toolchain linked here
> https://eewiki.net/display/linuxonarm/BeagleBone+Black#BeagleBoneBlack-ARMCrossCompiler:GCC
> ( https://releases.linaro.org/14.09/components/toolchain/binaries/gcc-linaro-arm-linux-gnueabihf-4.9-2014.09_linux.tar.xz
> )
> ???

yes, although it may not work very well. I'm not sure that a linaro
crosstoolchain will find libraries in multiarch locations? Check its
search paths. If it doesn't then it's probably only good for building
kernels and bootloaders, or using dpkg-cross-ified libraries.

> What are the steps required to get that Linaro toolchain into the
> schroot and have it jive with the debian packages kernel, and whatever
> dependencies?

I don't know in detail as I've never tried.

> Do I need to symlink the compiler to a particular location under
> /usr/bin and give it the correct name?

package builds expect to be able to run <triplet>-gcc (or g++, or
gconv, or cpp, or pkgconfig) so you need links for all of
those. (pkgconfig is handled separately from the toolchain - but I
don't think it's working yet in stretch).

> How do I need to handle libc and c++ libraries?

You can just install them in the chroot.
You can tell sbuild to install then when crossing (see other mail)

> How does the kernel fit into the picture? (Can I use the standard
> packaged kernel, or do I have to mess with building an own one?)

why do you care about a kernel when crossbuilding? do you mean the
kernel-header (linux-libc-dev:armhf package? the cross-toolchain may
come with its own. you may need a multiarch copy too (i..e
linux-libc-dev:armhf for some packages to build against)

Wookey