[OE-core] Building older releases on modern distros (and vice versa)

[Richard Purdie]

On Fri, 2020-01-17 at 10:39 -0800, Khem Raj wrote:
> On 1/17/20 9:59 AM, Richard Purdie wrote:
> > We've been discussing how we could:
> > 
> > a) build old releases on newer distros
> > 
> > as well as
> > 
> > b) how we could build new releases on old distros.
> > 
> > Our proposed answer has been "buildtools-extended-tarball" which
> > includes nativesdk-gcc.
> > 
> > We need b) so we can install this on Centos7 and stop having to
> > work
> > around its really old compiler. In general this should improve our
> > ability to support stable branches in general.
> > 
> > I wanted to stress test a) a bit, partly to prove that b) could
> > work
> > longer term.
> > 
> > I did this by attempting to build buildtools-extended-tarball on
> > pyro
> > which has a gcc v6 and then using that to build morty on an Ubuntu
> > 18.04 system.
> > 
> > It wasn't plain sailing, I had to:
> > 
> > * Upgrade the uninative in pyro
> > * Switch to xz uninative to allow latest uninative to work
> > * Patch binutils to fix an ld.so.conf relocation issue
> > * Add an ld.so.conf to buildtools
> > * Add the buildtools-extended-tarall recipe
> > 
> > Patches are in:
> > 
> > http://git.yoctoproject.org/cgit.cgi/poky-contrib/log/?h=rpurdie/pyro
> > 
> > (some need forward porting to master)
> > 
> > Having got the output from the pyro build, in the morty build I
> > added
> > buildtools tarball to PATH before running the build. I had to
> > disable
> > uninative since it was going to get in the way and conflict:
> > 
> 
> do we intend to generate extended buildtools tarballs for all
> releases 
> if it works out well ?

Going forward there will be one generated as part of the release
process for each release, they're part of master builds already.

We only really need a couple of older older ones with older gccs to be
able to support a range of different older releases but we should look
to generate those.

Cheers,

Richard