[tlbuild] PPC builds

[Johannes Hielscher]

Am Sat, 15 Feb 2020 08:27:39 +0100
schrieb Mojca Miklavec <mojca.miklavec.lists at gmail.com>:
> What we could easily to as a first step is to automatically disable
> LUAJIT on this platform (we do it for sparc solaris, ppc darwin ...)
> until the patches get accepted upstream.

That sounds very sensible to me.


> You mention issues with GD and libpng. I have issues building those
> on a regular aarch64 platform (using armbian) which lacks png
> development headers (as in: did not run "apt install" yet), so fixing
> anything in that area would certainly also benefit other (way more
> frequent) users.

You run ./Build --enable-arm-neon=check ? Back then some 2⅓ years ago,
pulling the update of libpng and propagating this through the configure
command line options, was the way Karl and me got TLbuild work on
aarch64-linux (Armbian as well), as native build without dependency on
system-provided libs/headers.

This was a bit tedious to figure out in the first place, but since
then, the platform is very well-behaved. See Build/source/README and
the 2017-12-02 entry in Build/source/libs/libpng/ChangeLog . Since
then, I set up build environments on three new aarch64-linux boxes
(based on various Debian flavours, and Archlinux ARM), and it worked
each time.

To our luck, upstream sources were in a aarch64-friendly state already,
and just had to be configured properly to use NEON. Dunno if this is as
easy on ppc64.

Best,
Johannes