[OpenPower-Firmware] Time to drop POWER8 support from op-build?

[Stewart Smith]

Hi all,

The current state of POWER8 platforms is that only OpenBMC or FSP based ones
get any testing - namely palmetto, vesnin, and firenze (which is special
as that doesn't involve an op-build built hostboot).

The other POWER8 platforms, namely barreleye, firestone, garrison,
habanero, and p8dtu are, effectively, unmaintained and untested
upstream.While there's no barrier (apart from developer time) to p8dtu,
the others don't have a functional OpenBMC port, which limits our
ability to run the op-test suite against them.

A few things have come up recently that challenge our ability to
continue to have POWER8 platforms remain in the op-build tree.

Currently, all platforms build with a GCC6 based toolchain. In an
upcoming buildroot release, this will no longer be possible to do (see
discussion over on the buildroot patch:
https://patchwork.ozlabs.org/patch/1119341/ ).

The barrier to just switching to a more modern GCC is hostboot, and
since Hostboot forked for POWER8 and POWER9 systems, hostboot commit
4995ec0ba6f15e03deb4b9ad1dc215f3f8993acb and
https://github.com/open-power/op-build/pull/2803/ look to bring Hostboot
for *POWER9* up to a point where it can be built with a more modern
toolchain, there does not currently exist any fixes for Hostboot for
POWER8.

It appears that there's also no budgeted time for IBM engineers to work
on backporting the GCC8 build fixes to POWER8 hostboot, and our testing
platforms are rather limited (only Palmetto, and even then, we have
*maybe* one or two that are reliable).

While we could look at having two separate toolchains, the upcoming
buildroot change would mean we just have the problem postponed for a
couple of months.

As such, I'd like to propose the following:

The upcoming op-build v2.4 release will be the last to support the
barreleye, firestone, garrison, habanero, and p8dtu platforms.

For support for palmetto and vesnin to continue we need someone to step
up to maintain Hostboot for POWER8, notably ensuring it builds (and
boots) with GCC8. In the absense of someone coming forward in the next
week or so, I propose we also remove support for these platforms after
tagging v2.4.

Thoughts?

-- 
Stewart Smith
OPAL Architect, IBM.