[OpenPower-Firmware] Dropping Power8 in op-build

[Klaus Heinrich Kiwi]

On 1/3/2020 6:05 AM, Artem Senichev wrote:
> On Thu, Jan 2, 2020 at 10:24 PM Stewart Smith <stewart at flamingspork.com <mailto:stewart at flamingspork.com>> wrote:
> 
> 
>      > On 1 Jan 2020, at 23:26, Joel Stanley <joel at jms.id.au <mailto:joel at jms.id.au>> wrote:
>      >
>      > Hello openpower firmware list,
>      >
>      > I maintain the buildroot overlay used in op-build, which normally
>      > follows upstream releases. Buildroot 2019.05 was the last release with
>      > GCC 6 support and hostboot for Power8 does not build with newer
>      > versions of GCC, so in order to keep Power8 in the tree we've not
>      > moved forward for some time now.
> 

Folks,

  I think it's time for us to move forward with this.

>     It’d probably be good to tag a final op-build before cutting p8 off, as there are platforms still used and maintained (vesnin).
> 
> 
> I would suggest to create a P8 branch in op-build, like it has been done for OCC and hostboot.
> Actually, we don't have any significant plans for P8, but as long as I have to support our VESNIN platform I can also maintain this branch by merging critical fixes from Skiboot, petitboot etc.
>
>     I have a PR up for cutting out p8 that’s sat idle for months.

I tried to collect the meaningful PRs below (in a somewhat reverse chronological order), but it's looking like
always converge towards not being able to keep Hostboot, OCC up-to-date with newer compilers.

P8 build fixes for modern GCC - https://github.com/open-power/hostboot/pull/193
P8 build fixes for modern GCC - https://github.com/open-power/occ/pull/28
Remove support for POWER8 - https://github.com/open-power/op-build/pull/3145
Remove all P8 platform except palmetto and vesnin - https://github.com/open-power/op-build/pull/3018
Configuration updates to compile with GCC 8 - https://github.com/open-power/op-build/pull/2803


>      > There is currently no one working on fixing hostboot. Without someone
>      > stepping forward, we will have to drop support for building Power8
>      > hostboot in op-build master.
>      >
>      > Meaningfully, this would mean removing the Power8 platforms. The
>      > non-hostboot components (skiboot, the kernel, the rootfs) are
>      > processor family agnostic, so the opal_defconfig could be used to
>      > generate firmware for Power8 machines should there be a desire.
>      >
>      > The Hostboot codebase for Power8 is not changing. If you would like to
>      > volunteer getting it building, once it builds the ongoing maintenance
>      > would be minimal.
> 
>     It’s pretty unfortunate that nobody is able to keep it going as p8 machines are coming up relatively cheaply now on the secondhand market.
> 
>     I am concerned that the same thing will happen to the p9 hostboot and friends as the next generation of chips come out.
> 
>     P9 has seen Talos II and Blackbird as good developer systems for people to get into the POWER ecosystem, and it would be good to continue to have that community grow with a good set of affordable second hand systems.
> 
>      > If no one steps up, I'll bump buildroot at the end of January
> 
>     Sounds reasonable. Although would suggest bumping sooner and if someone steps up then reverting the commit is also okay.
> 
>     Got a tree somewhere? I’m happy to try it out/build upon it.


My proposal here is to remove all Power8 support from master op-build, and if someone is still interested in
maintaining a Power8 branch, we have op-build-2.5.y or other older branches available for that (patches welcome),
or one could fork and maintain their own tree (I'd be happy to point to it in our official documentation).

I want to start merging patches in that direction starting next week.

Thanks,

  -Klaus

-- 
Klaus Heinrich Kiwi <klaus at linux.vnet.ibm.com>