Re: Deprecate the ppc405 boards in QEMU? (was: [PATCH v3 4/7] MAINTAINERS: Orphan obscure ppc platforms)

[BALATON Zoltan]

On Tue, 5 Oct 2021, Cédric Le Goater wrote:
> On 10/5/21 08:18, Alexey Kardashevskiy wrote:
> > On 05/10/2021 15:44, Christophe Leroy wrote:
> > > Le 05/10/2021 à 02:48, David Gibson a écrit :
> > > > On Fri, Oct 01, 2021 at 04:18:49PM +0200, Thomas Huth wrote:
> > > > > On 01/10/2021 15.04, Christophe Leroy wrote:
> > > > > > Le 01/10/2021 à 14:04, Thomas Huth a écrit :
> > > > > > > On 01/10/2021 13.12, Peter Maydell wrote:
> > > > > > > > On Fri, 1 Oct 2021 at 10:43, Thomas Huth <thuth@redhat.com> wrote:
> > > > > > > > > Nevertheless, as long as nobody has a hint where to find that
> > > > > > > > > ppc405_rom.bin, I think both boards are pretty useless in QEMU (as 
> > > > > > > > > far as I
> > > > > > > > > can see, they do not work without the bios at all, so it's
> > > > > > > > > also not possible
> > > > > > > > > to use a Linux image with the "-kernel" CLI option directly).
> > > > > > > >
> > > > > > > > It is at least in theory possible to run bare-metal code on
> > > > > > > > either board, by passing either a pflash or a bios argument.
> > > > > > >
> > > > > > > True. I did some more research, and seems like there was once
> > > > > > > support for those boards in u-boot, but it got removed there a
> > > > > > > couple of years ago already:
> > > > > > >
> > > > > > > https://gitlab.com/qemu-project/u-boot/-/commit/98f705c9cefdf
> > > > > > >
> > > > > > > https://gitlab.com/qemu-project/u-boot/-/commit/b147ff2f37d5b
> > > > > > >
> > > > > > > https://gitlab.com/qemu-project/u-boot/-/commit/7514037bcdc37
> > > > > > >
> > > > > > > > But I agree that there seem to be no signs of anybody actually
> > > > > > > > successfully using these boards for anything, so we should
> > > > > > > > deprecate-and-delete them.
> > > > > > >
> > > > > > > Yes, let's mark them as deprecated now ... if someone still uses
> > > > > > > them and speaks up, we can still revert the deprecation again.
> > > > > >
> > > > > > I really would like to be able to use them to validate Linux Kernel
> > > > > > changes, hence looking for that missing BIOS.
> > > > > >
> > > > > > If we remove ppc405 from QEMU, we won't be able to do any regression
> > > > > > tests of Linux Kernel on those processors.
> > > > >
> > > > > If you/someone managed to compile an old version of u-boot for one of 
> > > > > these
> > > > > two boards, so that we would finally have something for regression 
> > > > > testing,
> > > > > we can of course also keep the boards in QEMU...
> > > >
> > > > I can see that it would be usefor for some cases, but unless someone
> > > > volunteers to track down the necessary firmware and look after it, I
> > > > think we do need to deprecate it - I certainly don't have the capacity
> > > > to look into this.
> > >
> > > I will look at it, please allow me a few weeks though.
> >
> > Well, building it was not hard but now I'd like to know what board QEMU 
> > actually emulates, there are way too many codenames and PVRs.
>
> yes. We should try to reduce the list below. Deprecating embedded machines
> is one way.

Why should we reduce that list? It's good to have different cpu options 
when one wants to test code for different PPC versions (maybe also in user 
mode) or just to have a quick list of these at one place.

Regards,
BALATON Zoltan