Re: [PATCH] hw/ppc: Deprecate the ref405ep and taihu machines and the 405 CPU models

[Peter Maydell <peter.maydell@linaro.org>]

On Fri, 1 Oct 2021 at 14:01, Thomas Huth <thuth@redhat.com> wrote:
>
> On 01/10/2021 14.46, Peter Maydell wrote:
> > On Fri, 1 Oct 2021 at 13:22, Thomas Huth <thuth@redhat.com> wrote:
> >>
> >> These machines need a firmware image called 'ppc405_rom.bin', and nobody
> >> seems to have such a firmware image left for testing, so the machines are
> >> currently unusable. There used to be support in U-Boot, but it has been
> >> removed a couple of year ago already.
> >> Thus let's mark these boards and the 405 CPU as deprecated now, so that we
> >> could remove them in a couple of releases (unless somebody speaks up and
> >> says that these are still usefull for them).
> >>
> >> Signed-off-by: Thomas Huth <thuth@redhat.com>
> >> ---
> >>   docs/about/deprecated.rst | 15 +++++++++++++++
> >>   hw/ppc/ppc405_boards.c    |  2 ++
> >>   2 files changed, 17 insertions(+)
> >>
> >> diff --git a/docs/about/deprecated.rst b/docs/about/deprecated.rst
> >> index 2f7db9a98d..27c03ef624 100644
> >> --- a/docs/about/deprecated.rst
> >> +++ b/docs/about/deprecated.rst
> >> @@ -238,6 +238,11 @@ The ``I7200`` guest CPU relies on the nanoMIPS ISA, which is deprecated
> >>   (the ISA has never been upstreamed to a compiler toolchain). Therefore
> >>   this CPU is also deprecated.
> >>
> >> +PPC 405 CPU models (since 6.2)
> >> +''''''''''''''''''''''''''''''
> >> +
> >> +The related boards ``ref405ep`` and ``taihu`` are marked as deprecated, too.
> >> +
> >
> > What is this "too" a reference to? The immediately preceding section
> > in the document is about the MIPS I7200 CPU model.
>
> It was meant as a reference to the machines below. I'll try to rephrase in v2.
> (As far as I can see, the 405 can only be used on these boards, it does not
> seem to be possible to use these CPU types on other boards)

OK. I think it's probably a good policy to make deprecation-notice
section text self-contained, because we're going to be regularly deleting
them, or moving them to removed-features.rst.

> > The not-being-deprecated sam460ex board also uses the ppc405 CPU
> > I think, so I don't think we can drop the CPU models.
>
> No, that board uses a 460exb CPU which is a slightly different kind of
> embedded PPC CPU, as far as I know.

Ah, right. I was confused because sam460ex.c calls ppc405_ebc_init(),
and so it came up from a quick grep for 'ppc405'.

If we want to deprecate the CPU models I think it would be useful
to list all the ones we're deprecating explicitly here (using the
names that the '-cpu' option accepts).

thanks
-- PMM