Re: qemu for bmc

[Patrick Venture <venture@google.com>]

On Wed, Nov 18, 2020 at 11:41 PM Cédric Le Goater <clg@kaod.org> wrote:
>
> Hello,
>
> On 11/18/20 10:11 PM, Patrick Venture wrote:
> > Patrick;
> >
> > I was looking at a patch series of yours that landed,
> > https://github.com/qemu/qemu/blob/master/hw/arm/aspeed.c#L517 <-- in
> > this line you're referencing a device that appears to be missing from
> > qemu - namely, the pca i2c mux.
> >
> > My question is to the community at large, and you also, is anyone
> > currently implementing this i2c-mux or a similar one?
>
> I haven't seen any patches for this device on the QEMU mailing
> list.
>
> John Wang from Bytedance has started developing some new I2C
> device models for their G220A board. We hope to get that merged
> in 6.0.
>
> If you are interested, we maintain a brief TODO list here
>
>   https://github.com/openbmc/qemu/wiki

Thanks, I'll take a look.

>
> Feel free to update.
>
>
> In terms of priority, I think that the support to boot from eMMC
> on the AST2600 is an important one. Reviewing the FSI patches
> also but that's an IBM thing, so it might not interest the
> community that much.
>
> There are quite a few I2C models missing.

Yes.

>
> All Aspeed models could be more precise.
>
>
> Google and Nuvoton have merged their models for the npcm750-evb
> and quanta-gsj boards. It would be good to have some interaction
> with them, on bus/device modeling but also on full system emulation.

Yeah, I believe you've seen my team's patches adding nuvoton support
to Qemu.  It's a WIP, but we're making a lot of headway and hope to
have more Nuvoton 730/750 qemu devices sent to qemu over the coming
days, weeks, etc.

One of the big gaps that I'm seeing is that we weren't yet looking at
the rest of the board as closely, to see what other devices are
missing, such as the i2c-muxes, etc.  This will be a really good
community convergence point as there are only so many i2c-muxes,
voltage regulators, temperature sensors, that are in common use.

I'll go through some of our plans as stated and add them to the todo
list.  My team currently isn't focused on aspeed support at present,
but we're keeping an eye on it and are definitely excited to see
others contributing in that space!

>
> Cheers,
>
> C.

- Patrick