Re: [PATCH v9 1/7] firmware: smccc: Add an Arm SMCCC bus

[Jason Gunthorpe]

On Fri, Sep 04, 2026 at 03:27:27PM +0100, Sudeep Holla wrote:

> > IMHO to lean into the bus design I would have a discovery SMCCC that
> > returns a list of supported ABIs, something like (spec, spec version,
> > ABI, FID, feature supported bitmap).  There could be overlaps if the
> > FW supports several ABI incompatible versions, like RSI v1 and RSI v2.
> > 
> 
> But then we will have to wait for that discovery SMCCC ABI first and that
> mean how will it work on existing deployed systems ? But I like the idea.

Oh, I wasn't saying to wait for anything. This is good enough as is.

I was suggesting a next step to make this even better and solve some
of the real problem the ecosystem feels with the FW/kernel ABI.

> the software that purely relies on feature bits. So a big yes for that
> idea and I think some specs and in some form are doing it. I can't
> recall specific but I have seen it. We just need push only for that
> in future specs.

I was advocating the approach of a discovery spec that codifies
exactly how all this should work. So each team writing a new spec
doesn't have to reinvent it.

Jason