Re: fu740 target

[Bin Meng]

On Wed, Jul 27, 2022 at 10:24 PM Ben Dooks <qemu@ben.fluff.org> wrote:
>
> Is anyone working on adding a sifive-u74 core to the list of supported
> CPU types? I was looking at full emulation of the Unmatched but at the
> moment the best we have is sifive-u54 and I think that misses at least
> two CSRs the sifive-u74 has.
>
> Does anyone have plans to add the sifive-u74, and if not, would a plan
> to add gradual support for it like adding CSRs 0x7c1 and 0x7c2 so we
> can run an Unmatched U-boot SPL against it.

Adding 0x7c1/7c2 would be a vendor-specific CSR approach?

>
> If not, is there a definitive U54->U74 set of public differnces around
> we could use to start from? I'd like to be able to run a full Unmatched
> image using qemu at some point to add to the current real-board testing
> we're doing.
>
> (I have a basic addition of the type and the two CSRs as a couple of
> patches if that would help as a start)
>

I am not aware of anyone doing U74 modeling in QEMU, but SiFive folks
(+Frank) may have one downstream as I see they posted several bug
fixes in the existing U54 model.

Regards,
Bin