Re: Deprecate the ppc405 boards in QEMU?

[David Gibson]

On Mon, Oct 11, 2021 at 10:10:36AM +0200, Thomas Huth wrote:
> On 06/10/2021 09.25, Thomas Huth wrote:
> > On 05/10/2021 23.53, BALATON Zoltan wrote:
> > [...]
> > > Maybe these 405 boards in QEMU ran with modified firmware where the
> > > memory detection was patched out but it seems to detect the RAM so I
> > > wonder where it gets that from. Maybe by reading the SDRAM
> > > controller DCRs ppc4xx_sdram_init() sets up. Then I'm not sure what
> > > it needs the SPD for, I forgot how this worked on sam460ex. Maybe
> > > for the speed calibration, so could be it detects ram by reading
> > > DCRs then tries to get SPD data and that's where it stops as i2c is
> > > not emulated on taihu. This could be confirmed by checking what it
> > > pokes with -d guest_errors that shows accesses to missing devices
> > > but don't know where 405 has the i2c controller and if it's the same
> > > as newer SoCs. If so that could be reused and an i2c bus could be
> > > added with the SPD data like in sam460ex to make u-boot happy or you
> > > could skip this in u-boot.
> > 
> > FWIW, I've just tried the latter (skipping the sdram init in u-boot),
> > and indeed, I can get to the u-boot prompt now.
> [...]> I've also attached the patch with my modifications to u-boot.
> 
> FYI, the changes can now be found on this branch here:
> 
>  https://gitlab.com/huth/u-boot/-/commits/taihu
> 
> I also added a gitlab-CI file, so you can now download the u-boot.bin as an
> artifact from the corresponding pipeline, e.g.:
> 
>  https://gitlab.com/huth/u-boot/-/jobs/1667201028

Thanks.

Are you going to send a v2 of your proposed deprecation patches?  If
you do can you please CC me explicitly.  I only scan qemu-ppc once a
week or so, and it goes into a different folder.  If I'm CCed I'll
notice and respond to it faster.

-- 
David Gibson                    | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au  | minimalist, thank you.  NOT _the_ _other_
                                | _way_ _around_!
http://www.ozlabs.org/~dgibson

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