Ultrasparc 3 support

[Joao Barros]

On 2/28/07, Gavin Atkinson <gavin.atkinson at ury.york.ac.uk> wrote:
> On Mon, 2007-02-26 at 22:50 -0600, Nathan Whitehorn wrote:
> > I've been given a pair of Sunfire v210s and a v440 (dual and quad
> > UltraSPARC 3, respectively), and would love to put FreeBSD on them.
> > Sadly, of course, the schizo chipset isn't supported.
> >
> > I'm planning on trying to port over OpenBSD's work in this area, but am
> > somewhat out of my depth (the only work I've ever done on the FreeBSD
> > kernel involves some fixes to nve(4)). Because we have no immediate need
> > to put any of these systems into production (and certainly not all
> > three), I currently can use any or all of them for experimentation and
> > development work for at least the next few months. I believe some
> > members of this list have done their own work in this regard in the
> > past, and was wondering if anyone wanted to collaborate or had done
> > anything that would serve as a starting point. Similarly, if anyone more
> > competent than I feels they just can just do it themselves, but needs
> > access to the hardware, I would be happy to provide that.
>
> A fair bit of work has already been put into supporting the Schizo
> chipset under FreeBSD, but it's a long way off being complete.  With the
> code that myself and Marius Strobl have published in the past, you can
> get US3 based machines booting multiuser off root stored on NFS or USB
> key.
>
> The single biggest part of the problem are the MMUs.  Actually routing
> read/writes and interrupts over the Schizo chipset isn't hard - but I
> believe a lot of work would be needed to support the IOMMU found in
> post-USII chipsets, along with the associated work to the PMAP code etc.
> This is not an area I've looked into at all.
>
> What would be interesting from my point of view is to see how well the
> OpenBSD code works.  I've heard a few reports that it is unusable, and a
> few reports that it sort of works.  Knowing whether you can use DMA
> under OpenBSD may be useful as it would give us another code base to
> gain information from.
>
> Gavin

I got this on my RSS today, Hope it shed's some more light on this
subject: http://undeadly.org/cgi?action=article&sid=20070301230514

-- 
Joao Barros