[rescue] Sun-2 in FPGA (and 3C400 are not very good)

[foo bar]

On Wed, Sep 2, 2026 at 1:56 PM Romain Dolbeau via rescue
<rescue at sunhelp.org> wrote:
> To support sun3x (SW or FPGA), I think having an AI look at the
> sun3/sun3x differences in available kernel sources would give a good
> starting point - I suspect the primary difference will be the DMA;
> sun2/sun3 is DVMA (all useful devices are connected on the CPU side of
> the MMU), while sun3x might not be as the MMU is internal to the '030.
> Whether Sun did regular physically addressed DMA or added a sort of
> IOMMU, I don't know.

The 3/80 uses an IOMMU, specifically the LSI L1A3625 (sun p/n
100-1783-01). The same chip is used on the 4300. I've only seen blurry
pics of the 3400 but it appears to use PAL/TTL logic like the sun3
boards.