Re: Some fixes for m68k users (incl/ for FPU emulation)

[David Rogers <davidrogers%me.com@localhost>]

I’ll give it a whirl here. I’ve got a Quadra 650 and IIci(in the middle of being recapped) that are up and running. I’ve been doing some llm assisted work with the Quadra to support Radius Rocket accelerator cards so it shouldn’t be too difficult.

David Rogers

> On Oct 30, 2026, at 1:00 PM, Romain Dolbeau <romain%dolbeau.org@localhost> wrote:
> 
> (relevant to all m68k, but mac68k is the most likely users of FPU
> emulation hence the cross-post; I didn't want to spam all the 68k
> lists)
> 
> Hello,
> 
> In the process of creating my litex68k port to my homegrown
> as-for-now-FPGA-based system (version with real CPUs still TBD :-) ),
> systematic testing has found some issues in m68k, in particular in the
> FPU emulation code.
> 
> Those patches are not eligible for submission to "gnats" as they were
> identified and fixed mostly by using a LLM, but they might be of
> interest to end-users building their own kernel. Hopefully this
> notification message (which is written without LLM assistance!) will
> be acceptable to the lists. Also, the CPU they were actually tested on
> are my own soft-core recreation of the MC680x0 and if anyone ever
> tests them on actual silicon, feedback is very welcome! (all my '040
> machines have full MC68040).
> 
> The list of patches and brief description can be found here:
> <https://github.com/MelkhiorVintageComputing/netbsd-litex-m68k/blob/litex68k/UPSTREAM.md>
> (beware: LLM-generated). The most relevant are the FPU emulation
> patches, there's also a couple minor performance improvements that
> could be relevant. The SMP patches are probably of interest to no-one
> but me as other than my litex68k port, there's no SMP support for
> m68k.
> 
> Cordially,
> 
> -- 
> Romain Dolbeau