Re: Panic at boot on 4/330 with cgfour and cgsix

On Wed, Jan 29, 2025 at 12:59 PM David Brownlee <[email protected]> wrote:
> There is no guarantee the issue is in cgfour.c, but it seems like an
> excellent place to start :)
>
> So:
>
> - bus_space_probe() lost an arg (zero in this case)
>
> - bus_space_mmap() gains an arg (offset) as "sc->sc_paddr + poff"
> becomes "sc->sc_paddr, poff"
>
> - conversion from obio_bus_map() to bus_space_map() loses two args.
> They look like offsets as the diff ~line 276 changes "oba->oba_paddr,
> PFOUR_COLOR_OFF_CMAP" to "oba->oba_paddr + PFOUR_COLOR_OFF_CMAP"
> That is supported by sys/arch/sparc/include/autoconf.h which had
> #define obio_bus_map(t, a, o, s, f, v, hp)              \
>         bus_space_map2(t, 0, (long)(a) + o, s, f, (vaddr_t)v, hp)
>
> My first suspicion would be something in the obio_bus_map() to
> bus_space_map() changes, particularly as FOUR_COLOR_OFF_CMAP is
> 0xfff00000 which is 4,293,918,720 - a fair sized offset to pass in on
> a 32 bit machine

So this comment made me curious why that offset is so large and that
turned out to be the problem. It's defined in sys/dev/sun/pfourreg.h
as

#define PFOUR_COLOR_OFF_CMAP 0xfff00000 /* (-0x00100000) */

Since the cgfour works on sun3 I went and looked at what it does and
it has an equivalent file sys/arch/sun3/dev/p4reg.h that says the same
thing. However I noticed the sun3 cgfour driver doesn't use that file
instead it's using sys/arch/sun3/dev/cg4reg.h which says something
different.

/*
 * Memory layout of the Type B hardware (OBMEM)
 * P4 appears on the Sun3/60 at 0xFF300000, so
 * define things relative to that.
 */
#define CG4B_OFF_CMAP  (-0x100000)

So I changed PFOUR_COLOR_OFF_CMAP to (-0x00100000) and I was able to
boot successfully. I don't know if this is the right way to fix it but
at least now I can boot the system and test things some more. Thanks
everyone for the help so far, I'll be trying to run X and other things
soon and hopefully have some good news.