Re: Kernel config for Sun 3/50

[David Brownlee <abs%absd.org@localhost>]

On Mon, 9 Jan 2023 at 06:13, Trent McNair <tmcnair%gmail.com@localhost> wrote:
>
> I've set up a cross-compile toolchain to build 9.3 for my Sun 3/50. I am able to build a kernel and userland, but I'm running into the "kernel too large" error in pmap.c:
>
>         if (cpu_machine_id == ID_SUN3_50) {
>                 hole_start = m68k_trunc_page(OBMEM_BW50_ADDR);
>                 hole_size  = m68k_round_page(OBMEM_BW2_SIZE);
>                 if (avail_start > hole_start) {
>                         mon_printf("kernel too large for Sun3/50 %d %d %d\n", hole_start, hole_size, avail_start);
>                         sunmon_abort();
>                 }
>         }
>
> I've looked through old mailing list threads and I guess this limit has to do with the location of the 3/50's frame buffer. I can't seem to remove enough
> functionality to get a small enough kernel to fit below hole_start. Can a working kernel be built for this machine?

It's likely to be a challenge to get something small enough to fit.
Sun3 GENERIC already has COPTS="-Os -fno-unwind-tables
-fno-omit-frame-pointer", which could be tweaked up to COPTS="-Os
-fno-unwind-tables" which might shave a fraction.

I'd be tempted to build a test kernel without any scsi and/or network
support just to confirm it will boot to get a baseline

David