[rescue] SPARCstation 1 boot woes

[David Brownlee]

On Wed, 22 Oct 2025 at 00:12, David McMackins II via rescue
<rescue at sunhelp.org> wrote:
>
> It is with great dismay that I report that this netboot setup exhibits
> the same behavior as current NetBSD. It seems there is a subtle
> hardware issue after all.
>
> The only idea that I've come up with as a shot in the dark is that it
> could be a power supply issue of some sort. That is, during the boot
> sequence (or POST sequence on OBP 1.0), the power demand from the
> system increases, and one of the PSU voltages drops below a critical
> threshold and causes malfunctions.
>
> I don't have a spare SS1 power supply laying around, though, and I'm
> not really sure how I'd go about testing this hypothesis otherwise,
> unless I could measure something very obviously wrong.

Another (possibly more outlandish) thought might be to try and extract
more information on where it is failing.

There is an ongoing thread on port-sparc64 at netbsd.org on writing a
custom sparc64 boot loader stub that just prints a text message.
https://mail-index.netbsd.org/port-sparc64/2025/10/15/msg003379.html

I wonder if a similar approach might be helpful here? (Or do the
existing boot blocks try to output a message as the very first
action?)

David