Re: SparcStation 4 serial console

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

On Wed, 29 May 2024 at 08:51, Riccardo Mottola
<riccardo.mottola%libero.it@localhost> wrote:
>
> Hi,
>
> David Brownlee wrote:
> > Hardware flow control? The old Sun FAQ should mention it if anything
> > is special on the SS4.
>
> I tried enabling and disabling it.
> I kept it disable, because I have it disable for the SS20, I guess my
> cable-contraption looses it?
> With a genuine cable I use for the Netra(s), I can use hardware flow
> control.
>
> Usually at least a character, some garbage... I really get nothing.

If a device is running with hardware flow control and the other end is
not setting it usually you'll see nothing at all.

Could ofw have had an unusual baud set (though then you would expect
to see an occasional garbled character :)

> > Could there be anything set in OpenFirmware to lock the console to framebuffer?
>
> I wonder... I think it should drop to serial without keyboard, right?
> If I force in/out devices to ttya, attach a monitor, I see a black
> screen, so these OF parameters do something...
>
> Further reasoning, even if I don't get OF, I still have old NetBSD
> booting and I don't get a login console (constty). So it appears as if
> the hardware is disbled
>
> I hope my UART didn't break? Or is it hidden?

It could have been fried - I don't know if there are specific fuses
for the serial ports on an ss4?
> When booting, can I check in dmesg for a device that would represent serial?

nycbug can be a handy reference -
https://dmesgd.nycbug.org/index.cgi?do=view&id=7702
something like:

zs0 at obio0 slot 0 offset 0x100000 level 12 softpri 6
zstty0 at zs0 channel 0 (console i/o)
zstty1 at zs0 channel 1

Are you able to test with a keyboard and display? - Just to confirm if
the firmware is able to route the console there

David