[rescue] automatically booting a sun 3/50

[BSD Bob the old greybeard BSD freak]

> 
> Hi folks,
> 
> I do have a sun 3/50. I would like to boot automatically sd(,,4). but
> after I turn on the computer I need to enter manually "b sd(,,4)"
> because I get the following "error" message:
> 
> Diagonstic autoboot in progress...
> invalid Device=''

This implies, I think, that the prom does not have any/the correct/usable
values for the boot device string.  Somewhere around 20h and beyond in
the nvram is a string that is in ascii that codes for the boot device
incantation...e.g., sd0a, or such.  If that is not set (dead nvram?),
or has been cleared to spaces, or zeros, it won't boot.  Look in the
sun on-line feh under the sun3 section for the nvram locations affected.
I don't remember them, offhand.  Others might, or I could maybe check
tonight.  It may be in the faq or in the sun3archive info, too.

> how can I convince my sun to boot directly sd(,,4)?

Why are you booting file 4 on the disk?  It normally should boot
sd(0,0,0)vmunix.  sd(0,0,4) is only used, AFIK, in the SunOS 4.1
boot tape where it skips over the copy and another binary to get
the kernel.

> if it should matter, my rom revision is 2.7 and the precise model is
> 3/50M.

Dunno if it matters, but I think that is fine.  Make sure the drive
you are booting is set to ID=3 on the early suntoyz.... for historical
gobbledygook reasons.

Bob