Re: SparcStation 4 serial console

[Brian Buhrow <buhrow%nfbcal.org@localhost>]

	hello.  Since you have a booting system on the ss4, the first thing I'd try is to alter
/etc/ttys so that a getty process would be started on the ttya serial port.  then, from the
root prompt, do a kill -1 1 to get init to reread the file and launch the getty process.  Then,
you should get a login prompt on the serial port, regardless of whether the console is on the
screen or the serial port.  If the console is on the serial port, you might not actually be
able to log in on the serial port because there are two gettys fighting for control, one from
the ttya specification in /etc/ttys and the other from the console line of the same file, but
in any case, that wil tell you whether your serial port is good.  If it is, then it's a matter
of getting the PROM to switch the console device to the serial port.  If it's not, then you
either have a cabling problem from the serial port to your terminal or the UART is bad.  

	Some additional notes, based on my memory, so take with grains of salt.  

1.  Be sure to check and make sure you're telling getty to initialize the serial port at the
same baud rate you're using on the terminal side.  This may or may not be the same baud rate
the PROM is using.

2.  I like to use the output of ps -l against the getty processes to see what they're actually
waiting on to determine whether they're actually talking to the serial hardware or something
else.  Unfortunately, I don't remember the name of the wait channel you're interested in.

3.  If memory serves, the ss4 has a port that combines ttya and ttyb into one DB-25 connector.
If you're using a 3-wire serial connector on the port, wired only for one serial port, then you
should have no trouble.  If, however, you're adding extra pins, be careful you're not hitting
lines that are used by ttyb instead of ttya from the ss4's perspective.  I don't remember the
pin-outs, but I'm sure there's a document running around on the Internet that tells those
details.


Hope that helps.
-Brian