Date: Thu, 20 Jun 2002 13:43:14 -0700 From: "Philip J. Koenig" <pjklist@ekahuna.com> To: questions@FreeBSD.ORG Cc: "Aaron Burke" <aburke@nullplusone.com> Subject: RE: Serial console issues Message-ID: <20020620204316053.AAA681@empty1.ekahuna.com@pc02.ekahuna.com> In-Reply-To: <bulk.99297.20020619222512@hub.freebsd.org>
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> Date: Wed, 19 Jun 2002 16:30:08 -0700
> From: "Aaron Burke" <aburke@nullplusone.com>
>
> <snip>
> > > > In my case I'm not able to get the serial console working at all.
> > > > All I get on my display is some periodic commas and D characters.
> > > > I have it set for Xon/Xoff flow control.
>
> I have had similar problems in the past. The reasons for the garbage
> have generally been speed related for me. I have just had to do things
> like make sure the Dumb Term and Serial port both communicate at the
> same speed. It appears that you have at least browsed over the
> communications settings.
>
> Also, the fact that you are getting info on the terminal at all does
> mean that the BSD box is sending data to it.
I'm not so sure. Those semi-random characters have nothing to do
with the OS because they occur prior to the bootblocks even being
looked at.
Speaking of communication parameters, do you use flow-control on your
terminal? I've had mine set to S/W flow control, ie Xon/Xoff.
> > > I believe that unless your box does not have a keyboard attached the
> > > box does not turn on COM1 unless you have specified that you want a
> > > login on /dev/cuaa1. You will want to check /etc/ttys for this value.
> > > I dont remember if its turned on by default, but I always turn it on
> > > myself. Also, unless you make changes to the boot loader, the system
> > > will default to the primary graphics adapter. But your suggestion of
> > > -Dh may fix the problem. I used to have that configured, but not any
> > > more, so your guess is better than mine right now.
> >
> >
> > Hmm. Well I got the impression the login getty was optional, I
> > figured at least I'd get console boot messages without enabling a
> > login in /etc/ttys.
>
> It seems that using the login getty is not the results your looking for.
Eventually I will want that, but I'm just trying to get the terminal
to display anything before I worry about getting a login prompt.
> > > > Current FBSD versions appear to enable console operations by default
> > > > on sio0, (with the "flags 0x10" argument in the kernal config file)
> > > > so in theory all I should have to do is connect a null-modem cable,
> > > > run a comm program at 9600,N,8,1 - create a boot.config file with a
> > > > "-D" or "-h" or "-Dh" in it (or specify it to the boot loader at boot
> > > > time) and get something. I don't get any output.
>
> You are right about the "flags 0x10". But by default (if my memory is
> correct) the com port will only be used if the box is turned on without
> a keyboard, or booted with one of the boot switches. "-Dh" Has worked for
> me in the past.
"-Dh" doesn't work for me, and for the record the switch that enables
the checks for keyboard presence is "-P". (see handbook section 15
and ../src/sys/i386/boot/biosboot/README.serial)
Since I've never done this before, perhaps I'm missing some signs.
IE, in the above document, pertaining to the "-D" switch, it says
among other things:
"However, the dual console configuration takes effect only
during the boot prompt. Once the kernel is loaded, the console
specified by the -h option becomes the only console."
Therefore should the fact that the regular VGA console is still
working and showing kernel messages and providing a login prompt clue
me in that something is not being switched or recognized properly?
Or is it normal for the VGA console to look and act the same as
always when specifying the serial port be used as console?
> > > > I'm going to try it on another box and see if it's hardware related.
> > >
> > > Ok but also check that /etc/ttys is configured the same way as the
> > > terminal that your gonna attach.
> >
> >
> > I'll go ahead and do that, although I would have thought it wouldn't
> > have any bearing on whether I should have been seeing boot messages
> > or not - given the fact that among other things, they all come before
> > a login prompt would appear.
>
> Actually, dont update /etc/ttys. It sounds like you are requesting the
> console on /dev/cuaa0 as well. Changing this file will give you a seperate
> terminal here. I dont this that this is what you want.
Can you clarify how you came to the conclusion that I am "requesting
the console on /dev/cuaa0"? I have never been quite clear on what
the difference is between "sio[x]" and "/dev/cuaa[x]".
--
Philip J. Koenig pjklist@ekahuna.com
Electric Kahuna Systems -- Computers & Communications for the New Millenium
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