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Date:      Wed, 19 Jun 2002 09:27:58 -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:  <20020619162802043.AAA668@empty1.ekahuna.com@pc02.ekahuna.com>
In-Reply-To: <NGBBLCIHCLNJAIGIFFHJOEICCFAA.aburke@nullplusone.com>
References:  <20020618235524270.AAA595@empty1.ekahuna.com@pc02.ekahuna.com>

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On 18 Jun 2002, at 23:26, Aaron Burke boldly uttered: 

> <snip>
> > djf2 <djf2@danu.ili.net> wrote:
> > > > On Tue, 18 Jun 2002, Aaron Burke wrote:
> > 
> > > > You should be able to use "dmesg | grep sio" to determine what kind
> > > > of hardware you are running.
> > >
> > >  I'm fairly certain it isn't the hardware, at least in my case. 
> > >  I've used several different machines that were at least 
> > relatively recent
> > > hardware (at least past the point where they wouldn't have had a 16550
> > > uart) and the serial console exhibited the same behavior each time.
> > 
> > 
> > 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 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.

According to the handbook section on serial consoles, all you are 
supposed to need is to make sure the kernel config enables console 
mode on a serial port (seems to be the default now on COM1) and 
create a /boot.config file using one or more of the following 
switches:

-D  (sends initial console output to both video and serial)

-h  (toggles console output - ie if normally to video, makes it go to 
serial)

-P  (this is the switch that is supposed to only redirect console 
output to serial if there is no keyboard attached)


From what I gather, recompiling the boot blocks is only required if I 
want to do something like change the default console COM port, or the 
default speed. (but as you know others mentioned they couldn't get 
the speed to change anyway)

I just updated the "BMC" code (Baseboard Management Controller) on 
the board which has some control over serial management stuff, but it 
didn't help.  Everything else is the latest.

I even tried 2 different kinds of "null modem" cables. (So did you 
know that both HP and Intel console cables for their Ethernet 
switches are not only different from, and incompatible with each 
other, but also different than a standard null modem cable?  Reminds 
me of the old adage: "The nice thing about standards is, there are so 
many to choose from..." :-)


> > 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.
> > 
> > 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.



--
Philip J. Koenig                                       pjklist@ekahuna.com
Electric Kahuna Systems -- Computers & Communications for the New Millenium


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