From owner-freebsd-current  Sat Dec 27 22:06:47 1997
Return-Path: <owner-freebsd-current>
Received: (from root@localhost)
          by hub.freebsd.org (8.8.7/8.8.7) id WAA20582
          for current-outgoing; Sat, 27 Dec 1997 22:06:47 -0800 (PST)
          (envelope-from owner-freebsd-current)
Received: from opus.cts.cwu.edu (opus.cts.cwu.edu [198.104.92.71])
          by hub.freebsd.org (8.8.7/8.8.7) with ESMTP id WAA20576
          for <freebsd-current@FreeBSD.ORG>; Sat, 27 Dec 1997 22:06:41 -0800 (PST)
          (envelope-from skynyrd@opus.cts.cwu.edu)
Received: from localhost (skynyrd@localhost)
	by opus.cts.cwu.edu (8.8.8/8.8.7) with SMTP id WAA08953;
	Sat, 27 Dec 1997 22:06:09 -0800 (PST)
	(envelope-from skynyrd@opus.cts.cwu.edu)
Date: Sat, 27 Dec 1997 22:06:09 -0800 (PST)
From: Chris Timmons <skynyrd@opus.cts.cwu.edu>
To: Greg Lehey <grog@lemis.com>
cc: Bruce Evans <bde@zeta.org.au>, julian@whistle.com,
        freebsd-current@FreeBSD.ORG
Subject: Re: Remote gdb (was: no boot: config -g and options DDB)
In-Reply-To: <19971228161844.52116@lemis.com>
Message-ID: <Pine.BSF.3.96.971227215431.8511C-100000@opus.cts.cwu.edu>
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII
Sender: owner-freebsd-current@FreeBSD.ORG
X-Loop: FreeBSD.org
Precedence: bulk


Hmmm - well allow me to babble some more when I should instead be UTS.

Is it the case then that flags 0x50 is presently just a hush for the
serial console (i.e. you have to have both flags on the same unit and
couldn't have sio0 with flags 0x10 and sio1 with flags 0x40 - preserving a
serial console at sio0 while debugging on sio1.)  How would you start the
debugger at boot on an sio with flags 0x40?  I remember seeing Bruce's
commit messages about this so I can go back and look. 

Not being a Real Hacker I can only imagine that you might have set a
breakpoint with gdb and be running along while possibly generating
interesting output for capture on a serial console.

-Chris

On Sun, 28 Dec 1997, Greg Lehey wrote:

> > Are you sure it chooses the first sio with flags 0x10, or does the first
> > boot prompt get squirted out all eligible sio units?
> 
> It's in sioncprobe(), the function for which Bruce supplied the
> patches.  It goes out and looks for the first "enabled" console, does
> its thing and breaks out of the loop.  Its thing includes setting the
> variable siocniobase, which is used by the other serial console
> routines to specify the output port.
> 
> This stuff's pretty basic.  Don't expect it to be clever enough to
> maintain the pressure in multiple pipes :-)
> 
> Greg
>