Serial console problems with stable/8

John Baldwin jhb at
Mon Sep 13 15:10:47 UTC 2010

On Monday, September 13, 2010 8:49:48 am Oliver Fromme wrote:
> Jeremy Chadwick wrote:
>  > On Mon, Sep 13, 2010 at 09:21:21AM +0200, Oliver Fromme wrote:
>  > > Jeremy Chadwick wrote:
>  > > > Is there a PS/2 keyboard hooked up to this machine when you're
>  > > > attempting to get serial console output?
>  > > 
>  > > Kind of.  It's connected to a local KVM switch.
>  > 
>  > Does the KVM switch provide power to a PS/2 port which isn't currently
>  > selected?  (E.g. on an A/B/C/D KVM switch, if the FreeBSD box is wired
>  > to port A, and the KVM switch has port C selected, does port A still get
>  > power?)  Some KVMs do this, others do not.
> Yes, it does.
> Now I get your point ...  Yes, -P does probe the keyboard
> first.  That's probably why I see the boot0/boot2 on the
> VGA console, not on the serial port.  As far as I know,
> /boot.config is read by the boot0/boot2 stage, not by
> loader(8).

But loader inherits the settings from boot2, so if you set it in /boot.config 
you do not need to set anything in loader.conf.  Also, having boot2 use serial 
is good in that you can boot loader.old if you ever get a broken /boot/loader.  
Using '-Dh' in /boot.config is what I do on all the boxes where I use a serial 

> Anyway, I don't care too much for boot0/boot2; I've never
> had to interact with them on that machine.  The important
> thing for me is that loader(8) and the kernel use the
> serial port for the console, and that I can login on it
> (i.e. there must be a getty running).  All of that seemed
> to be accomplished with the console="comconsole" entry in
> /boot/loader.conf ...  At least it worked when I first
> installed that machine in September 2000 (yeah, exactly 10
> years ago) with FreeBSD 4.1, then updated it roughly every
> two years ...  And it stopped working in 8.x.

Did you update your hints to rename the 'sio' hints to 'uart'?

John Baldwin

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