Serial console problems with stable/8

Oliver Fromme olli at
Mon Sep 13 15:55:46 UTC 2010

John Baldwin wrote:
 > On Monday, September 13, 2010 8:49:48 am Oliver Fromme wrote:
 > > 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 console.

Makes sense.  I'll change -P to -Dh.

But having console="comconsole" in loader.conf should also
enable the serial console, except that it happens a little
later (in loader instead of boot2), right?

I think the boot.config stuff might be a red herring.
The console breaks (i.e. freezes) as soon as I try to run
a getty process on it -- That seems to indicate that getty
does *something* to the console device which causes the
problem.  The wchan "ttydcd" seems to indicate is has
something to do with carrier detection or flow control.
This points to the uart driver as the culprit which
replaced sio.

 > > 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'?

Yes, mergemaster did that for me.  I double-checked it."isa"

Best regards

Oliver Fromme, secnetix GmbH & Co. KG, Marktplatz 29, 85567 Grafing b. M.
Handelsregister: Registergericht Muenchen, HRA 74606,  Geschäftsfuehrung:
secnetix Verwaltungsgesellsch. mbH, Handelsregister: Registergericht Mün-
chen, HRB 125758,  Geschäftsführer: Maik Bachmann, Olaf Erb, Ralf Gebhart

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