RELENG_6: serial console drops back from 115200 to 9600 baud

[Ed Maste]

On Sun, Feb 26, 2006 at 02:37:08AM +0100, Dimitry Andric wrote:

> Ed Maste wrote:
> > What's in your /boot.config?
> 
> In my case, I use -P, because I usually don't have a keyboard hooked up,
> but ocasionally do use it.  Additionally, I had console="comconsole" in
> my /boot/loader.conf.  However, commenting that out doesn't help either.
> 
> I guess the -P option causes the console variable to be set too?  In
> that case comc_probe might pick it up, and never change the speed from
> what the BIOS configured.  (Note that I've never used boot0sio, and
> AFAICs the 'normal' boot0 doesn't mess with the serial port speed.)

True, but boot.config is processed by boot1/2 that's installed in the
slice.  That boot does have knowedge of the serial port and sets the
speed as Ian points out.

So I suspect that the following happens when you boot:

- your BIOS sets the serial port to 9600
- boot0 does nothing with the serial pot
- boot1/2 reads the -P in /boot.config and detects no keyboard, and
  then sets the serial port to 9600 and the console to comconsole
- the loader detects that the serial port is enabled and is already
  set to 9600

Thus, I'm not surprised that you get a 9600 baud console without
an rc.conf setting.  The thing that concerns me is your report that
the console does not run at 115200 even if /boot/loader.conf
contains comconsole_speed="115200".

-ed