Serial speed for boot device selection prompt

[Jeremy Chadwick]

On Wed, Oct 24, 2007 at 10:50:21AM -0700, Sean Bruno wrote:
> I have a drive that contains two seperate bootable partitions(ad0s1a and 
> ad0s2a).  The boot device selection menu(boot0?) appears to only be able to 
> support 9600 8N1.  I wanted to run the serial console at 115200, but I 
> currently have to switch to 9600 if I need to change the boot device.  Is 
> there a way around this that I can't see?  Could I get around this with a 
> BIOS that can do console redirection?

Which "boot device selection menu" are you referring to?  "boot0?"
implies you don't know.  Here's the difference:

boot0 is this stage:

F1  FreeBSD
F5  Drive 1
Default: F1

boot2 is this stage:

>> FreeBSD/i386 BOOT
Default: 0:ad(0,a)/boot/loader
boot:

If you want serial capability in boot0, you should set
BOOT_COMCONSOLE_SPEED=115200 in your make.conf.  After you do that,
you'll need to rebuild the boot blocks.  The procedure for doing that is
step 4 of Section 24.6.5.2 in the Handbook:

http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/serialconsole-setup.html

You'll also need to update the MBR boot code on-disk to use the new
serial version (called boot0sio).  boot0cfg -b /boot/boot0sio should
do the trick.

If you want serial capability in boot2, it's much easier.  All you have
to do is make a file called /boot.config and place -S115200 in it.  You
may also want to consider using -S115200 -Dh.  See the boot(8) manpage
for details on what -S, -D, and -h do.  Make sure you don't have a
CONSPEED setting in your kernel config as well.

All that said, chances are the boot blocks you're using are likely
configured to use data from ad0s1a (for booting).  So that would be the
place to put the /boot.config file.

-- 
| Jeremy Chadwick                                    jdc at parodius.com |
| Parodius Networking                           http://www.parodius.com/ |
| UNIX Systems Administrator                      Mountain View, CA, USA |
| Making life hard for others since 1977.                  PGP: 4BD6C0CB |