Documentation: Installing FreeBSD 7.0 via serial console and PXE

Ed Maste emaste at
Tue Jan 29 11:51:45 PST 2008

On Tue, Jan 29, 2008 at 11:09:13AM -0800, Jeremy Chadwick wrote:

> I spent 7-8 hours yesterday working on accomplishing ${SUBJECT}, and in
> the process wrote a document on it.  There are scattered docs all over
> the Web describing how to do this, but all of them are either outdated
> or incorrect in some regards (no offence intended), hence what I wrote.

Thanks for putting this together; I've also noticed there's (sometimes
conflicting) documentation on this scattered around various places.

There are a few things in your document that I question though.  For
example, you mention that installing FreeBSD via PXE requires

> iv.  Knowledge of how TFTP and DHCP work, and how to debug them if
>      they break,
> v.   Intricate knowledge of configuring a DHCP server (common
>      question: "what's the 'next-server' and 'option root-path'
>      stuff? Is it needed? Why?")

I admit that I haven't tried installing Linux or Solaris via PXE, but I
find it interesting that such knowledge wouldn't be required for them.

> vii. ... not being able to do a complete 100% TFTP-based (e.g. no
>      NFS) install

Well, you _can_ do a complete 100% TFTP-based install, but the loader
has to be compiled with an option.  I agree that is rather unfortunate.

> If you tell boot2 to set the speed to 115200 (e.g.
> comconsole_speed="115200"), it won't work ? you'll still get 9600bps.

Sure, since boot2 doesn't look at loader.conf.  You're right, if you
have a hard disk putting -S115200 in /boot.config is the best bet, and
the loader will pick the speed setting up automatically.

> But when PXE booting, there's only one piece of the bootstrap used:
> pxeboot(8). This means the only solution is to rebuild the boot
> blocks with a serial port speed that has the speed you want -- in this
> case, 115200bps. 

That shouldn't be the case; comconsole_speed="115200" should be
sufficient to set the speed.  (Granted the port will start out at 9600
until the conf file gets parsed.)

How is the console speed handled when PXE booting other operating


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