dual boot with freebsd boot loader

Björn König bkoenig at cs.tu-berlin.de
Tue Aug 2 15:41:39 GMT 2005

Petre Bandac wrote:

> I have the following configuration
> ad0s1 - win xp with ntfs 
> ad0s2 - freebsd
> they were installed in the above order, so now I can use only freebsd
> is there a way to configure freebsd's boot loader to be able to boot
> from the win partition (I googled around and found boot0cfg (8), but
> didn't have the time to play with it)

Yes, this is possible.

     # sysctl kern.geom.debugflags=16    // make the MBR writable
     # boot0cfg -s 1 /dev/ad0            // set default selection

You'll find further information and even examples in the manpage of 

> what I want to know is if (making a similarity with linux's lilo) I can
> make the boot loader to  have the options 1) boot win, 2) boot freebsd

This should be the default behaviour of boot0. In case you didn't 
installed it yet you can do it with

     # sysctl kern.geom.debugflags=16    // make the MBR writable
     # boot0cfg -B /dev/ad0              // install boot0

Regards Björn

Björn König (bkoenig at cs.tu-berlin.de)
student at the Technische Universität Berlin

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