How to reinstall the loader?

[Frank Denis (Jedi/Sector One)]

  Hello.
  
  In order to perform some benchmarks, I tried to install FreeBSD 5.3 on a
spare partition of the same disk as my DragonFlyBSD partition.

  The FreeBSD installation was a nightmare. The keyboard didn't work
(Logitech Di Novo) until I unplugged the USB cable. The installer refused to
format the partition and to install the disk labels, saying that "ad1" could
not be opened. After manual operation, the installer stopped its work during
the installation of the base system because "/" (the ramdisk) was full or
because it wasn't able to copy "-1" bytes. My external USB CDR writer froze
the kernel. Once I logged out, I couldn't log in any more until the next
reboot because the dynamic linker couldn't find any symbol in binaries.

  The worse thing is when I tried to boot my DragonFlyBSD partition
afterwards. The DragonFlyBSD loader has been replaced by the FreeBSD one,
that tries to boot FreeBSD and not DragonFlyBSD. I don't know why it has
been installed both on the FreeBSD and on the DragonFlyBSD partition. The
data is still on the DragonFlyBSD partition, but I don't know how to boot it
now.

  Is there any way to reinstall the DragonFlyBSD loader? By chance, it is
possible to do it while running FreeBSD ?

  Best regards,
  
     -Frank.