Debian and Freebsd; booloader behaviour

[Marco Calviani]

Hi list,
   i would like to install Freebsd 6.0 in a separate partition within my HD in which Debian Sid is perfectly running.
Does anyone had some advice on how to setup the freebsd bootloader during installation to enable GRUB (of my Debian box) to recognize the freebsd partition?
Or in a second place how to setup again GRUB after having deleted it for the BSD bootloader, if the first one is not possible?

Thanks in advance,
MC