"Problem", when one has in mind the tip made by Gregg - I was unable to rely
  just on fdisk, because I didn't want to have a whole disk occupied just by
  NetBSD.

You can give the 169 partition only part of the disk, use a second for
Linux (1 fs, whole system as is the custom), a third for Linux swap,
and the fourth for freedos.   You can add then make the b partition in
the netbsd disklabel refer to the linux swap partition.  See mbrlabel
to do this automatically.


-- 
        Greg Troxel <gdt@ir.bbn.com>