quite impossible...yes. linux and freebsd can share swap http://www.linux.org/docs/ldp/howto/mini/Linux+FreeBSD-3.html but it doesn't help you out(and no longer necessary). you have at most 4 primary partitions on a disk. 1. you can have winxp and win98 in the same partition (if you choose vfat32); 2. and you need a small primary partition for /boot of linux; 3. a ext2/3 partition for linux. 4. a swap for linux 5. although freebsd can squeeze into one single partition, including swap, you don't have this last one.