# etc/group
echo "root:x:0:" > tempfs/etc/group
echo "daemon:x:1:" >> tempfs/etc/group
echo "bin:x:2:" >> tempfs/etc/group
echo "sys:x:3:" >> tempfs/etc/group
echo "adm:x:4:" >> tempfs/etc/group
echo "tty:x:5:" >> tempfs/etc/group
echo "disk:x:6:" >> tempfs/etc/group
echo "utmp:x:43:" >> tempfs/etc/group

Making groups is probably overkill on a single floppy, but again, it's a small file and may make things easier in the future.