boot-v0.img is the boot floppy image for machines with PROM version
less than 2.x.  boot-v2.img is the boot floppy image for machines with
PROM version greater than or equal to 2.0.

tftpboot.img is the TFTP bootable image.  It can be served via
TFTP through a 'boot net' command from the PROM to allow an install
to be started without CD or floppy.