Run the resource manager (edge.resmgr) program and define your cd rom drive to the resource manager.
Give it a name and define the device node.
If it isn't a recordable drive, type N for recordable.
Save the resource.
Then run /usr/bin/re2, select Configure->Boot Media. Select the cd rom as the boot resource, leave the output device node blank if running UnixWare,. Back out to the main menu and select make disks.
This will create the file /usr/lib/edge/recover2/images/cdrom.img.