on the boot floppies to set the 'driver_floppy' variable in the loader so
that it ends up in the kernel environment and sysinstall will prompt for the
diskette. Booting from CD-ROM does not use this loader.rc file, so folks
booting from CD to do an install will not be prompted.
X-MFC after: as soon as I finish committing to current
Approved by: re (blanket)