Sun Box will not auto boot

I have my Sparc 5 up and running now. I have a Debian distro of Linux
running on it. I want to make it a firewall but I have one problem. When I
boot it up there is a message about a bad argument from the boot prom. If I
boot it from the boot floppy I made it boots. This means that I must type
the command "boot floppy" every time I boot up. If I do not type the command
it can not boot. What to I have to do to boot from the hard drive
automatically at boot up time?

David