Bootable CD BSD system?

[MacMan20001]

Hello.

I'm trying to make a BSD system from a bootable CD. I don't need 
anything fancy, just a shell and a few basic commands. I have the 
structure of the CD in line. My problem is with the boot image.

I've read the FAQ on bootable CDs with mkisofs, and I did what it 
said: use the format

mkisofs -U -R -b /boot/image/here -o /cd/image/here /tree/to/copy

I set the boot image to /boot/cdboo, making a guess. It said 
something like "boot image size not allowed." Then, I remembered the 
manual page where it said "boot images must be the size of a 1200, 
1440, or 2800 KB floppy". Unfortunately, none of the files in /boot 
were that size.

So, I tried a generic boot image with this command.

mkisofs -U -R -G /boot/cdboot -o /home/image.iso /home/discfolder

It accepted it, and made image.iso without error. I burned it onto 
the CD, rebooted, and it went straight for the hard disk.

I double checked my BIOS. I had put CD above the hard disk before 
when I installed, and sure enough, it never changed. I popped the 
install CD in and rebooted, and it accepted that as the boot disk.

Do I have the wrong idea about what a boot image is? or did I miss 
something? I am new at this...

Any help would be nice.
-- 
Signed,
Dan Harrison