[CUWiN-Dev] reviving the boot floppy with FreeDOS

[David Young]

CUWiN used to use some PCs *so* ancient that they didn't know how to boot
off of CD-ROM.  We had to boot from a special floppy disk containing the
NetBSD bootloader and kernel.  The kernel would mount the root filesystem
on the CD-ROM.

CUWiN doesn't use those computers, currently, but we might use them again.
The NetBSD kernel we use has long since outgrown a floppy, and I'm not
too interested in maintaining a special, tiny kernel, so I have let the
floppy bootdisk bit-rot.  Today I will deactivate it altogether.

Maybe somebody out there still has a computer that is too old to boot a
CD-ROM, but not too old to have a PCI bus.  Let me propose a way to boot
such a computer from the floppy: use FreeDOS.  No, I'm not kidding.
There is a NetBSD bootloader for DOS, dosboot(8).  Make a FreeDOS
boot floppy, install dosboot.com, and add CONFIG.SYS and AUTOEXEC.BAT
files that load CD-ROM extensions (remember MSCDEX.SYS?) and then run
dosboot.com with appropriate arguments to boot D:NETBSD.

If this will work, I especially like that it gets the kernel *off*
of the floppy.  It makes upgrades easier: less media to distribute.
Also, it lets us use the floppy for storing volatile information.

Dave

-- 
David Young             OJC Technologies
dyoung at ojctech.com      Urbana, IL * (217) 278-3933