root and boot floppy on ISC

James P. H. Fuller jim at crom2.uucp
Sat Apr 13 03:53:37 AEST 1991


> > > 	copy /etc/boot to track 0 (for 386/ix 1.0.6 anyway)
> >     ^^^^^^^^^^^^^^^^^^^^^^^^^
> > This is the part I can't figure out how to do.  Any hints?
>
> Oh, heck, people--just use dd to read the install floppy into a file,
> and then back onto a formatted new disc. Mount it, and hack away.
> This way, you copy the boot loader plus the existing file structure
> (and most of the stuff in /dev, /bin, and /etc that you'll need anyway).

     This seems to work, and gives you a *pair* of "emergency boot floppies"
since what ISC gives you is a boot disk that brings up unix and then passes
control to an install disk with a small file system, utilities (like cpio),
and all the ISC installation scripts.  But I'm still curious -- first off, the
boot loader can't be on the install disk, can it?  I mean, that isn't the one
that boots!  And it seems that you ought to be able to make *a* boot floppy,
not a pair of 'em, since /unix can't take up anything like all of a 1.2 meg
floppy (my hard drive /unix is only 581206 bytes right now) and that leaves
plenty of room for all the utilities you would need for emergencies, (after
you wiped the install scripts.)

     But you *can't* hack a copy of the boot floppy itself (even though it's
cloneable by either dd or DOS diskcopy) because it isn't mountable, because
mount doesn't recognize it as containing any kind of valid filesystem.  It
isn't 1K, it isn't 2K, it isn't DOS, it isn't XENIX, and that's all the types
of filesystem that come with ISC.  fstyp(1M) can't make head or tail of the
boot floppy.  Has anyone got any idea what it is?

                                              James P. H. Fuller
                                              jim%crom2 at nstar.rn.com



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