Path: utzoo!mnetor!uunet!lll-winken!lll-tis!oodis01!uplherc!nrc-ut!nrcvax!kosman!kevin
From: kevin@kosman.UUCP (Kevin O'Gorman)
Newsgroups: comp.sys.att
Subject: Re: 3b1 3.51a kernel
Message-ID: <371@kosman.UUCP>
Date: 19 Apr 88 17:15:04 GMT
References: <1603@lll-lcc.aRpA> <339@icus.UUCP> <270@amanue.UUCP>
Reply-To: kevin@kosman.UUCP (Root)
Organization: K.O.'s Manor - Vital Computer Systems, Oxnard, CA 93035
Lines: 25
Keywords: 3b1 3.51a fix disk unixpc

In article <270@amanue.UUCP> jr@amanue.UUCP (Jim Rosenberg) writes:
>In article <339@icus.UUCP> lenny@icus.UUCP (Lenny Tropiano) writes:
>>|>This brings up another question, has anyone or can you build a bootable
>>|>floppy which you can run, of course, a minimal system under?  [...]
>>
>>Yeah, I been experimenting with this with minimal luck.  I know that the
>>".vl and .sl" extentions on the fdfmt and fdfmt10 command create floppies
>>with the system loader on it.  I've booted them with a copy of /unix and
>>other stuff and it still seems to want to boot off the hard disk.
>
> ... some stuff about rootdev, pipedev, and swapdev
>
>Of course the *easy* way is to snarf the kernel from a floppy that's already
>bootable.  Has anyone tried mounting one of the bootable floppies and rooting
>around for a kernel?

Yah.  I found some interesting things a while ago when I was looking at the
boot stuff.  I didn't know what to make of it at the time, but this fits.

Try doing a cmp of the kernels on the Floppy Boot and Hard Disk Boot disks;
at that time there were only a few bytes of difference.  I didn't try comparing
with the kernel you finally wind up running, but it would not surprise me to
find something similar.  Hopefully, one part says which disk we're really
booting from, and another may say whether to pause to allow switching floppies
(the Boot floppies have a kernel and nothing else, so you can switch to a floppy
with a minimal filesystem).