*BSD News Article 2746


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From: rick@postmaster@hq.af.mil (Rick Weldon)
Newsgroups: comp.unix.bsd
Subject: Setting up bootable DOS pertition by hand
Keywords: DOS
Message-ID: <4500@hq.hq.af.mil>
Date: 29 Jul 92 14:42:46 GMT
Sender: news@Pt.hq.af.mil
Reply-To: rick@hq.af.mil
Organization: 7TH Communications Group
Lines: 72

I want to be able to boot DOS as well as 386BSD from the 
HD. I haven't seen much discussion on this specifically.
Most of the discussion seems to be around accessing DOS 
from 386BSD.

My questions though are centered around getting DOS to boot.

I tried to use the automated install script and it blew up.
I did as the release notes suggested and used fdisk to create
a DOS partion on the beginning of the drive, but install munged
things, so I ended doing a manual install to the whole disk.
I used Chris Demetriou's method to install everything on seperate
partitions. Boot from HD-- no problem --all is well.

Now what I want to do is set up that DOS partition by
hand. I want to use the first 30Mb of the disk and leave the
rest for 386BSD. I am assuming that I will have to write the
disklabel by hand taking into consideration the DOS partition.

So I am assuming something like this: 

wd0a 32 Mb into the disk -- to 37 Mb
wd0b 37 Mb to 42 Mb swap
wd0c whole disk
wd0d 0 Mb to 30mb for DOS
wd0h 42Mb to end of disk

Now the  fun part. 

1. If I put DOS on to the first 30 Mb of the 
drive how does the boot image know where to go to boot 386BSD.
I would assume that it reads the disklabel and then looks for 
the kernel image 32 Mb into the disk on the wd0a partition.
Is this the case?

2. When I shutdown todos I assume that the shutdown program
tweaks the boot image to tell it to boot DOS instead, Or 
simply makes the DOS partition active. If the latter
is true all I should have to do is run fdisk and de-activate
the DOS partition to get back to 386BSD. This is where
things get hazy, I was hoping someone might be able to explain 
this a little better.  Another words how do I get back and
forth between DOS and 386BSD. 


I also remember reading that a lot of people were having trouble
with the shutdown -to-dos script. A complaint that shutdown
couldn't make dos bootable or something similar. Was this ever 
resolved? 


Any help at all would be appreciated. I was hoping for 
something like Chris Demetriou's step by step, but edited
to include how to set up a DOS partition by hand.

Please post here.
I read this group all of the time |-).

(Have you ever noticed that the people who want the most
information from a particular group don't read the group.
They always ask for any helpers to e-mail because they don't have
time to read the news.) 

If anyone cares I'll put the whole thing together and post it.
I have Chris's step by step. 

Thanks so much to Bill, Lynne and Chris Demitriou 

-- 
Rick Weldon     I-NET Inc. (Pentagon, 7TH Com Group)
E-mail: rick@hq.af.mil
Phone:  703-695-5060