Return to BSD News archive
Path: sserve!newshost.anu.edu.au!munnari.oz.au!constellation!ucsvax!ns1.nodak.edu!netnews.nwnet.net!news.clark.edu!spool.mu.edu!howland.reston.ans.net!xlink.net!gmd.de!mururoa!veit
Newsgroups: comp.os.386bsd.misc
Subject: Re: booting 386bsd from dos prompt
Message-ID: <1993Aug23.163606.5280@gmd.de>
From: veit@mururoa.gmd.de (Holger Veit)
Date: Mon, 23 Aug 1993 16:36:06 GMT
Sender: veit@mururoa (Holger Veit)
References: <4868@bsu-cs.bsu.edu>
Organization: GMD - German National Research Center for Computer Science
Nntp-Posting-Host: mururoa
Lines: 31
In article <4868@bsu-cs.bsu.edu>, alambert@bsu-cs.bsu.edu (Aric B. Lambert) writes:
|> Is there a way to bootup 386bsd from dos prompt ?
Actually, this should be quite simple. In one of the first issues
on 386bsd in DDJ (Dr. Dobbs's Journal, see FAQ on the numbers of issues),
Bill Jolitz describes "Three essential utilities", one of them allowing
to load a *standalone* 386bsd executable (read: kernel) from a file.
The code was written in Turbo C or MS-C, if I remember correctly.
If not available, it is a matter of some hours to write a program,
which:
1. reads the exec header of a 386bsd file,
2. from that determines where to put it in memory,
3. goes into protected mode (see primary boot loader on that), and
4. jumps to the starting location.
For 2. a kernel running above 1MB is useful, because you mustn't overwrite
the DOS while reading from file (although buffering is possible). A hard part
is probably copying into extended memory, without the services of himem.sys
(mustn't use this).
A third method is getting the secondary boot loader in memory from DOS,
and triggering it with the proper parameters (disk#, disk partition, etc.)
--
Dr. Holger Veit | INTERNET: Holger.Veit@gmd.de
| | / GMD-SET German National Research | Phone: (+49) 2241 14 2448
|__| / Center for Computer Science | Fax: (+49) 2241 14 2342
| | / P.O. Box 13 16 | Had a nightmare yesterday:
| |/ Schloss Birlinghoven | My system started up with
53731 St. Augustin, Germany | ... Booting vmunix.el ...