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From: Mark Valentine <mark@linus.demon.co.uk>
Newsgroups: comp.unix.bsd.freebsd.misc
Subject: Re: FreeBSD Boot Manager on OS/2 Dual Boot System?
Date: Sun, 31 Dec 1995 02:52:07 GMT
Lines: 56
Message-ID: <DKFJyv.1Ky@linus.demon.co.uk>
References: <4c128e$5hh@news1.cle.ab.com> <4c20ij$b4r@uriah.heep.sax.de> <DKEpz1.36q@linus.demon.co.uk> <4c48m9$f8v@uriah.heep.sax.de>
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In article <4c48m9$f8v@uriah.heep.sax.de>,
J Wunsch <joerg_wunsch@uriah.heep.sax.de> wrote:
>Mark Valentine <mark@linus.demon.co.uk> writes:
>
>> >Choose ``Let my MBR alone'' in the installation menu.
>>
>> Are you confusing Dual Boot with the Boot Manager, or am I? :-\
>
>The boot manager is installed to the Master Boot record. Well, of
>course, you could still install it, but it doesn't make any sense.
>(At least, i think that OS/2's boot manager is able to boot foreign
>partitions, so why not use _it_ instead of booteasy to select your
>system to boot?)
OK, here's the confusion...
The original question was about OS/2 *Dual Boot*. This isn't the same
as the OS/2 *Boot Manager*! "Dual Boot" is a program "boot" which allows
OS/2 to coexist with DOS on a single DOS partition, by switching the
FAT *partition* boot code just before the reboot - the syntax is "boot
/dos" from OS/2 and "boot /os2" from DOS.
OS/2 "Boot Manager", on the other hand, is the thing that installs itself in
its own little partition, and can boot operating systems in other partitions
(it's documented to handle at least DOS, OS/2 and AIX ;-). I think it uses
some trickery to boot OS/2 from extended partitions, among its other features.
I'll always refer to FreeBSD's boot manager by name ("Booteasy") to avoid
confusion in what follows. It gets installed in the Master Boot Record (MBR),
and its sole purpose is to select between individual partition bootstraps (it
can boot from a second disk, whose boot code might be a second copy of Boot-
easy...).
The OS/2 Boot Manager alone might suffice for the case of FreeBSD sharing
a single disk with DOS and OS/2, but I know at least that it won't see my
FreeBSD partition on another disk, so it's not as flexible a solution as
Booteasy. (It's also not an option in the configuration we're discussing.)
(My current setup boots either DOS or OS/2 Boot Manager or "disk 2" via Boot-
easy, and from Boot Manager I can boot either DOS or OS/2. I'm not sure if I
could have persuaded OS/2 to install without the Boot Manager, even by hiding
my DOS partition from it temporarily, and so use Booteasy instead. Possibly,
though Booteasy doesn't see the OS/2 partition itself, maybe because it's an
extended partition?)
More relevant to the original question was the setup I had previously, sharing
a FAT partition on my IDE disk between DOS and OS/2 using Dual Boot, and using
Booteasy to select between that and my SCSI disk containing FreeBSD. The same
setup works if the FreeBSD partition is also on the first disk. Without Boot-
easy, you could only ever boot whichever of DOS or OS/2 has its partition boot
code installed from the last invocation of Dual Boot.
Hope this helps,
Mark.