Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!wuarchive!cs.utexas.edu!samsung!munnari.oz.au!bruce!cechew
From: cechew@bruce.OZ (Earl Chew)
Newsgroups: comp.os.minix
Subject: Re: How to use a hard disk with Minix
Message-ID: <1727@bruce.OZ>
Date: 2 Dec 89 10:56:41 GMT
References: <89334.224050TAR@MAINE.BITNET>
Organization: Monash Uni. Computer Science, Australia
Lines: 55

From article <89334.224050TAR@MAINE.BITNET>, by TAR@MAINE.BITNET (Thom Rounds):
>     You don't NEED shoelace to do that. Any fdisk (Minix or MS-DOS) will allow
> you to select the active partition. The point is, you would have a very funny
> setup if you booted off the hard disk. Minix needs to load the ramdisk, and
> having THAT on hdisk would just mean duplicate roots. Plus, the bootblock is
> NOT compatible with Minix data (i.e., it MUST be on a seperate disk). Having
> a teeny-tiny partition on your hdisk for the bootblok is rather silly, don't
> you think?

No, you're missing the my point. Booting off the hard disk is *not* a funny
setup. Requiring a floppy to boot off the hard disk *is* a funny setup. Just
count how many commercial machines require you to put a floppy in to boot off
the hard disk!

Selecting active partitions is not what's at issue here. I agree, any fdisk
will allow you to select *active* partitions. But all that does is set a bit
in the partition table. It has little to do with booting Minix off the hard
disk.

Yes, Minix needs to load the ram disk. Yes, that does mean that you need an
image of the ram disk on secondary memory. Having it on a hard disk is just as
good as having the image on floppy disk --- mind you, the hard disk version
loads much faster. I can't see what you're objecting to. You already have a
duplicate image of the root file system (on floppy). Some people even keep
their ram disk image in /dev/hd3.

Yes, the bootblock is incompatible with Minix data. Yes, teeny-tiny partitions
are silly. The solution is to throw bootblock away.

AST has allocated one block for bootstraps at the beginning of all Minix
file systems (check the book). BootLace fits in there. It will read in ShoeLace
which will load Minix from the file system. No special boot disk is necessary.
You can keep the Minix kernel image as a normal file anywhere on the hard disk
partition (eg /etc/system/minix). Or, you can keep the a.out files for the
kernel (eg /etc/system/kernel, /etc/system/mm, /etc/system/fs and
/etc/system/init) and ShoeLace will build the Minix at boot time.

This also means that you can construct a single stand-alone boot floppy instead
of the current two (one kernel image and one root file image).

WiniBoot resides in the partition table sector (cylinder 0, head 0, sector 1)
and will prompt you for the partition that you wish to boot. In this way you
can boot dos or Minix on separate partitions.

>         The Moral: No, you cannot have your cake and eat it too,
>                    even if the cake is called ShoeLace.

I *can* have my cake and eat it too. In fact, I'm eating it now and having been
feasting for quite some time now.

Earl
-- 
Earl Chew, Dept of Computer Science, Monash University, Australia 3168
ARPA: cechew%bruce.cs.monash.oz.au@uunet.uu.net  ACS : cechew@bruce.oz
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