Re: [debian-knoppix] Problem: Dual booting from HD without using floppy/cdrom drive.
On Wed, May 15, 2002 at 11:56:00PM +0200, David GLAUDE Mailing wrote:
> > This will not work. I'm pretty sure it won't.
>
> Well, I see no difference in booting a FAT12/16/32.
The problem is, you DON'T boot FAT, you boot a file that contains an
operating system from a device. Your BIOS has no idea what a DOS or ext2
or any other filesystem is before an operating system is running. The
bootloader loads a file block-wise from a device.
Floppy disks are devices (BIOS device number 0), andthe Bios El Torito
extension maps a CD to this device number when booting from CD.
The boot process is different from HD.
> I guess if you dd a floppy on an HD and set the partition as bootable
> and put something resonable in the MBR you can boot the "floppy-like"
> partition.
If you get this working without writing a special bootloader in
assembler, I would be amazed. :-)
> This is not unresonable, I believe.
No, but more work than necessary, I would say.
> And the reason I wanted to do it with a floppy image
> was to automate the process and if you change the floppy,
> it should be easy to re-install the boot mechanism.
What you CAN do is install a LILO bootrecord on the partition that
contains Kernel and miniroot.gz, and create a boot redirector for that
partition (dd if=/dev/hda2 of=hd2.mbr count=1 bs=512 should do the
trick), and tell your Windows boot.ini that this hd2.mbr file is an
operating system.
> > Hmm, can't tell you anything about that, I never had a Windows partition
> > anywhere on my computers. :-)
>
> Ha, you must be one of those pure from GNU religion.
No, definitely not. I started with AT&T Unix, worked with Solaris and Aix
for a while, occasionally on AmigaDOS and more frequently on Linux.
But I need an operating system to be flexible enough to do what _I_
want, not the other way round. ;-)
Windows is simply too complicated for me. I don't understand what to do
if it tells me that the general protection fault 0x06347 just destroyed
several hours of my work, and how I can fix it. And I find most of its
applications way too complicated to use.
But that's my personal preference. Everyone should use the OS he/she can
work best with.
> Are you a saint?
No.
> Are you using vi or emac?
Emacs is too complicated for me. I use different editors as needed.
vi most often because it is the fastest way for my programming needs.
Sometimes OpenOffice or xfig.
Btw. is this some kind of questionaire? ;-)
> Well to boot knoppix of course. ;-)
> Apparently if you put the boot sector of a system into a file,
> then tell Win2k (in boot.ini) that it should boot that...
> Then it boot. At least that is one way to dualboot.
Yes, this could work, but if you try to do that with the boot sector of
a floppy, it will probably try to load a kernel from the floppy device,
not from the image on HD. Just an educated guess. ;-)
> If you say so. ;-)
> I guess it should be possible to chain bootloader and boot sector.
> Did I say that I am not a boot expert, nor a windows expert. ;-)
If you manage to get a floppy image in HD to boot from Windows, I
would consider you an expert in both, and would feel honoured to
be allowed to include your discovered procedure on the CD.
> > Ok, I guess you can stop now and go for something that is more likely to
> > succeed. ;-)
>
> We will see at the autopsy.
I'm looking forward to it. :-)
> > What you are trying to do is running a floppy image from a HARDDISK in
> > "el torito boot mode". This is not possible. Your Computer's BIOS simply
> > won't understand your intention.
>
> I hope some reader from the mailing list will understand what I try to do,
> and have enough Win2k booting background to help me.
What you can probably do is copying Kernel and miniroot.gz from the
floppy to a HD partition, write a lilo bootrecord to this partition and
then copy the bootrecord to a file like mentioned above.
You could maybe also do this with a loopback mount of the floppy from
HD and lilo, but this could fail due to mapping errors between loopback
blocks and physical blocks.
Oliver says he could do this with a script if the loopback procedure
works, you may want to contact him. (I think he is bluffing, though). ;-)
-Klaus
--
Klaus Knopper LinuxTag 2002 - Europes largest Linux Expo
Technical Solutions Where .com meets .org
knopper@linuxtag.de http://www.linuxtag.de/
Phone +49-(0)180-5-546898 Fax +49-(0)180-5-546893
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