####[ How-Do-I Documents ]#######################################
Sub : Using NT Boot Loader to boot Linux HDI - 002
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Contents:
1. LILO and dual boot
2. Why use the NT loader
3. Preparing for dual installation
4. Install Windows-NT
5. Install Linux
6. Linux part of job
7. Then in Win-NT
8. Installing other Operating Systems
9. Bootpart
10. Kudos and brickbats
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1 LILO and dual boot
1.1 There is a tendency amongst most Linux users to consider
LILO (Linux Loader) as the "pure" Linux booting system and
therefore do all sorts of re-arrangements within their own
systems to accommodate LILO ... Nearly all distros (except
for the ones operating from UMSDOS partitions), install
LILO as the default boot loader, irrespective of the fact
that the performance of LILO is at best average under some
dual boot / multi-boot conditions.
1.2 When it comes to NT, the main problem arises from the fact
that Linux as of now cannot access NTFS partitions, though
drivers are under development ( http://www.informatik.hu-
berlin.de/~loewis/ntfs ). Secondly, the boot process in NT
is at variance with the Win-9x systems, having its own
boot loader which cannot be fired off from LILO using the
"other" label in lilo.conf.
1.3 Under such conditions, I would always advocate the use of
other boot loaders.In the case of NT, I would advocate the
use of NT boot loader itself.
1.4 Besides the elegance of the boot process, you have the
advantage that there is no messing with the MBR with LILO
specially when NT is loaded on /dev/hda1 ... There are no
warnings received from few virus checkers when they find a
non-M$ boot sector on MBR !
2 Why use the NT Loader ?
2.1 Boot sector of any Operating System essentially calls the
code, somewhere within its own partition to continue with
the boot process. Essentially the boot sector has execu-
table code (along with other basic info) ... This code is
strictly in x86 machine code, and therefore independent
of any OS.
2.2 The NT boot loader makes use of this fact, and is able to
execute any such code, if available as a file within its
own NTFS partition ... It has a configurable text file by
the name of boot.ini, which can be used to fire the other
operating systems using their own boot mechanisms.
2.3 The only QR being that the boot sector of the alien OS in
its "raw" executable form should be available in its NTFS
partition, irrespecive of what the OS is. The subsequent
boot process is done using the native boot mechanism of
the concerned OS.
3 Preparing for a dual installation.
3.1 When preparing for a multi-boot installation having Linux
NT and probably a 3rd OS (Win 9x, Win-2k or QNX etc). It
is best to formulate a plan about how to go about frag-
menting your disk. It is beyound the scope of this docu-
ment to digress into those areas.
3.2 Ony one point needs to be emphasised, is that each boot-
able OS should have its installation root in a *PRIMARY*
partition. This is necessary because boot info may have
to be written on them seperately. An IDE drive can have a
maximum of four primary partitions, or three primary and
one extended partition. The extended partition may then
be subdivided into numerous logical partitions but shared
between them there is only one boot record, the one belo-
nging to the mother extended partition.
3.3 Setting the partitions
3.3.1 There are two types of situation here. Firstly, where all
operating systems are installed on a clean hard disk. And
secondly, where Win-NT may already be existing on it with
data which you can ill afford to lose. In the second case
the extended partitions would have to be deleted to make
space for the Linux installations to follow.
3.4 Marking the partitions
3.4.1 This needs to be done through Linux fdisk. The fdisk which
comes with MS-DOS or NT cannot make Linux partitions. The
tools available at this stage is to use:
a) Rescue disk sets of any distro (e.g. Slackware root and
boot disk sets, Debian rescue disk) and depending upon
the Linux flavour you wish to install, their boot disks
themselves provided they give scope for the Linux fdisk
program to be run in the beginning, and quitting with
no further installation.
b) Use stand alone disk based distros like alfalinux or
Toms root/boot disk (http://www.toms.net/rb/).
3.4.2 After booting through the rescue disk run the fdisk program
which invariably comes with the rescue disk set. Mark the
partitons as per your installation plan. In case Win-NT is
preloaded in /dev/hda1, this may be shown as Type 7. Linux
fdisk assumes the ntfs-partition to be a HPFS-partition !
This is normal. Ignore. Other extended partitions need to
be deleted before fresh ones are created/ marked.
3.4.1 For a clean state installation, mark your partitions as per
your plan. Since you would be booting through NT loader no
consideration needs to be given about the 1024th cylinder
boundary.
3.4.2 The partitions where you want Win-NT to be loaded should be
marked (Type 6 or Type 7). Normal ext2 partitions for load-
ing Linux should be marked Type 83, and one small partition
meant for Linux swap (Type 82). Make sure you keep at least
one extended-logical partition as Type 6 (DOS 16 bit). This
would be needed to share data between NT and Linux ... This
partition will be seen as D: after NT is loaded. Creating
this partition is extremely important, since this would be
needed for data transport between the two OSs.
3.4.3 Convert this partition to MS-DOS immediately. NT cannot do
a FAT-16 format. Through Linux it is easier. At this stage
do:
mkfs /V -t msdos /dev/hdaN (where N is the no of partition)
3.5 Once this part has been done, basic preparation for install
is ready. Exit out of the rescue disk session ...
4 Install Windows NT
4.1 Install Windows NT first, using the normal convention. You
will notice that C: (/dev/hda1) and D: (/dev/hdaN) are seen
Install NT on C: alone. Ensure that a boot disk is created,
and ensure that NT is functioning normally.
5 Install Linux
5.1 There is nothing different from a normal Linux installation
only that you need not create the partitions again and just
mount them as per your plan and proceed ... It is advisable
that "/" is kept on a *PRIMARY* partition because the boot
record needs to be written there.
5.2 There are only three things to look out for:
a) Some smart distros suggest mounting the HPFS partition
which it detected as part of the installation process -
IGNORE it.
b) Always make a boot disk (if not two) ... You would need
this to boot into Linux till the NT boot loader has been
charged with this duty.
c) DO NOT place LILO on the MBR. Write LILO information on
the boot-sector of the partition (usually /dev/hda2).
5.3 Once the boot-sector info has been written, either before
you quit (if your installation permits shell access) or on
first boot from floppy, ensure that the root-entry and the
boot-entry in /etc/lilo.conf is in consonance. If you have
an IDE HDD and your "/" partition is in /dev/hda2, then the
entry in /etc/lilo.conf should look like this:
boot=/dev/hda2
5.4 You would have to boot Linux through disk at this stage.
6 Linux part of job
6.1 Things to be done are:
a) Create a raw file of the boot-sector image
b) Make a mount point for 16 bit DOS partition
c) Copy file to 16 bit DOS partition
6.2 To create a raw file of the boot-sector of the Linux root
partition (/dev/hda2 for example), you need to do:
#dd if=/dev/hda2 of=/bootsect.img bs=512 count=1
This will extract exactly 512 bytes of the boot sector of
/dev/hda2 and place it in a file called bootsect.img, under
the root directory. Ensure that the filename you give con-
forms to 8.3 convention because it needs to be transported
over a MS-DOS 16 bit medium.
6.3 Since you cannot directly copy this file to the NTFS parti-
tion where the NT system lies, we need to go through the
16 bit partition we created (or carry over a floppy).
#mkdir /mnt
#mkdir /mnt/DOS-D
#mount -t msdos /dev/hdaN /mnt/DOS-D
#cp /bootsect.img /mnt/DOS-D/
#umount /mnt/DOS-D
6.4 The Linux job is over, we can quit.
7 Then in Win-NT
7.1 Copy the file from D:\bootsect.img (or floppy) to Win-NT
partition. Keep it safe in a directory (say C:\BootImg).
7.2 Edit C:\boot.ini. This is a system, readonly file. To edit
this, the attributes need to be changed. Go to a DOS shell:
C:\>attrib -s -r c:\boot.ini
C:\>edit boot.ini
7.3 Change the file boot.ini with edit (or notepad if in GUI),
as follows:
------------<snip>----------------------------------------
[boot loader]
timeout=30
default=multi(0)disk(0)rdisk(0)partition(1)\WINNT
[operating systems]
multi(0)disk(0)rdisk(0)partition(1)\WINNT="Windows NT ..."
multi(0)disk(0)rdisk(0)partition(1)\WINNT="Windows NT ..."
C:\BootImg\bootsect.img="My Linux"
------------</snip>---------------------------------------
7.4 Note : Only the last line has been added. The rest is as it
was originally. Restore the attributes after saving.
C:\attrib +s +r c:\boot.ini
7.5 The next time you boot, you should see something like:
--------------<snip>-------------------------
OS Loader V4.00
Please select the operating system to start:
Windows NT Workstation Version 4.0
Windows NT Workstation Version 4.0 [VGA mode]
My Linux
--------------</snip>-------------------------
7.6 If you select "My Linux", you will see the familiar ...
LILO loading vmlinuz ....
7.7 Note: you need to repeat this proceedure every time boot-
sector info changes, e.g. Installing a new kernel.
8 Installing other Operating Systems
8.1 As long as you have Linux and NT running, any OS running
from its own primary partition, can be made to run this way
If you have QNX on /dev/hda3, repeat steps above, only that
the partition id and filename will change:
dd if=/dev/hda3 of=/mnt/DOS-D/qnxboot.img
The NT procedure remains the same ...
9 Bootpart
9.1 There are several people who are new to Linux and would
like to tread on familiar waters. There is a Win-NT program
called "bootpart" written by G Vollant that can do the same
thing from NT directly, with no need to bother about going
into Linux to get a boot sector image, or having to change
attributes of boot.ini for editing. The URL is:
http://ourworld.compuserve.com/homepages/gvollant/bootpart.htm
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10 Kudos and Brickbats
10.1 This document is released under GNU/ GPL licence. You are
free to use and distribute this without any encumberances
10.2 Any kudos and brickbats should be directed at:
USM Bish <bish@nde.vsnl.net.in>
23 Sep 2001