NT OS Loader + Linux mini-HOWTO
Bernd Reichert, <reichert@dial.eunet.ch>
v1.11, 2 September 1997
Abstract
This document describes the use of the Windows NT boot loader to
start Linux.
This procedures have been tested with Windows NT 4.0 WS and Linux 2.0.
How does the NT OS Loader work
The NT OS loader likes to have the boot sector from the other
operating systems available as a file. It reads this file and
starts the operating system selected, i.e. either Windows NT in
different Modes or any other OS.
Tips on how to install Windows NT and Linux on the same System
Windows NT installation
Try to install Windows NT first. If you want to use NTFS for your Windows
NT-partition, keep in mind, that the todays production version of Linux
cannot access NTFS partitions.
An alpha driver that can read NTFS-Partitions is available at
http://www.informatik.hu-berlin.de/˜loewis/ntfs.
You may create a separate FAT-Partition for data exchange
or you have to use DOS-formatted floppies.
Partitioning
Another Mini-howto recommends not to use NTs "Disk Administartor"
to create the Linux swap- and root-partitions. It is sufficient to
see the free space there. I also recommend to use linux's fdisk later.
Linux installation
Now boot linux from diskettes, create the swap and root-partition.
Fdisk assumes the ntfs-partition to be a HPFS-partition.
This is normal.
Boot again from diskettes and install Linux as you like.
Just in case the installation procedure suggests that you could mount
the HPFS partition which it has found: Ignore it.
Lilo
When you come to the Lilo-Section, specify your Linux-root-partition
as your boot device because the Master Boot Record (MBR) of your
harddisk is owned by Windows NT. This means that the root-entry and
the boot-entry in your /etc/lilo.conf have the same value.
If you have a IDE-harddisk and your Linux-partition is the second
partition, your boot-entry in /etc/lilo.conf looks like:
boot=/dev/hda2
If you have two disks and your Linux resides on the first partition
of your second disk, your boot-entry in /etc/lilo.conf looks like:
boot=/dev/hdb1
Run lilo with a kernel that matches your system.
Check the kernel by booting from diskette first if you are not sure.
If you cannot boot Windows NT now, you have a problem.
I hope you have created a repair-disk recently.
Bootpart
There is a NT-programm called bootpart written by G. Vollant that can do
the jobs from the next two points for you. Bootpart is available at
http://ourworld.compuserve.com/homepages/gvollant/bootpart.htm.
If you want to know how things are working together, use the procedures
described in point 5 and 6.
The Linux part of the work
You have to boot from diskettes until the NT-part is fixed.
Now you have to peel the bootsector from your Linux-root-Partition.
With /dev/hda2 as your linux-partition, the dd-command is:
# dd if=/dev/hda2 of=/bootsect.lnx bs=512 count=1
There is something wrong if your bootsect.lnx has more
than 512 bytes.
Now copy the file bootsect.lnx to a DOS-formated floppy if this is
your way to transfer files to the NTFS-Windows-partition.
You can copy it with
# mcopy /bootsect.lnx a:
or with
# mount -t msdos /dev/fd0 /mnt
# copy /bootsect.lnx /mnt
# umount /mnt
The Windows NT part of the work
Copy the file from the diskette to C:\\bootsect.lnx. I don't tell you
how to do that.
What lilo.conf is for linux is c:\\boot.ini for Windows NT.
Remove the, system- and the read-only-attribute before you
can modify it with:
C:\attrib -s -r c:\boot.ini
Now change the file boot.ini with an editor, notepad for example, as follows:
[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 Workstation ...
multi(0)disk(0)rdisk(0)partition(1)\WINNT="Windows NT Workstation ...
C:\BOOTSECT.LNX="Linux"
Only the last line has been added in this example.
Restore the attributes after you have saved boot.ini with:
C:\attrib +s +r c:\boot.ini
After a shutdown of your Windows NT and a restart your should
see the following:
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]
Linux
Select Linux and see
LILO loading zImage ....
Play it again Sam
A new copy of bootsect.lnx must be transfererd to C:\BOOTSECT.LNX
evry time the bootsector of your linux-partition has been modified.
This happens for example when you install a new kernel with lilo.
As you can see such a system in not ideal for testing experimental
kernels.
Troubleshooting
If things do not work as expected, check bootability with a floppy disk.
With /dev/hdb1 as your Linux-partition, your /etc/lilo.conf
has the following entries:
root=/dev/hdb1
boot=/dev/fd0
Run lilo with a diskette inserted. Now try to boot from the diskette.
If your Linux on /dev/hdb1 can't be
started, the NT OS loader will also fail to start it.
If you see a lot of 01 01 01 01, your root-disk is not accessible.
Check whether all your disks are known by the bios.
If the floppy boots your Linux partition, you can peel of your
boot-sector for the NT OS loader with:
# dd if=/dev/fd0 of=/bootsect.lnx bs=512 count=1
You can keep this diskette as your rescue-diskette just in case
your Windows NT installation breaks.
References
The Linux+WindowsNT mini-HOWTO
The FAQ for FreeBSD 2.X
Acknowledgements
Thanks to Xiaoming Yi <z3c20@ttacs.ttu.edu> for the tip that
the procedures work also with other disks than the first one.
Thanks to Frank Dennler <Frank.Dennler@zkb.ch> for the
diskette-trick.
Feedback
Any comments are welcome.