NT OS Loader + Linux mini-HOWTO Bernd Reichert, v1.0, 5 May 1997 1. Abstract This document decribes the use of the Windows NT boot loader to start Linux, a procedure which works only if you have Windows NT and Linux installed on separate partitions on the _same_ disk. This has been tested with Windows NT 4.0 WS and Linux 2.0. 2. How the NT OS Loader works The NT OS loader likes to have the boot sector from the other operating system 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. 3. Tips on how to install Windows NT and Linux on the same Disk 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. I have read from a beta driver that can read NTFS-Partitions. You may create a separate FAT-Partition for data exchange or you have to use DOS-formatted floppies. 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. 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. 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. If you have a IDE-harddisk and your Linux-partition is is the second partition, your boot-entry in /etc/lilo.conf looks like: boot=/dev/hda2 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. 4. 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 the 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 5. 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 .... 6. Play it again Sam A new copy of bootsect.lnx must be transfererd to C:\BOOTSECT.LNX every 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. 7. Open points How can I boot Linux on another disk. 8. References * The Linux+WindowsNT mini-HOWTO * The FAQ for FreeBSD 2.X 9. Feedback Any comments are welcome.