Running Minix 2.0 on a PC with NT Installed on It

Running Minix 2.0 on a PC with NT Installed on It

This describes how to add an option to boot Minix from the NT4.0 loader.
The description is based on the Minix Example file on the Minix cdrom.

Aside:
        Minix does not have cdrom drivers loaded in the distribution kernel. 
        The main reason seems to be the requirement to simplify the install 
        procedure and to minimise the size of the kernel. The cdrom driver 
        is for the SoundBlaster.

        This means that if you want to load Minix onto your hard disk, you 
        have to make the set of floppy disks as described in the Minix 
        documentation.

So...

In the example script, the command:
        make hdboot
causes the boot sector image to be writen to the /dev/hd3a boot sector.
This boot sector has been set to boot from /dev/hd3a as the root device.
Also, if you have used the Minix part system to modify your partitions, then
you should note the comment in "9. Active On Boot" about marking the partion 
as active. If you do this, then you will not be able to boot NT until you 
make the c: partition active again. You can do this using the MSDOS fdisk 
utility. But be warned, you can lose all of the data on the disk by making 
the wrong move with the part or fdisk utilities.


To get the NT4.0 loader to boot Minix from /dev/hd3a we have to make a 
copy of this boot sector in a file that is accessable by the ntldr.

We can use the Minix/Unix utility dd to create the file. You have to be 
logged in as root to read the /dev/hd3a device.
We then have to use the Minix utility doswrite to write the file to 
a floppy disk.
The file can then be copied onto NT drive containing ntldr.
The boot configuration file is modified to include the new operating system.

So, after the make hdboot, login as root. 
login: root
# dd if=/dev/hd3a of=bootsect.mnx count=1
        +----------------------------------------------------------------+
        | dd lists two lines showing the number of blocks read & written |
        | use:                                                           |
        | man dd                                                         |
        | to have a look at the details of the dd utility                |
        | Use the q key to quit the man utility                          |
        +----------------------------------------------------------------+
        +----------------------------------------------------------------+
        | put a dos formated floppy disk in fd0 (drive a:)               |
        +----------------------------------------------------------------+
# doswrite fd0 bootsect.mnx < bootsect.mnx
        +----------------------------------------------------------------+
        | man doswrite                                                   |
        | to have a look at the details of the doswrite utility          |
        | dosdir fd0 will list the files on the disk                     |
        +----------------------------------------------------------------+
# dosdir
        +----------------------------------------------------------------+
        | remove the floppy from the fd0 drive                           |
        +----------------------------------------------------------------+
# shutdown -h
...
System halted
hd3a< exit
        +----------------------------------------------------------------+| The system will start booting.                                 |
        | Boot the system into NT                                        |
        | Open Windows Explorer                                          |
        | Open the drive where ntldr and boot are located. I have assumed|
        |   that this is c:                                              |
        | Put the "fd0" floppy into the floppy drive a:                  |
        | Copy the bootsect.mnx file to the c:\ directory                |
        | Right click on the boot file and select the properties entry.  |
        | Remove the Read Only state and click on apply.                 |
        | Open the boot file with Notepad or Wordpad.                    |
        | Add the following line at the end:                             |
        | c:\bootsect.mnx="Minix"                                        |
        | Write the file back to disk and close Notepad/Wordpad.         |
        | Use the properties dialog to set the ReadOnly state on the     |
        |   boot file.                                                   |
        | Shutdown NT and reboot.                                        |
        | Use the new entry displayed by ntldr to boot Minix.            |
        +----------------------------------------------------------------+



Ian Cowell, MU, Department of Computing, 23 Feb 99