Installing Minix 2 on VirtualBox

Minix 3 has been out for a long time, but Minix 2 is simpler and can be a better basis for experimentation. It's convenient to install Minix on a virtual machine so that installations can be cloned in seconds, trashed at leisure and discarded at will. Although it's possible to download an installation of Minix 2 on VMware Player, I find VirtualBox more convenient for experimenting, even though the networking doesn't seem to work.

Here's a step-by-step guide to installing Minix 2 on VirtualBox with a Linux host.

Stage 1: fetch the software and prepare a boot disk.

• Download the Minix 2 distribution from http://www.minix3.org/previous-versions/gzipped/Intel-2.0.4.tar.gz and untar it.
• Make an empty 1440kB floppy disk image with

dd if=/dev/zero of=boot.img bs=1k count=1440

• Concatenate the root and usr images from the Minix distribution and write them to the floppy image with

cat Intel-2.0.4/i386/ROOT.MNX Intel-2.0.4/i386/USR.MNX | dd of=boot.img conv=notrunc

Stage 2: create a virtual machine

• Now make a new VirtualBox machine as follows:
  • Name=Minix, Operating System=Other, Version=Other/Unknown.
  • Base Memory Size=64MB.
  • Create new hard disk, VDI, Dynamically allocated, 200MB.
• Choose Settings/Storage for the new machine.
  • Delete the CD drive
  • Add a second hard disk to the IDE controller: Create new disk, VDI, Fixed size, Location=MinixDist.vdi, Size=20MB. Put the image in the same directory as boot.img.
  • Add a floppy controller and a floppy drive containing your image boot.img.

Stage 3: prepare the installation disk

• Cross your fingers and boot the machine.
  • Type = to boot, fill in the /usr device as /dev/fd0p2, login as root.
  • Partition (using part) and format (using mkfs) the 20MB drive that appears as /dev/c0d1 with a single Minix partition that fills the disk.
  • Make a minix file system, and mount it to check.

mkfs /dev/c0d1p0
mount /dev/c0d1p0 /mnt
df

• Type shutdown and close the window to power off the virtual machine.
• Now mount the disk image under Linux, copy the Minix files, and unmount it.

sudo mount -o loop,offset=2129408 MinxDist.vdi /mnt
sudo cp Intel-2.0.4/i386/* Intel-2.0.4/src/* /mnt
sudo umount /mnt

Stage 4: actually install Minix.

• Now boot the virtual machine again.
• Follow the instructions in usage.txt to install Minix.
• There's no need to create a swap partition, because 64MB RAM is plenty to run Minix.
• When you get to the stage of installing the rest of /usr and the system source, mount the 20MB disk on /dist, and all the files you need will be there.

mkdir /dist
mount /dev/c0d1p0 /dist
setup /usr </dist/USR.TAZ etc

• Don't forget to remove the floppy disk image from the virtual drive when you've finished.

Stage 5: enjoy.

• You can mount the 20MB disk under Linux again or under Minix to transfer files back and forth. Just don't try to mount it in both places at once.

Issues

• Minix 3 installs in VirtualBox with no problems. Just insert the ISO image into the virtual CD-ROM drive, boot the virtual machine, and follow the instructions. Choose the PCnet-PCI II network adapter, which Minix can access using the LANCE driver, included in the 2.04 fixes.
• The ethernet driver doesn't seem to work in Minix 2, but the one provided in Minix 3 does work. Maybe the working one can be ported across. [Update: yes it can. Details to follow. (29/9/2011)]
  • I can't now find any evidence that I ported the Minix 3 version of lance.c – Mike (talk) 00:17, 8 June 2016 (BST)
    • On further experimentation, it seems that I didn't port it. But it seems best to set up Minix with a fixed IP address and not rely on DHCP.
• On my laptop, there's no NumLock key (or rather, there is one, but it functions in a non-standard way). Sometimes, VirtualBox thinks the NumLock is on, and unhelpfully inserts a NumLock keypress into the keyboard buffer of Minix at startup. The result is that the arrow keys don't work. Fixes: use an external keyboard to turn NumLock off; or hack the Minix keyboard driver to ignore NumLock.

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