Minor modification to Minix

In this exercise you will make the following minor modify the Minix startup banner.

As part of the boot process the Minix kernel displays a startup banner, that includes the following line:

Minix is open source software, see http://www.minix3.org

You should be able to see this line when startup has finished and the console login prompt is displayed. Modify the startup banner by adding the following line:

Minor mod 1.0 by <Your First Name> <Your Last Name> (<Your student id>)

after the line about Minix being open source software.

After modification, the startup banner will display the following two lines:

Minix is open source software, see http://www.minix3.org
Minor mod 1.0 by Joe Bloggs (120456789)

with "Joe Bloggs" and the student number replaced by your own details.

The startup banner is hard-coded in the kernel source code. To make the changes you must:

  1. Modify the kernel source code by adding a printf statement as the last line of the announce function that displays the startup banner. That is, find the announce function in /usr/src/kernel/main.c and add an appropriate printf statement after the statement that displays the "Minix is open source software ... " line. The text to display is as specified above.
  2. Compile and install a new version of Minix

Minix uses make to compile and install a new version of the kernel and operating system. All you need to know for now is that there is a Makefile in /usr/src/releasetools that automates this process. To compile and install your new version of Minix:

  1. Go to the /usr/src/releasetools directory.
  2. At the shell prompt, in /usr/src/releasetools, type make usage
    You will see a list of usage options including options to create a fresh Minix configuration.
  3. At the shell prompt, type the make option to install a new boot image:
    make clean install

Assuming compilation and installation succeeded, you have now compiled and installed a new Minix boot image.

Reboot Minix and choose option 2 - "Start Latest Minix3" - from the boot menu. Your modified startup banner should be displayed. The original boot image is still available and you can boot from it. You can verify this by looking in the /boot/minix directory where you will see the different versions of minix that have been compiled and installed.

When you have completed the above, move on to the C exercises.

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