ECS150: Introduction to Operating Systems

What to do when everything else has gone wrong

What do you do when you have really messed up the source code and want to start again from scratch? What do you do when your new kernel does not boot properly, thus leaving you with a hosed test_kernel parition? You refresh the kernel.

Refreshing the Kernel

So far, most of the work done has been on the test_kernel partition. This is because, for the most part, the student parition is off limits. There is, however, one account any student can log into: the student account. It is used to refresh the test_kernel partition.

To access the refresh program, start up the student partition (described here) by pressing 's'. When prompted to log on, use "student" as your username. This will start up the refresh menu:

  s	refresh source
  k	refresh kernel
  b	refresh both
  e	refresh everything
  q	quit

The options are fairly intuitive. Refreshing the source will remove any changes and restore the MINIX source code tree (/usr/src) to its original state. Refreshing the kernel will restore the default kernel and allow the machine to boot. Refreshing everything will restore the entire file system from the root directory down. Note, none of these changes will affect the student partition; changes will affect the test_kernel partition only.

After choosing your option, you may be prompted to make sure you really want to refresh the machine. Afterwards, you will be back at the menu. After quitting, use the Three-Fingered-Salute (Control-Alt-Delete) to restart the machine.