Step 1: Add a Source File to the Build System

To begin adding a new plugin, create a new source file in the litmus/ directory and add it to the build system.

1. Create the empty file litmus/sched_demo.c (all file names are relative to the kernel repository).

   •  $ touch litmus/sched_demo.c

2. Edit the file litmus/Makefile to add sched_demo.o to the list named obj-y.

3. Compile the kernel to ensure that everything works.

After you've verified there are no errors, create commit with git.

$ git add litmus/Makefile
$ git add litmus/sched_demo.c
$ git commit

On to the next step.