Lab 1 will cover some of the basic modules and the concepts behind it.
Module 1 (helloworld) - Hello World
As per norms we start with a Hello World. This module prints "Hello World 1" to the kernel logs on insertion(insmod) and prints "Goodbye World 1 " on removal(rmmod).
You are introduced to init_module() and cleanup_module() functions.
Module 2 (hello2) - Init macros
Now let's see how we can we can change the names of the init_module() and the cleanup_module() functions - This is one of the preffered practices in the kernel programming space.
You are introduced to the module_init() and the module_exit() macros.
Module 3 (hello3) - More macros
We now try to define a global variable and print its value during the insmod to the kernel logs.
You are introduced to the __initdata macro.
Module 4 (hello4) - Module Documentation
Learn to License your driver with the GPL license and add information about your driver.
Check out the description by running the modinfo command
Module 5 (hello5) - Parameters
Learn to pass arguments to the kernel module while inserting it. And then use it
Assignment Module (assignment) - Everything UP to now
Let's Test - Complete the module as mentioned
- Take a string as a argument during
insmod - Have a integer variable 'key' defined as 13.
- Print the string taken from the user and the key in the init_module()
- Perform Ceaser Cipher on the string and print the result during cleanup_module()
- Add the name of the file in the Makefile
- Compile and test it.