Kernel Development Learning Pipeline

It’t time to write your first driver!

Get familiar with which system calls can be performed on a character device file.
Get familiar with how the behavior of a character device is specified by its file_operations in the driver.
Get familiar with how userspace code can invoke kernel code.

You will be assigned a random sequence of operations.
Get the code for a character driver that logs the operations preformed on it that was shown in class working on your machine
Add the ioctl and llseek syscalls to your driver (make sure to make a commit of the driver for your second patch before you add them)
- Your implementations should be based on the implementations of the read and write operations.
Write a userspace program to interact with the character driver from class.
- The userspace program will call the syscalls available through the driver in order of the sequence assigned to you. The userspace program should produce a matching output to what is assigned to you.
- Your program should check for system call errors.

A patch which adds a directory named firstname_lastname/ to the assignment repo containing a copy of your sequence from the sequence folder.
The second patch should add your version of the character driver from class
The third patch should add the ioctl and llseek operations to the existing driver.
The fourth patch should add your userspace program that implements the assignment and should add the ability to compile it to the existing Makefile.
- Make sure to have compiler warnings enabled (at least -Wall but ideally -Wextra and -Wpedantic too, or even -Weverything if you use clang) and that your code doesn’t have any warnings or errors.
The fifth patch should add a file containing the dmesg log from the driver upon a successful run of your program.
Don’t forget the cover letter.