Add a System Call to the Linux kernel

You will create a new system call and add it to the Linux kernel.

The new system call is called qotd, which stands for quote of the day.

qotd will randomly select a famous quote from a set of famous quotes.

find your own quotes and add them to a static array. simple. examples:

"Don't go around saying the world owes you a living. The world owes you nothing. It was here first. \n-- Mark Twain" "You miss 100% of the shots you dont take - wayne gretzkY - \nMichael Scott"

Guidance

There are one thousand and one tutorials (at least) that shows you how to go about it. Find one you like and follow it.

The process goes like this:

• Download the linux kernel and extract it.
• Modify the kernel
  • Add the system call entry to arch/x86/entry/syscalls/syscall_64.tbl (assuming a 64 bit version)
  • Write the C code that implements this function. kernel/sys.c works.
• You can also create your own C file (make sure you add it to the build).
  • Look for SYSCALL_DEFINE macro.
• Create a declaration for your system call in include/linux/syscalls.h . Remember, it's only the declaration. The function is defined in the step above.
• Compile the kernel, generate the image.
• Test the new system call: create a C program that calls the new system call.

Pro-tip

• You need a machine running Linux for this project. Windows will not help you.
• You don't have to replace Windows with Linux if you don't want to, use a virtual machine instead.
• It is ok to follow a (slightly) different path. For example, you can add your function to sys.c or add a new file. It's all good (as long as it works).
• I recommend using qemm since it is free, lightweight and easy to configure. Find a tutorial that uses qemm. Those are the best.
• Really, there's a ton of tutorials. Go read them.

Turning in the assignment

• Follow the instructions above.
• Fork this repo to your github (read the Github tutorial if you haven't already.)
• Add the files you changed to the repo, with its directories and all.
• Send me a pull request (again, see the Github tutorial.) I will give you feedback and grade you based on your pull requests.

Before I go...

Yes, this is a bit complicated, but I know you can do this. Yes, I know this. You are the very best, my little ones. YOU CAN DO THIS.