1. YOU CAN BE A
KERNEL HACKER
by Julia Evans
titrcmbr
wte.o/0k
gtu.o/vs
ihbcmjn
jn.a
vsc

3. WHERE WE'RE GOING
1. WTF is a kernel?
2. Why should you care?
3. Strategies for getting started with kernel programming
1. Read some kernel code!
2. Write a kernel module!
3. Write your own operating system
4. Do an internship

4. 1. WTF IS A KERNEL?

5. KERNELS ARE
JUST CODE!

6. When I go to http://google.com, kernel code runs for:
Typing in the address
Handling every network packet
Writing history files to disk
Allocating memory
Communicating with the graphics card

7. HOW TO CALL
KERNEL CODE
System calls!!!

8. SYSTEM CALLS:
A KERNEL'S API
open a file! (o e )
pn
start a program! (e e v )
xce
change a file's permissions! (c m d
ho)

9. WHAT WE'VE LEARNED
Your kernel does tons of stuff
Programs tell it what to do using system calls

10. 2. WHY SHOULD YOU
CARE?
People will think you're a badass
You'll become a better programmer

11. USUAL STRATEGIES
Read LKML
Submit patches
Linus yells at you for being dumb
Cry

12. OUR STRATEGIES
1.
2.
3.
4.
Read some kernel code!
Write a kernel module!
Write your own operating system
Do an internship

13. 3. STRATEGIES FOR
GETTING STARTED

14. STRATEGY 1:
READ SOME
KERNEL CODE

15. BUT THAT'S
TERRIFYING!!!!!
Pick one system call and try to understand one thing about it

16. Linux kernel: LXR, h t : / i e r p c m
tp/lvge.o
OS X kernel: h t : / p n o r e a p e c m
tp/oesuc.pl.o

19. STRATEGY 2:
WRITE A
LINUX KERNEL MODULE
DEMO DEMO DEMO

24. OKAY NO MORE
CODE I PROMISE

25. STRATEGY 3:
WRITE YOUR OWN OS
Not as scary as it sounds. I promise!

26. STRATEGY 4:
DO A LINUX KERNEL
INTERNSHIP

27. LINUX INTERNSHIPS
Google Summer of Code
GNOME Outreach Program for Women

28. QUESTIONS?
ht:/ihbcmjn
tp/gtu.o/vs
ht:/wte.o/0k
tp/titrcmbr
jlajn.a
ui@vsc
Resources:
ht:/i.ykrefn
tp/btl/enlu