For both CS 35400-LE1 and CS 35400-001 (DIS)
lectures are available as video recordings via asynchronous access
firstname.lastname@example.org (HAAS 220, 765-494-7821)
office hours: M 1-2pm, W 2:30-3:30pm, or by appointment
(office hours are online; for on-campus students physical meetings can be set up when needed)
(office hours are online)
email@example.com, F 1-2:30pm
firstname.lastname@example.org, M 3:30-5pm
email@example.com, M 10:30-noon
firstname.lastname@example.org, W 10-11:30am
email@example.com, M 2-3:30pm
firstname.lastname@example.org, F 2:30-4pm
PSOs: (HAAS 257 and online)
T 9:30-10:20am (Jeong)
T 10:30-11:20am (Jeong)
T 11:30-12:20pm (Kochpatcharin)
T 12:30-1:20pm (Jahandideh)
T 1:30-2:20pm (Abubakar)
T 2:30-3:20pm (Abubakar)
W 11:30-12:20pm (Wu)
W 12:30-1:20pm (Wu)
W 3:30-4:20pm (Cheng)
W 4:30-5:20pm (Cheng)
R 9:30-10:20am (Wu)
R 10:30-11:20am (Jahandideh)
R 11:30-12:20pm (Jahandideh)
R 12:30-1:20pm (Cheng)
R 1:30-2:20pm (Jeong)
R 2:30-3:20pm (Abubakar)
F 9:30-10:20am (Kochpatcharin)
F 10:30-11:20am (Kochpatcharin)
Operating System Design – The Xinu Approach, Douglas Comer, 2nd edition
The midterm is scheduled on 10/08/2020.
Per Purdue regulations, the exam will be
open for a 24-hour period from 9AM EDT until 9AM EDT the following day. Exam
duration is 50 minutes but you will have 2 hours to complete. The scope of
the exam is the material covered in the lectures until (and inclusive)
10/07/2020. You may also be queried on the first two lab assignments including
code that you submitted.
We will use Gradescope, an online exam administration software provided through Purdue. You will receive notification from Gradescope with access information a few days before the exam. I will also send a broadcast email with additional logistic information on using Gradescope for the midterm exam.
- The first lab assignment has been graded. Please follow the instructions in scores.txt in the course directory to access your scores. You have one week to follow up if you have questions.
- For those interested in programming and robotics: pdf.
- The first lab assignment, lab1, will be released 09/03/2020. PSOs and TA office hours will commence when lab1 is released.
- No PSOs and TA office hours in the first week of class. Although not required, it is strongly recommended that students utilize the PSOs where lab assignment assistance is provided.
- Video lectures are recorded using Kaltura and stored on Google Drive as mp4 files for streaming and downloading. They can be accessed via links in lec.txt in the course directory. A broadcast email has been sent on 08/21/2020 with relevant details.
- PSOs and office hours will be held at designated times using a combination of Piazza and Google Meet. Please follow the procedure noted here. Do not use Piazza and Google Meet outside the times specified on the course web page.
- Lab assignments will be submitted using turnin. Details will follow when the first assignment, lab1, is released including the procedure for accessing scores.
- Midterm and final exams will be administered using Gradescope and Brightspace.
Please follow instructions given in the broadcast email on 08/21/2020 for accessing lecture slides (pdf) in the course directory. The topics listed below include material not covered in the pdf lecture slides. They should be referenced from the online lectures and additional pdf slides.
- What is CS 354 about? (pdf)
- Overview of operating system concepts.
- Von Neumann architecture, CPU instruction set, registers, main memory, programs, compilers, assembly and machine code, static and dynamic linker, loader. [Additional background for reference (pdf) which is optional.]
- Memory layout produced by C compilers, run-time stack and CDECL caller/callee convention. (pdf)
- Steps of XINU boot loading and initialization on galileo backends.
- Isolation/protection: motivation, hardware and software support.
- Organization of kernel into upper and lower halves, two pathways for switching from user mode to kernel mode.
- XINU's run-time environment, sharing, and absence of isolation/protection.
- x86-specific features: privilege levels and user/kernel mode, GDT and CS/DS/SS registers, software disabling of memory segment bound checking, GDT setup in Linux and Windows versus difference in XINU.
- Role of IDT in managing interrupt handling by operating system lower half.
- Synchronous vs. asynchronous interrupts, IF bit of EFLAGS register and interrupt disabling.
- IDT configuration and interrupt handling in XINU.
- Additional x86 and XINU interrupt/trap handling discussion for lab2. [Additional material is for further clarification and optional.]
- Process models, role of null/idle process.
- Position of scheduler within kernel upper/lower halves, two pathways of scheduler invocation.
- Management of time slice by clock interrupt handler in lower half.
CS 250, 251, 252. Ability to understand and write complex programs in C. Familiarity with system development tools.
The grade will be determined by a midterm, final, and lab assignments. Their relative weights are:
Lab assignments will have opportunities to earn bonus points. These points serve to more easily reach the maximimum achievable points in the lab assignment component. The points do not carry over and are capped at 50%.
Labs and Policies
We will use the XINU operating system for the lab assignments. The XINU lab is located in the HAAS Building, room 257. The lab is comprised of frontend machines xinu01.cs.purdue.edu, xinu02.cs.purdue.edu, ..., xinu21.cs.purdue.edu which are Linux PCs. You will use the frontend machines for operating system code development (coding and compiling/linking) and to access one of the backend machines galileo101.cs.purdue.edu, galileo102.cs.purdue.edu, ..., galileo196.cs.purdue.edu.
The fronend machines can be remotely accessed via TLS/SSL applications such as ssh on Linux/MacOS and PuTTY (or OpenSSH) on Windows. They can be used by multiple users concurrently to develop and test code. The backend machines are x86-compatible Intel Galileo boards equipped with Quark X1000 processors that are dedicated to running your implementation of XINU. Thus you are loading/running your own OS binary developed on the frontends on dedicated backend hardware. The specifics of developing and testing code in the XINU Lab will be covered in lab1.
Getting Your CS Account
Students registered in the course should have an account automatically set up. Please check by going to HAAS 257 or remote accessing one of the frontend lab machines. If you have registered but don't have an account, please contact ScienceHelp@purdue.edu.
To help manage unexpected scheduling demands, you are given a budget of 4 late days in total that may be used for late submissions of lab assignments. For example, you may submit 1 day late on four lab assignments, or 4 days late on one lab assignment. Any combination is valid as long as the total days delayed does not exceed 4. There will be a total of 5 lab assignments. Late days not utilized at the end of the semester will be converted to 15 bonus point each (maximum of 60). Outside of the 4 late days, all deadlines are hard and no partial credit will be given.Due to the low-level systems nature of the lab assignments, coding and evaluating parts of an operating system running on hardware is time intensive. To encourage proactive tackling of assignments, all submissions turned in 2 days prior to its deadline will be given a 5% bonus credit (as a fraction of the points received).
We wish to foster an open and collegial class environment. At the same time, we are vigorously opposed to academic dishonesty because it seriously detracts from the education of honest students. Because of this, we have the following standard policy on academic honesty, consistent with Purdue University's official policy.
All CS354 assignments are individual efforts and collaboration of any form is not allowed. This includes discussing solution ideas and sharing of code. Utilizing others' code found on the Internet is not allowed. If you have a question or are unsure, please contact me.
Students who share their work with others are as responsible for academic dishonesty as the student benefiting from the material. Students are not to show work to other students, and are responsible for the security of their work. File/directory permissions must be set to be unreadable to others (e.g. use "chmod -R 700 *" from your home directory). If you need assistance protecting your work, please contact the TAs or the instructor.
Students who encourage others to cheat or plagiarize, or students who are aware of plagiarism or cheating and do not report it are also participating in academically dishonest behavior.
We will use a software tool, MOSS, to check for copying among submitted assignments. Additionally, we will inspect all submitted material to detect academic integrity violation.
If you have any assignment related questions, please utilize the PSOs and office hours which are scheduled Monday-Friday. The main difference between getting help on coding related questions from the instructor/TAs versus a fellow student is that the instructor/TAs will provide assistance that help you tackle a problem on your own without revealing the solution.
Any case of academic dishonesty will be dealt with by a severe grade penalty in the overall class grade and referral to the office of the Dean of Students.
In the event of an emergency, course requirements, deadlines, and grading percentages are subject to changes that may be necessitated by a revised semester calendar. If such unusual circumstances arise, students may determine any such changes by contacting their instructors via email or phone, and checking the course web page for updates.
Campus emergencies and closings will be announced on local media and on the main Purdue University WWW site http://www.purdue.edu. Please consult the Purdue emergency preparedness resources web site for detailed information and relevant resources. Consult the Protect Purdue Plan for COVID-19 specific information.
In the event of health issues, including COVID-19, please contact the Protect Purdue Health Center (if on-campus), or a physician, to receive medical attention. Then contact the instructor, when feasible, so that remedial actions can be undertaken such as deadline extensions and make-up exams.
This is an undergraduate introductory course to operating systems that investigates how modern operating systems are architected and implemented. Extensive implementation experience is gained by coding, testing, and benchmarking key components of the XINU operating system on dedicated backend hardware. Our main implementation platform will be x86-compatible backend machines and Intel x86 frontend PCs where code is developed. Most coding is done in C, with some hardware dependent components utilizing assembly language.
The topics covered in the course include: evolution of computing systems and their operating systems, process management, inter-process communication, memory manangement, virtual memory, I/O subsystems and device management, file systems, virtualization and security, and mobile operating systems. In addition to implementing key OS features in XINU, we will examine case studies in Linux, UNIX (Solaris and BSD), and Windows that differ from XINU and each other in significant ways. One important example is how I/O subsystems are architected to handle a range of heterogenous devices and their interrupts, including high-speed USB and wired/wireless network interfaces, that characterize many of today's computing systems. Kernel dependence on changing hardware features and support is an important theme throughout the course that will help familiarize with recent developments such as non-traditional file systems for flash memory prevalent in mobile systems. We will touch upon mobile OS (e.g., iOS, Android) with emphasis on differences with desktop/server operating systems.
Upon successful completion of the course, you will understand how modern operating systems are designed and implemented. You will understand how operating systems interface with hardware. You will have gained the technical skills to program operating systems and evaluate their performance.