605.612.81 - Operating Systems

Course Structure

The course content is divided into modules. Course Modules can be accessed from the Course Modules page located on the left navigation. A module will have three main sections: Overview, Content, and Assignments. Students are encouraged to preview all sections of the module before starting. Most modules run for a period of seven (7) days, exceptions are noted on the Course Outline located in the Syllabus and Course Information page; module start dates are also clearly posted on the Course Calendar. Students should regularly check the Calendar and Course Announcements for assignment due dates.

Course Topics

The theory and concepts related to operating system design are presented from both developer and user perspectives.

Core concepts covered include process management, memory management, file systems, I/O system management including device drivers, distributed systems, and multi-user concepts including protection and security. Process management includes discussions on threads, scheduling, and synchronization. Memory management includes discussions on paging, segmentation and virtual memory. Students will examine how these concepts are realized in several current open source operating systems including Linux and others. Students should also expect to design and implement several of the covered concepts using a high-level language.

Course Goals

The goal of this course is to identify and describe operating system design concepts, to ascertain how these concepts are properly applied in various types of operating systems, and to implement some of these concepts in modern operating systems.

Course Learning Outcomes (CLOs)

• Describe operating system design concepts.
• Analyze modern operating systems to explain how operating system concepts are realized.
• Construct new operating system capabilities in the content of modern operating systems.

Textbooks

Tanenbaum, A. S., & Bos, H. (2023). Modern operating systems (5th ed.) Pearson.

ISBN-10: 0-13-761887-5

ISBN-13: 978-0-13-761887-3

Textbook information for this course is available online through the appropriate bookstore website: For online courses, search the MBS website at http://ep.jhu.edu/bookstore.

Other Materials & Online Resources

Additionally, any of the following texts or other texts that you may have from previous courses may be useful for this class:

Silberschatz, A., Galvin, P. B., & Gagne, G. (2007). Operating system concepts with java (7th ed.). Hoboken, NJ: John Wiley & Sons.

ISBN-10: 047176907X

ISBN-13: 978-0471769071

McKusick, M. K., Bostic, K., Karels, M. J., & Quarterman, J. S. (1996). The design and implementation of the 4.4 BSD operating system (2nd ed.). Reading, MA: Addison-Wesley.

ISBN-10: 0201549794

ISBN-13: 978-0201549799

Required Software

SSH

For this course, you will use a UNIX account on absaroka.jhuep.com. Login access to this server is via the SSH protocol. Thus, in order for you to easily interact with the UNIX system you must get a secure terminal emulation program that uses ssh. There are several good programs available for free; for example PuTTY, a free software program available from http://www.chiark.greenend.org.uk/~sgtatham/putty/.

SFTP

You may also want to be able to transfer files between your system and the UNIX systems. Some type of "file transfer protocol" (FTP) client will be required. I recommend that you try "FileZilla", which can be downloaded from: http://sourceforge.net/project/showfiles.php?group_id=21558. Make sure when you install this program, you configure it to use SFTP (Secure FTP).

VirtualBox

VirtualBox is an open-source, free virtual machine that runs on Linux and other platforms. You will be able to use VirtualBox directly on the Linux server absaroka.jhuep.com where you can boot, modify, build and test your own operating system. Although VirtualBox is available on the absaroka server, you may wish to download VirtualBox for easier local access (https://www.virtualbox.org/wiki/Downloads, or search for ‘VirtualBox download' from google, or ‘VirtualBox windows download' for a VirtualBox version that runs on Windows). Keep in mind that even if you work on a local copy of VirtualBox, you must verify that you can properly boot your operating system image on the VirtualBox virtual machine on absaroka.jhuep.com (enough disk space shall be provided).

VNC Client

The UNIX server used for this course supports a "Virtual Network Computing" server which allows you, via a VNC client, to connect to a desktop session on the UNIX server. From there, you can run VirtualBox to fully run your operating system with a virtual machine. You must pick up a VNC client compatible with your computer to support your project development.

Student Coursework Requirements

It is expected that each module will require 5–8 hours per week to complete. Here is an approximate breakdown: reading the module content and the assigned sections of the texts as well as some possible outside reading (approximately 2–3 hours per week), discussion participation (1 hour per week) and assignments including hands-on operating system projects using Minix (approximately 2–4 hours per week).

Note that the operating system projects are spread out over several weeks or modules, so if a student does not put the time into the project during the initial days of the project assignment, a student will need to make up that time as the due date of the project approaches. In other words, course work will be available to allow students to maintain a consistent week by week workload, but procrastination may require a heavier workload as the due date of a project approaches.

This course will consist of four basic student requirements:

• Class Discussions (25% of Final Grade)
• Problem Sets (25% of Final Grade)
• Projects (25% of Final Grade)
• Quizzes (25% of Final Grade)

Each of these requirements is discussed in detail below.

Class Discussions (25% of Final Grade)

Each student is responsible for carefully reading all assigned material and being prepared for discussion. The majority of readings are from the course text. Additional reading may be assigned to supplement text readings.

A minimum of two posts are required for each discussion question: an initial post and a response. These posts are due by midnight of the due date as specified in the Course Calendar. Be concise, but support any assertions using the textbook or other external sources. Keep your posts to a single topic to promote lively discussion. Feel free to agree or disagree with your classmates, but please ensure that your postings are civil and constructive.

Responding to Class Discussion Topics— Your instructor will monitor class discussions and will respond to some of the discussions as needed. In some instances, your instructor may summarize the overall discussions and post the summary for the class (or may assign a student to do so).

Grading the Class Discussions— Your instructor will provide a grade (with rationale, if necessary) for your post within 48 hours of your post.

Each discussion is worth 6 points— 3 points for the initial post, and 3 points for a response.

If a student receives less than full credit for an initial post, they may post follow-up responses to their own initial post to further clarify and repair shortcomings.

Students are not limited in the number of responses they can provide for a discussion. Each response is graded independently, so regardless of the number of responses, you will receive a grade for your best follow up post.

Each discussion post is graded as follows:

3 points— a full credit posting will thoughtfully consider and respond to the question (or classmate's message), demonstrating critical thought with support from course resources. Not only will such a post engage with the ongoing conversation in a rhetorically suitable fashion, it will foster further discussion on the topic, perhaps exploring new lines of discussion or different perspectives. The three-pointer isn't just a response; it's proof that you are facilitating learning both for yourself and your fellow students. Usually, you should include a reference to support your claims in the post.

2 points— this posting is a competent response to the subject. It addresses the question, without demonstrating sufficient critical thought, and perhaps missing support for your assertions from your course or other on-line resources. This post contributes to the overall conversation as another voice on the subject.

1 point— reflects a less-than-adequate engagement with the subject, perhaps repeating a thought from another student in the discussion without adding much to it. It does little to advance the discussion underway, and does not demonstrate critical thought. Provided information is thin and commonplace. External support for your assertions are missing.

0 points— No post, only a brief nod toward the discussion, a post that is completely unrelated to the discussion or module content, or a post which detracts from the discussion (e.g. is a "flame").

A post missing the deadlines as laid out in the Course Calendar by a few days lose a point; posts made more than a few days after the deadline will not be graded.

Problem Sets (25% of Final Grade)

Reading assignments are important sources of material for your written assignments.

There will be 5 problem sets assigned throughout the course, one for each major topic. Each problem set is graded based on 100 percentage points. Problem Sets consist of several questions (not quite short-answer). Problem sets are not timed (but do have a firm due date). You may use whatever references at your disposal to complete the problem set. The problem set grades are averaged together to a single score, which is averaged into the final course grade.

Problem sets include a mix of quantitative and qualitative problems (mostly qualitative). Problem sets will be assigned using an assignment item within the corresponding module.

Qualitative assignment problems will be evaluated using the following grading elements:

1. Each part of question is answered.
2. Rationale for answer is provided.
3. Outside references are included if needed.
4. Writing quality and technical accuracy (Writing is expected to meet or exceed accepted graduate-level English and scholarship standards. That is, all assignments will be graded on grammar and style as well as content).

Qualitative assignments will be graded as follows:

• 90–100(A)—All parts of question are addressed; Writing Quality/ Rationale/ Examples/ Outside References [rich in content; full of thought, insight, and analysis].
• 80–89(B)—All parts of the question are addressed; Writing Quality/ Rationale/ Examples/ Outside References [substantial information; thought, insight, and analysis has taken place].
• 70–79(C)—Majority of parts of the question are addressed; Writing Quality/ Rationale/ Examples/ Outside References [generally competent; information is thin and commonplace].
• <70(F)—Some parts of the question are addressed; Writing Quality/ Rationale/ Examples/ Outside References [rudimentary and superficial; no analysis or insight displayed].

Quantitative assignments will be evaluated using the following grading elements:

1. Each part of question is answered;
2. All assumptions are clearly stated;
3. Intermediate derivations and calculations are provided;
4. Technical correctness;
5. Answer is clearly indicated;
6. Answer precision and units are appropriate.

Quantitative assignments will be graded as follows:

• 90–100(A)—All parts of question are addressed; All assumptions are clearly stated; All intermediate derivations and calculations are provided; Answer is technically correct and is clearly indicated; Answer precision and units are appropriate.
• 80–89(B)—All parts of question are addressed; all assumptions are stated, some intermediate derivations and calculations are provided, the answer is technically correct, the answer is indicated, the answer precision and units are appropriate.
• 70–79(C)—Majority of parts of question are addressed; assumptions are partially stated, few intermediate derivations and calculations are provided, the answer is not technically correct, the answer is indicated, the answer precision and units are indicated but inappropriate.
• <70(F)—Some parts of question are addressed; assumptions are not stated, intermediate derivations and calculations are not provided, answer is missing or incorrect, answer precision is inappropriate and units are missing.

Projects (25% of Final Grade)

Throughout the class, there will be four projects. In each project, you will be modifying the Minix operating system to illustrate various operating system design concepts presented throughout the course.

Each project will be worth 100 percentage points. At the end of the semester your project grades will be averaged together. This average is worth 25% of your final grade.

Your project will be submitted as a bootable Minix image under VirtualBox on the absaroka server (sufficient disk space shall be provided). If you develop the project on your local system, you should copy it on absaroka, and assure that it runs properly on using the VirtualBox virtual machine available on absaroka.

Each project is evaluated by the following grading elements:

1. The submitted operating system implements all technical requirements correctly, and as stated in the project assignment. (50%)
2. All grader tests on your operating system pass successfully. (30%)
3. The implementation is well-written, clearly understood and properly commented. Also, any external required and/or needed documentation is provided. (20%)

Projects are graded as follows:

• 90–100(A)—Project meets all technical requirements, only minor errors when the OS is tested, the implementation is well-written, clearly understood, commented appropriately and documented.
• 80–89(B)—Project meets most of the technical requirements, some grader tests fail, or documentation is incomplete, code is reasonably well written.
• 70–79(C)—Project meets some of the technical requirements, many grader tests fail, documentation sparse, code is poorly written.
• <70(F)—Few technical requirements met, OS doesn't boot, grader tests fail or cannot be run.

Quizzes (25% of Final Grade)

There shall be five on-line quizzes throughout the course, one for each major topic. These quizzes shall be true/false, multiple choice, and short answer. These assessments are generally timed at about an hour each. The quizzes are "open-book", however, when taking the quiz, you must limit yourself to the module content, your notes, your text, and one other external reference. No "google" please!

Each quiz will be worth percentage 100 points. The quizzes shall be averaged together to provide a score which will make up 25% of your final grade.

Grading Policy

Student assignments are due according to the dates in the Calendar and assignment item within the corresponding module. Grades will be posted one week after assignment due dates.

We generally do not directly grade spelling and grammar. However, egregious violations of the rules of the English language will be noted without comment. Consistently poor performance in either spelling or grammar is taken as an indication of poor written communication ability that may detract from your grade.

A grade of A indicates achievement of consistent excellence and distinction throughout the course—that is, conspicuous excellence in all aspects of assignments and discussion in every week.

A grade of B indicates work that meets all course requirements on a level appropriate for graduate academic work. These criteria apply to both undergraduates and graduate students taking the course.

Final grades will be determined by the following weighting:

Academic Policies

Deadlines for Adding, Dropping and Withdrawing from Courses

Students may add a course up to one week after the start of the term for that particular course. Students may drop courses according to the drop deadlines outlined in the EP academic calendar (https://ep.jhu.edu/student-services/academic-calendar/). Between the 6th week of the class and prior to the final withdrawal deadline, a student may withdraw from a course with a W on their academic record. A record of the course will remain on the academic record with a W appearing in the grade column to indicate that the student registered and withdrew from the course.

Academic Misconduct Policy

All students are required to read, know, and comply with the Johns Hopkins University Krieger School of Arts and Sciences (KSAS) / Whiting School of Engineering (WSE) Procedures for Handling Allegations of Misconduct by Full-Time and Part-Time Graduate Students.

This policy prohibits academic misconduct, including but not limited to the following: cheating or facilitating cheating; plagiarism; reuse of assignments; unauthorized collaboration; alteration of graded assignments; and unfair competition. Course materials (old assignments, texts, or examinations, etc.) should not be shared unless authorized by the course instructor. Any questions related to this policy should be directed to EP’s academic integrity officer at ep-academic-integrity@jhu.edu.

Students with Disabilities - Accommodations and Accessibility

Johns Hopkins University values diversity and inclusion. We are committed to providing welcoming, equitable, and accessible educational experiences for all students. Students with disabilities (including those with psychological conditions, medical conditions and temporary disabilities) can request accommodations for this course by providing an Accommodation Letter issued by Student Disability Services (SDS). Please request accommodations for this course as early as possible to provide time for effective communication and arrangements.

For further information or to start the process of requesting accommodations, please contact Student Disability Services at Engineering for Professionals, ep-disability-svcs@jhu.edu.

Student Conduct Code

The fundamental purpose of the JHU regulation of student conduct is to promote and to protect the health, safety, welfare, property, and rights of all members of the University community as well as to promote the orderly operation of the University and to safeguard its property and facilities. As members of the University community, students accept certain responsibilities which support the educational mission and create an environment in which all students are afforded the same opportunity to succeed academically. 

For a full description of the code please visit the following website: https://studentaffairs.jhu.edu/policies-guidelines/student-code/

Classroom Climate

JHU is committed to creating a classroom environment that values the diversity of experiences and perspectives that all students bring. Everyone has the right to be treated with dignity and respect. Fostering an inclusive climate is important. Research and experience show that students who interact with peers who are different from themselves learn new things and experience tangible educational outcomes. At no time in this learning process should someone be singled out or treated unequally on the basis of any seen or unseen part of their identity. 
 
If you have concerns in this course about harassment, discrimination, or any unequal treatment, or if you seek accommodations or resources, please reach out to the course instructor directly. Reporting will never impact your course grade. You may also share concerns with your program chair, the Assistant Dean for Diversity and Inclusion, or the Office of Institutional Equity. In handling reports, people will protect your privacy as much as possible, but faculty and staff are required to officially report information for some cases (e.g. sexual harassment).

Course Auditing

When a student enrolls in an EP course with “audit” status, the student must reach an understanding with the instructor as to what is required to earn the “audit.” If the student does not meet those expectations, the instructor must notify the EP Registration Team [EP-Registration@exchange.johnshopkins.edu] in order for the student to be retroactively dropped or withdrawn from the course (depending on when the "audit" was requested and in accordance with EP registration deadlines). All lecture content will remain accessible to auditing students, but access to all other course material is left to the discretion of the instructor.