CS 450: Operating Systems

Overview

Operating systems run the world. Without an OS, you couldn't have hundreds of programs running at once, you'd have to have deep understanding of hardware, and you'd have to rewrite your code for each new machine on the market. You wouldn't have web servers, desktop machines, laptops, phones, or smart watches; no Siri, no Alexa, no TensorFlow or CUDA programs.

In this course, you will dive straight into the deepest and often most confounding component of a computer system's software stack. You will become familiar with both the high-level concepts underpinning modern operating systems and with low-level mechanisms, in addition to new and emerging techniques and programming models for computer systems. I am a strong believer in learning by doing, so the majority of your time for this course will be spent working on programming projects, both very low-level work and high-level (user-space) work. This course will be challenging! It will bring together a lot of concepts you've learned in your previous courses, from data structures and algorithms to assembly language, computer architecture, virtual memory, and advanced C programming.

For this course, I assume that you have basic familiarity with computer organization (as introduced in CS 350), data structures, C, and systems programming (as covered in CS 351). You will for sure need to be able to program in C and should be able to navigate around a UNIX environment.

Lectures and COVID

While we are online only, lectures and office hours will be held on zoom. If students have issues with this medium, we may switch (e.g. to Blackboard Collaborate). The link for these will be posted on the course Piazza. Recordings of the lectures will be posted afterwards on Blackboard.

Communication

We will be primarily using Piazza as a course communication mechanism. If you have an issue or question that is not strictly private (especially one that would benefit everyone were it answered), please use Piazza as your first resource. The instructor, the TA, and your fellow classmates will be there to help. Note that you can also post anonymously if you so choose.

Homeworks

While there will be no homework to turn it, it is a very good idea to do some of the homeworks associated with the readings as I post them. These are usually short coding tasks that use a simulator for the OS component in question. These homeworks will help solidify knowledge needed for the exams.

Readings

In addition to the projects (and homeworks if you're studious), you'll be needing to do the readings I post (almost) every lecture. These will primarily come from the OSTEP book, but I will also post other required and optional readings from seminal research papers, articles, and books.

We will, when time allows, also be spending some time reading code! This will likely include code snippets from real OSes including the Linux kernel.

The following is a rough schedule of the class. Note that it is subject to change.

Books

The following book is the only required textbook for this course. It is not only an excellent textbook, but is also freely availble online:

Operating Systems: Three Easy Pieces by Remzi H. Arpaci-Dusseau and Andrea C. Arpaci-Dusseau, 2015.

The below books are also great and often-used texts on Operating Systems. If you find a copy of one for a good price, snatch it. Keep in mind, however, that the best way to earn operating systems is by building!.

This is probably my favorite OS textbook after OSTEP. Full disclosure, I took undergrad OS with Dahlin many years ago.

Operating Systems: Principles and Practice (2nd Edition), by Thomas Anderson and Michael Dahlin, Recursive Books 2014.

Operating System Concepts (9th Edition), by Abraham Silberschatz, Peter Baer Galvin, and Greg Gagne, 2012 Wiley.

Modern Operating Systems (4th Edition), by Andrew S. Tanenbaum and Herbert Bos, Pearson 2014.

For general systems design, a good one to have on the shelf:

Principles of Computer System Design: An Introduction (1st Edition), by Jerome H. Saltzer and M. Frans Kaashoek, Morgan Kaufmann 2009.

The following book, while outdated (uses a 2.6.10 kernel as a reference), still provides one of the best references for practical kernel hacking:

Understanding the Linux Kernel (3rd Edition), by Daniel P. Bovet and Marco Cesati, O'Reilly Media 2005.

Good book on Linux kernel programming:

Linux Kernel Development (3rd Edition), by Robert Love, Addison-Wesley Professional, 2010.

If you're interested in the macOS kernel, this one is not out yet, but will be soon:

OSX Internals, Volume II, 2nd Edition, by Jonathan Levin.

Similarly for Windows:

Windows Internals, Part 1: System Architecture... (7th Edition), by Pavel Yosifovich, Mark E. Russinovich, Alex Ionescu, and David A. Solomon, Microsoft Press 2017.

Development Environment

We will primarily be using Docker for development. You will need to have the Docker client installed on your machine.

Other Useful Links and Resources

This is a list of other resources that you might find useful for this class. Feel free to peruse them at your own convenience.

Links

• Good resource for OS development
• Resources for learning Git
• Another nice Git resource
• QEMU documentation
• Nice article on virtual memory
• The ELF executable format
• Intel Architecture Manuals
• AMD Architecture Manuals
• Brennan's Guide to Inline Assembly
• GCC Inline Assembly
• Various simulators, e.g. for process schedulers, disk head schedulers, etc.
• Code for various Linux kernel and Windows kernel security exploits

Interesting, important, historical, and new OS Kernels

• The Linux Kernel, arguably the most important kernel of our time
• FreeBSD
• Nautilus, a research OS written by your instructor for parallel runtime systems
• Plan 9, an important (but commercially unsuccessful) UNIX successor by Bell Labs
• Harvey OS, a new successor to Plan 9
• Drawbridge, research prototype from MSR (components of which are now in the NT kernel).
• MINIX 3, a historically important microkernel (originally---and still---used for teaching). Intel chips actually run this internally!
• Several OSes based on the L4 kernel, an important early microkernel
• Android OS, Google's mobile OS (based on Linux kernel, but probably soon Fuchsia (below))
• Fuchsia OS, a new microkernel-based OS from Google
• Barrelfish OS, an important research OS from ETH Zurich (the OS is a distributed system)
• Redox, an OS written in Rust (UNIX-like)
• Kitten Lightweight Kernel, an OS kernel designed for supercomputing
• Scout, a network-oriented research OS
• MirageOS, a Unikernel for OCaml applications
• OSv, a popular new Unikernel
• Pintos, a teaching OS based on the Nachos research OS.
• JOS, another teaching OS
• OS/2, an important mainframe OS from IBM
• COS, an OS for some of the first supercomputers
• CP/M, an OS for some of the first microcomputers. Here is the code.
• code for the OS of Xerox Alto, the first computer with a GUI
• source code for MS-DOS 1.25 and 2.0
• source code for the XNU kernel, part of Darwin, which powers macOS
• source code for ReactOS, a WindowsNT-compatible kernel
• System software for the Apollo Guidance Computer
• Code for the Apple II's DOS
• Code for the Atari 7800's OS