This document serves as both the course's syllabus and its main web page.
In this course you will not only open the curtain to see the wizard, you will strip the wizard bare.
The biggest parts of this course include:
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We will cover nearly all of the great free textbook: OSTEP - Operating Systems in Three Easy Pieces. This book is written at a popular level and is very accessible.
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We will leverage the Unix programming environment in a deep and meaningful way. These are marketable skills.
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We will do up to 8 projects both inside an OS itself and in userland.
There are too many learning outcomes in this course to name them all.
These four learning outcomes are highlighted:
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At the end of this course, students will be able to design and implement complex multi-process and threaded applications.
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At the end of this course, students will be able to design and implement various synchronization schemes using mutexes, condition variables and semaphores.
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At the end of this course, students will have mastered user level memory allocation schemes including free space management.
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At the end of this course, students have designed and synthesized complex data structures and algorithms demonstrating mastery of the structure of at least one kind of file system.
Implicit in this course is learning the lessons of care, testing, debugging and commenting.
| Days | Times | Room |
|---|---|---|
| TR | 2:20 PM to 4:00 PM | CC 114 |
Should we meet via Zoom. All cameras must be on to the maximum degree possible. If you are on a desktop, get a Webcam, they are cheap enough. Not having a Webcam is not an allowable excuse.
The link given below will be used for classes, should that be needed.
All office hours are held via ZOOM. This link will remain valid all term.
| Day | Times |
|---|---|
| M | 11 AM to 12 PM |
| T | 11 AM to 12 PM |
| R | 7 PM to 9 PM |
| F | 12 PM to 1 PM |
Office hours may be recorded if the content is deemed by me to be of general use to the class.
Due to abuse of the instructor's time during Spring 2023, help shall be largely limited to the above hours. Make sure you ask your questions during class or during posted office hours.
With some exceptions, to be decided by me, help on projects will not be available within 24 hours of a project's due date. This prohibition is imposed to encourage good working habits including but not limited to starting work early / working steadily. This is not intended punitively.
Primary: OSTEP This book is free.
Ancillary:
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Required: Advanced Programming in the UNIX environment, third edition. I will refer to this as Stevens and Rago. If you have any questions about the Unix / Linux environment and APIs, consult this book before approaching me.
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xv6 risc-v This book is free.
There are two types of readings in this class.
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Assigned readings will come from OSTEP.
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Unassigned readings will come from the two ancillary texts. Being unassigned, you will not be told when to do them. Instead, review the table of contents in each of the two ancillary sources to get a general idea of that they contain. Then, later in the course, when you have a question, review the ancillary texts for details.
You expected to have consulted the texts before approaching me with questions. If I should answer something to the effect that the answer is in the book, you are expected to explain to me what you read and articulate what you found unclear. This step is take to encourage good working habits on your part and is not punitive.
The following are the topics which we can expect to be covered:
| OSTEP | Topic | OSTEP | Topic |
|---|---|---|---|
| 4 | Processes | 21 | Swapping Mechanisms |
| 5 | Process API | 22 | Swapping Policies |
| 6 | Limited Direct Execution | 23 | Complete VM System |
| 7 | CPU Scheduling | 26 | Concurrency and Threads |
| 8 | Multi-level Feedback | 27 | Thread API |
| 9 | Lottery Scheduling | 28 | Locks |
| 10 | Multi-CPU Scheduling | 29 | Locked Data Structures |
| 13 | Address Spaces | 30 | Condition Variables |
| 14 | Memory API | 31 | Semaphores |
| 15 | Address Translation | 32 | Concurrency Bugs |
| 16 | Segmentation | 33 | Event-based Concurrency |
| 17 | Free Space Management | 36 | I/O Devices |
| 18 | Introduction to Paging | 37 | Hard Disk Drives |
| 19 | Translation Lookaside Buffers | 38 | RAID |
| 20 | Advanced Page Table | 39 | Files and Directories |
| 40 | File System Implementation |
There are 31 chapters listed above. While we may not get to all, you can be certain there will be weeks in which you will be responsible for reading more than one chapter. This is not a major burden as the chapters are short and the text is written at a popular level.
All projects require use of WSL on Windows or the terminal on the Mac. If you're passionate about using Linux directly, this is also an option but no help will be provided.
The easiest way to install WSL (Ubuntu) on Windows 11 is to run a command prompt as Administrator and then:
wsl --install
If this doesn't work, use the Microsoft Store to install Ubuntu.
It is possible you'll have to turn on the Windows Subsystem for Linux in the Add Remove Windows Features settings.
I recommend you select a trivial user name and password. For example,
for my WSL I use user name a and password a.
You'll then need to install the C and C++ environment.
sudo -i
apt update
apt upgrade
apt install build-essential gdb
By now you will likely have already installed the plugins in VS Code needed to work inside WSL. If not, ask a friend.
On the Mac, ensure you have gcc and g++ available to you on the
command line.
On WSL:
sudo -i
apt update
apt install crossbuild-essential-riscv64
apt install qemu-system
exit
# decide where you want to load the original xv6
# and change directory to there.
git clone https://github.com/mit-pdos/xv6-riscv.git
Make a copy of the xv6 directory for each of the projects using it.
On Mac:
Ensure you have the latest brew.
If you don't have brew, run this:
/bin/bash -c "$(curl -fsSL <https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh>)"
You'll also need the riscv toolchain plus qemu.
To access the riscv tools you need to add the right tap.
brew tap riscv/riscv
Then (this does BOTH qemu and the riscv tools):
brew install qemu riscv-gnu-toolchain
And as per Windows, get the xv6 repo. It is likely there is a small
change to be made to the makefile to specify the appropriate tool
chain.
If this is your first time using brew, you will have to make sure it
is in your path. Add this to the end of your .zshrc file (in your
home directory). Or maybe it's in your .zprofile. Or maybe it's in
your .zshenv. Why so many possibilities? Because Apple.
export PATH=$PATH:/opt/homebrew/bin
Since the early days, Unix has had the man command. For example:
man man
or
man 2 chdir
Consult the man pages before approaching me with questions. Prior to my answering a question whose answer is found in the man page, I will require you to state your understanding of the man page and articulate where your understanding is insufficient. This step is taken to encourage good working habits and is not punitive.
Attendance will be taken at nearly every class. The only exceptions will be when I am so excited to get down to business, that I forget to take it.
You get 6 free absences. After that each absence will remove 1 percent from your aggregate score at the end of the term. All absences are treated equally. That is, there are no "excused" absences.
The number of free absences equates to three weeks of missed class time so it is unlikely you'll exceed this and incur a penalty.
Should a long-term absence due to uncontrollable circumstances become necessary, please speak to me as soon as possible.
Once attendance has been taken, anyone arriving after than will be counted as absent. Generally, attendance will end between five and ten minutes after the official start of class.
No, your coach cannot force you to leave class early to make practice. This comes directly from the current Athletic Director. If you are friends with persons arriving at practice before 4 PM, they do not have afternoon classes or are choosing to put their extra-curricular sports ahead of the REST OF THEIR LIVES.
Here is a link to an essay assignment. You can look at it at your convenience but do it only when assigned. The essay is six percent of your grade and, at 500 words, is one third to one sixth the length of a typical college essay. Five hundred words about life, death and your responsibility as a coder is not too much to ask.
Below is a listing of 10 "projects" of which only 8 are truly projects. One is a tutorial and another is just to provide proof you're ready to tackle the two kernel projects.
The Weight column provides a weighting of the project within the Project Grading Component. It suggests my anticipation of the relative difficulty of each project compared to the others.
The OSTEP column indicates how the projects correspond to course material. The indicated chapters will be most helpful.
The S&R column indicates which chapters of Stevens and Rago can be helpful.
The warmups each contribute one point to your final grade.
The projects together contribute 92 percent of your final grade.
| # | Project | Space | Weight | OSTEP | S&R |
|---|---|---|---|---|---|
| - | getopt |
User | N/A | N/A | N/A |
| 1 | Shell | User | 80 | 4, 5 | 1, 3, 4, 5, 8, 15 |
| - | Working xv6 | N/A | N/A | N/A | N/A |
| 2 | System Call | Kernel | 60 | 6 | N/A |
| 3 | Schedulers | User | 70 | 7, 8, 9 | N/A |
| 4 | Guard Page | Kernel | 60 | 13 | N/A |
| 5 | Allocators | User | 70 | 17 | 7 |
| 6 | Semaphores | User | 70 | 26, 27, 28, 29, 30, 31 | 8, 11, 12 |
| 7 | Named Pipe | User | 100 | 26, 27, 28, 29, 30, 31 | 8, 11, 12 |
| 8 | FSCK | User | 100 | 39, 40, 42 | 3, 4, 5 |
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You are required to use a partner for all non-warmup projects.
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Your partner will be assigned to you by me.
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Members of the team must be specified by the partner handing in the project within the code they are handing in.
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The partner not handing in the project must submit a text file stating who their partner is.
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Both partners receive the same grade.
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Any partnership problems should be worked out by you but I can step in if necessary.
This is not intended punitively. In your future you will be required to work with others. Failure in this can result in your dismissal even if your other performance is superlative. Lone Rangers are not desireable within teams.
It is your responsibility to ensure you and your partner work as a team. Remember, your partner is assigned to you and you will have them only once.
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Requirements are spelled out in each specification.
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Any deviation from the specification likely results in penalties.
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Generating even a single warning during building your own code will result in a 10 percent penalty. I will build on MacOS.
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Commenting is required. Failure to adequately comment is a mandatory 5 percent penalty.
Late work (factoring in one free grace day) will not be accepted.
To state this differently, if an assignment is due on day n, you have until the end of day n + 1 to turn it in. After that, it will not be accepted.
I award partial credit for substantial but incomplete work. This is unlike the real world where incomplete work earns termination of your employment. Hand in what you have... it's better than a zero.
| Gradable Component | Weight | Notes |
|---|---|---|
| Projects | 92% | |
| Essay | 6% | |
getopt |
1% | warm up |
working xv6 |
1% | warm up |
| Attendance | Deduction Only |
There is very little likelihood a curve will be applied in computing your final grade.
There are no exams in this course and projects already include a grace day. Therefore, no significant accommodations ought to be necessary but present your papers to me at the start of the semester anyway. We'll discuss what should be done.
The Health and Counseling Center (HCC) addresses student physical, mental, and emotional well-being. All services, provided by experienced professionals, are free and confidential to currently enrolled, full-time undergraduate students. Students must call or visit the HCC to schedule an appointment. Health services are available by walk-in or appointment from 8:30am - 3:30pm. Counseling walk-in sessions are available Monday through Friday from 11:30am to 1:00pm, last appointment begins around 12:30pm, first-come first-seen. TWC, first floor(behind mailboxes)| 262-551-5710 | Website | Mon-Fri 8:30am to 1pm and 2pm to 4:00pm.
Carthage College strives to make all learning experiences as accessible as possible. If you anticipate or experience academic barriers due to your disability (including mental health, learning disorders, and chronic medical conditions), please let me know immediately so we can discuss options privately. To establish reasonable accommodations, you must register with Warren Wolchuk in Learning Accessibility Services wwolchuk@carthage.edu.
All work will be examined for originality. Should I find evidence of copied work, all parties shall receive a grade of zero. If any individuals are found to have copied a second time, the individuals will be reported to the Provost's office for discipline and will receive a zero for the assignment. Should an individual be associated with a third instance, in addition to a second trip to the Provost, the individual shall receive an F in the course.
The decision of the instructor is final.
See here for some very old slides I made describing a few topics in very succinct terms.
Apart from lecture, I will not "just give you the answer." Rather, you must demonstrate that you have exhausted the means available to you to learn on your own. This is not punitive. This will be a requirement for your future. You'll get in the habit now. This may be a lasting and meaningful "gift" to you from me.
When I was an undergraduate, Jishnu Mukerjee was the graduate student who was in charge our department's PDP-11/60. It ran an early version of Unix, V6 to be exact... sound familiar?
The first time I had a question, I asked Jishnu and he answered it.
The second time I had a question, I asked Jishnu and he answered it.
The third time I had a question, I asked Jishnu and he handed me a print out of the entire OS. He said, "All your answers are in here."
It was the greatest gift he could possibly give and I am thankful to him to this day.