CS179F Fall 2023

Catalog Description

CS179F delves into the design and implementation of operating systems by conducting a quarter-long project.

Team

• Instructor: Emiliano De Cristofaro
  • Email: emilianodc AT cs DOT ucr DOT edu
  • Lectures: Tuesdays 3:30 - 4:20 PM Gordon Watkins Hall, Room 1101
  • Office hours: TBD
• Teaching Assistant: Gao Lian
  • Email: lian DOT gao AT email DOT ucr DOT edu
  • Office hourse: TBD

Textbooks

• Operating Systems: Three Easy Pieces, Remzi H. Arpaci-Dusseau and Andrea C. Arpaci-Dusseau
• XV6: A Simple UNIX-like Teaching Operating System, Russ Cox, Frans Kaashoek, and Robert Morris
• Lions' Commentary on UNIX' 6th Edition, John Lions, Peer to Peer Communications. ISBN: 1-57398-013-7. 1st edition (June 14, 2000)

Communication

• Piazza for announcement, discussions, and help
• Canvas for assignments and grading

Acknowledgments

• MIT 6.1810 Operating System Engineering class series for setting up the projects and maintaining xv6-riscv
• Prof. Heng Li for sharing material related to his iteration of the class in W'21 and W'20

XV6

• We will use the XV6 operating system as a base for our projects
• Please familiarize yourself with XV6 to get a grasp on how it is organized and implemented, e.g., using:
  • Online version of the Lions commentary
  • Source Code, also available through the Unix Heritage Society
  • If you are curious, you can also see the original code in the PDP11/40 Processor Handbook, Digital Equipment Corporation, 1972 [PDF] [Web]

Environment

• You need three main things:
  • xv6-riscv, a re-implementation of Unix Version 6 for a modern RISC-V multiprocessor using ANSI C
  • qemu, an open source machine emulator and virtualize
  • class git repository, https://github.com/emidec/cs179f-fall23/
• Please see https://pdos.csail.mit.edu/6.828/2023/tools.html for instructions re. how to set up xv6 on your local machine, or see below
• Note: I've encountered problems with running qemu on Macs running Apple M1/M2 silicon. I'm still working on possible solutions, but my advice for the moment is to use a virtual machine running Ubuntu
• Note: I also encountered problems with latest versions of qemu. My advice is to get (and compile from source) qemu 4.1.1 from https://download.qemu.org or even better 5.10 rather than the latest version installed via packages. You can do so by running (replace version to 5.10 if you want to install that):

wget https://download.qemu.org/qemu-4.1.1.tar.xz
tar xf qemu-4.1.1.tar.xz
cd qemu-4.1.1
./configure --disable-kvm --disable-werror --prefix=/usr/local --target-list="riscv64-softmmu"
make
sudo make install

Install on Linux

• Debian/Ubuntu:
  • sudo apt-get install git build-essential gdb-multiarch qemu-system-misc gcc-riscv64-linux-gnu binutils-riscv64-linux-gnu
• Arch Linux:
  • sudo pacman -S riscv64-linux-gnu-binutils riscv64-linux-gnu-gcc riscv64-linux-gnu-gdb qemu-emulators-full
• To test your installation, run:
  • $ qemu-system-riscv64 --version
QEMU emulator version 5.1.0
  • $ riscv64-linux-gnu-gcc --version
riscv64-linux-gnu-gcc (Debian 10.3.0-8) 10.3.0
  • Checkout to the util branch (git checkout util), then run make qemu, you should get a shell and an output to ls like this:

$ ls
.              1 1 1024
..             1 1 1024
README         2 2 1982
xargstest.sh   2 3 93
cat            2 4 22360
echo           2 5 21304
forktest       2 6 11976
grep           2 7 25648
init           2 8 21928
kill           2 9 21192
ln             2 10 21056
ls             2 11 24608
mkdir          2 12 21312
rm             2 13 21296
sh             2 14 39408
stressfs       2 15 22280
usertests      2 16 104752
wc             2 17 23360
zombie         2 18 20576
cow            2 19 28168
uthread        2 20 23968
call           2 21 21136
kalloctest     2 22 25992
bcachetest     2 23 26800
mounttest      2 24 33064
crashtest      2 25 22176
console        3 26 0

Projects

We will have five projects, each counting 20% of the final grade, aimed to making several improvements on xv6:

1. Unix Uilities: sleep, find, xargs
2. Memory Allocation
3. Copy-On-Write
4. File System: large files and symbolic links
5. mmap

Grading

Each lab will be graded based on:

• Source code and comments
• Lab report
• Tests created and passed
• In-person answers to questions regarding the work ("demo") with TA

Late Submissions

• Late submissions within 48 hours will be graded with 20% penalty
• Late submissions beyond 48 hours will not be graded
• Exceptions may only be granted case by case with evidence presented