Lab 7: Final JOS Project

Piazza Discussion Due, March 28, 2019
Proposals Due, April 4, 2019
Code repository Due, May 2, 2019
Check-off, May 3 or 6, 2019

Introduction

For the final project you have two options:

Work on your own and do lab 6, including one challenge exercise in lab 6. (You are free, of course, to extend lab 6, or any part of JOS, further in interesting ways, but it isn't required.)
Work in a team of one, two or three, on a project of your choice that involves your JOS. This project must be of the same scope as lab 6 or larger (if you are working in a team).

The goal is to have fun and explore more advanced O/S topics; you don't have to do novel research.

If you are doing your own project, we'll grade you on how much you got working, how elegant your design is, how well you can explain it, and how interesting and creative your solution is. We do realize that time is limited, so we don't expect you to re-write Linux by the end of the semester. Try to make sure your goals are reasonable; perhaps set a minimum goal that's definitely achievable (e.g., something of the scale of lab 6) and a more ambitious goal if things go well.

If you are doing lab 6, we will grade you on whether you pass the tests and the challenge exercise.

Deliverables

March 28: Piazza discussion and form groups of 1, 2, or 3 (depending on which final project option you are choosing). Use the lab7 tag/folder on Piazza. Discuss ideas with others in comments on their Piazza posting. Use these postings to help find other students interested in similar ideas for forming a group. Course staff will provide feedback on project ideas on Piazza; if you'd like more detailed feedback, come chat with us in person.

April 4: Submit a proposal at the submission website, just a paragraph or two. The proposal should include your group members list, the problem you want to address, how you plan to address it, and what are you proposing to specifically design and implement. (If you are doing lab 6, there is nothing to do for this deliverable.)

May 9: submit source code along with a brief write-up. Put the write-up under the top-level source directory with the name "README.pdf". Since some of you will be working in groups for this lab assignment, you may want to use git to share your project code between group members. You will need to decide on whose source code you will use as a starting point for your group project. Make sure to create a branch for your final project, and name it lab7. (If you do lab 6, follow the lab 6 submission instructions.)

May 3 or May: check-off with instructor. Demo your project to the instructor so that I can ask you some questions and find out in more detail what you did.

Project ideas

If you are not doing lab 6, here's a list of ideas to get you started thinking. But, you should feel free to pursue your own ideas. Some of the ideas are starting points and by themselves not of the scope of lab 6, and others are likely to be much of larger scope.

Build a virtual machine monitor that can run multiple guests (for example, multiple instances of JOS), using x86 VM support.
Do something useful with the hardware protection of Intel SGX. Here is a recent paper using Intel SGX.
Make the JOS file system support writing, file creation, logging for durability, etc., perhaps taking ideas from Linux EXT3.
Use file system ideas from Soft updates, WAFL, ZFS, or another advanced file system.
Add snapshots to a file system, so that a user can look at the file system as it appeared at various points in the past. You'll probably want to use some kind of copy-on-write for disk storage to keep space consumption down.
Build a distributed shared memory (DSM) system, so that you can run multi-threaded shared memory parallel programs on a cluster of machines, using paging to give the appearance of real shared memory. When a thread tries to access a page that's on another machine, the page fault will give the DSM system a chance to fetch the page over the network from whatever machine currently stores it.
Allow processes to migrate from one machine to another over the network. You'll need to do something about the various pieces of a process's state, but since much state in JOS is in user-space it may be easier than process migration on Linux.
Implement paging to disk in JOS, so that processes can be bigger than RAM. Extend your pager with swapping.
Implement mmap() of files for JOS.
Use xfi to sandbox code within a process.
Support x86 2MB or 4MB pages.
Modify JOS to have kernel-supported threads inside processes. See in-class uthread assignment to get started. Implementing scheduler activations would be one way to do this project.
Use fine-grained locking or lock-free concurrency in JOS in the kernel or in the file server (after making it multithreaded). The linux kernel uses read copy update to be able to perform read operations without holding locks. Explore RCU by implementing it in JOS and use it to support a name cache with lock-free reads.
Implement ideas from the Exokernel papers, for example the packet filter.
Make JOS have soft real-time behavior. You will have to identify some application for which this is useful.
Make JOS run on 64-bit CPUs. This includes redoing the virtual memory system to use 4-level pages tables. See reference page for some documentation.
Port JOS to a different microprocessor. The osdev wiki may be helpful.
A window system for JOS, including graphics driver and mouse. See reference page for some documentation. sqrt(x) is an example JOS window system (and writeup).
Implement dune to export privileged hardware instructions to user-space applications in JOS.
Write a user-level debugger; add strace-like functionality; hardware register profiling (e.g. Oprofile); call-traces
Binary emulation for (static) Linux executables