This is a simple exercise designed to get you started on seL4. It contains very detailed instructions, together with the existing source code and the seL4 manual you should have no problem doing it.
Most of the 9242 binaries (eg. cross compilers) are in ~cs9242/crossdev/arm-2013.05. You can add this to your path with:
export PATH=$PATH:/home/cs9242/crossdev/arm-2013.05/bin export PYTHONPATH=$PYTHONPATH:/home/cs9242/bin/py
If you are lazy you can just use the 9242 command for the cs9242 shell:
~ % 9242 newclass starting new subshell for class COMP9242... ~ % arm-none-linux-gnueabi-ld arm-none-linux-gnueabi-ld: no input files
Note: Your minicom should default to 115200, 8N1, no hardware flow control. If it doesn't then you will have problems talking to your Sabre.
Get yourself a copy of the skeleton SOS. We use
git for revision control for this project, and
it will be simplest if you do also. You will be submitting
patches/diffs for each milestone in the project. We support
and expect only git generated patches/diffs. You will need
to support yourself if you use any other tools.
You can find some pointers on using
our git page
git clone /home/cs9242/public_git/aos-2017
gitis in your
$PATHat CSE (as well as installed on your local machine!) before performing a check-out. Put this line in your
git clone ssh://YOURLOGIN@login.cse.unsw.edu.au//home/cs9242/public_git/aos-2017
The sources to the project are also available at https://bitbucket.org/kevinelp/unsw-advanced-operating-systems for anybody outside UNSW who wishes to take a look at the project.
Booting your Sabre Lite for the first time is easy:
We have developed a few tools to speed the development cycle along. The makefile can copy the sos operating system, known as a bootimage to your tftp directory and reset the Sabre. Below is a typical development cycle, assuming the path changes to your login script:
The example skeleton operating system includes an application
tty_test which starts up, prints out its name, and then
blocks itself forever.
The example includes a
printf implementation that outputs
data to seL4's debug console. In fact it uses the seL4 debug API
seL4_DebugPutChar. This function should only be used for internal
SOS debugging, not as a console for applications, so, your
task is to modify the
sos_write function to send data through the
operating system and across the network to your netcat(
The second part of milestone zero is to find a partner for the rest of the project. The project is to be completed, in pairs, unless prior permission has been obtained from the LiC.
Before you complete this milestone, be sure to spend time becoming familiar with the seL4 Debugging Guide. It will save you a lot of debugging effort throughout the project.
apps/sos/src/main.cand the code in the
main.cto recognise your new protocol, and print out a debug message when you receive one of these messages.
tty_test.cso that it tests your
tty_test's output now goes to the netcat console, not the console debugger.
See the milestone submission guidelines for instructions on submitting your milestone solution.
You will need to demonstrate user applications printing to the 2nd console via libserial, running on the Sabre Lite hardware to the tutor during the demonstration period. You should be prepared to show your tutor which files you modified in your solution, and explain any design decisions you made.
Note that since you do not have consistent virtual memory management yet, your protocol will be fairly simple for now. However, it should be upgraded as more parts of the system are completed. Your tutor will be particularly interested in the details of your IPC interface with different sized blocks of data etc, and how you plan to improve it in future.
Hint: sending a byte at a time is not a good solution.
You will let the tutor know who your partner is so that group accounts can be created for you.