CS3 Operating Systems 2013-14, Practical Exercise.

INTRODUCTION
------------

This practical exercise starts in week 3, and runs until week 8,
with a final submission deadline of

      16:00 Friday 8 November 2013.

The submission mechanism will be electronic, by the "submit" command.
No other form of submission will be accepted.

The practical instructions will be issued in three phases.


Phase 1
-------

In the first phase, you will be asked to do some background reading.
You will be given instructions on using the VirtualBox emulator, and
expected to become familiar with it.
You will take a first look at the Linux kernel source, and at the
kernel build procedure.
During this phase, you should work on revising and extending your 
knowledge of C. The key concepts that differ from Java are structs and
pointers. You should also aim to get a general understanding of
Makefiles and the kernel build procedure, although no detailed
knowledge of this will be needed.

The main objectives and intended outcomes for phase 1 are:
 + [course objective] understanding of the basic structure of the
   Linux kernel, and how that structure is reflected in the structure
   of the source code
 + [course objective] understanding of the virtual machine concept as
   provided by VirtualBox
 + [transferable skills] basic C skills
 + [transferable skills] use of online resources for system programming

Time: about 2 weeks, continuing into phase 2.


Phase 2
-------

In this phase, you will be be given instructions on how to build a
kernel module that can be loaded into a running kernel.  You
should study appropriate documentation (key references will be given)
to ensure that you understand the supplied module template, and you
will need to ensure that you can successfully compile a module,
transfer it to your VirtualBox system, and load it into the running
kernel. You will continue your acquisition of basic C knowledge, and
you will be asked to look at one component of the Linux kernel source
in more detail.

Main objectives and intended outcomes:
 + [course objective] understanding of the principle of modular kernel
   design, as implemented in Linux
 + [course objective] deeper understanding of one component of the
   Linux kernel and its relation to the general presentation in
   lectures.
 + [transferable skills] continuing basic C skills

Time: about 1 week.


Phase 3
-------

Phase 3: in the final phase, which will produce the assessed result
of the exercise, you will be asked to write a module to perform a
specific function (possibly purely information gathering) connected
to the kernel component studied in phase 2. You will submit your
final module code; it will be automatically tested, and manually
reviewed for style.

***Your code must compile in the specified environment.
***If your code contains any hidden dependencies on another system,
***and therefore fails to compile, it will receive a fail mark.

Main objectives:
 + to demonstrate your successful attainment of the Phase 1 and 2
   objectives
 + to reinforce your understanding of operating system implementation

Time: about 1 week.



Permissible collaboration
-------------------------

The primary purpose of this practical is educational. However, it also
contributes to your mark for this course. Therefore the following
policy on collaboration applies:

During Phases 1 and 2, you are permitted, and actively encouraged, to
discuss any aspect of the exercise, whether in person with each
other, or via the course newsgroup.

During Phase 3, you should be working mainly on your own. That means that
the module code you submit must be your own code, produced without
significant assistance from others. The following forms of
collaboration and discussion are permitted:
 + asking for assistance (from each other or the newsgroup) with
   any problems you have with the C language or the compilation process;
 + asking a colleague to help you debug your code by, for example,
   listening to you talk through it and trying to spot mistakes;
 + asking for assistance using any debugging facilities provided by
   the system.
If you have any question or difficulty that does not obviously fall
into the above categories, you should ask it publicly on the
newsgroup, and I will determine a suitable public answer.


Using other machines
--------------------

The practical material will be provided to you in the DICE file
system, and the instructions will assume that you are working on a
DICE workstation.
You are welcome to do the practical on a home machine. However, if you
do this, you must be aware that:
 + I will not provide any support or assistance in transferring the
   practical to another system
 + you will need to copy several hundred megabytes of files to your
   home machine
 + your final submitted code must compile and run, unmodified, in the
   specified environment.