Courses/Computer Science/CPSC 457.F2014/Tutorial Schedule
Tutorial topics that we will discuss each week are below.
T01 WF MS160 8:00 James, C. T02 TR MS160 8:00 Afshar, A. T03 TR MS119 17:00 Gonzalez, R. T04 TR MS119 11:00 Afshar, A. T05 MW MS160 13:00 Gonzalez, R.
Tutorials begin on September 17, 2014 (All dates on this website are tentative and subject to changes)
Contents
- 1 September 17: Introduction to VirtualBox
- 2 September 18: Introduction to SVNs
- 3 September 23: Introduction to C (Part 1)
- 4 September 25: Introduction to C (Part 2)
- 5 September 30: Writing a Linux Shell (Part 1)
- 6 October 2: Writing a Linux Shell (Part 2)
- 7 Oct 7: LKM Intro
- 8 October 14th: Downloading and Compiling the Kernel Source
- 9 October 16th: Adding a System Call
- 10 October 21st: Adding a System Call (continue)
- 11 October 23rd: Kernel Data Structures
- 12 October 28th: Patch / Diff
- 13 Oct 30th Open Work Period
- 14 Nov 4th: Open Work Period
- 15 Nov 6th: Open Work Period
- 16 Nov 11th: Time Measurement
- 17 Nov 14th: Time Measurement
- 18 Nov 19th: Work Period
- 19 Nov 25th: Source Code Comments
- 20 Nov 27th: Open Work Period
- 21 Dec 2nd: Open Work Period
- 22 Dec 4th: Open Work Period
September 17: Introduction to VirtualBox
Give the students an understanding of how virtualization works, setting up hardware specifications for a VM, and how to boot a VM.
September 18: Introduction to SVNs
Brief tutorial on using SVN as a revision control for software, file management, or documentation.
Helpful Links
September 23: Introduction to C (Part 1)
Introduction to the C syntax and compilation of C programs. We wrote a small Hello World program and compiled it, then worked with calling different functions to print the Hello World message and to get used to the C syntax. We also briefly introduced makefiles and the advantages of using them when developing our code.
September 25: Introduction to C (Part 2)
We continued our C introduction by studying other components that are not found in other programming languages. In this class we studied structures, unions, and arrays. We also studied pointers and how we can pass variables by value and by reference. We also worked with Makefiles and compiling several files at once.
Exercise for this tutorial
http://pages.cpsc.ucalgary.ca/~gonzalre/CPSC457/IntroC2.pdf
September 30: Writing a Linux Shell (Part 1)
We studied how to implement the parsing and prompting of a linux shell using the C programming language.
Exercise for this tutorial
http://pages.cpsc.ucalgary.ca/~gonzalre/CPSC457/Shell1.pdf
October 2: Writing a Linux Shell (Part 2)
Continuation of previous tutorial. We studied how to execute commands generated by an user in the shell programmed in the previous tutorial. For this, we use the system calls fork() and execve().
Exercise for this tutorial
http://pages.cpsc.ucalgary.ca/~gonzalre/CPSC457/Shell2.pdf
Oct 7: LKM Intro
Notes
Helpful Links
October 14th: Downloading and Compiling the Kernel Source
Follow these directions from the kernel itself
http://lxr.cpsc.ucalgary.ca/lxr/#linux/README#L138
Example
(eye@mordor ~)$ cd 457/kernel/ (eye@mordor kernel)$ ls kernel-2.6.32-358.18.1.el6.src.rpm linux-2.6.32/ (eye@mordor kernel)$ cd linux-2.6.32/ (eye@mordor linux-2.6.32)$ make oldconfig ...answer a few dozen questions, mostly with "no"... (eye@mordor linux-2.6.32)$ make CHK include/linux/version.h CHK include/linux/utsrelease.h SYMLINK include/asm -> include/asm-x86 CALL scripts/checksyscalls.sh CHK include/linux/compile.h CHK include/linux/version.h ...1.5 hours and 79% of my battery later... make[2]: `scripts/unifdef' is up to date. Kernel: arch/x86/boot/bzImage is ready (#1) Building modules, stage 2. MODPOST 1785 modules WARNING: modpost: Found 2 section mismatch(es). To see full details build your kernel with: 'make CONFIG_DEBUG_SECTION_MISMATCH=y' (eye@mordor linux-2.6.32)$
So what's new here?
(eye@mordor linux-2.6.32)$ ls arch/ drivers/ Kbuild modules.order scripts/ virt/ block/ firmware/ kernel/ Module.symvers security/ vmlinux* COPYING fs/ lib/ net/ sound/ vmlinux.o CREDITS include/ MAINTAINERS README System.map crypto/ init/ Makefile REPORTING-BUGS tools/ Documentation/ ipc/ mm/ samples/ usr/
Oh, this vmlinux file looks like an interesting excutable.
(eye@mordor linux-2.6.32)$ file vmlinux vmlinux: ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV), statically linked, not stripped
It's an ELF???!!??!? Yep.
(eye@mordor linux-2.6.32)$ ls arch/x86/boot/ a20.c copy.S mca.c regs.o video.c a20.o cpu.c mca.o setup.bin* video.h apm.c cpucheck.c memory.c setup.elf* video-mode.c apm.o cpucheck.o memory.o setup.ld video-mode.o bioscall.o cpu.o mkcpustr* string.c video.o bioscall.S cpustr.h mkcpustr.c string.o video-vesa.c bitops.h edd.c mtools.conf.in tools/ video-vesa.o boot.h edd.o pm.c tty.c video-vga.c bzImage header.o pmjump.o tty.o video-vga.o cmdline.c header.S pmjump.S version.c vmlinux.bin* cmdline.o install.sh pm.o version.o voffset.h code16gcc.h main.c printf.c vesa.h zoffset.h compressed/ main.o printf.o video-bios.c copy.o Makefile regs.c video-bios.o (eye@mordor linux-2.6.32)$ file arch/x86/boot/bzImage arch/x86/boot/bzImage: Linux kernel x86 boot executable bzImage, version 2.6.32 (eye@mordor) #1 SMP Wed , RO-rootFS, root_dev 0x803, swap_dev 0x3, Normal VGA (eye@mordor linux-2.6.32)$
Now I can go on to 'sudo make modules_install install', which will create the appropriate entry in /etc/grub.conf for me, and then I can boot into my "new" kernel.
October 16th: Adding a System Call
In this tutorial, we are learning how to add a simple system call to our new Kernel. A system call is a way to allow users, use low level system functionalists like working with hardware. The following exercises are based on kernel version 2.6.32; it will help you how download, compile, configure and install the kernel and how to add a simple system call to our new kernel.
Slide [ https://www.dropbox.com/s/mulsuvyp9yzj2gt/System%20Call.pdf ]
Exercises: [ https://www.dropbox.com/s/ixdhfdv0usucqkz/BUILD%26ADDSYSTEMCALL.pdf ]
"Sample User Space Code" [ https://www.dropbox.com/s/8bqbd4808fiwhoh/hello.c ]
Helpful Links: [ http://arvindsraj.wordpress.com/2012/10/05/adding-hello-world-system-call-to-linux/]
http://www.cs.ucr.edu/~kishore/cs153_w09/syscall-assignment/how-to-add-system-call.txt
October 21st: Adding a System Call (continue)
Exercises http://pages.cpsc.ucalgary.ca/~gonzalre/CPSC457/Exercises/Reeducate.pdf
System call sample "http://pages.cpsc.ucalgary.ca/~gonzalre/CPSC457/sys_reeducate.c"
October 23rd: Kernel Data Structures
In this tutorial we work with the task_struct of a PID using the implementation of the system call "reeducate" for the Assignment#2.
Procedure for adding our system call:
http://pages.cpsc.ucalgary.ca/~gonzalre/CPSC457/Exercises/Reeducate.pdf
Source Code for part of the implementation of reeducate(2):
http://pages.cpsc.ucalgary.ca/~gonzalre/CPSC457/Source_Code/sys_reeducate.c
October 28th: Patch / Diff
In this tutorial, we go through how to patch the kernel source code. After downloading a fresh copy of our kernel version, we used the diff command to get a patch with our modifications. We then applied the patch to the fresh copy of the kernel to update it according to our customizations.
Exercise:
http://pages.cpsc.ucalgary.ca/~gonzalre/CPSC457/Exercises/Patching.pdf
Oct 30th Open Work Period
This tutorial is going to be dedicated on solving any doubts on assignments/exercises/concepts.
Nov 4th: Open Work Period
This tutorial is going to be dedicated on solving any doubts on assignments/exercises/concepts.
Nov 6th: Open Work Period
This tutorial is going to be dedicated on solving any doubts on assignments/exercises/concepts.
Nov 11th: Time Measurement
This tutorial is about measuring how long any part of your program may take. We introduce two system calls for this purpose: Time and Gettimeofday.
Notes for today: https://www.dropbox.com/s/dwwiq7deqnaicjl/Timemeasurement%20Tutorial.pdf
Exercises for today: http://pages.cpsc.ucalgary.ca/~gonzalre/CPSC457/Exercises/Measuring_time.pdf
Nov 14th: Time Measurement
In this tutorial we got familiar with rdtsc instruction in order to measure the time in a more precise mod.
Notes for this tutorial: https://www.dropbox.com/s/n0ti5qlvhfadqyg/TimeStampCounter.pdf
HelpfulLinks:
http://software.intel.com/en-us/forums/topic/287418
Nov 19th: Work Period
Nov 25th: Source Code Comments
In this tutorial, we will examine the value of Linux kernel comments and get some practical experience commenting the kernel source itself.
First, read "Chapter 8: Commenting" in the Linux Kernel Coding Style document:
http://lxr.cpsc.ucalgary.ca/lxr/#linux+v2.6.32/Documentation/CodingStyle#L425 (through line 462). Note that this "chapter" is 37 lines long.
Next, spend 10 minutes grepping through the source code for interesting turns of phrase or salty language. You might want to search for keywords like: XXX, TODO, TOFIX or FIXME. You may want to look for words like "impossible, incorrect, not right, broken, silly" or similar terms.
Now, glance over the comments in these files:
- http://lxr.cpsc.ucalgary.ca/lxr/#linux+v2.6.32/drivers/net/3c501.c#L1
- http://lxr.cpsc.ucalgary.ca/lxr/#linux+v2.6.32/kernel/kthread.c
- http://lxr.cpsc.ucalgary.ca/lxr/#linux+v2.6.32/block/blk-core.c
Do there seem to be enough comments to understand what these pieces of code do?
Warmup
- Comment these functions:
- Using the COMTOR model, rate the quality of comments of the file or the structure or function at the given line:
Task
- Pick an arbitrary .c, .h, or .S file in the Linux kernel source code. Comment it.
- Using the COMTOR model, rate the quality of comments in a kernel source file of your choosing.
- Commit your work to your svn repository. You'll receive 1 point of extra credit for each function you comment or file you rate, up to maximum of 15.
