Project 2 in COMP3500 Operating Systems class at Auburn University. The objectives of this project are: • Use your installed CentOS to build OS/161 and run Sys/161 • Configure and build OS/161 kernels • Discover important design aspects of OS/161 by examining its source code • Manage OS/161 using a version control system called cvs; apply cvs to create a repository and tracking your source code changes • Use GDB to debug OS/161

1. 1
COMP 3500
Introduction to Operating Systems
Project 2 – An Introduction to OS/161
Overview
Dr. Xiao Qin
Auburn University
http://www.eng.auburn.edu/~xqin
xqin@auburn.edu

2. A Survey Question in Fall’16
Our OS projects should be due on:
(A)Friday (my vote)
(B)Saturday
(C)Sunday
(D)Monday
(E) Tuesday
(F) Wednesday
(G)Thursday

3. Candidate Programing Environments
2. Your Own Linux Machine1. OS Lab
3. Gate/Tux Machine 4. Virtue Machine on your PC
Same as the OS Lab case
except that its your PC
Remote access: using ssh.
Local access: Davis Hall room 123
(Aerospace)
You have installed CentOS. You
may use IDE or Vim/gcc/gdb
Install VirtualBox, then
CentOS, then its your virtual
OS Lab
Options 2-3: How to use CVS to maintain the source code
developed by multiple group members? GitHub.com?
3

4. Project Objectives
• To use your installed CentOS for project 2
• To configure and build OS/161 kernels
• Discover design aspects of OS/161
• To learn CVS - a version control system
• To learn GDB to debug OS/161
Two weeks to achieve the above objectives!

5. Eight Tasks
• Task 1-Environment (toolchains): 10%, 30 min - 4 hours
• Task 2-Setup CVS: 10%, 10 min
• Task 3-Reading Code: 30%, 4 hours (Wait for me)
• Task 4-Build OS161: 10%, 10-30 min
• Task 5-Run OS161: 10%, 10-30 min
• Task 6-Rebuild os161: 10%, 10-30 min
• Task 7-Use GDB: 10%: 10-30 min
• Task 8-Use CVS: 10%, 10 min

6. Collaboration Strategies
• A Bad (really bad) Plan: One member works on
COMP4300; one member works on COMP3500
• Two members A and B (who are not familiar with Linux):
work on projects 0/1 in Week 1
• One member C (who are a Linux expert): immediately
work on project 2 in Week 1
• Members A and B start working project 2 in week 2.
• Member C is the mentor for A and B.

7. Overall Strategy
Project 2 – An Introduction to OS/161
Build OS/161:
Section 6
Setup CVS reposition: read Section 3.1
Walkthrough Sections 4.1 and 4.4
Run OS/161:
Section 7
Modify OS/161:
Section 8
Setup the toolchain including cs161-gcc, cs161-gdb, and
sys161: Sections 4.2 and 4.3
Run OS/161:
Section 7
Code Reading: Section 5
(wait for me)

8. Tool 1: the script command
• Save a session of your Linux terminal.
• A typescript of everything that happens.
$ script
$Script started, file is typescript
$ cd
$ ls
file1 file2 file3
$ exit
exit
Script done, file is typescript

9. Tool 1: the script command
$ script sample.script
$Script started, file is typescript
$ cd
$ ls
file1 file2 file3
$ exit
exit
Script done, file is sample.script

10. Tool 2: CVS
(Concurrent Versions System)
• Source code version control system
• To merge multiple programmers' modifications
• To detecting conflicts when merges fail

11. Tool 2: CVS (Cont.)
• Create CVS repository directory
%cvs –d ~/cs161/cvsroot
• Set your CVSROOT environment variable
%export CVSROOT=~/cs161/cvsroot
• Start CVS
%cvs init
• Import your source tree
%cd ~/cs161/os161
%cvs import -m "Import of os161" src os161 os161-1_10

12. Tool 2: CVS (Cont.)
• Delete your os161 source tree
%cd ..
%rm -rf os161
• Checkout now
% cd ~/cs161
% cvs checkout src