1. Project 0: Linux and Virtual Machine Dabbling
CS-3013 Operating Systems Hugh C. Lauer
(Slides include materials from Slides include materials from Modern Operating Systems, 3rd ed., by Andrew Tanenbaum and from Operating System Concepts, 7th ed., by Silbershatz, Galvin, & Gagne)
CS-3013, C-Term 2012
Project 0 — Linux Dabbling

2. In this project, we will …
Install our virtual machines and learn how to use them
This is the place you will work during this course!
Build and install the Linux kernel
With your name on it!
Follow Linux naming & numbering conventions
Turn in the project using web-based Turnin
CS-3013, C-Term 2012
Project 0 — Linux Dabbling

3. In this project, we won’t …
… try to change anything in the kernel yet
This is for a future project
… try to support more than one machine architecture
However, 32-bit and 64-bit architectures are different at the kernel level!
Hardware-level code for different processor families is organized differently in kernel source code!
Your kernel is not portable from one to another
CS-3013, C-Term 2012
Project 0 — Linux Dabbling

4. Using your Virtual Machine
Characteristics
Guest OS is OpenSUSE Linux 11.4
Configured for projects of this course
Configured to work with VMware
Just the basic devices needed for this course
Host system
Your own or corporate PC or Mac
VMware Player, VMware Workstation, or VMware Fusion
Virtual Fossil Server
CS-3013, C-Term 2012
Project 0 — Linux Dabbling

5. Starting your Virtual Machine
Download from
See “cookbook” for how to clone or copy
Don’t waste too much time trying to figure it out on your own
Start it
Click in virtual machine screen
Use arrow keys to select OpenSUSE 11.4
Login is as student, password = CS-3013/502 …
CS-3013, C-Term 2012
Project 0 — Linux Dabbling

6. Starting your Virtual Machine (continued)
Switching between Host and Guest
Click in guest window to focus mouse and keyboard
Type CTL-ALT to return focus to host
Full screen mode
Type CTL-ALT-Enter to switch to or from guest full screen
Interrupting
CTL-ALT-DEL always goes to host system
Use VM menu command to “send CTL-ALT-DEL to guest”
CS-3013, C-Term 2012
Project 0 — Linux Dabbling

7. KDE – a Linux GUI interface
Looks and acts a lot like Windows or Mac GUI
Many similar tools and applications
“Start” menu is in lower left corner under the “Gecko” icon
YaST, the SUSE administration tool
Select User and group administration
Create new user identity for yourself
Log out, log in as new identity, delete student
CS-3013, C-Term 2012
Project 0 — Linux Dabbling

8. YaST, the SUSE administration tool
A much more efficient/effective way to manage your system
Administer hardware, software, users, services, etc.
Root password
CS-3013/502 (same as student password)
Access via third tab under “Gecko” icon
Use it to
Set up your own user ID and delete student ID
Fix your network configuration
CS-3013, C-Term 2012
Project 0 — Linux Dabbling

9. Project 0 — Linux Dabbling
Other Notes
If not, see VM menu
Usually!
When input focus is in guest window
Inserted CD/DVD is recognized by guest OS
Same for USB flash drive
Snapshots
Makes a record of the state of your virtual machine
Any subsequent changes are made in copy-on-write mode
Shared folder with host operating system
Extremely useful!
Not available in VMware Player
CS-3013, C-Term 2012
Project 0 — Linux Dabbling

10. Share your thoughts and experiences with your colleagues
Use the class list!
CS-3013, C-Term 2012
Project 0 — Linux Dabbling

11. Project 0 — Linux Dabbling
Questions?
CS-3013, C-Term 2012
Project 0 — Linux Dabbling

12. To get started with kernel build
Find kernel sources in /usr/src
i.e., a link to /home/src
Current version is linux
Clone kernel source tree by linked copy: –
In a command shell, do
cp –al /usr/src/linux kernelSrc
Creates a linked copy of original tree in new directory called kernelSrc
Or whatever you wish to name it
CS-3013, C-Term 2012
Project 0 — Linux Dabbling

13. Digression on Linux Hard Links
Directory entries point directly to files
Multiple directory entries may point to same file!
Same or different directories (within same file system)
Same or different name
Name attached to directory, not file
Permissions & attributes attached to file, not directory
Called hard links (as opposed to symbolic links)
Modifications to file seen thru all hard links
mv and rm commands change directories, not files!
File goes away when all directory entries (i.e., hard links) to that file are deleted and file is closed.
CS-3013, C-Term 2012
Project 0 — Linux Dabbling

14. Project 0 — Linux Dabbling
Cloned Source Tree
All directories are copied
All directory entries are hard-linked to files in original source tree
I.e., only one copy of each file exists
A good thing, because kernel sources are hundreds of megabytes!
To modify a file:–
Unlink it in your directory (via mv or rm)
Replace with modified copy in your directory
Original still remains intact in original directory
CS-3013, C-Term 2012
Project 0 — Linux Dabbling

15. Project 0 — Linux Dabbling
To Modify a File
mv file.c file.c~
AND THEN
Edit file.c~ in your favorite editor
Save as file.c OR
Copy file.c~ back to file.c in your kernel source tree
Edit file.c directly
(Eventually) rm file.c~
Some editors try to do this automatically
DO NOT edit kernel source files as root
CS-3013, C-Term 2012
Project 0 — Linux Dabbling

16. Project 0 — Linux Dabbling
To Build Linux Kernel
“Make configuration” step
As ordinary user
Build kernel files and modules
Install modules, boot file, etc.
Need root privileges
CS-3013, C-Term 2012
Project 0 — Linux Dabbling

17. To Build Linux Kernel (continued)
Always build to a separate destination tree
mkdir ~/kernelDst
make O=~/kernelDst …
Reason
Making the configuration generates a lot of include files and other sources
If you don’t specify a destination, it fills up your source tree
Submitted project files grow to megabytes!
Graders unable to build your kernel!
CS-3013, C-Term 2012
Project 0 — Linux Dabbling

18. Making the Configuration
In a command shell
cd kernelSrc
Do one of:–
make O=~/kernelDst config
Very long and tedious
make O=~/kernelDst menuconfig
Still somewhat long and tedious; also hokey
make O=~/kernelDst xconfig
Really nice; a better GUI; highly recommended
make O=~/kernelDst gconfig
Used to be better, but has not kept up with xconfig
CS-3013, C-Term 2012
Project 0 — Linux Dabbling

19. Make configuration (continued)
Edit configuration file
Load course configuration file from
Edit “General setup” to add your name
No other edits necessary for this project.
Save and quit
If need to rebuild, use
make O=~/kernelDst oldconfig
to reuse same configuration
CS-3013, C-Term 2012
Project 0 — Linux Dabbling

20. Project 0 — Linux Dabbling
To Build Kernel
In a terminal window (i.e., a shell), do:–
cd kernelSrc
make O=~/kernelDst
Takes
More than one hour on 3 gigahertz Pentium, 3 GByte, hypterthreaded
~25 minutes on dual-core 2.4 GHz Core2 Duo, 1 GByte RAM in VM (2 GByte real memory)
~6-7 minutes on quad-core 3.4 GHz Core i7
Rebuilds after small edits are much faster
Changing .h files causes longer rebuilds
I.e., letter “O”
CS-3013, C-Term 2012
Project 0 — Linux Dabbling

21. Note: building with multiple processors
Generally faster to do
cd kernelSrc
make –j4 O=~/kernelDst
j = number of concurrent build “jobs”
SUSE advice
Set j to 2  number of processors
CS-3013, C-Term 2012
Project 0 — Linux Dabbling

22. Project 0 — Linux Dabbling
Warnings
Lots of warnings from files you never touched
Not your problem
No warnings allowed in your own code!
In this course
CS-3013, C-Term 2012
Project 0 — Linux Dabbling

23. For Project Submission
Redirect output of build step to a file
Submit
A subset of that file (this project only)
E.g., first two dozen and last dozen or so lines.
Output of uname –a command
README file with a summary of any difficulties or issues
README.txt, README.doc, or README.pdf
CS-3013, C-Term 2012
Project 0 — Linux Dabbling

24. Project 0 — Linux Dabbling
To Install Kernel
Requires root privileges
sudo make modules_install install
Root password = CS-3013/502
Note order of arguments!
This
puts driver modules into /lib/modules
puts kernel, initrd file & symbols into /boot
Changes links for vmlinuz, initrd
adds entries to /boot/grub/menu.lst
So your kernel shows up on boot screen
So you can select which kernel to boot
CS-3013, C-Term 2012
Project 0 — Linux Dabbling

25. Project 0 — Linux Dabbling
Running Your Kernel
Restart your virtual machine
Click in boot window
Use arrow keys to select desired kernel or system
To determine which kernel is running:–
uname -a
CS-3013, C-Term 2012
Project 0 — Linux Dabbling

26. Submitting your Project
From within your virtual machine, visit
Log in
Submit output of your build as Project 0
This is a sanity check on your ability to submit projects from the virtual machine!
CS-3013, C-Term 2012
Project 0 — Linux Dabbling

27. Project 0 — Linux Dabbling
Project Due
Due date:–
Tuesday, January 17, 2012
When should projects be due:–
4:00 PM vs. 11:59 PM?
Day before class vs. day of class
Other thoughts?
CS-3013, C-Term 2012
Project 0 — Linux Dabbling

28. Project 0 — Linux Dabbling
Questions?
CS-3013, C-Term 2012
Project 0 — Linux Dabbling

29. Project 0 — Linux Dabbling
CS-3013, C-Term 2012
Project 0 — Linux Dabbling