Project 0 -- Linux Dabbling CS-502 (EMC) Fall Project 0 Linux & Virtual Machine Dabbling CS-502, Operating Systems Fall 2009 (EMC)

Project 0 -- Linux Dabbling CS-502 (EMC) Fall 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 via myWPI

Project 0 -- Linux Dabbling CS-502 (EMC) Fall 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

Project 0 -- Linux Dabbling CS-502 (EMC) Fall Using your Virtual Machine Characteristics Guest OS is openSUSE Linux 11.1 Configured for projects of this course Configured to work with VMware Just the basic devices needed for this course You may use Fossil Lab (VMware Workstation) Your own PC or Mac –VMware Player or VMware Fusion

Project 0 -- Linux Dabbling CS-502 (EMC) Fall Starting your Virtual Machine 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 11.1 Login is as student, password = CS-502 Switching between Host and Guest Click in guest window to focus mouse and keyboard Type CTL-ALT to return focus to host …

Project 0 -- Linux Dabbling CS-502 (EMC) Fall Starting your Virtual Machine (continued) 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”

Project 0 -- Linux Dabbling CS-502 (EMC) Fall 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

Project 0 -- Linux Dabbling CS-502 (EMC) Fall YaST, the SUSE administration tool A much more efficient/effective way to manage your system Administer hardware, software, users, services, etc. Root password CS-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

Project 0 -- Linux Dabbling CS-502 (EMC) Fall Other Notes 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 Seems to work this term! Usually! If not, see VM menu

Project 0 -- Linux Dabbling CS-502 (EMC) Fall Share your thoughts and experiences with your colleagues Use the class or discussion list!

Project 0 -- Linux Dabbling CS-502 (EMC) Fall Questions?

Project 0 -- Linux Dabbling CS-502 (EMC) Fall 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

Project 0 -- Linux Dabbling CS-502 (EMC) Fall Digression on Unix/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.

Project 0 -- Linux Dabbling CS-502 (EMC) Fall 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 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

Project 0 -- Linux Dabbling CS-502 (EMC) Fall To Modify a File mv file.c file.c~ Edit file.c~ in your favorite editor Save as file.c (Eventually) rm file.c~ EMACS and patch do this automatically Most other editors require you to do it manually

Project 0 -- Linux Dabbling CS-502 (EMC) Fall To Build Linux Kernel “Make configuration” step –As ordinary user Build kernel files and modules –As ordinary user Install modules, boot file, etc. –Need root privileges

Project 0 -- Linux Dabbling CS-502 (EMC) Fall 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 –Your patch files grow to megabytes!

Project 0 -- Linux Dabbling CS-502 (EMC) Fall 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

Project 0 -- Linux Dabbling CS-502 (EMC) Fall Make configuration (continued) Edit “General Setup” line to name your “Local version” No other edits necessary for this project. Save and quit If need to rebuild, use make O=~/kernelDst oldconfig to reuse same configuration

Project 0 -- Linux Dabbling CS-502 (EMC) Fall To Build Kernel In a terminal window (i.e., a shell), do: – –cd kernelSrc –make –j4 O=~/kernelDst Takes ~25 minutes on dual-core 2.4 GHz Core Duo, 1 GByte RAM in VM (2 GByte real memory) Much more than one hour on 3 gigahertz Pentium, 3 GByte, hypterthreaded Rebuilds after small edits are much faster Changing.h files causes longer rebuilds

Project 0 -- Linux Dabbling CS-502 (EMC) Fall Note: building with multiple processors Generally faster to do –cd kernelSrc –make –j4 O=~/kernelDst –j = number of concurrent build “jobs” SUSE advice –2  number of processors –Fossil Lab workstations have two processors (dual core)

Project 0 -- Linux Dabbling CS-502 (EMC) Fall Warnings Lots of warnings from files you never touched Not your problem No warnings allowed in your own code! In this course

Project 0 -- Linux Dabbling CS-502 (EMC) Fall For Project Submission Redirect build output to a file Submit –A subset of that file (this project only) E.g., first two dozen and last two dozen lines. –Output of uname –a command

Project 0 -- Linux Dabbling CS-502 (EMC) Fall To Install Kernel Requires root privileges –sudo make modules_install install –Root password = CS-502 –Note order of arguments! Puts kernel, initrd file, symbols in /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

Project 0 -- Linux Dabbling CS-502 (EMC) Fall 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

Project 0 -- Linux Dabbling CS-502 (EMC) Fall Submitting your Project From within your virtual machine, visit Log in Submit output of your build as Project 0 This is to test your ability to submit projects from the virtual machine!

Project 0 -- Linux Dabbling CS-502 (EMC) Fall Project Due Due date:– –Monday, September 29, 11:59 PM When should projects be due? –Before class? –After class the same day? –Other thoughts?

Project 0 -- Linux Dabbling CS-502 (EMC) Fall Questions?