Project 0 Linux & Virtual Machine Dabbling

1. Project 0 Linux & Virtual Machine Dabbling CS-3013, Operating Systems 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 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 Project 0 -- Linux Dabbling

4. 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

5. 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-3013 • 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

6. Starting your Virtual Machine (continued) • Full screen mode • Type CTL-ALT-Enter to switch to or from guest full screen • Interrupting • CTL-ALT-DELalways goes to host system • Use VM menu command to “send CTL-ALT-DEL to guest” 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 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 (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

9. Usually! If not, see VM menu 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! Project 0 -- Linux Dabbling

10. Share your thoughts and experiences in the Fossil Lab with your colleaguesUse the class e-mail list! Project 0 -- Linux Dabbling

11. Questions? 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-2.6.27.25-0.1 • Clone kernel source tree by linked copy: – • In a command shell, do cp –al /usr/src/linux-2.6.27.25-0.1 kernelSrc • Creates a linked copy of original tree in new directory called kernelSrc • Or whatever you wish to name it Project 0 -- Linux Dabbling

13. 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

14. 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

15. 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

16. 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

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 • Your patch files grow to megabytes! 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 Project 0 -- Linux Dabbling

19. 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=~/kernelDstoldconfig to reuse same configuration Project 0 -- Linux Dabbling

20. 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

21. 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

22. 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

23. 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

24. To Install Kernel • Requires root privileges • sudo make modules_install install • Root password = CS-3013 • 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

25. 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

26. Submitting your Project • From within your virtual machine, visit https://turnin.cs.wpi.edu:8088/ • 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

27. Project Due • Due date:– • Tuesday, September 2, 11:59 PM • When should projects be due:– • 6:00 PM vs. 11:59 PM? • Day before class vs. day of class • Other thoughts? Project 0 -- Linux Dabbling

28. Questions? Project 0 -- Linux Dabbling