[HowTo] Create Ubuntu Live CD

Ubuntu 10.10 code name Maverick Meerkat has been released on October 10th 2010 you can download it from ubuntu.com for free. But when you are an Ubuntu advance user, you need to add more package or remove some package that you won’t use. Then you can live boot your custom Ubuntu live CD. And it’s not limited to live CD, you can make it as live USB too.

There are some reasons you want to customize Ubuntu live CD:

1. Make your own Linux / Ubuntu distribution, something like rebranding but based on Ubuntu
2. Show off a particular application
3. Localise to a certain language
4. Remove software packages
5. Add software packages
6. Update software packages
7. Change system defaults (theme, icons, desktop background, panels, browser homepage, etc)

To make custom Ubuntu live CD:

1. Open your terminal and install squashfs-tools and genisoimage:

   sudo apt-get install squashfs-tools genisoimage
   

2. Download Ubuntu Desktop CD:

   wget http://releases.ubuntu.com/maverick/ubuntu-10.10-desktop-i386.iso
   

3. Move it to working directory, call it livecdtemp:

   mkdir ~/livecdtmp
   mv ubuntu-10.10-desktop-i386.iso ~/livecdtmp
   cd ~/livecdtmp
   

4. Extract the CD .iso contents

   mkdir mnt
   sudo mount -o loop ubuntu-10.10-desktop-i386.iso mnt
   

5. Extract .iso contents into dir ‘extract-cd’

   mkdir extract-cd
   rsync --exclude=/casper/filesystem.squashfs -a mnt/ extract-cd
   

6. Extract the SquashFS filesystem to edit folder

   sudo unsquashfs mnt/casper/filesystem.squashfs
   sudo mv squashfs-root edit
   

7. Give network connection within chroot

   sudo cp /etc/resolv.conf edit/etc/
   sudo cp /etc/hosts edit/etc/
   sudo mount --bind /dev/ edit/dev
   sudo chroot edit
   mount -t proc none /proc
   mount -t sysfs none /sys
   mount -t devpts none /dev/pts
   export HOME=/root
   export LC_ALL=C
   

8. Customization time!
   To enable apt-get within chroot:

   dbus-uuidgen > /var/lib/dbus/machine-id
   dpkg-divert --local --rename --add /sbin/initctl
   ln -s /bin/true /sbin/initctl
   

   Update your sources.list if necessary:

   vim /etc/apt/sources.list
   

   Update your repository:

   apt-get update
   

   To install new package:

   apt-get install [package-name]
   

   To remove unwanted package:

   aptitude purge package-name
   

   To customize Gnome:
   a. Customize background:
   * add wallpaper file to /usr/share/backgrounds
   * edit /usr/share/gnome-background-properties/ubuntu-wallpapers.xml to point to your wallpaper file
   b. Change font, panels, etc:
   To make any change on the gconf attributes you must add the value that you want in the file /etc/gconf/gconf.xml.defaults/%gconf-tree.xml. Adding a value in that file will change the default values of Gnome or other applications, so you can change fonts, backgrounds, themes, cursors etc. You can use gconftool-2, under the chroot environment to adjust the gconf file:

   gconftool-2 --direct --config-source xml:readwrite:/etc/gconf/gconf.xml.defaults --type string --set yourkey "yourvalue"
   

   I haven’t do this much, since the livecd i create is for disaster recovery, so default desktop it’s fine with me. But it’s worth to try.

   Change the default timezone used by the live cd:

   dpkg-reconfigure tzdata
   

   Change local setting:

   locale-gen new_locale
   update-locale LANG=new_locale LANGUAGE=new_locale LC_ALL=new_locale
   

9. Clean up

   aptitude clean
   rm -rf /tmp/* ~/.bash_history
   rm /etc/resolv.conf
   rm /var/lib/dbus/machine-id
   rm /sbin/initctl
   dpkg-divert --rename --remove /sbin/initctl
   

10. Regenerate manifest:

    chmod +w extract-cd/casper/filesystem.manifest
    sudo chroot edit dpkg-query -W --showformat='${Package} ${Version}n' > extract-cd/casper/filesystem.manifest
    sudo cp extract-cd/casper/filesystem.manifest extract-cd/casper/filesystem.manifest-desktop
    sudo sed -i '/ubiquity/d' extract-cd/casper/filesystem.manifest-desktop
    sudo sed -i '/casper/d' extract-cd/casper/filesystem.manifest-desktop
    

11. Compress filesystem:

    sudo rm extract-cd/casper/filesystem.squashfs
    sudo mksquashfs edit extract-cd/casper/filesystem.squashfs -nolzma
    

12. Remove old md5sum.txt and calculate new md5 sums

    cd extract-cd
    sudo rm md5sum.txt
    find -type f -print0 | sudo xargs -0 md5sum | grep -v isolinux/boot.cat | sudo tee md5sum.txt
    

13. Create the ISO image:

    sudo mkisofs -D -r -V "$IMAGE_NAME" -cache-inodes -J -l -b isolinux/isolinux.bin -c isolinux/boot.cat -no-emul-boot -boot-load-size 4 -boot-info-table -o ../ubuntu-10.10-desktop-i386-custom.iso .
    

14. Testing the CD image:

    qemu -cdrom ubuntu-10.10-desktop-i386-custom.iso -boot d -m 512
    

15. Burn the CD:
    You can use any tools you like, for example Gnomebaker. Or:

    cdrecord dev=/dev/cdrom ubuntu-10.10-desktop-i386-custom.iso
    

    You can make the USB live with Unetbootin.

That’s it. You can create your custom Ubuntu live cd or even rebranded it. Long live Ubuntu!

There is online tools to create custom Ubuntu and Debian live CD it is called Reconstructor. You can see the tutorial from How-To Geek article.

Credits:
LiveCDCustomization Documentation