Creating a UW CSCF Customized Ubuntu 9.04 Desktop Live CD Image.

Currently I'm building a customized Ubuntu 9.04 (Jaunty Jackalope) 64-bit PC (AMD64) desktop CD image on a Ubuntu 8.10 (Intrepid Ibex) 64-bit PC (AMD64) desktop system.

Following along from the notes in Ubuntu documentation: LiveCDCustomization.

The Process

During the section I used these replies:

• sudo aptitude install squashfs-tools genisoimage
  • No addition replies for this step needed however my current setup already had genisoimage installed.
• sudo modprobe squashfs
  • No addition replies for this step needed since squashfs was already installed.

This is where I deviate just a little, in that I like to get a fresh copy of the ISO I'm going to customize.

• mkdir UWcustom && cd UWcustom
• wget http://mirror.cs/ubuntu-releases/jaunty/ubuntu-9.04-desktop-amd64.iso

We want an emulator/virtual machine to test the new image and we can use this image to test if our emulator is working.

Tried "qemu -cdrom ubuntu-9.04-desktop-amd64.iso" only to get "This kernel requires an x86-64 CPU, but only detected an i686 CPU." The host I'm running on is a 64 bit kernel:
"root@cutter:/.Previous_OS/UWcustom/UWcustom# uname -m"
x86_64

So I choose KVM:

• see https://help.ubuntu.com/community/KVM/Installation
  1. sudo apt-get install kvm libvirt-bin ubuntu-vm-builder qemu bridge-utils
     which might not be needed as the following is new starting with the intrepid release.
  2. sudo apt-get install ubuntu-virt-server ubuntu-virt-mgmt
  3. sudo sudo modprobe dm-loop
  4. sudo kvm -cdrom ubuntu-9.04-desktop-amd64.iso

     Which does allow you to see that the boot process is working, although I couldn't get a working GUI screen.

OK, exit out of the virtual host and lets get back to making the custom image.

Extracting the CD contents

• mkdir mnt && sudo mount -o loop ubuntu-9.04-desktop-amd64.iso mnt
  • I had to enter the proper sudo passwd here.
• mkdir extract-cd && rsync --exclude=/casper/filesystem.squashfs -a mnt/ extract-cd

Extracting the Desktop system

• mkdir squashfs && sudo mount -t squashfs -o loop mnt/casper/filesystem.squashfs squashfs
• mkdir edit && sudo cp -a squashfs/* edit/
  • Wow this took a long time (ie minutes rather than seconds), however be patient, it does complete.

Prepare and chroot

• sudo cp /etc/resolv.conf edit/etc/
• sudo cp /etc/hosts edit/etc/
• sudo cp /etc/adduser.conf edit/etc/
  • We have some very old (20+ years) user accounts with UID's and GID's around the 100 range so I'm adding 2*10^10 to the FIRST and LAST UID,GID configuration options in adduser.conf.
  • We need to run a "fixids" shell script (put URL to it here).
  • We then need to fix edit/etc/passwd and edit/etc/group.
• update /etc/apt/sources.list to use local repositories and some that aren't included by default.
  • sudo wget http://www.medibuntu.org/sources.list.d/hardy.list -O /etc/apt/sources.list.d/medibuntu.list
  • sudo apt-get update && sudo apt-get install medibuntu-keyring && sudo apt-get update
• sudo mount --bind /dev/ edit/dev
• sudo chroot edit
• mount -t proc none /proc
• mount -t sysfs none /sys
• export HOME=/root
• export LC_ALL=C

Customizations

• mkdir -p /home/UWcustom/doc && cd /home/UWcustom/doc
• dpkg-query -W --showformat='${Installed-Size} ${Package}\n' | sort -nr > PackageListInitial
• aptitude purge `grep games PackageListInitial | cut -d" " -f 2`
• aptitude install msttcorefonts
• aptitude install some other packages

Rebuilding initrd

• sudo chroot edit
• mkinitramfs -o /initrd.gz
  where is a file from "ls /lib/modules"
• exit
• mv edit/initrd.gz extract-cd/casper/

Cleanup