Live custom Ubuntu from scratch

Prerequisites (GNU/Linux Debian/Ubuntu)

Install applications we need to build the environment.

sudo apt-get install \
    debootstrap \
    squashfs-tools \
    genisoimage \
    syslinux \
    syslinux-utils \
    imagemagick \
    isolinux

mkdir $HOME/live-ubuntu-from-scratch

Bootstrap and Configure Ubuntu

sudo debootstrap \
    --arch=amd64 \
    --variant=minbase \
    bionic \
    $HOME/live-ubuntu-from-scratch/chroot \
    http://us.archive.ubuntu.com/ubuntu/

sudo mount --bind /dev $HOME/live-ubuntu-from-scratch/chroot/dev

sudo mount --bind /run $HOME/live-ubuntu-from-scratch/chroot/run

Access chroot environment

sudo chroot $HOME/live-ubuntu-from-scratch/chroot

1. Configure mount points

   mount none -t proc /proc
   
   mount none -t sysfs /sys
   
   mount none -t devpts /dev/pts
   
   export HOME=/root
   
   export LC_ALL=C
   

2. Set a custom hostname

   echo "ubuntu-live" > /etc/hostname
   

3. Configure apt sources.list

   Edit /etc/apt/source.list

   cat <<EOF > /etc/apt/sources.list
   deb http://us.archive.ubuntu.com/ubuntu/ bionic main restricted universe multiverse 
   
   deb http://us.archive.ubuntu.com/ubuntu/ bionic-security main restricted universe multiverse 
   
   deb http://us.archive.ubuntu.com/ubuntu/ bionic-updates main restricted universe multiverse 
   EOF
   

4. Upgrade packages if you want

   apt-get update
   
   apt-get -y upgrade
   

5. Install and configure dbus

   apt-get install -y systemd-sysv
   
   apt-get install -y dbus
   

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

6. Install packages needed for Live System

   apt-get install -y \
       ubuntu-standard \
       casper \
       lupin-casper \
       discover \
       laptop-detect \
       os-prober \
       network-manager \
       linux-generic
   

7. Graphical installer

   apt-get install -y \
       ubiquity \
       ubiquity-casper \
       ubiquity-frontend-gtk \
       ubiquity-slideshow-ubuntu \
       ubiquity-ubuntu-artwork
   

8. Install window manager

   apt-get install -y \
       plymouth-theme-ubuntu-gnome-logo \
       ubuntu-gnome-desktop \
       ubuntu-gnome-wallpapers
   

9. Install usefull applications

   apt-get install -y \
       clamav-daemon \
       terminator \
       apt-transport-https \
       curl \
       vim \
       nano
   

10. Install Visual Studio Code

    1. Download and install the key

       curl https://packages.microsoft.com/keys/microsoft.asc | gpg --dearmor > microsoft.gpg
       
       install -o root -g root -m 644 microsoft.gpg /etc/apt/trusted.gpg.d/
       
       echo "deb [arch=amd64] https://packages.microsoft.com/repos/vscode stable main" > /etc/apt/sources.list.d/vscode.list
       
       rm microsoft.gpg
       

    2. Then update the package cache and install the package using:

       apt-get update
       
       apt-get install -y code
       

11. Install Google Chrome

    1. Download and install the key

       wget -q -O - https://dl-ssl.google.com/linux/linux_signing_key.pub | sudo apt-key add -
       

    2. Add the key to the repository

       echo "deb http://dl.google.com/linux/chrome/deb/ stable main" > /etc/apt/sources.list.d/google-chrome.list
       

    3. Finally, Update repository and install Google Chrome.

       apt-get update
       
       apt-get install google-chrome-stable
       

12. Install Java JDK 8

    apt-get install -y \
        openjdk-8-jdk \
        openjdk-8-jre
    

13. Remove unused applications

    apt-get purge -y \
        transmission-gtk \
        transmission-common \
        gnome-mahjongg \
        gnome-mines \
        gnome-sudoku \
        aisleriot \
        hitori
    

14. Remove unused packages

    apt-get autoremove -y
    

15. Cleanup the chroot environment

    1. If you installed software, be sure to run

       rm /var/lib/dbus/machine-id
       

    2. Remove the diversion

       rm /sbin/initctl
       
       dpkg-divert --rename --remove /sbin/initctl
       

    3. Clean up

       apt-get clean
       
       rm -rf /tmp/*
       
       rm /etc/resolv.conf
       
       umount /proc
       
       umount /sys
       
       umount /dev/pts
       
       exit
       

Unbind mount points

sudo umount $HOME/live-ubuntu-from-scratch/chroot/dev

sudo umount $HOME/live-ubuntu-from-scratch/chroot/run

Create the CD image directory and populate it

1. Access build directory

   cd $HOME/live-ubuntu-from-scratch
   

2. Create directories

   mkdir -p image/{casper,isolinux,install}
   

3. Copy kernel images

   sudo cp chroot/boot/vmlinuz-**-**-generic image/casper/vmlinuz
   
   sudo cp chroot/boot/initrd.img-**-**-generic image/casper/initrd.gz
   

4. Copy isolinux and memtest binaries

   sudo cp /usr/lib/ISOLINUX/isolinux.bin image/isolinux/
   
   sudo cp /usr/lib/syslinux/modules/bios/{chain,gfxboot,ldlinux,libutil,libcom32,vesamenu}.c32 image/isolinux/
   
   sudo cp chroot/boot/memtest86+.bin image/install/memtest
   

Boot Instructions

1. Access build directory

   cd $HOME/live-ubuntu-from-scratch
   

2. Create image/isolinux.txt

   cat <<EOF > image/isolinux.txt
   splash.rle
   ************************************************************************
   
   This is an Ubuntu from scratch Live CD.
   
   For the default live system, enter "live".  To run memtest86+, enter "memtest"
   
   ************************************************************************
   EOF
   

Splash screen

1. Access build directory

   cd $HOME/live-ubuntu-from-scratch
   

2. Create image 640x480 in png format (splash.png)

3. Convert png image to ppm (indexed 16 colors)

   convert +dither -colors 16 splash.png splash.ppm
   

4. Convert ppm to rle

   ppmtolss16 '#ffffff=7' < splash.ppm > splash.rle
   

5. Move image

   sudo mv splash.rle image/
   

Boot-loader configuration

1. Access build directory

   cd $HOME/live-ubuntu-from-scratch
   

2. Create image/isolinux.cfg

   cat <<EOF > image/isolinux.cfg
   path 
   include menu.cfg
   default vesamenu.c32
   prompt 0
   timeout 50
   EOF
   

3. Create image/menu.cfg

   cat <<EOF > image/menu.cfg
   menu hshift 13
   menu width 49
   menu margin 8
   
   menu title Installer boot menu
   include txt.cfg    
   

4. Create image/txt.cfg

   cat <<EOF > image/txt.cfg
   default live
   label live
       menu label ^Try Ubuntu from scratch without installing
       kernel /casper/vmlinuz
       append  file=/cdrom/preseed/ubuntu.seed boot=casper initrd=/casper/initrd quiet splash ---
   label live-install
       menu label ^Install Ubuntu from scratch
       kernel /casper/vmlinuz
       append  file=/cdrom/preseed/ubuntu.seed boot=casper only-ubiquity initrd=/casper/initrd quiet splash ---
   label check
       menu label ^Check disc for defects
       kernel /casper/vmlinuz
       append  boot=casper integrity-check initrd=/casper/initrd quiet splash ---
   label memtest
       menu label Test ^memory
       kernel /install/memtest
   EOF
   

Create manifest

1. Access build directory

   cd $HOME/live-ubuntu-from-scratch
   

2. Generate manifest

   sudo chroot chroot dpkg-query -W --showformat='${Package} ${Version}\n' | sudo tee image/casper/filesystem.manifest
   
   sudo cp -v image/casper/filesystem.manifest image/casper/filesystem.manifest-desktop
   
   REMOVE='ubiquity ubiquity-frontend-gtk ubiquity-frontend-kde casper lupin-casper live-initramfs user-setup discover1 xresprobe os-prober libdebian-installer4'
   
   for i in $REMOVE
   do
       sudo sed -i "/${i}/d" image/casper/filesystem.manifest-desktop
   done
   

Compress the chroot

1. Access build directory

   cd $HOME/live-ubuntu-from-scratch
   

2. Create squashfs

   sudo mksquashfs chroot image/casper/filesystem.squashfs
   

3. Write the filesystem.size

   printf $(sudo du -sx --block-size=1 chroot | cut -f1) > image/casper/filesystem.size