Casenium: May 2022

Linux Mint XFCE (livecd custom) 19 ubuntu

> System requirements
* Ram 1024
* CPU Pentium 4
* HardDisk 40GB
* Onboard VGA 1024x768

* Kernel 4.15

1. Install the required softwares:

sudo aptitude install squashfs-tools genisoimage fakeroot build-essential ncurses-dev xz-utils libssl-dev bc flex libelf-dev bison gcc gcc-multilib make autoconf git nasm unetbootin extlinux syslinux qemu-system-x86 libpcre3 libpcre3-dev

2. Prepare the temporary system:

linuxmint-17-cinnamon-64bit-v2.iso is used as the base iso image throughout this tutorial. Change the name according to the downloaded image.

mkdir ~/mylivecd

cp /path_to_the_downloaded_iso_directory/linuxmint-19-xfce-64bit.iso ~/mylivecd

cd ~/mylivecd

mkdir mnt

sudo mount -o loop linuxmint-19.iso mnt

mkdir extracted

sudo rsync --exclude=/casper/filesystem.squashfs -a mnt/ extracted

sudo unsquashfs mnt/casper/filesystem.squashfs

sudo mv squashfs-root edit

3. Prepare network connection in the temporary system:

sudo cp /etc/resolv.conf edit/etc/

sudo cp /etc/hosts edit/etc/

4. Prepare a chroot environment:

xhost + //it will enable you to run GUI applications like synaptic but this will disable the x server access control, so use it at your own risk.

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

Now this terminal is in your new system. Don't close this in any circumstances. We will call this the chroot terminal and let's open another terminal and run

cd ~/mylivecd

and call this the host terminal. We will use this terminal when needed. You can differentiate between these two by comparing the command history. (This is very important, don't mix up these two terminals in anyway.)

Run codes in chroot terminal if nothing is specified about which terminal to use.

5. Preparing customization:

dbus-uuidgen > /var/lib/dbus/machine-id

dpkg-divert --local --rename --add /sbin/initctl

ln -s /bin/true /sbin/initctl

6. Now customize at your hearts content:

The filesystem is now the "edit" folder inside "mylivecd" directory. You can modify this filesystem to meet your needs. But you only have access to the chroot terminal. So make sure you can do everything with only a terminal. You can use this terminal to run GUI applications too.

To view installed packages by size:

dpkg-query -W --showformat='${Installed-Size}\t${Package}\n' | sort -nr | less

6.1 Installing softwares:

First update the repository (in chroot terminal):

apt update

Install softwares from the chroot terminal by:

apt install some-package

aptitude install packag1 package2 ....

dpkg -i some_package.deb

synaptic

sudo update-initramfs -u

then use synaptic package manager to install software.You can run other GUI applicaions too.

If you use synaptic then you will probably need to delete the edit/home/* manually and also delete the edit/run/synaptic.socket in the cleaning step.

In this case the some_package.deb must be located somewhere inside the "edit" directory. So copy the deb files that you want to install by dpkg to a location inside that edit folder and use correct path to the files or use my conventions as below (in chroot terminal):

mkdir /mydir

chmod -R 777 /mydir

cd /mydir

Now use your file manager (open as root) to copy files for your packages to this folder or you can use the host terminal too (to copy files here). Now you can use the chroot terminal to install softwares from that directory (.deb files or source). To install softwares you can see the methods written in this tutorial:

Installing softwares in linux

and to get a menu entry for the installed software (if it doesn't have any by default) you can see my other tutorial:

Adding menu item in linux mint

If you have the latest .deb packages then you can copy them into the "/var/cache/apt/archives" directory so that you will be able to install them with the

apt install package_name

command in chroot terminal without downloading them. But if they are not latest, then this will do no good at all.

To install all the .deb packages in any directory simply run in chroot terminal:

cd path_to_that_directory

dpkg -i *.deb

6.2 You can do other types of modifications as you have full access to the whole filesystem, if you know how to do it in any regular distro. The main problem is, you have no GUI (Desktop) for making modifications, all there is to edit the config files and the filesystem to modify everything. So you need to be sure about the modifications that they will work correctly beforehand.

6.3 Kernel installation (optional):

First install any kernel (see this for reference) with the chroot terminal then to boot this kernel in live cd/dvd run these codes in the host terminal:

cp edit/boot/vmlinuz* extracted/casper/vmlinuz

cp edit/boot/initrd.img* extracted/casper/initrd.lz

If you install more than one kernel then replace * in the above two commands with correct version codes.

6.4 At last, run this code in chroot terminal to make sure the Linux mint installation application (in live dvd/cd) is up-to-date:

apt install ubiquity-frontend-gtk

create live user:

sed -i -e 's@user-uid [0-9]*@user-uid 990@' /usr/share/initramfs-tools/scripts/casper-bottom/25adduser

sudo adduser live

sudo passwd live

sudo useradd live -p live

sudo usermod -a -G sudo live

sudo groups live

7. Cleanup your new system:

aptitude clean

rm -r /var/cache/apt/archives/*

rm -r /mydir

rm -rf /tmp/* ~/.bash_history

rm /var/lib/dbus/machine-id

rm /sbin/initctl

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

umount /proc || umount -lf /proc //ignore warning in this command

umount /sys

umount /dev/pts

exit //if fails try exit 0

sudo umount edit/dev //ignore error/warning in this command

xhost -

If you used synaptic (or any other GUI) then you will probably need to do this extra cleaning:

sudo rm -rf edit/run/synaptic.socket

sudo rm -rf edit/home/*

From this moment the chroot environment is no more, but this terminal will be used for the rest of the commands, you can close the other (host) terminal.

8. Regenerate manifest (ignore any warning):

chmod +w extracted/casper/filesystem.manifest

chroot edit dpkg-query -W --showformat='${Package} ${Version}\n' > extracted/casper/filesystem.manifest

cp extracted/casper/filesystem.manifest extracted/casper/filesystem.manifest-desktop

sed -i '/ubiquity/d' extracted/casper/filesystem.manifest-desktop

sed -i '/casper/d' extracted/casper/filesystem.manifest-desktop

9. Compress:

rm extracted/casper/filesystem.squashfs

mksquashfs edit extracted/casper/filesystem.squashfs -comp xz

10. Update some required files:

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

open extracted/README.diskdefines file with a text editor and change the name of the disk.

Remove old md5sum and calculate new md5sums:

cd extracted

rm MD5SUMS

find -type f -print0 | sudo xargs -0 md5sum | grep -v isolinux/boot.cat | sudo tee MD5SUMS

11. Create the ISO image:

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 ../linuxmint_custom.iso .

grub-mkrescue --iso-level 3 -o linuxmint_custom.iso extracted

exit

sudo chmod 777 ~/mylivecd/linuxmint_custom.iso