Mulai Remastering Yuk.. :D

Install pre-requisities

• Make sure that you have installed the needed tools

sudo aptitude install squashfs-tools genisoimage

Obtain the base system

• Download an official Desktop CD from http://releases.ubuntu.com/

Note: the example shown here uses the ubuntu-9.04-desktop-i386.iso Desktop CD

• Move or copy it into an empty directory

mkdir ~/livecdtmp
mv ubuntu-9.04-desktop-i386.iso ~/livecdtmp
cd ~/livecdtmp

Extract the CD .iso contents

Mount the Desktop .iso

mkdir mnt
sudo mount -o loop ubuntu-9.04-desktop-i386.iso mnt

Extract .iso contents into dir 'extract-cd'

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

Extract the Desktop system

Extract the SquashFS filesystem

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

Prepare and chroot

If you need the network connection within chroot

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

Depending on your configuration, you may also need to copy the hosts file

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

(these mount important directories of your host system - if you later decide to delete the edit/ directory, then make sure to unmount before doing so, otherwise your host system will become unusable at least temporarily until reboot)

To avoid locale issues and in order to import GPG keys

export HOME=/root
export LC_ALL=C

Customizations

Apt-get

Prerequisites

In 9.10, before installing or upgrading packages you need to run

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

and

dpkg-divert --local --rename --add /sbin/initctl
ln -s /bin/true /sbin/initctl

Tasks

To view installed packages by size

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

When you want to remove packages remember to use purge

aptitude purge package-name

Custom Background for GNOME

Generally background files are located in /usr/share/backgrounds. Copy your png file there, adjust owner and file access, and edit the files:

1. /usr/share/gnome-background-properties/ubuntu-wallpapers.xml and
2. /usr/share/gconf/defaults/16_ubuntu-wallpapers or other files in the same directory. by changing the string /usr/share/backgrounds/warty-final-ubuntu.png to point to your file

Eventually change or add attributes to other configuration files such as: /var/lib/gconf/debian.defaults/%gconf-tree.xml or /etc/gconf/gconf.xml.defaults/%gconf-tree.xml).

Historical: More for Dapper...

Change gconf values (fonts, 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.

Instead of editing the file with gedit or another text editor, you can use the gconftool-2, under the chroot environment, running the following line:

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

where string, yourkey and yourvalue must be the type, key and value that you want to change...

Making several gconf changes

Editing gconf by setting each value separately takes too much time. There is a better way:

Make a test user and adjust the settings as you wish. Run

gconftool-2 --dump /the/settings/branch/you/need > ~/live/your-new-settings.xml
sudo chown root:root ~/live/your-new-settings.xml
sudo mv ~/live/your-new-settings.xml ~/live/edit/your-new-settings.xml

and then, in the chroot environment, run

gconftool-2 --direct --config-source xml:readwrite:/etc/gconf/gconf.xml.defaults --load /your-new-settings.xml
rm /your-new-settings.xml

This way you can import the whole branch, e.g. /apps/panel - all settings for Gnome's panels. Note that this way you import not only the keys, but also their descriptions, so all GConf descriptions will be changed to the language which was set for the test user, and there will be no way to safely change them back. Some programs (for example, keyboard shortcuts in Preferences menu) use descriptions from GConf.

Change default language of gfxboot

This customization must be done outside the chroot.

sudo aptitude install dpkg-dev uck
apt-get source gfxboot-theme-ubuntu gfxboot
cd gfxboot-theme-ubuntu*/
make DEFAULT_LANG=fi
sudo cp -af boot/* ../extract-cd/isolinux/

Change "fi" to your preferred locale. Note that this does not change which languages are available in the F2 menu. For more info about gfxboot customization, see Ubuntu Customization Kit.

• A other way to change the default language of gfxboot without rebuild the packages is to create a file name lang in the isolinux directory containing your locale's name.

Customization limits

After customization make sure that there are no users with an UID > 999. Otherwise your image won't boot because no initial user is available (see /usr/share/initramfs-tools/scripts/casper-bottom/10adduser). While in chroot:

awk -F: '$3 > 999' /etc/passwd

If you get any hits, try changing the uid:

usermod -u 500 $hit

Miscellaneous Defaults

You may wish to edit the files in /etc/default to change system behavior at startup. You might also edit /etc/profile, /etc/bash.bashrc, and /etc/bash_completion to change login settings for all users on the system. You cannot directly edit defaults for the live cd user (e.g., casper, ubuntu, or user) since that account is created at boot time. You can directly edit root's default files (/root in the chroot environment).

If you wish to change the default timezone used by the live cd, run:

dpkg-reconfigure tzdata

If you have added a locale and wish to make it the default, update /etc/default/locale. You may have to compile the locale:

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

These changes must be made as root in the chroot environment.

Advanced Customizations

Live CD Kernel

If you want to customize further the boot process, you can change the livecd kernel, by copying the vmlinuz and initrd you want in place of the ones you find in extract-cd/casper.

i.e.

sudo cp edit/boot/vmlinuz-2.6.15-26-k7 extract-cd/casper/vmlinuz
sudo cp edit/boot/initrd.img-2.6.15-26-k7 extract-cd/casper/initrd.gz

Note that the initial ramdisk filename for newer releases (since 9.10) is casper/initrd.lz (not .gz).

Removing the (Casper) Autologin

The autologin feature of the Jaunty/9.04 live CD is a bit of an on-the-fly boot-hack. After extracting the initrd.gz, you need to edit the casper-bottom/25configure_init script and then recreate the initrd.gz file, replacing the original in extract-cd/casper. The process to do so goes like this:

# cd extract-cd/casper
# mkdir tempdir
# cd tempdir
# gunzip -dc ../initrd.gz | cpio -imvd --no-absolute-filenames
# cp scripts/casper-bottom/25configure_init scripts/casper-bottom/25configure_init.orig
# vi scripts/casper-bottom/25configure_init

Now look for line 25 which has the conditional statement to test $USERNAME.

Line 25 performs a conditional evaluation and if it evaluates to true, it will execute the code within the if block. The if block contains code to modify files used in the boot process to create the live cd autologin.

To disable the autologin feature, Remove $USERNAME, but just leave the quotes. The -n modifier tests the $USERNAME string to see if it's length is non-zero. By removing the variable, and leaving two double quotes, this statement evaluates to false because the two double quotes effectively make a zero-byte string. Be sure to leave no whitespace between the quotes because whitespace will make the evaluation true and execution wil fall into the if block.

21:log_begin_msg "$DESCRIPTION"
22:
23:# Arrange for shells on virtual consoles, rather than login prompts
24:
25:if [ -n "$USERNAME" ]; then

After making the change, line 25 will look like this:

25:if [ -n "" ]; then

Save the file and quit the editor. Then, from extract-cd/casper/tempdir run the following command to re-create the initrd.gz file. There are other methods for re-creating the initrd.gz file on this page which may work also.:

# cp ../initrd.gz ../initrd.gz.orig
# find . | cpio -o -H newc | gzip -9 > ../initrd.gz

This will create a new initrd.gz file with no auto login. You can then continue to remaster the CD as described on this page. Be sure to create a user and password to login with before you remaster the cd. If you do not, you will not be able to login after booting!

Also, I have read a few articles mentioning that Karmic (9.10) uses initrd.lz instead of initrd.gz. I do not know if this is true, but should mention it in case you are not getting the expected results. To unpack the initrd.lz file, you need to do this:

# cd extract-cd/casper
# mkdir lztempdir
# cd lztempdir
# lzma -dc -S .lz ../initrd.lz | cpio -imvd --no-absolute-filenames

And to re-create the initrd.lz file:

# cp ../initrd.lz ../inird.lz.orig
# find . | cpio --quiet --dereference -o -H newc | lzma -7 > ../initrd.lz

Boot init

You have to edit the files in edit/usr/share/initramfs-tools/scripts/casper-bottom/* For example you can change the hostname or the livecd user.

i.e.

sudo nano edit/usr/share/initramfs-tools/scripts/casper

and edit the username or hostname

sudo nano edit/usr/share/initramfs-tools/scripts/casper-bottom/10adduser

to edit even the livecd user's password.

If you're customizing 10.04, you need to edit variables in /etc/casper.conf for the user and host names instead of modifying the scripts

P.S. in order to obtain an encrypted password, you have to use the mkpasswd program that's shipped with whois package!

Rebuilding initrd

After you've modified the kernel, init scripts or added new kernel modules, you need to rebuild the initrd.gz file and substitute it into the casper directory.

sudo chroot edit
mkinitramfs -o /initrd.gz 2.6.15-26-k7

(replace the kernel version with the one that the CD will boot with - this can be found in edit/lib/modules) *** do I need to mount proc, sys, devpts after chroot here ? Gordon

Exit from the chroot jail and move this file to extract-cd/casper:

exit
mv edit/initrd.gz extract-cd/casper/

Cleanup

Be sure to remove any temporary files which are no longer needed, as space on a CD is limited. A classic example is downloaded package files, which can be cleaned out using:

aptitude clean

Or delete temporary files

rm -rf /tmp/* ~/.bash_history

Or delete hosts file

rm /etc/hosts

Or nameserver settings

rm /etc/resolv.conf

If you installed software, be sure to run

rm /var/lib/dbus/machine-id

and

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

from within the chroot environment.

now umount (unmount) special filesystems and exit chroot

umount /proc || umount -lf /proc
umount /sys
umount /dev/pts
exit
sudo umount edit/dev

• Note: if "umount /proc" command fails, "umount -lf /proc" will be used to retry automatically.

Producing the CD image

Assembling the file system

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

Compress filesystem

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

• Note: The -nolzma option is only available from Hardy , and was removed in Karmic. Also, the squashfs has to be generated using a version of mksquashfs that is compatible with the kernel used on the CD you are customizing. For example, you cannot generate a jaunty squashfs on karmic, as the jaunty kernel is not able to mount a squashfs prepared using mksquashfs from karmic.

For slightly higher compression at the cost of compression time, you can increase the block size:

sudo mksquashfs edit extract-cd/casper/filesystem.squashfs -b 1048576

Update the filesystem.size file, which is needed by the installer:

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

Set an image name in extract-cd/README.diskdefines

sudo vim extract-cd/README.diskdefines

(you can use "sudo nano extract-cd/README.diskdefines" if you have difficulties understanding vim)

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

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-9.04.1-desktop-i386-custom.iso .

Testing the CD

Test using qemu emulator

qemu -cdrom ubuntu-9.04.1-desktop-i386-custom.iso -boot d -m 512

Or if you have hardware acceleration for kvm

kvm -cdrom ubuntu-9.04.1-desktop-i386-custom.iso -boot d -m 512

You can also test with virtualbox-ose, which is free software and available in the Ubuntu universe repository.

Troubleshooting

Some experience problems virtualizing the iso after changing the livecd linux kernel. If you do, go click F6 when the boot screen is showing. Move the cursor between splash quiet and -- and write: all_generic_ide

Burning the image to CD

Simple! Just do

cdrecord dev=/dev/cdrom ubuntu-9.04-desktop-i386-custom.iso

from https://help.ubuntu.com/community/LiveCDCustomization