Knoppix Remastering Howto

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This is a guide that will show you how to remaster KNOPPIX using the old "chroot method". The command lines within "Instructions" and "Remastering the ISO" are tested with Knoppix V7.0.4CD. Please do not use old versions of Knoppix!


Setting up for Remastering

  • Boot from the Knoppix CD
  • Open a terminal and type "su" to become root.
  • Configure your Internet connection. If you use DHCP, it should already be configured. ( Run ifconfig to check.)
  • Find the partition you will use to work on and change the variable "PFAD" within the scripts as you need. In this example it is called /media/sda1. The partition should have a minimum of 5 GB free space for CD remaster and 20 GB for DVD remaster.
  • Make sure the partition is mounted!! (Run mount or df to check.)
  • The first script makes all needed preparations:
#! /bin/sh
# krhowto_1
# Path to partition you will work on
START=$(date +'%s')
# Disable screensaver
xscreensaver-command -exit
# One sub-directory will be used for the Master-CD
mkdir -p $PFAD/knx/master
cd $PFAD/knx
# You will need a swapfile
dd if=/dev/zero of=swapfile bs=1M count=500
mkswap swapfile ; swapon swapfile
# Make a sub-directory for the source
mkdir -p $PFAD/knx/source/KNOPPIX
echo "Copy the KNOPPIX files to your source directory."
echo "This will take a long time!"
cp -rp /KNOPPIX/* $PFAD/knx/source/KNOPPIX
# Additionally, copy the files to build the ISO later
rsync -aH --exclude="KNOPPIX/KNOPPIX*" /mnt-system/* $PFAD/knx/master
# gunzip inital RAM-disk
mkdir -p $PFAD/knx/minirt/minirtdir
cp $PFAD/knx/master/boot/isolinux/minirt.gz $PFAD/knx/minirt/
cd $PFAD/knx/minirt/
gunzip minirt.gz
cd minirtdir
cpio -imd --no-absolute-filenames < ../minirt
# Enable screensaver
su knoppix -c "xscreensaver -nosplash &"
echo -e "\nFinished! Used time: $(expr $(expr $(date +'%s') - $START) / 60) min. \
  and $(expr $(expr $(date +'%s') - $START) % 60) sec."

Setup the environment for chroot

  • Use this script to build the chroot environment:
#! /bin/sh
# krhowto_2
# Path to partition you will work on
# To use the Internet add your nameserver into the chroot folder
cp /etc/resolv.conf $PFAD/knx/source/KNOPPIX/etc/resolv.conf
# Allow X-based programs in chroot
[ -e $PFAD/knx/source/KNOPPIX/home/knoppix/.Xauthority ] \
   && rm $PFAD/knx/source/KNOPPIX/home/knoppix/.Xauthority
cp /home/knoppix/.Xauthority $PFAD/knx/source/KNOPPIX/home/knoppix
chown knoppix:knoppix $PFAD/knx/source/KNOPPIX/home/knoppix/.Xauthority
# prepare enviroment for chroot
mount --bind /dev $PFAD/knx/source/KNOPPIX/dev
mount -t proc proc $PFAD/knx/source/KNOPPIX/proc
mount -t sysfs sysfs $PFAD/knx/source/KNOPPIX/sys
mount --bind /dev/pts $PFAD/knx/source/KNOPPIX/dev/pts
mount --bind /tmp $PFAD/knx/source/KNOPPIX/tmp

Working in the Chroot Environment

  • Now you can "chroot" into the copied KNOPPIX:
 chroot /media/sda1/knx/source/KNOPPIX
  • Remember that anything you do or create in the chrooted environment will get burned to the CD.
  • Within the chroot you can also start X-based programs from command line of the terminal.
  • Type "su knoppix" to become user knoppix; use "Strg D" to be root again.
  • Update your package list with: apt-get update
    • Warning: apt-get upgrade is a BAD IDEA. It will, quite probably, render your KNOPPIX remaster unbootable, or broken in some way. A far safer method is to only upgrade packages as necessary.
    • Before you can add stuff, you will probably need to remove some packages.
  • To get a list of packages installed, you can use kn-what to get lists sorted by size etc.

Leaving the Chroot

  • Press CTRL+D to leave being chrooted; then use this schript:
#! /bin/sh
# krhowto_3
# Path to partition you will work on
for i in dev/pts proc sys dev tmp; do
  umount $PFAD/knx/source/KNOPPIX/$i
sed -i '2,$d' $PFAD/knx/source/KNOPPIX/etc/resolv.conf

Changes outside from chroot enviroment

  • If you want another way to start with Knoppix, make changes in '/media/sda1/knx/master/boot/isolinux/isolinux.cfg':
    • for example replace all 'tz=localtime' with 'tz=America/New_York'
  • You can append in this file cheatcodes, which you need all the time:
    • for example write 'no3d' (without ' ') to each Append line, if you don't like compiz 3d
  • Read knoppix-cheatcodes.txt. You can find the newest version of this file on the Mirrors.
  • In '/media/sda1/knx/source/KNOPPIX/etc/X11/Xsession.d/45knoppix' you can find, which wallpaper Knoppix uses or which startup-sound.
  • In '/media/sda1/knx/source/KNOPPIX/etc/init.d/knoppix-halt' you'll find which sound you hear during shutdown.
  • Create a file '/media/sda1/knx/master/KNOPPIX/' in order to start additional services.

Remastering the ISO

  • We've finished customizing and ready to burn!
#! /bin/sh
# krhowto_4
# Path to partition you will work on
START=$(date +'%s')
# Disable screensaver
xscreensaver-command -exit
# Build new inital RAM-disk
cd $PFAD/knx/minirt/minirtdir/
find . | cpio -oH newc | gzip -9 > ../minirt.gz
cp $PFAD/knx/minirt/minirt.gz $PFAD/knx/master/boot/isolinux/
# Make the big  compressed filesystem KNOPPIX
genisoimage -input-charset ISO-8859-15 -R -l -D -V KNOPPIX_FS -quiet \
  -no-split-symlink-components -no-split-symlink-fields \
  -hide-rr-moved -cache-inodes $PFAD/knx/source/KNOPPIX \
  | /usr/sbin/create_compressed_fs -q -B 65536 -t 8 -L 9 \
  -f $PFAD/knx/isotemp - $PFAD/knx/master/KNOPPIX/KNOPPIX
# Update the file hashes used by the "testcd" boot option
cd $PFAD/knx/master ; find -type f -not -name \
  sha1sums -not -name -not \
  -name isolinux.bin -exec sha1sum '{}' \; > KNOPPIX/sha1sums
# Create new Knoppix ISO
genisoimage -l -r -J -V "KNOPPIX" \
  -b boot/isolinux/isolinux.bin -no-emul-boot -boot-load-size 4 \
  -boot-info-table -c boot/isolinux/ \
  -o $PFAD/knx/remastered.iso $PFAD/knx/master
# Enable screensaver
su knoppix -c "xscreensaver -nosplash &"
echo -e "\nFinished! Used time: $(expr $(expr $(date +'%s') - $START) / 60) min. \
  and $(expr $(expr $(date +'%s') - $START) % 60) sec. \
  \n\nThe new ISO is stored in '$PFAD/knx/remastered.iso' "

Test CD Image Without Burning a CD


If your processor supports virtualization and it is enabled by the BIOS you can test the new ISO by kvm-qemu. Check for support by:

egrep '(vmx|svm)' --color=always /proc/cpuinfo

If you get the result "vmx" type

modprobe kvm-intel

otherwise if you get the result "svm" type

modprobe kvm-amd

to load the kvm module. Now you can test the new ISO by

kvm -m 512 -cdrom $PFAD/knx/remastered.iso


VirtualBox can be used to test a newly generated ISO as well.

  • End of revised version of this HowTo
  • Please post at Customizing and Remastering if you find errors or in case you have any question or suggestion.

See also:

Old stuff of this HowTo

  • Be aware, all in this chapter may work or not - I didn't tested it!

Autorunning Programs

When you want to autorun some programs, one can create a script and put the script in /etc/init.d, then add it to the SERVICES variable in /etc/rc.local. For X-programs consider /home/knoppix/.kde/Autostart

Editing the KNOPPIX auto-configuration script

You can find a lot of interesting information about how KNOPPIX auto-configures your system by looking in '/etc/init.d/knoppix-autoconfig' and '/etc/X11/Xsession.d/45knoppix' scripts.

Changing the boot graphic, boot message, and startup script text

While you are in the chroot environment you can easily change the boot messages, the boot graphic, and the default KDE background graphic.

Changing the boot graphic

The 'boot graphic' is the first image you see when the CD or DVD boots. It looks similar to ASCII art and it is normally something flashy that says 'Knoppix'. You can change this to be any graphic that you please, but you must use a 640x400 graphic that has only 16 colors.

  1. Change to the /mnt/sda1/knx/master/boot directory. Swap '/mnt/sda1/' for whatever disk you are using.
    • cd /mnt/sda1/knx/master/boot/isolinux
  2. Back up your old logo in case you break things.
    • mv logo.16 logo.16.backup
  3. Make a 640x400 pixel 16 color graphic and save it as a GIF, e.g. 'logo.16.gif'. GIMP can easily do this. Note, you can use a graphic that originally had more than 16 colors, but it is critical that you convert the graphic to 16 colors before doing the next step.
  4. Convert the GIF to lss16 using the tools included on the Knoppix CD.
    • giftopnm < 640x400x16.gif > logo.ppm
    • ppmtolss16 <logo.ppm > logo.16

Changing the boot message

The 'boot message' is the message that you see under the 'boot graphic' on the initial screen when the Knoppix CD or DVD loads. It normally says something along the lines of Knoppix with the version number and includes a link to the Knoppix website. You can change this text to be whatever you please, but you shouldn't add too much text or it will make the boot screen look funny. Restricting yourself to a single line of text that is no larger than the default one is a good idea.

  1. Change to the /mnt/sda1/knx/master/boot directory. Swap '/mnt/sda1/' for whatever disk you are using.
    • cd /mnt/sda1/knx/master/boot/isolinux
  2. Back up your old message in case you break things.
    • cp boot.msg boot.msg.backup
  3. Edit the message with a text editor. You'll see at the top of the message that it shows the graphic. Don't change this text, just the line under.
    • vi boot.msg

Changing the startup script text

The 'startup script text' is the text that you see after the initial boot screen, while Knoppix loads and configures your system. You can change as much of this text as you please. You can even add addition lines to the script; however, it is recommended that you don't play with this file. Limiting yourself to editing the 'Welcome to KNOPPIX' message is a good idea.

How to add new device driver to KNOPPIX

Recently in a client project, I added the Digital Persona’s finger print driver to the Knoppix 5.1 distribution as an embedded solution to this project. This is a typical case where both the kernel level driver and the user level drivers and libraries are involved.

Most of the Knoppix books and online documentation have documented about how to keep a persistent storage of user configuration and user data. But those persistent configuration only saves the data in /home and /etc directories. If you have added kernel level drivers and/or other system libraries which are not in above two directories, you have to save the file images as a whole right after the boot. The saved file image can be big and may not what you want as a regular usage model. If you are building a customed Knoppix image for a long term solution, definitely you want to remaster the Knoppix to make the new drives be a permanent part of it.

The Digital Persona’s OneTouch SDK for their finger print scanner driver comes with a kernel level driver source code, plus a set of user level application libraries, as well as a sample test application. The SDK do not have a ready made binary for Debian or Knoppix. So I have to compile it from the source SDK. However, the CD version of Knoppix 5.1 do not even come with the source include header files to compile a kernel level driver. So I have to compile it under the DVD version of the Knoppix 5.1 and copy the compiled binary to the CD version of Knoppix 5.1 to do testing and remastering. The steps I have tried to make it work under Knoppix are as follows:

1. First compile the driver under DVD version of the Knoppix. Change the source code build scripts so that the include files and library path are matching what we have in Knoppix. The details are specific to the OneTouch SDK itself. If you are interested about this detail, write to me.

2. Install the just built kernel driver, the user libraries to their regular location as we will show in following step 4. And then build and run their sample applications per Digital Persona’s instruction. This proves that the basic kernel module build steps are built correctly and the user level libraries are working properly in a standard installation. This is important before we moved to chroot environment to make this changes permanent to our remastered Knoppix.

3. Then I followed the Knoppix remastering instructions documented in the book of “Live Linux CD” by Christoper Negus.

4. In the above remastering instructions, there is a step to update all the Debian packages and other software under the chroot environment. It is at this step that I re-run the drivers installation steps like I have done in above step 2 in the real root environment. In this particular case, it is make a directory and copy the kernel module file mod_usbdpfp.ko to that directory as follows:

mkdir /lib/modules/2.6.19/kernel/drivers/biometric cp mod_usbdpfp.ko /lib/modules/2.6.19/mod_usbdpfp.ko

And also copy all those Digital Persona user level libraries to following location:

cp libdpfp* /usr/lib

5. I then run /sbin/depmod to let system detects the new kernel mode driver I have installed. This will refresh the /dev directory so it will have entries like:

/dev/usbdpfpPNP /dev/usbdpfp0

At this time, if all works right, when you run command lsmod, you will also see something like:


shows up in the loaded module list

6. At this time, you are ready to make a remaster of the Knoppix. Next time when you boot up with this remastered Knoppix, it will have the kernel driver and user level libraries setup ready for you to run the sample applications. Just as if you have done above step 2 and step 4 right after a refresh reboot from the original Knoppix CD.

John Xu, USA. ( johnxu at )

Test remastered version without creating cloop file/iso

i use a setup similar to knoppix terminal server to test the remastered files without having to recreate a cloop image every time: the remastered files live in an ext2 filesytem in a loopfile (knoppix_loop) mounted rw (this is where i chroot in). when i want to test the current setup, i have another machine network boot and use the files from the loopfile directly (needs another miniroot.gz). See User:Ml#dev_setup

If you want to use only one machine, you'll have to reboot (or use qemu) and use the "loopfile" and "fromhd" cheatcodes (see User:Ml#miniroot_changes). For example, this is what my grub boot entry looks like:

title           Remastered Knoppix
root            (hd0,0)
kernel          /boot/myknoppix/vmlinuz fromhd=/dev/hda4 loopfile=/samba/share/isos/knoppix_loop lang=us ramdisk_size=100000 init=/etc/init apm=power-off nomce vga=791 quiet BOOT_IMAGE=knoppix
initrd          /boot/myknoppix/miniroot.gz

Booting Knoppix images with GRUB

  • First copy /boot off the Knoppix cd to your boot partition (or even your dos partition). I named mine boot.knoppix

Copy the master/KNOPPIX directory to your root directory of any hard disk. You may place it somewhere other than the boot partition (ext2/3, reiserfs, vfat are supported).

        root   (hd0,0)
        kernel /boot.knoppix/isolinux/linux 2 fromhd=/dev/hda4 lang=us
        initrd /boot.knoppix/isolinux/minirt.gz
  • notice the fromhd parameter: it's the location of the /KNOPPIX directory
  • reboot and have fun.

Tips around apt-get to install/update/remove applications

(by gnarvaja)

  • If you booted from CD, even on a HD install (example: Pivot Install) instead of copying the original CD and KNOPPIX directory to the HD, you can use them directly from their mount points.
  • Another alternative is to mount an ISO image of the original CD as a loop device and mount the KNOPPIX image as a cloop device. You will save close to 2GB of space. Script to mount from an ISO image:
# Assumes that the current directory is the working space
# original.iso is an image of the CD we will be using as master
mount -t iso9660 original.iso ./oldcd -o ro,loop
# initialize the compressed loop device
losetup /dev/cloop1 ./oldcd/KNOPPIX/KNOPPIX
mount -t iso9660 /dev/cloop1 ./KNOPPIX -o ro,loop
  • Get apt-spy and use it to modify the sources.list file with the best mirrors for your particular region. This will speed up the downloading. Backup the original sources.list just in case.
  • Another technique is to modify sources.list. Replace the string .de. in the ftp addresses ( with the code corresponding to your country. Examples: USA -> .us. (, Brazil -> .br. ( Check the Debian site for mirrors in your country.
  • Remember to uncomment the linuxtag ftp addresses to get the latest and greatest from Knoppix
  • Use apt-get update to get the lists with the latest releases and patches. Do not update a package if you don't need to, it may lead to the use of additional disk space (precious commodity when you want to keep everything below 700MB) and you may brake something else without knowing. Abuse the -s option to simulate the installation.
  • Before doing the update, I modified my default releases to testing, that means that the software I'll be using will have a good balance of stability and features. Knoppix uses unstable by default, which is too risky for my personal taste.
  • Get [apt-get install] locale and configure it with the locales you are going to use. It will save lots of space when downloading applications with plenty of locale modules and localized manual pages.
  • I use aptitude to get/remove applications, it is character based so it works with init 2. As you mark packages for install/update/removal, it will tell you how much disk space you will save/use, try to solve depencies problems and give you plenty control to fix them manually when possible.
  • When installing applications it is likely that your /etc/rc?.d directories will have new entries, many of them unwanted or unplanned. Make sure you check them and remove the new entries based on your preferences. I usually leave /etc/rc2.d and /etc/rc5.d as close as the originals as possible and modify /etc/rc3.d and /etc/rc4.d to test new stuff. Example: You may want to have ntfs installed, but not necessarily running by default. Same with apache, mysql and many others.
  • When removing/purging applications, they may leave behind non-empty directories. Usually this is announced by aptitude, apt-get or any other installation utilty. Make sure to check the messages and manually remove those directories.
  • After you are done, aptitude may leave some files behind. Here's a clean up script I use:
# !/bin/bash
# Clean package files generated by aptitude
rm /var/log/aptitude
rm /var/lib/apt/lists/*debian*
rm /var/lib/apt/lists/*knoppix*