DoudouLinux dev's blog

One issue we had in mind for a while is the fixed size of icons in LxLauncher. Depending on screen resolution, this size can be fitting well (small resolutions) or really too small (large resolutions). In the later case, the interface of advanced activities like “Whole DoudouLinux” and “Mini DoudouLinux” can look very empty, just as the screenshot that is unfortunately available on our DistroWatch page.

With automatic icon size computation, we are now able to get a similar rendering on various screen resolutions as shown on the photo composition below. In this case, screen resolutions are 1280×800 (HP), 1280×1024 (CRT display), 1024×768 (Dell) and 1024×600 (Genesi), leading to screen size ratios 5÷4, 4÷3 or between 16÷10 and 16÷9. If you want to give it a try, just download one of our recent dailybuilds, in English or French only.

We hope then to not see this kind of screenshot anymore:

Now few words about the way we achieved it.

In Debian Squeeze, the LxLauncher version, v0.2.1, features icon size tuning in a configuration file, /etc/xdg/lxlauncher/settings.conf. This is an easy way to change the icon size but, of course, requires user action. This is why we've developed a shell script that is called during GDM initialization to adapt the icon size to the actual screen resolution. The algorithm is the following:

1. compute screen surface in pixels-square
2. compute the width of icons to have a given number of them in a given portion of the screen (45% in our script)
3. compute the rounded number of icons per row using the previous width
4. compute the final icon width using screen width and number of icons per row

This script is available on our SVN server. Its algorithm is designed to be independent of screen orientation since it does not uses the screen width to compute the icon size but the screen surface. We hope then to be able to run DoudouLinux on any device in the future, from the smallest handheld devices to the largest TV screens :).

Finally, what about the stable DoudouLinux release Gondwana? Well it is shipping with LxLauncher v0.2.0 which does not allow to set icon size (it is hard-coded). Nevertheless trials have been performed to backport icon size setting from 0.2.1 and it seems to work! We should then release the latest update of Gondwana, v1.2, with this new feature :).

Thanks to Genesi who graciously donated smartbooks to our project, porting DoudouLinux to ARM™ has started. It is then time to host new architectures in our Debian package repository: armel for both squeeze and wheezy, armhf for wheezy only.

Although we haven't started to generate ARM™-specific packages, we can first copy our architecture independent packages. The tool reprepro that we're using to make our own repository provides a convenient function flood that copies all the packages of architecture all from one architecture to another, in the same distribution codename. The following command is copying existing squeeze packages of architecture all to armel:

$ reprepro -V --basedir debian/ flood squeeze armel

As the previous command is not talkative at all, let's check it worked well:

$ reprepro -V --basedir debian/ --architecture armel list squeeze
squeeze|main|armel: childsplay-session 1.1-1
squeeze|main|armel: dansguardian-squid 1.0-2
squeeze|main|armel: doudou-hwreport 1.1-1
squeeze|main|armel: doudou-icons-extra 1.0-1
squeeze|main|armel: doudou-installer 1.0-3
squeeze|main|armel: doudoulinux-base 1.0-2
squeeze|main|armel: doudoulinux-desktop-environment 1.0-2
squeeze|main|armel: doudoulinux-dev-artists 1.0-1
squeeze|main|armel: doudoulinux-dev-build 1.0-1
squeeze|main|armel: doudoulinux-dev-l10n 1.0-1
squeeze|main|armel: doudoulinux-dev-system 1.0-1
squeeze|main|armel: doudoulinux-games 1.0-1
squeeze|main|armel: doudoulinux-keyring 2011.01.10
squeeze|main|armel: doudoulinux-kids 1.0-2
squeeze|main|armel: doudoulinux-mouse 2.1-1
squeeze|main|armel: doudoulinux-multimedia 1.0-2
squeeze|main|armel: doudoulinux-sessions 1.1-1
squeeze|main|armel: doudoulinux-sound 2.1-1
squeeze|main|armel: doudoulinux-splashimages 1.0-4
squeeze|main|armel: doudoulinux-timezone 1.0-2
squeeze|main|armel: doudoulinux-utils 1.4-1
squeeze|main|armel: doudoulinux-work 1.0-2
squeeze|main|armel: empathy-salut-nickname 1.0-3
squeeze|main|armel: epiphany-adblock-lists 1.0-1~20111122
squeeze|main|armel: gamine-session 1.0-3
squeeze|main|armel: gcompris-session 1.0-3
squeeze|main|armel: gdm-theme-doudoulinux 1.2-1
squeeze|main|armel: gnome-backgrounds-doudoulinux 1.0-3
squeeze|main|armel: grub-splashimages-doudoulinux 2.0-1
squeeze|main|armel: kde-l10n-doudou-es 4:4.4.5-1
squeeze|main|armel: kde-l10n-doudou-fr 4:4.4.5-1
squeeze|main|armel: kde-l10n-doudou-it 4:4.4.5-1
squeeze|main|armel: kde-l10n-doudou-ru 4:4.4.5-1
squeeze|main|armel: live-boot 2.0.15-1doudou1
squeeze|main|armel: live-boot-initramfs-tools 2.0.15-1doudou1
squeeze|main|armel: live-persistence 1.0-7
squeeze|main|armel: liveusb-write 1.0-14
squeeze|main|armel: lxlauncher-session 1.8-2
squeeze|main|armel: plymouth-themes-all 0.8.3-20doudou1
squeeze|main|armel: plymouth-themes-doudoulinux 1.0-1
squeeze|main|armel: plymouth-themes-fade-in 0.8.3-20doudou1
squeeze|main|armel: plymouth-themes-glow 0.8.3-20doudou1
squeeze|main|armel: plymouth-themes-script 0.8.3-20doudou1
squeeze|main|armel: plymouth-themes-solar 0.8.3-20doudou1
squeeze|main|armel: plymouth-themes-spinfinity 0.8.3-20doudou1
squeeze|main|armel: pysycache-session 1.0-4
squeeze|main|armel: python-editobj2 0.3-1.1
squeeze|main|armel: songwrite2 0.4.1-1+0.4.2
squeeze|main|armel: soundsetting-session 1.0-1
squeeze|main|armel: tbo-common-data 0.98~git20110321-0doudou2
squeeze|main|armel: tbo-data-doodle-accesories 0.98~git20110321-0doudou2
squeeze|main|armel: tbo-data-doodle-all 0.98~git20110321-0doudou2
squeeze|main|armel: tbo-data-doodle-arcadia 0.98~git20110321-0doudou2
squeeze|main|armel: tbo-data-doodle-bubble 0.98~git20110321-0doudou2
squeeze|main|armel: tbo-data-doodle-dgm 0.98~git20110321-0doudou2
squeeze|main|armel: tbo-data-doodle-doodle1 0.98~git20110321-0doudou2
squeeze|main|armel: tbo-data-doodle-facilware 0.98~git20110321-0doudou2
squeeze|main|armel: tbo-data-doodle-guadalinex 0.98~git20110321-0doudou2
squeeze|main|armel: tbo-data-doodle-linuxhispano 0.98~git20110321-0doudou2
squeeze|main|armel: tbo-data-doodle-political 0.98~git20110321-0doudou2
squeeze|main|armel: tbo-data-doodle-southpark 0.98~git20110321-0doudou2
squeeze|main|armel: tbo-data-doodle-tbo 0.98~git20110321-0doudou2
squeeze|main|armel: ttf-lohit-font 2.4.6-1
squeeze|main|armel: tuxpaint-session 1.1-1

Everything is fine :). So now we can copy the squeeze packages to wheezy, still for the architecture all. The tool reprepro provides another convenient function copy that performs copies across different distribution code names. As we want to copy the architecture all only, we'll feed this copy command with the list of packages from the newly created armel architecture in squeeze:

$ reprepro -V --basedir debian/ copy wheezy squeeze \
    $(reprepro -V --basedir debian/ --architecture armel list squeeze | cut -d ' ' -f 2)

Finally, as wheezy has armhf while squeeze doesn't, we need to use flood again to populate armhf in wheezy:

$ reprepro -V --basedir debian/ flood wheezy armhf
$ reprepro --basedir debian/ list wheezy tuxpaint-session
wheezy|main|i386: tuxpaint-session 1.1-1
wheezy|main|amd64: tuxpaint-session 1.1-1
wheezy|main|armel: tuxpaint-session 1.1-1
wheezy|main|armhf: tuxpaint-session 1.1-1
wheezy|main|any: tuxpaint-session 1.1-1
wheezy|main|source: tuxpaint-session 1.1-1

That's it! Our first ARM™ repository is online and can be tested. Note however that all the wheezy packages may not be relevant (eg. Plymouth packages or KDE language packages). The objective is to start to play with packages that are really DoudouLinux-specific. Later we'll work on refining our ARM™ repository. We also plan to move it to a custom buildd server to avoid all the manual operations that reprepro is currently needing.

The default behavior of DoudouLinux is to show the menu of activities (see below) after the system has started and as soon as any activity is leaved. This is good for small children because the activities menu offers activities in the increasing order of difficulties, from top to bottom. However, for older children, the first activities are or will quickly become of poor interest. This is why the list of activities shown – but not their order – can be changed with the activities menu editor .

However the oldest children may still have no interest at all in seeing a menu of activities, since they will surely login into “Whole DoudouLinux”. The new version of the activities menu editor can now do this. The trick is quite simple: if only one activity is selected in the menu, DoudouLinux will not show the activities menu but instead will enter this activity directly. Activities menu settings are recorded in the directory /home/etc/, which means that any data persistence (user data or user+system) is sufficient to make settings survive a reboot or a shutdown.

This new version of the activities menu editor will be available with next releases: the coming development release numbered 2011-11 and the planned official release update Gondwana 1.2, due to mid January.

We've been providing a DoudouLinux Debian repository for binary packages since the beginning of the project but no source package repository. As we're now part of Debian Derivatives and as we're also moving to ARM™ architecture, we needed to setup a source repository too. For Debian Derivatives, this will allow our father project Debian to automatically fetch all our patches of standard Debian packages. For our ARM™ port, this will ease the compilation of binary packages targeting either the armel or armhf flavor.

Our source package is now online, although it is not complete yet. It can be fetched using the standard way to add source repositories, in /etc/apt/sources.list or /etc/apt/sources.list.d/:

deb-src http://debian.doudoulinux.org/ lenny main
deb-src http://debian.doudoulinux.org/ squeeze main

The source repository is completed for the stable version of DoudouLinux, based on Debian Lenny. The development branch, based on Squeeze is not completed yet, due to difficulties to deal with the new package format Quilt 3. Most of packages have their sources for the development version however :). Finally we now have to set up an experimental branch based on Wheezy to be able to build armhf packages (only armel can be built upon Squeeze).

The way we built the source repository consisted in changing first our package build script to make it automatically generate and collect source packages, then our repository build script to make it handle source packages too. To build the Debian repository, we're using reprepro, an official Debian tool which is quite simple to use:

1. Create a directory for your Debian repository, say debian/.
2. Create a file debian/conf/distributions that sets your repository parameters (name, architectures, codename, etc.).
3. Invoke reprepro for each package to be added, with the options matching your package.

For a binary package:

reprepro -V --basedir debian/ --architecture <arch> includedeb <codename> <debfile>

where <arch> is i386, amd64, armel, etc., <codename> is your distribution codename and <debfile> the binary package to be added.

For a source package the command is slightly different:

reprepro -V --basedir debian/ --type dsc includedsc <codename> <dscfile>

where <dscfile> the DSC file of your source package. It will copy the corresponding .tar.gz file and .diff.gz file (whenever available) that are used to restore the patched source code.

In the future we intend to setup a buildd or buildd-like server that will build all our packages transparently, automatically from source code, whatever the target architecture and the distribution flavor. This way we won't have to do manual operations to update our repository any more.

Currently the DoudouLinux installer just copies onto disk the Live media as is. While this is very practical for us and brings interesting features to users (rock-solid read-only system), this also has drawbacks:

• the system is still compressed and slows down startup on old computers
• you can not remove software
• upgrading software creates a duplicate version of each software
• many boot parameters cannot be changed (they're not persistent)

One of our most active contributors, Richard, suggested to use Remastersys. This is a tool whose goal is to perform full system backup onto a Live CD for Debian-based distributions. One of its features is to let users re-install a clean system onto hard disk from the Live CD: just what we need!

Thanks to it, on a laptop from 2003-2004, DoudouLinux is now booting in 40s instead of 120s from CD. I installed the system in 3 separate partitions: root, home and swap. The root system needs 1.9 GB so you have to setup at least a 2.5 GB root partition. Of course if you want to add software or don't want a separated home partition (bad idea), make it larger! Now let's look at the recipe :).

Remastersys is offered as a Debian package. The package provides a shell script to install the running Live system on disk: “remastersys-installer”. Reading the script showed that it is doing what we need. We have then successfully performed a clean install of DoudouLinux with the following operations:

1. add Remastersys repository to a running DoudouLinux
2. install Remastersys
3. run the Remastersys script called “remastersys-installer”
4. reboot!

Note that there are some issues to be corrected after the first boot (see after the source code below). We also have to customize the Remastersys script for use in an official future DoudouLinux release. In the meanwhile, if you want to test it by yourself, you need to type several code lines as root then as the main user to be able to use the graphical Gtk interface:

# log as root
su -

# define parameters
SOURCESLIST=/etc/apt/sources.list
DANSREGEXPEXCEPT=/etc/dansguardian/lists/exceptionregexpurllist
DANSSERVICE=/etc/init.d/dansguardian

# register remastersys repository
echo 'deb http://www.geekconnection.org/remastersys/repository debian/' >> $SOURCESLIST

# fix bug DansGuardian blocking some deb's files
# see: https://gna.org/bugs/index.php?18003
echo '\\.deb$' >> $DANSREGEXPEXCEPT
$DANSSERVICE restart

# install remastersys
apt-get update
apt-get install --assume-yes --force-yes remastersys

# call installer as normal user
exit
sudo remastersys-installer gui

Once completed, if you see messages complaining about the impossibility to unmount /TARGET and /TARGET/home, just unmount them manually in the console:

sudo umount /TARGET/home/
sudo umount /TARGET/

Finally please note that there are few details to be corrected:

• at boot GRUB is complaining about a missing splash image
• network may not work because the file /etc/network/interfaces is appended with another network configuration at each boot (which causes inconsistencies)
• boot is hanging tens of seconds when network is not plugged because it is waiting for a DHCP lease

The first point can be solved by editing /boot/grub/menu.lst and adding “boot” between the double slash (//) in the line speaking of splash. Note that the Remastersys splash image is not childish at all. Prefer installing the package grub-splashimages-doudoulinux instead! (and replace the file /boot/grub/splash.xpm.gz)

The second one can be solved by removing the for loop of the 3rd block of code in /etc/rc.local.

The last one cannot be simply solved. We have to achieve additional experiments to find a solution. They'll be reported in the ticket related to this topic: Provide a way to do a real DDL installation.

Have nice DoudouLinux installs!

A question that is regularly asked is how to remove some entries in the session menu (shown on the screenshot below). The standard session menu has 7 sessions. If you want a DoudouLinux for very young children, you may wonder how to remove the two most advanced sessions, Mini and Whole DoudouLinux. On the contrary the first 2 or 3 sessions are quite useless if your children are bigger.

The solution is to enter the session Whole DoudouLinux and open a console. Because the session menu is based on GDM, the tool that will allow you to hide sessions is “gdmsetup”:

$ sudo gdmsetup

In the latest tab you can add or remove users in the list of users who are not shown in the menu:

Of course changes are lost after shutdown or reboot if you have not installed DoudouLinux on hard disk or if full persistence is not set. The session names to be used in the order of session difficulty are:

0gamine
1pysycache
2childsplay
3tuxpaint
4gcompris
5doudoulinux
tux

The resulting session menu with “5doudoulinux” and “tux” removed is the following:

So everything is OK but you may have noticed that a problem occurs if you want to change the sound volume or to make removed sessions reappear: you do not have access to the required tools anymore through the remaining sessions… The solution is simple: just type the name of the Whole DoudouLinux session user, which is “tux”, then press Return. This is shown in the following screenshot:

To conclude there is just one thing to add: it would be better to have a small but nice interface to set the session menu. Be patient, this will come!

A first DoudouLinux logo has been designed from the website artwork. It is available as PNG files as well as SVG source file. To draw it we used Inkscape 0.46 and draws from the Open Clipart Library, just as we did for our website. Pages and news will be published soon on our website to inform our visitors that they can now use it to promote our project.

logo-100x48.png

logo-150x72.png

logo-200x96.png

logo-300x144.png

logo-400x192.png

The next DoudouLinux release should be available by the end of November. We are already starting to build pre-releases in order to test it. If you are interested in testing by yourself, just visit the dailybuild section:

http://download.doudoulinux.org/liv...

Currently only CD's are available and not for all languages already published. But note that there is the first Ukainian build though. Concerning improvements, the list is on the page Realease notes.

We have created a new download section named “Daily build”. There is a section for LiveCD images and section for USB key images. Please note that these files cannot be downloaded from the standard download web page because these files are uploaded onto the server for testing purposes only. As usual, this does not mean that they do not work correctly at all!

Unlike what its name suggests, we do not intend to build a DoudouLinux version every night in this directory for obvious upload bandwidth reasons. Instead you may find sometimes versions that are being developed and made available during several days (say at least 7 days). The page Release notes provide information about what has been changed from the latest official build (currently the 2010-08).