Migration to Debian Squeeze

DoudouLinux is based on the famous Debian distribution. It is currently using the old stable version, Lenny. As Squeeze was published during February, we are looking at migrating DoudouLinux to the new stable version. This migration requires that we change many things:

1. the tools to build the CD have changed, we need to adapt our build scripts
2. packages used in DoudouLinux may have changed, been removed, been fixed
3. texts to be translated may have changed
4. the CD size may exceed 700 MB with the same set of applications
5. our repository has to offer Squeeze packages

The migration is currently under work in the SVN branch “experimental/squeeze/”. If you feel that the migration process is too slow, do not hesitate to contact us to come and help!

Live-helper migration

The new version of live-helper is bringing the following known modifications:

• script variables may have changed of name or value, or may have been removed or added
• boot parameters may have changed of name or value
• a single ISO file can be used to write on an USB disk

Status: migration has started.

• Gérald changed the live-helper parameters and had a first build of 800 MB.
• Jean-Michel performed the first tests to boot an ISO file as an ISO or a hard disk.

Packages

Here is the list of packages that are known to have changed or to pose problem:

• lxsession-lite has been replaced with lxsession
• lxlauncher changed the name of its global system configuration files + text of icons is aligned left instead of center

to be completed…

In the current version based on Lenny, we also patched several packages:

• apertium-dbus → fixed bug preventing the GUI to communicate with the CLI (see http://bugs.debian.org/cgi-bin/bugr...)
• live-initramfs → removed support for ext4 since it’s not in kernel 2.6.26, removed DHCP configuration of network at boot
• lxlauncher → moved “back” buttons in sub-dirs from right to left, added option to use a custom file launcher.menu
• pysycache → fixed launch icon not working (see http://bugs.debian.org/cgi-bin/bugr... and http://bugs.debian.org/cgi-bin/bugr...)
• vkeybd → fixed hanging when pressing keys of notes outside the displayed piano keyboard (see http://bugs.debian.org/cgi-bin/bugr...), fixed Tab/Capslock that make vkeybd stop working (see http://bugs.debian.org/cgi-bin/bugr...), added PO translation files

We need to decide what needs to be ported to the Squeeze packages. Note that some patches may have been ported to Squeeze (case of vkeybd a priori).

Status: migration has just started.

In depth analysis

lxlauncher

Here are its new global system configuration files:

$ dpkg -L lxlauncher | grep xdg
/etc/xdg
/etc/xdg/lxlauncher
/etc/xdg/lxlauncher/settings.conf
/etc/xdg/lxlauncher/gtkrc
/etc/xdg/menus
/etc/xdg/menus/lxlauncher-applications.menu

We need to change the corresponding files in “live/config-base/chroot_local-includes/”.

Case of KDE translations

KDE packagers have put all the localization files of all the KDE applications in a single package per language. To avoid installing tens of useless MB, a script in “packages/trunk/kde-i18n/” unpacks the i18n package and repacks only the files of interest in a package named kde-i18n-doudou-LL, where LL is the language code.

We have to check that KDE localization packages did not change their structure, eventually adapt our script, then rerun it on Squeeze packages to produce new versions of kde-i18n-doudou-LL packages.

Translations

Many packages may have partially changed their text strings in the user interface. As a result, translations may not be totally correct anymore. The process is then the following:

1. create an empty tree in “lang/experimental/squeeze/”
2. unpack in this tree all the PO files for all the DoudouLinux applications of Debian Squeeze
3. backport translations from “lang/trunk/” using a dedicated tool from gettext to merge translation catalogs

We have to check that merging catalogs is not removing strings from the Squeeze PO files. Of course automation scripts are required to do the second and third tasks.

Status: to be started.

Final size of CD

Nothing ensures that building the CD with exactly the same packages will lead to the same CD size. This is why it seems the Squeeze based build is currently using about 100 MB more than the Lenny based one. The extra space used has to be analyzed. Here some ways to reduce the CD space:

• Remove unneeded packages! We must also be sure that the package manager did not install recommended packages but only strict dependencies.
• Remove unneeded translations. Some applications are shipping audio files in English in their core package. We can try to remove them.
• Replace some packages with alternatives that require less disk space or are not using extra libraries. For example vkeybd is the only package requiring Tcl/Tk, it may be replaced with Vmpk. OpenDict may also be the only one using WxGtk.
• Remove duplicate files. Some packages are using the same files, eg. Gamine is using files from Gcompris and TuxPaint, as far as we know. We could replace them with hard links.
• Put some packages on a diet. We can try to remove data files in applications such as TuxPaint, SuperTuxKart or Gcompris. This will reduce their functionalities a bit of course.
• Remove the Linux kernel in the squashfs filesystem. The Debian Live wiki indicates that only the Linux kernel installed in the ISO filesystem is in use.
• Use kernel 2.6.38 instead of the official Squeeze one which is 2.6.36. The 2.6.38 one is shipping a better squashfs compression algorithm. However we have to be sure that Live helper tools can handle this alternative compression algorithm.

Status: to be started.

Package repository

We have to start registering our packages that are ready for use with Debian Squeeze in our Debian package repository. At least all the DoudouLinux specific packages should be moved to Squeeze and certainly as is. They are located in the branch “packages/trunk/apps/” on SVN.

to be completed…

Status: to be started.