The biggest remaining issue in making Embedded Debian is how to store and control package metadata which describes how to reduce package size, increase granularity, reduce the size of the essential package set, etc.

This page tries to document the issues and the pros and cons of the current active proposals.

The issues have been developed in discussion with emdebian and debian developers at the Extremadura Work Session, Debconf and LinuxWorld Expo, in 2006 and further optimised at Fosdem 2007.

Composite method.

emdebian diff contains changes that are implemented via patch files kept in svn superimposed on the Debian diff, managed with emdebian-tools. Emdebian diff applied after debian diff, then standard build tools used on the result. i.e. The upstream .tar.gz needs to be debianised to make a working Debian package, then the Debian package can be emdebianised. Patch files can be reversed to regain the original Debian package.





Status: All already achievable with normal Debian tools. emdebian-tools scripts act as standardised wrappers.


  1. Wherever possible, emdebian will use standard Debian packaging scripts - only tweaking those related to the content needing to be removed or ignored in emdebian packages. i.e. the burden of changes has moved from Debian developers to emdebian developers. Packages like apt-cross and dpkg-cross can be further enhanced to ensure the correct versions of the debhelper tools are used. Overall, this leads to changes in fewer files than using the $DEBIAN_DIR approach, as well as less duplication.
  2. Those packages that need further customisation can have patches stored in the emdebian SVN repository. The emdebian build script - emdebuild - will checkout and apply the patches before debian/rules is called. This is vital because using existing patch methods like CDBS and dpatch relies on debian/rules being called to perform the patch. In order to successfully patch debian/rules itself, the patch process needs to begin before debian/rules is called. The repository holds patches on a per-source basis.

Status: Implemented in emdebian-tools, currently in Debian unstable.

  1. Unlike Debian packages, emdebian packages will not have individual emdebian maintainers. Instead, any emdebian developer will be able to update the emdebian customisations for a particular Debian package, e.g. when a new version is uploaded to unstable.
  2. An emdebian buildd can then package and upload archives to the emdebian repository to remove the delay between packages reaching testing and being built for emdebian.

Overall, this method uses the best of each of the previous ideas but large amounts of work remain.

A useful thing to do would be set up an emdebian BTS. Repackaging Debian archives through automated systems can cause mysterious bugs.


<explanation/example> - used by STAGv2 and STAGE




<explanation/example> - used by Debian-installer



Just change /debian files



<explanation/example> - used by SLIND

In fact this is really a variant of the $DEBIAN_DIR example and could be implmented that way too(this assertion needs testing)

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