• Launchpad Entry: arm-m-xdeb-cross-compilation-environment

• Created: 2010/05/25

• Contributors: LoicMinier

• Packages affected: xdeb

Summary

Provide a new xdeb tool to easily cross-build a set of packages.

Release Note

If we have ARM specific release notes: A new xdeb tool allows easy cross-compilation of a set of packages.

Rationale

When repeatedly working on a package or a small set of packages, it is useful to have the fastest develop/build/deploy cycles as possible. On ARM, this still means cross-compilation.

User stories

Rob would like to work on GStreamer plugins for his ARM !SoC, he needs to rebuild repeatedly a library and a plugins package and he would like to take advantage of his fast x86 desktop for rebuilds, but he doesn't want to rebuild all recursive build-deps of these packages before being able to work.

Assumptions

No build-deps loops between the packages to rebuild.

Design

An existing almost complete implementation exists in the form of chromiumos-build, but it's a bit picky about build-deps loops.

Implementation

Rebrand chromiumos-build to xdeb.

Change the logic of xdeb to graph the build-deps of the packages which should be rebuilt instead of all packages.

Test/Demo Plan

Cross-rebuild a couple of gstreamer packages, in the right order, for armel.

Unresolved issues

Build-deps loops are not handled between packages to rebuild.

BoF agenda and discussion

Discussion

• Allows cross building of one or many packages.
• Based on Googles chromeos-build tool (built on dpkg-cross).
• Google wanted to take Ubuntu ARM packages and cross-build them on x86.
• Google switched to portage (Gentoo) but xdeb is still valid for Ubuntu.
• The tool cannot cope with dependency build loops ATM.
• xdeb is something to use now but could be replaced by multiarch later.
• chromeos-build needs rebranding and dependency loops need handling.
  • apt-ma-emu was suggested as an addition to xdeb, discounted due to xdeb being 95% complete.

    • http://www.mail-archive.com/debian-embedded@lists.debian.org/msg04991.html

• pbuilder-cross could be extended to build multiple packages.

  • http://www.linux.codehelp.co.uk/serendipity/index.php?/archives/203-pdebuild-cross.html

• multiarch meta data may need extending.
• gstreamer packages need testing with this tool as vendors mainly cross build these.

• https://wiki.ubuntu.com/MultiarchSpec is a good example of a multi-arch document that came from a UDS session.

Actions

• rebrand
• extend to compute build-dep loops
• testing against a subset of packages (gstreamer e.t.c)
• make sure xdeb keeps native builds
• [optional] pbuilder integration

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