Buildroot 2010.02 released, contributions from Free Electrons!

Buildroot logoBuildroot is a embedded Linux system build system. It automates the process of downloading, configuring, compiling and installating all the components of an embedded Linux system, from Busybox to more complicated software stacks using Gtk, Qt,, Gstreamer, etc. Buildroot is easy to use and extend, making it a nice choice for small to medium-sized embedded Linux systems.

As promised by the fixed-release schedule, a 2010.02 release has been published on Friday, with numerous improvements over the previous version 2009.11, many of which are part of the general cleanup process that the project is doing since the beginning of 2009. These improvements are detailed in the project CHANGES file.

Thomas Petazzoni, from Free Electrons, implemented several of these improvements :

  • Creation of a package infrastructure for non-autotools packages. Buildroot had for a long time an infrastructure to factorize the code needed to build packages based on the autotools build systems. But all other packages were using hand-made Makefiles, which were hard to write and generated a lot of code duplication. Therefore, we have introduced an infrastructure that makes adding new packages much easier, and which allows us to cleanup the existing codebase significantly by factorizing a lot of common code. The autotools infrastructure has also been reworked on top of the generic infrastructure to avoid code duplication as well. At the same time, we have significantly improved the documentation on how to add new packages. This infrastructure is a building block that will allow us to easily add more features to all packages in Buildroot (such as package generation).
  • Removal of the external toolchain source mechanism, which was merged with the normal toolchain building procedure. This special casing was implemented to allow the compilation of AVR32 toolchains, but such an additional complexity wasn’t needed. Now, Buildroot continues to build AVR32 toolchains as it used to do, but the code is much cleaner. Another illustration of our large cleanup effort.
  • Many, many, many fixes to different packages, many of them to ensure that we do not depend on development packages being installed on the host. This is very important to ensure that our build procedure is as independent as possible from the development machine configuration.

From the list of contributors, ordered by the number of patches, Thomas Petazzoni of Free Electrons has been the first Buildroot contributor for this last release :

$ git shortlog -e -n -s 2009.11..2010.02  (removed e-mail addresses)
139 Thomas Petazzoni
124 Peter Korsgaard
26  Lionel Landwerlin
23  Gustavo Zacarias
7   Julien Boibessot
4   Nigel Kukard
4   Sven Neumann
2   Anders Darander
2   Chris Packham
2   Daniel Mack
2   H Hartley Sweeten
2   Richard van Paasen
2   Will Wagner
2   William Wagner
2   Yann E. MORIN
1   Cameron Hutchison
1   Clark Rawlins
1   Francisco Gonzalez
1   Francisco Gonzalez Morell
1   Hans-Christian Egtvedt
1   Lionel Landwerlin
1   Ormund Williams
1   Rob Alley
1   Sagaert Johan
1   grante

For the next release, we will work on additional cleanup of Buildroot and particularly the target/ directory, which contains the code to build the Linux kernel, different bootloaders, and to generate the final root filesystem image in various formats. Improving support for external toolchains is also on our TODO list : supporting multilib toolchains such as the CodeSoucery toolchain, and fixing a long-standing issue with libtool.

Don’t hesitate to try Buildroot, and to report your successes and failures on the mailing-list, in our bug tracker, or on our IRC channel, #uclibc on Freenode.

On the road to Buildroot 2009.08

Buildroot logoAs I posted back in March, the Buildroot project has begun a new life since January. One of the aspects this new life is the fact that stable releases are delivered every three months. So we had one in February (2009.02), one in May (2009.05) and therefore we’re going to have one release soon in August (2009.08).

Peter Korsgaard, Buildroot’s maintainer, has just released 2009.08-rc1, a good opportunity to look at what’s new in Buildroot since the last release. To highlight Free Electrons’ participation in the free software community, it is worth noting that in number of patches, I’m the second most important contributor to Buildroot, right after Peter, the maintainer. It’s really nice that I’ve been able to find enough time to contribute at such a level to Buildroot, and hope to be able to dedicate more time in the future to Buildroot, since we have lots of ideas to improve the project.

Back to the 2009.08 release specifically, in the notable features or improvements, we have :

  • Improvement of external toolchain support. I’ve already posted about this specific feature, that I find very important. Several reports from people using this feature have been received since then, which means that it is a useful feature for some of the Buildroot users. So, we have now support for glibc toolchains, the configuration provided to Buildroot is verified against the real toolchain configuration, the copy of the toolchain libraries to the target has been improved (including the C++ standard library) and other minor improvements have been. I’ve been the major contributor of these improvements, together with the reports provided by Buildroot users
  • Integration of the QT-based configurator. Buildroot uses the kconfig system from the kernel to allow its users to configure the different elements of the system to be built. Until now, only the ncurses interface (make menuconfig) was supported. In the 2009.08, the QT interface (make xconfig) will also be supported, adding a little more userfriendliness to Buildroot. This feature was contributed by Alper Yildirim, and I helped in polishing the remaining issues.
  • Support for the Xtensa architecture has been contribued by Maxim Grigoriev, from Tensilica, the company designing the Xtensa architecture.
  • Cleanup of support. the configuration options were clarified, and mandatory dependencies on useless libraries such as libXt or libXaw were removed, some components were upgraded to fix build issues. It’s also a task I contributed to.
  • Of course, toolchain components have been upgraded (GCC 4.4.1, 2.6.30 kernel headers), new packages have been added (bmon, ctorrent, dosfstools, enchant, gst-plugins-bad, iw, libmms, libnl, netstat-nat, ntfsprogs, sdl_gfx, spawn-fcgi), and many more packages have been upgraded (bind, busybox, coreutils, sqlite, directfb, expat, gamin, gnuconfig, haserl, ipsec-tools, classpath, libcurl, libglib2, liblockfile, libpng, libsoup, libxml2, lighttpd, ltp-testsuite, lvm2, matchbox, memstat, gst-plugins-good, gstreamer, libogg, libvorbis, mplayer, neon, openssl, pciutils, php, qt, ruby, sawman, webkit, wpa-supplicant, xdriver_xf86-input-synaptics, xdriver_xf86-video-intel, xlib_libXfont, xlib_libXft, xlib_libXt, xproto_xproto, xserver-xorg, xutil_makedepend, xutil_util-macros)
  • We’re also paying a lot more attention to the bugs reported in our bugtracker than we used to do in the past. Since 2009.05, 43 reported issues have been fixed, and I except that we will fix some more before the 2009.08 release

Shortly after the 2009.08, we will set the goals for the next 2009.11 release, and I’d like to do a lot of cleanup to make Buildroot easier to use and to understand. We’ll see how things go.

In the mean time, if you’re interested in testing and improving Buildroot, don’t hesitate to grab 2009.08-rc1, try it in your conditions with your package set, and report your issues!

2008 contributions

Here are the contributions that we made to the user and developer community in 2008, thanks to the customers who ordered our engineering and training services.

As you can see, we do our best to have all our contributions merged into mainline sources. So, if you need a new feature in the Linux kernel (supporting your new boards, for example), in development tools and libraries (Buildroot, QEMU…), and want to enjoy this feature in all future updates and releases, don’t hesitate to ask us. We will be glad to work with the community and find a long lasting solution.

Linux kernel

  • [x86] use ELF section to list CPU vendor specific code (commit)
  • [MTD] fix minor typo in the MTD map driver for SHARP SL series (commit)
  • [x86] configurable DMI scanning code (commit)
  • [mm] directly use kmalloc() and kfree() in init/initramfs.c (commit)
  • [x86] consolidate the definition of the force_mwait variable (commit)
  • inflate: refactor inflate malloc code (commit)
  • fs/buffer.c: uninline __remove_assoc_queue() (commit)
  • [x86] make movsl_mask definition non-CPU specific (commit).
  • [x86] move cmpxchg fallbacks to a generic place (commit)
  • [x86] configuration options to compile out x86 CPU support code (commit)
  • Configure out file locking features (commit)
  • Fix comment in include/linux/mmc/host.h (commit)
  • Configure out AIO support (commit)
  • [PCI] allow quirks to be compiled out (commit)
  • [x86] remove PC speaker code (commit)
  • [Doc] improvement to Documentation/SubmittingPatches (commit)
  • Work on multicast and ethtool configurability. Not merged yet.
  • 65 e-mails sent to the kernel newbies mailing list to help new kernel developers.


Thomas Petazzoni became official committer in November 2008. In addition to contributions, patch review and integration of patches into the official Buildroot repository, and discussions on the mailing list.

  • Thumb support, not integrated yet (post)
  • Fixed URL for fakeroot sources, integrated (post)
  • Bumped libpng version, integrated (post)
  • Added the DirectFB examples package, integrated (post)
  • Bumped up libgtk2 version, integrated (post)
  • Work on external toolchain support, integrated. Several iterations, patches and discussions.
  • External toolchain support improvements, integrated (post)
  • More external toolchain fixes, integrated (post)
  • External toolchain C++ cross-compiler fix, integrated (post)
  • Kernel build fix related to external toolchain use, integrated (post)
  • Fixed external toolchain build, integrated, and replaced later with an improved version (post)
  • Fix Qtopia build issues, integrated and then replaced by an improved version (post)
  • Another external toolchain support solution, integrated (post)
  • Fixed TARGET_PATH for external toolchain builds, integrated (post)
  • Fixed strange problems in pango configure target, integrated (post)
  • Strip libgtk2 in the target, integrated (post)
  • Strip pango libraries on the target, integrated (post)
  • Strip gettext libraries on the target, integrated (post)
  • Fix matchbox build, integrated (post)
  • Create zlib installation directory in the staging dir, integrated (post)
  • Bump up lite version, integrated (post)
  • Added a parallel compilation fix for fontconfig, integrated (post)
  • Documentation fixes (post, post)


  • Increased write buffer size in pflash emulation, integrated (post)
  • Reset wcycle after erase confirm, integrated (post)
  • Improved pflash cfi01 debug messages, integrated (post)
  • Added missing parenthesis in qemu_ram_alloc(), integrated (post)
  • Add Flash support to the Versatile PB platform (post)


New training materials

All our training materials can now be found on our docs page. Some of them are not new, but have undergone substantial updates.

See our recent post for details.

Financial support

We support organizations promoting Free Software:

You may also count our subscriptions to the most useful resource.


Kernel 2.6.28 is out with a few Free Electrons contributions

A few hours before Christmas, Linus Torvalds released the latest stable version of the Linux kernel, 2.6.28. Jake Edge from LWN sums up the major highlights of this new release: « Some of the highlights of this kernel are the addition of the GEM GPU memory manager, the ext4 filesystem is no longer “experimental”, scalability improvements in memory management via the reworked vmap() and pageout scalability patches, moving the -staging drivers into the mainline, and much more ». As usual, the Kernel Newbies website offers an excellent human-readable summary of the changes.

Of particular interest to embedded developers will be the new boot tracer facility, which allows to draw SVG graphs of the kernel initialization procedures execution time, in order to analyze the boot time and possibly reduce it. Of course, a lot of architecture-dependent improvements have also been made (for example OProfile support for ARMv7 CPUs but also new supported boards) and a lot of drivers have been merged or improved, as usual.

Free Electrons has contributed a few patches that have been merged and released in 2.6.28. While being a small contribution compared to the 9.000+ patches added to the kernel between 2.6.27 and 2.6.28, they still slightly improve the kernel for embedded users. Part of the Linux-Tiny efforts, these patches allow to reduce the size of the kernel by disabling features that may not be necessary on embedded systems. More specifically, these patches allow :

From the existing Linux Tiny patch ideas, the only one left in the feature removal area are the multicast support removal and ethtool removal. They have already been submitted a few months ago, but got rejected by the network maintainers. I will work on them again to fix the issues and try to re-submit them later.

Finally, Jonathan Corbet has published an analysis of the 2.6.28 developement cycle in terms of contributors and changes. An interesting reading.