Category: News

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.

Buildroot

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)

QEMU

  • 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)

Conferences

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 LWN.net resource.

Miscellaneous

Many new training materials

12 pages with new training materials!

We are happy to release many new training materials that we created along the course of 2008, for our embedded Linux and kernel training sessions:

Many thanks to customers who asked us to cover new topics!

This is actually the tip of the iceberg (with penguins standing on top of it, of course). The documents that have been around for a long time have also undergone significant improvements and have been updated every time new versions with interesting features were released. We are doing our best to keep our training sessions up to date, and this keeps us pretty busy! So, if you haven’t had a look at these documents for a while, you will probably learn new things if you open them again.

Why so many documents at once? Well, we usually try to release the new documents that we create as early as possible. Here are a few excuses for doing this late this time:

  • We’ve had a very busy year (new training sessions, development and service work), preventing us from polishing our new documents and creating new pages describing them.
  • The switch to our new website took more time than expected. We were reluctant to add more pages that would have caused more migration work, and we were also busy deploying the KVM virtualization technology on our new server.
  • We are also switching the documents to a new template, which leaves more space for real content and less space for logos and for information repeated on every page. This work is far from being over yet!
  • We couldn’t release them for National Security reasons Winking smiley.

Now that there’s no infrastructure work left, and that we have run out of excuses (except the one about being busy, we still are), we should be able to release our new documents much earlier.

So, stay tuned on our RSS feed, more will come soon!

Kernel 2.6.28 is out with a few Bootlin 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.

Bootlin 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.

Bootlin at FOSDEM 2009

The Free and Open Source Developer European Meeting (FOSDEM) is a major event for open source developers in Europe. This two-days event takes place in Brussels since several years and attracts 2000-3000 people around conferences and development rooms. The program for the main tracks has been recently announced, but the program for the development rooms is not available at this time. However, I’ve been at FOSDEM the last two years and always found interesting talks and discussions.

FOSDEM Banner

Of course, I’ll be particularly interested by the Embedded Devroom, and will record videos of the talks that will be posted on Bootlin website after the conference, as usual.

If you happen to come to FOSDEM, I’ll be happy to meet you!

New LXR website

I am pleased to announce that our https://elixir.bootlin.com website is back on line.

As some of you probably noticed, our service had been down for several months. When it was working, it was based on LXR 0.9.5. This version had nice improvements over the stable release (0.3.1), like better display of the kernel sources, but on the other hand, it also had ugly drawbacks. In particular, it stored data in an SQL database. This made the server consume more CPU resources, and made it very long to index a new kernel version (about 10 hours instead of just a few minutes). Disk space was also multiplied by 3 or 4, if I recall correctly. Anyway, the major problem was that that version didn’t scale: the service was getting slower each time a new version was added. Apparently, the bigger the database, the slower the server got.

Eventually, that 0.9.5 based server just died. I didn’t change anything before this happened and everything looked all right. I checked configuration files and packages, but there seemed to be no way to make it run again. The only solution left was a brand new install from scratch.

I first evaluated the LXRng, a new fork of the software on the http://lxr.linux.no website. This new version looks nice. In particular, though it’s still using a database, this new branch seems to withstand a greater number of kernel source versions, as http://lxr.linux.no answers pretty fast now and indexes a pretty long list of versions. However, I found its interface confusing and not as convenient as it was in the original branch, especially for identifier search. It could be because this new version is not mature enough yet, or just because I was too familiar with the original interface. The best is to try by yourself!

I also tried to make a new installation of the latest CVS sources of the main branch. However, this didn’t work as expected, as I wanted to run the new service on a recent distro with long term support (Ubuntu Gutsy Gibbon). Gutsy Gibbon only supports MySQL 5.0, but LXR-CVS proved to be only compatible with MySQL 4.0. I did apply some patches, but still got SQL query errors with MySQL 5.0.

I eventually decided to go back to the good old 0.3.1 stable version, and I don’t regret it:

  • This version is extremely simple. You just need a web server with CGI scripts. No trouble with Apache2, no need to make modperl work. No need to install database software.
  • This version is extremely fast too. It just takes a few minutes to add a new version, and serving identifier searches is very fast. Just try with a widely used function, like outb. With LXR 0.9.5, it could take up to 1 minute to display all the files in which the symbol was found.
  • This version scales by design. Each supported source version has its own index files, and there is no central blob getting bigger and bigger. This simple design also makes it very easy to remove or to update source versions (like upgrading 2.6.28 sources to 2.6.28.1). With LXR 0.9.5, you had to make your own SQL queries to remove a version from the database!
  • This version lacks a few features (like direct links to C include files, or like file descriptions), but hey, the main features are there: source navigation and identifier search. The only significant feature that is kind of missing in our site is freetext search. Version 0.3.1 only supported a proprietary searching tool, so we decided to rely on Google’s search instead. This is not perfect as we won’t have version-specific search, but freetext search is a secondary feature for us anyway. We wanted to have this service back on line, with at least its main features.
  • Note that I had to make minor changes to make the website XHTML 1.0 Transitional compliant and pass the W3C Markup Validation Service checks I also fixed a bug in the diff markup script. Here is an archive of our install. Don’t hesitate to compare it with the original code and templates, and reuse our modified templates if you like them.

Thanks to this, the code hyperlinks in our kernel training slides work again at last! Every time we mention the name of a kernel source file or quote example code, you can click on the file name or on each function or structure type name, and you will be taken to the corresponding page on our LXR site!

Don’t forget that other valuable LXR websites exist for the Linux kernel. See our LXR websites list. Don’t hesitate to post a comment if you know other useful ones.

Happy New Year!

Our very best wishes for 2009!

Usually, we create special wish cards for our customers and for the whole community. Unfortunately, we didn’t have enough time last year, and this happened again this year. Actually, higher priority projects are keeping us busy:

  • Fixing our LXR website. Thanks to this, the code hyperlinks in our kernel slides work again!
  • Preparing our new training sessions. We now propose two new training agendas, one full week only about the Linux kernel, and another full week on embedded Linux system development. Last but not least, we now use real hardware in our training sessions, and not just emulated boards.
  • Processing the videos we took at the 2008 edition of the Embedded Linux Conference Europe. We hope to release them by the end of January.
  • Migrating the French part of our website to WordPress, as we did with the English one.
  • Releasing new technical documents that we haven’t had time to polish yet.
  • Making contributions to community projects (Linux kernel, QEMU, Buildroot…).
  • Working on development projects

Anyway, we really hope that this year will be very busy for you too, despite the economic slowdown. With sustainable and cost-effective solutions, backed by a huge community of developers and users, you could really make a difference.

OLS 2008 videos

30 videos from the Linux Symposium in Ottawa

We are pleased to release 29 videos that we took at the Linux Symposium in Ottawa, Canada, in July 2008:

  • Keynote: The Kernel: 10 Years in Review, by Matthew Wilcox (Intel)
    video (57 minutes, 175M)
  • Talk: Tux on the Air: State of Linux Wireless Networking, by John W. Linville (Red Hat)
    paper, video (52 minutes, 168M)
  • Talk: Suspend to RAM in Linux: State of the Union, by Len Brown and Rafael Wysocki (Intel)
    paper, video (52 minutes, 163M)
  • Talk: Real Time vs Real Fast: How To Choose?, by Paul E. McKenney (IBM)
    paper, video (45 minutes, 166M)
  • Tutorial: ftrace: latency tracer, by Steven Rostedt (Red Hat) video (98 minutes, 772M)
    • BOF: Embedded Linux, by Tim R. Bird (Sony)
    video (42 minutes, 200M)
  • BOF: Embedded Microcontroller Linux, by Michael Durrant (Arcturus Networks)
    video (42 minutes, 243M)
  • Talk: Energy-aware task and interrupt management, by Vaidyanathan Srinivasan (IBM)
    paper, video (52 minutes, 182M)
  • Talk: Application Testing Under Realtime Linux, by Luis Claudio R. Gonçalves (Red Hat)
    paper, slides, video (54 minutes, 297M)
  • Talk: Application Framework for Your Mobile Device, by Shreyas Srinivasan (Geodesic Information Systems)
    paper, video (25 minutes, 146M)
  • Keynote: The Making of OpenMoko Neo, by Werner Almesberger (OpenMoko)
    video (94 minutes, 463M)
  • BOF: U-Boot by Wolfgang Denk (Denx)
    video (54 minutes, 362M)
  • BOF: Linux Compiler, by Rob Landley (Impact Linux)
    video (100 minutes, 765M)
  • Tutorial: Practical Guide to Using Git, by James Bottomley (Hansen Partnership)
    video (61 minutes, 357M)
  • Talk: Advanced XIP File System, by Jared Hulbert (Numonyx)
    paper, video (49 minutes, 160M)
  • Talk: SELinux for Consumer Electronic Devices, by Yuichi Nakamura (Hitachi)
    paper, video (31 minutes, 113M)
  • Talk: Around the Linux File System World in 45 Minutes, by Steve French (IBM)
    paper, slides, video (49 minutes, 298M)
  • BOF: Linux The Easy Way with LTIB, by Stuart Hughes (Freescale)
    slides, video (25 minutes, 144M)
  • Keynote: The Joy of Synchronicity: Coordinating the Releases of Upstream and Distributions, by Mark Shuttleworth (Canonical)
    slides, video (76 minutes, 458M)
  • Talk: Smack in Embedded Computing, by Casey Schauffer
    paper, video (59 minutes, 211M)
  • Talk: Bazillions of Pages: The Future of Memory Management, by Christoph H. Lameter (SGI)
    paper, video (49 minutes, 258M)
  • Tutorial: Writing application fault handlers, by Gilad Ben-Yossef (Codefidence)
    video (49 minutes, 275M)
  • Talk: Linux, Open Source and System Bringup Tools, by Tim Hockin (Google)
    paper, video (51 minutes, 229M)
  • Talk: DCCP Reached Mobiles, by Leandro Melo Sales (Federal University of Campina Grande)
    paper, video (42 minutes, 193M)
  • Talk: Building a robust Linux kernel, by Subrata Modak (IBM)
    paper, slides, video (51 minutes, 249M)
  • CELF BOF presentation: Best of recent CELF Conferences, by Tim Bird (Sony)
    slides, video (10 minutes, 88M)
  • CELF BOF presentation: Developing Embedded Linux with Target Control, by Tim Bird (Sony)
    slides, video (17 minutes, 145M)
  • CELF BOF presentation: Embedded Building Tools – An Audience Survey, by Michael Opdenacker (Bootlin)
    slides, video (17 minutes, 127M)
  • CELF BOF presentation: GCC Tips and Tricks Highlights, by Gene Sally
    video (14 minutes, 62M)

See also all the papers, and a report from the CELF BOF.

We could only shoot the presentations we attended. You can see that our main interests are embedded systems and the Linux kernel wink smiley.

Conference videos and report

27 free videos from the ELC and FOSDEM 2008 conferences. Extensive technical report from ELC 2008.

After participating to the Embedded Linux Conference (ELC) in Mountain View, and to FOSDEM in Brussels, we are pleased to release the videos that we managed to shoot.

These videos should be useful to anyone interested in the multiple topics covered by these very interesting conferences, either to people who couldn’t join these conferences, or to single core participants who couldn’t attend more than one presentation at once. These videos are also interesting opportunities to see and hear key community members like Andrew Morton, Keith Packard, Henry Kingman, Tim Bird and many others!

While we’ve been releasing free technical videos for a few years now, ELC is the first conference for which we are also offering an extensive report, written by Thomas Petazzoni, one of our kernel and embedded system developers. This report is trying to sum up the most interesting things learned at this conference, at least from the presentations Thomas could attend. This way, you shouldn’t have to view all the videos to identify the most interesting talks.

Creative commons In agreement with the speakers, these videos and the report are released under the terms of the Creative Commons Attribution-ShareAlike 3.0 license.

We hope that sharing this knowledge will attract new contributors and users, and will bring our community one step closer to world domination…

Embedded Linux Conference, Mountain View, Apr. 2008

Don’t miss our detailed report on the below presentations!

  • Keynote: The Relationship Between kernel.org Development and the Use of Linux for Embedded Applications, by Andrew Morton (Google):
    video, slides (55 minutes, 240 MB)
  • UME – Ubuntu Mobile and Embedded, by David Mandala (Canonical):
    video, slides (30 minutes, 145 MB)
  • Appropriate Community Practices: Social and Technical Advice, by Deepak Saxena (MontaVista):
    video (thanks to Kevin Hilman, MontaVista)(44 minutes, 139 MB)
  • Adventures In Real-Time Performance Tuning, by Frank Rowand:
    video,slides (50 minutes, 251 MB)
  • Shifting Sands: Lessons Learned from Linux on an FPGA, by Grant Likely:
    video, slides (44 minutes, 262 MB)
  • Disko – An Application Framework for Digital Media Devices, by Guido Madaus:
    video (27 minutes, 190 MB)
  • Keynote: Tux in Lights, by Henry Kingman (LinuxDevices.com):
    video, slides (44 minutes, 139 MB)
  • Back-tracing in MIPS-based Linux Systems, by Jong-Sung Kim (LG Electronics):
    video, slides
    (54 minutes, 160 MB)
  • Making a Phone Call With Phase Change Memory, by Justin Treon (Numonyx):
    video, slides (28 minutes, 159 MB)
  • Building Blocks for Embedded Power Management, by Kevin Hilman (MontaVista):
    We couldn’t film his presentation, but we already shot a similar presentation he gave at Fosdem 2008: video ((56 minutes, 183 MB)
  • Using Real-Time Linux, by Klaas van Gend (MontaVista):
    video, slides (53 minutes, 263 MB)
  • Every Microamp is Sacred – A Dynamic Voltage and Current Control Interface for the Linux Kernel, by Liam Girdwood (Wolfson Microelectronics):
    video, slides (35 minutes, 71 MB)
  • Power Management Quality of Service and How You Could Use it in Your Embedded Application, by Mark Gross (Intel):
    video, slides (57 minutes, 401 MB)
  • OpenEmbedded for product development, by Matt Locke (Embedded Alley):
    video, slides (49 minutes, 141 MB)
  • Kernel Size Report, and Bloatwatch Update, by Matt Mackall (Selenic Consulting):
    video (49 minutes, 146 MB)
  • Leveraging Free and Open Source Software in a Product Development Environment, by Matt Porter (Embedded Alley):
    video, slides (45 minutes, 220 MB)
  • Using a JTAG for Linux Driver Debugging, by Mike Anderson (PTR Group):
    video, slides (113 minutes, 694 MB)
  • DirectFB Internals – Things You Need to Know to Write Your DirectFB gfxdriver, by Takanari Hayama ():
    video (43 minutes, 200 MB)
  • Linux Tiny – Penguin Weight Watchers, by Thomas Petazzoni (Bootlin):
    video (thanks to Jean Pihet, MontaVista), slides (32 minutes, 140 MB)
  • Keynote: Status of Embedded Linux and CELF Plenary Meeting, by Tim Bird (Sony):
    video, slides (49 minutes, 112 MB)

Slides are collected on http://www.celinux.org/elc08_presentations/.

Fosdem, Brussels, Feb. 2008

  • Modest, email client for embedded systems, by Dirk-Jan Binnema (Nokia):
    video (34 minutes, 121 MB)
  • Design a Linux robot companion with 8 bits microcontrollers, by David Bourgeois:
    video (54 minutes, 211 MB)
  • Linux on the PS3, by Olivier Grisel:
    video (47 minutes, 272 MB)
  • Xen for Secure Isolation on ARM11, by Jean-Pihet (MontaVista):
    video (41 minutes, 207 MB)
  • Building blocks for Embedded Power Management, by Kevin Hilman (MontaVista):
    video (56 minutes, 183 MB)
  • Emdebian Update: Rootfs, GPE and tdebs, by Neil Williams:
    video (47 minutes, 226 MB)
  • pjsip: lightweight portable SIP stack, by Perry Ismangil:
    video (55 minutes, 194 MB)

Additional video

  • Roadmap to recovery – pain and redemption in X driver development, by Keith Packard:
    video (44 minutes, 168 MB)

ELCE 2007 videos

Free videos of CELF’s Embedded Linux Conference Europe / 9th Real-Time Linux Workshop in Linz, Austria, November 2007.

We are happy to release the videos that we took at the CELF Embedded Linux Conference Europe 2007 / 9th Real-Time Linux Workshop which happened in Linz, Austria in November, 2007.

  • Detection & Resolution of Real Time Issues Using TimeDoctor, by François Audeon (NXP):
    video (32 minutes, 359 MB)
  • Fancy and Fast GUIs on Embedded Devices, by Gustavo Sverzut Barbieri (INDT):
    video, slides (46 minutes, 146 MB)
  • arch/ppc, arch/powerpc and Device Trees – A Walk Through a Port, by Hugh Blemings (IBM):
    video (30 minutes, 534 MB)
  • Free Software, Licensing and Business Processes, by Shane Martin Coughlan (FSF Europe):
    video, slides (40 minutes, 138 MB)
  • Introduction to LogFS, by Jörn Engel:
    video, slides (46 minutes, 260 MB)
  • WebKit on Linux and How It Compares to Other Open Source Engines, by Holger Freyther (Trolltech):
    video, slides (49 minutes, 205 MB)
  • Status Overview of Real-Time, by Thomas Gleixner (Linutronix.de):
    video (47 minutes, 236 MB)
  • Kernel Summit Report, by Thomas Gleixner (Linutronix.de):
    video (34 minutes, 520 MB)
  • Writing DirectFB gfxdriver For Your Embedded System, by Takanari Hayama (igel):
    video, slides (31 minutes, 223 MB)
  • Improving JFFS2 RAM Usage and Performance, by Alexey Korolev (Intel):
    video, slides (20 minutes, 141 MB)
  • YAFFS, by Wookey:
    video, slides (45 minutes, 194 MB)
  • Parallelizing Linux boot on CE Devices, by Vitaly Wool (Embedded Alley Solutions):
    video, slides (40 minutes, 185 MB)
  • Linux Suspend-to-Disk Objectives for Consumer Electronic Devices, by Vitaly Wool (Embedded Alley Solutions):
    video, slides (35 minutes, 652 MB)
  • Evaluation of Linux rt-preempt for embedded industrial devices for Automation and Power technologies – A case study, by Morten Mossige, Pradyumna Sampath, Rachana Rao (ABB):
    video, paper (22 minutes, 224 MB)
  • Assessment of the Realtime Preemption Patches (RT-Preempt) and their impact on the general purpose performance of the system, by Arthur Siro (DSLab / OSADL):
    video, paper (31 minutes, 224 MB)
  • Panel: the ideal embedded Linux distribution, by Tim Bird (Sony):
    video (65 minutes, 465 MB)

To speed up the processing of these videos, we contracted Jan Gerber, the developer of ffmpeg2theora, to add denoising support to this tool. Thanks to this contribution, it is now possible for anyone in the community to directly denoise DV camcorder input and generate Ogg/Theora video in just 1 step. Before it was necessary to use mencoder‘s denoising filter, and because mencoder couldn’t process DV input properly, a preprocessing stage with ffmpeg was also required. This new functionality can also improve the quality and compression rate of live Ogg/Theora video broadcasts.

Linux USB drivers

Learning how to write USB device drivers for Linux

Bootlin is proud to release a new set of training slides from its embedded Linux training materials. These new ones cover writing USB device drivers for Linux.

Like everything we create, these new materials are released to the user and developer community under a free license. They can be freely downloaded, copied, distributed or even modified according to the terms of the Creative Commons Attribution-ShareAlike 2.5 license.