Free Electrons Quarterly – 2012 Q2

The below message has been posted on our English and French newsletters. Don’t hesitate to subscribe to these newsletters if you are interested in getting these news by e-mail.

This is the second Free Electrons newsletter for 2012. We are happy to share with you the latest news about our projects, training courses and contributions.

New “Android system development” training

As announced in our previous newsletter, we have created a new Android system development training course.

This course targets engineers who need to develop embedded systems with Google Android. In four days, through theory and practical labs, the course makes you familiar with compiling and booting Android, with adapting Android to support a new embedded board (assuming that it is already supported by the Linux kernel), and with building a real system through accessing specific hardware, customizing the filesystem and using debugging techniques. More details and the complete agenda.

The first public session of this training will take place on June 11-14 2012 in Toulouse, France (session taught in English). There are still seats available for this session.

We will start giving on-site sessions of this course in July 2012. Do not hesitate to contact us if you want to organize on-site sessions.

Opening our training materials source code

Since Free Electrons’ creation in 2004, we have been releasing our training materials under the Creative Commons Attribution Share-Alike license, a free license that allows anyone to share, improve and use our embedded Linux and Linux kernel training materials. Since that time, our training materials were available as PDF files, and as OpenDocument files for the source code, but we were only updating their online version from time to time.

Now, we are proud to announce that our training materials are being converted to the LaTeX language, and their latest version is available at any time from our public Git repository.

For the moment, our embedded Linux slides have been published (about 500 slides) in this Git repository, as well as the instructions for the practical sessions of our embedded Linux and Linux kernel courses. In the near future, we will also publish in LaTeX the slides of our Linux kernel training (which remain available under PDF and OpenDocument formats) as well as the materials of our new “Android system development” course.

The creation of this public Git repository is a strong sign of our commitment for open training materials.

The LaTeX format and the public Git repository now make it easy for everyone to follow updates on our materials, to keep one’s knowledge up to date, and even to teach a training session using our materials (commercial use of our materials is welcome, as it helps to spread knowledge about Free and Open Source Software for embedded systems).

Upcoming public training sessions

Our next public training sessions dates and locations are:

  • Embedded Linux kernel and driver development
    June, 4-8 2012
    Toulouse, France
    Session given in French
    Details
  • Android system development
    June, 11-14 2012
    Toulouse, France
    Session given in English
  • Embedded Linux system development
    June, 18-22 2012
    Avignon, France
    Session given in French
    Details
  • Embedded Linux kernel and driver development
    July 2-6, 2012
    Avignon, France
    Session given in French
    Details
  • Embedded Linux kernel and driver development
    October, 8-12 2012
    Avignon, France
    Session given in English
    Details
  • Embedded Linux system development
    October, 15-19 2012
    Toulouse, France
    Session given in French
    Details
  • Embedded Linux system development
    December, 3-7 2012
    Avignon, France
    Session given in English
    Details
  • Embedded Linux system development
    February, 4-8 2013
    Lyon, France
    Session given in French
    Details

Projects

Since the beginning of the year, we have been involved in the following projects for various customers:

  • Boot time optimization and power management evaluation for a MIPS-based platform used in a payment terminal;
  • Filesystem size optimization, embedded Linux build system integration, Ethernet PHY driver development for an AT91 ARM platform used in satellite video processing;
  • Embedded Linux build system integration and generic embedded Linux debugging and support for an AT91 ARM platform used as a gateway between medical devices;
  • Starting in April, we will be working with a major ARM SoC vendor to help mainlining support for their latest SoC in the official Linux kernel sources;
  • Continued the creation of materials for our new “Android system development” course.
  • Continued our work on the Linux kernel driver for the Analog-to-Digital converters of the AT91 ARM SoC (see ‘Contributions’, below);
  • Continued our work on real-time Linux evaluation on AT91 ARM SoC (see ‘Contributions’, below.).

Career opportunities

Free Electrons is looking for a kernel developer in the the French Riviera, to be hired with a permanent contract. The job is open to English speaking people who do not speak French, but are ready to settle in the area of Nice, and be hired through a French contract. See details.

Conferences and contributions

Embedded Linux Conference and Android Builders Summit

Three engineers of Free Electrons attended the Embedded Linux Conference 2012 and Android Builders Summit 2012 in Redwood Shores, near San Francisco in California, on February. This strong participation of our engineers to technical conferences is a key factor to make sure we remain up to date on embedded Linux technologies and keep a close contact with the community.

During the conference, we have published daily reports about the various talks that we thought were interesting:

After the conference, we also posted videos of the talks:

Our scripts to encode videos to the royalty-free VP8 codec and add a title sequence to the videos are now available on on our public git server.

At this conference, our engineer Thomas Petazzoni has given a talk titled “Buildroot, a nice, simple and efficient embedded Linux build system”. Here are the slides and the video.

FOSDEM conference

Two of our engineers participated to the FOSDEM conference, a community-driven open-source conference, in early February.

Our engineer Maxime Ripard gave a talk on his work around the IIO kernel subsystem, which he used to write an ADC driver for the AT91 SoC. Here are the slides.

Our engineer Thomas Petazzoni gave a talk about “Using Qt for non-graphical applications”. Here are the slides.

AT91 Analog-to-Digital converter drivers

Details about the driver for the AT91 Analog-to-Digital converters driver written by Maxime Ripard from Free Electrons have been published on the Atmel Linux4Sam wiki. This driver relies on the IIO framework, and we are in the process of getting this driver merged upstream. See the Atmel Linux4Sam wiki page.

Real-time Linux benchmarks

A report of extensive real-time benchmarks conducted by Gregory Clement from Free Electrons on AT91 platforms has been published on the Atmel Linux4Sam Wiki. This report compares a vanilla Linux kernel, the PREEMPT-RT patches and the Xenomai co-kernel approach through timer-based and GPIO-based benchmarks. See the Atmel Linux4Sam wiki page.

Buildroot

Free Electrons’ involvement in Buildroot is still strong:

  • Maxime Ripard and Thomas Petazzoni participated to the Buildroot Developer Day organized in Brussels before the FOSDEM conference. A report of this meeting, which gathered several other Buildroot developers, is available at the Buildroot mailing list archives.
  • Since the beginning of the year, Thomas Petazzoni has contributed 64 patches that have been merged: support for the LTT-ng Linux tracing solution, support to represent host utilities in the menuconfig, many updates and fixes to external toolchain support and many other fixes.
  • In the same time-frame, Maxime Ripard has contributed 13 patches that have been merged: support for systemd, improvements to the package infrastructure and various fixes.
  • Thomas Petazzoni has implemented a Web interface that publicly shows the result of our random configuration builds, available at http://autobuild.buildroot.org. The Buildroot community is doing random configuration builds 24/7 on three machines, with various configurations. This Web interface collects the build results and sends a summary every day on the Buildroot mailing-list. This has already allowed to fix many build issues, and will help to improve Buildroot’s quality in the future.

Linux kernel course

Participants to our Embedded Linux kernel and driver development course have also started contributing to the Linux kernel sources during the course itself. Here are the patches which have been merged so far:

During our git lab, instead of asking people to make dummy code changes, we ask them to make real improvements to the Linux sources, and send them for real to the right maintainers and mailing lists. This way, people get a better understanding of how they can interact with the Linux kernel developers to merge their changes and contributions.

See our slides and practical lab instructions for our git lectures and lab.

Blog posts

Free Electrons has published several blog posts:

You can follow Free Electrons’ news by reading our blog and by following our quick news on Twitter.

By the way, the right column of the Free Electrons blog now lists the most popular posts and pages. This can help you to find useful content that you may have missed.

Free Electrons remains available to help you in your embedded Linux projects, either through its development and support services or through its training sessions. Do not hesitate to contact us!

Gregory, Maria, Maxime, Michael and Thomas – Free Electrons

Linux kernel engineer job in Nice

Penguin worksFree Electrons is looking for a embedded Linux and kernel engineer in the area of Nice in France (on the French Riviera). The contract will be home based, but will also involve working at customer locations in the same area, possibly for long periods of time.

A detailed job description is available on our careers page.

For this particular job opening, we absolutely need someone with prior experience with kernel and driver development, and contributions to the official Linux kernel sources will be a strong advantage. This is because a customer of ours is looking for an engineer to develop new drivers and port the Linux kernel to pre-silicon and silicon platforms.

Once we find a candidate with the expected skills and profile, and once the customer agrees to contract this person for this initial project, the engineer will be hired by Free Electrons under a permanent contract, and will work on the customer site for at least 6 months.

Once the initial assignment is over, our engineer will continue to work on projects for other Free Electrons customers, and will also give embedded Linux and kernel training sessions to customers throughout the world.

Note that this position is open to people who do not speak French, but are ready to settle in the French Riviera and to be hired through a French contract.

If you are interested in this position, see our job description for details about how to apply.

New quarterly newsletter: 2011 report, best wishes and 2012 plans

The below message has been posted on our English and French newsletters. Don’t hesitate to subscribe to these newsletters if you are interested in getting quarterly news about Free Electrons.

The Free Electrons team wishes you a Happy New Year 2012 and all the best for your professional and personal projects. We are taking this opportunity to give some news about Free Electrons.

In 2011, Free Electrons has:

Worked on multiple development projects for various customers. Amongst the most important ones:

  • development of an embedded Linux system and Qt-based application for a RFID/GSM device based on the AT91 ARM processor
  • boot time reduction on a MIPS-based point-of-sale system, by improving the embedded Linux system integration
  • development of an embedded Linux system for an AT91-based device for the medical field (kernel and bootloader adaptation, system integration, application porting)
  • porting of the PREEMPT_RT patch set to the 2.6.32 kernel delivered by Texas Instruments
  • developed the driver for the Analog to Digital converters built-in the AT91 processors
  • conducted a real-time performance analysis of the PREEMPT_RT and Xenomai solutions on AT91 based processors
  • developed an Ubuntu-based embedded system on a BeagleBoard, for image acquisition and analysis with OpenCV
  • boot time reduction on an i.MX-based device, with major bootloader modifications
  • developed a demonstration system for a racing car control panel on a AT91-based device, with a Qt graphical application

Helped customers solve various embedded Linux related problems, through the support provided by Free Electrons engineers

Contributed to various open-source projects:

  • 167 patches to the Buildroot build system
  • 6 patches to the Linux kernel, and more are coming with the mainlining of our AT91 ADC driver
  • 6 patches to the Barebox bootloader
  • 4 patches to the U-Boot bootloader
  • 3 patches to the LTT-ng project

Given multiple sessions of our Embedded Linux system development and Linux kernel and driver development courses. The materials of these courses are being constantly updated and are still freely available under a Creative Commons license.

Prepared materials for a new Android system development course. A four days training session to understand the Android system architecture, how to build and customize an Android system for a given hardware platform, how to extend the Android platform to take new hardware devices into account. A first public session will be organized in June in Toulouse.

Switched the hardware platform used in our Embedded Linux system development course from the aging Calao USB-A9263 platform (AT91-based) to the much more powerful IGEPv2 platform from ISEE (OMAP3-based), offering more possibilities to improve our course.

Hired a new engineer, Maxime Ripard, with Android and embedded Linux experience, and created a new office in Toulouse, France.

Moved its headquarters to Orange, France. While we remain reasonably close the Nice area, where we started, we get closer to other parts of France.

Given two presentations at the Embedded Linux Conference Europe in Prague (Using Buildroot for real projects and Qt for non-graphical applications), gave one presentation on boot time reduction at the GENIVI meeting in Dublin, and gave five editions of an embedded Linux introduction seminar in France.

Attended multiple conferences, for which the Free Electrons team also recorded and published videos of the talks:

Participated to the development of the community of Linaro, an engineering organization working on improving Linux on the ARM platform. In addition to making sure that Linaro has all the infrastructure required to nurture a community of developers and users, we also supported Linaro release users on AskLinaro.

In 2012, we expect to:

Work on more development projects in the field of kernel porting, boot time reduction, power management and embedded Linux system integration.

Announce several new training sessions:

  • Git training. A two days training session to clearly understand how to use the Git distributed version control system, both for internal projects and for contribution to open-source projects.
  • Advanced Buildroot training. A three days training session to get a clear and detailed understanding of the Buildroot embedded Linux build system: how to add new packages, how to customize it to generate the embedded Linux system for a given hardware platform.

As we are currently preparing those courses, we are definitely interested in having feedback. Do not hesitate to contact us with your ideas and needs about those topics.

Switch our Linux kernel and driver development course to an OMAP3-based platform, and expand it to the development of a driver for an I2C-attached device.

Convert our training materials to a text source format (LaTeX), and maintain them in a public git tree, making it easier to contribute to them and to follow changes between between versions.

Participate to multiple conferences. Free Electrons will be present at the FOSDEM in Brussels in February, at the Android Builders Summit and the Embedded Linux Conference in San Francisco in February, and also at the Embedded Linux Conference Europe in Barcelona in October. This participation to conferences allows Free Electrons engineers to remain up-to-date with the latest developments in the embedded Linux area and to create useful contacts in the community.

You can follow Free Electrons news by reading our blog (24 articles in 2011) and by following our quick news on Twitter.

Free Electrons remains available to help you in your embedded Linux projects, either through its development and support services or through its training sessions. Do not hesitate to contact us!

Best regards, and again, Happy New Year 2012!

Gregory, Maria, Maxime, Michael and Thomas – Free Electrons

Back from Embedded Linux Conference Europe 2011

As we announced in a previous blog post, a large part of the Free Electrons team attended the 2011 edition of the Embedded Linux Conference Europe in Prague last week.

This was the first european edition of the conference to last three days, and this was much appreciated as it gave the opportunity to attend a lot more conferences and to spend more time talking with developers of the community. My colleagues Michael Opdenacker and Maxime Ripard as well as myself really enjoyed this conference. It really allows to connect with members of the community, learn a lot of new things, and bring home a huge motivation to work on various projects. Despite a few marketing-oriented keynotes, the conference has kept its highly-technical profile, which is great.

Prague

We have recorded all the talks of the three tracks of the Embedded Linux Conference Europe (unfortunately, there wasn’t a similar video crew for the LinuxCon Europe conference which was taking place at the same time). Many of those videos should have a much higher audio quality than what we had in the past, since we could capture the audio directly for the conference room sound system. Unfortunately, one of our camcorders generates a loud noise when connected both to the audio system of the conference room and to the power adapter (this noise disappears when the camcorder is on battery). Therefore, not all conferences could be recorded with this improved audio quality. The encoding and upload of those videos has started on Sunday evening, just a few hours after landing in Toulouse when coming back from ELCE. The process is running 24/24 on two machines in parallel, and we therefore hope to be able to provide those videos online by the end of the week, or at worst at the beginning of next week.

Kernel Developer Panel
Kernel Developer Panel. From left to right: Linus Torvalds, Paul McKenney, Alan Cox, Thomas Gleixner and the moderator, Lennart Poettring

As we also announced, I gave two talks at this Embedded Linux Conference Europe event. One on Buildroot, titled Using Buildroot for real projects, which slides are available on the elinux.org site. More than 50 persons attended the conference which seems to indicate that there is interest around Buildroot. I had a few questions but unfortunately had to stop the conference after just 2/3 questions since I had exhausted my time slot. My second conference was titled Qt for non-graphical applications, and the slides are also available on the elinux.org site. About 45-50 persons attended the conference and in this case as well, I had to speak quite fast to make the 40+ slides discussion fit within the time slot allocated for the conference, which gave only the time for a few questions at the end. Generally speaking, these talks have attracted a nice number of attendees compared to many other talks I’ve seen, so it seems that all the preparation work was not done needlessly.

Nicolas Deschene (TI) and Loïc Minier (Linaro)
Nicolas Deschene (TI) and Loïc Minier (Linaro)

If you couldn’t attend ELCE and are waiting for the videos, I’m sure you’ll also be interested by the date and locations of the next editions of the conference :

  • The next Embedded Linux Conference, US edition, will take place on February 14-16 2012 in Redwood City, near San Francisco in California. This is an unusual date for the ELC (which traditionally took place in April), but it allows the conference to match with the Linaro Connect event for the first quarter of 2012.
  • The next Embedded Linux Conference Europe will take place on November 6-9 2012 in Barcelona, Spain. This is a just a ~4h drive from Toulouse, so definitely, several Free Electrons people should be there.

GStreamer 2010 conference videos

Videos from the 2010 edition of the GStreamer conference, Cambridge, UK, Oct. 26, 2010.

After releasing ELC-E videos, here are videos from the 2010 edition of the GStreamer conference. As usual, these videos are released under the terms of the Creative Commons Attribution – ShareAlike Licence version 3.0.

Jonas HolmbergVideo capture
Axis
Case study – GStreamer on Axis devices
Slides
Video (26 minutes):
full HD (223M), 450×800 (72M)

Sebastian DrögeVideo capture
Collabora Multimedia
WebM and GStreamer
Slides
Video (8 minutes):
full HD (75M), 450×800 (24M)

Florent ThieryVideo capture
UbiCast
Using gstreamer for building automated webcasting systems
Slides
Video (31 minutes):
full HD (361M), 450×800 (107M)

Zeeshan AliVideo capture
Nokia
Implementing DLNA using GStreamer
Slides
Video (29 minutes):
full HD (282M), 450×800 (88M)

Olivier CrêteVideo capture
Collabora
Integrating VideoConferencing into Everyday Applications
Slides
Video (29 minutes):
full HD (334M), 450×800 (103M)

Håvard GraffVideo capture
Tandberg
Case study – Tandberg and GStreamer
Video (61 minutes):
full HD (734M), 450×800 (212M)

Wim TaymansVideo capture
Collabora Multimedia
Keynote – GStreamer – Current and future development
Video (47 minutes):
full HD (310M), 450×800 (136M)

Rob ClarkVideo capture
Texas Instruments
GStreamer and OMAP4
Video (37 minutes):
full HD (336M), 450×800 (128M)

Martin BissonVideo capture
3D Stereoscopic and GStreamer
Video (13 minutes):
full HD (124M), 450×800 (39M)

Jan SchmidtVideo capture
Oracle Corporation
Interactivity in GStreamer pipelines
Slides
Video (20 minutes):
full HD (265M), 450×800 (76M)

Mike SmithVideo capture
Songbird
Cross platform development with GStreamer
Video (51 minutes):
full HD (542M), 450×800 (165M)

Emanuele QuacchioVideo capture
ST Microelectronics
A GStreamer based framework for adaptive streaming applications
Video (54 minutes):
full HD (592M), 450×800 (174M)

Josep TorraVideo capture
Fluendo
Intel SMD elements in GStreamer
Slides
Video (50 minutes):
full HD (371M), 450×800 (151M)

Philippe NormandVideo capture
Igalia
Webkit, HTML5 and GStreamer
Slides
Video (38 minutes):
full HD (229M), 450×800 (106M)

Edward HerveyVideo capture
Collabora Multimedia
Challenges of video editing in your pocket
Slides
Video (53 minutes):
full HD (416M), 450×800 (174M)

David SchleefVideo capture
Entropy Wave
Optimizing multimedia with Orc
Slides
Video (58 minutes):
full HD (493M), 450×800 (175M)

Luciana FujiiVideo capture
Holoscopio
Landell – live streaming for the masses
Slides
Video (21 minutes):
full HD (110M), 450×800 (58M)

Zaheer MeraliVideo capture
Flumotion and GStreamer
Video (35 minutes):
full HD (202M)

Andrey Nechypurenko and Maksym ParkachovVideo capture
Adaptive video streaming with Ice and GStreamer
Slides
Video (35 minutes):
full HD (279M), 450×800 (107M)

ELCE 2010 videos – Now in full HD

Videos from the Embedded Linux Conference Europe, Cambridge, UK, October 2010

Just a few weeks before the next edition of the Embedded Linux Conference in San Francisco, here are the videos from the previous edition in Europe a few months ago.

These videos took more time to process than expected, because of intense months on our side, but also because of the switch to the VP8 video codec. VP8 is the new Open Source and royalty free video codec, and is a successor to the codec that Theora was derived from. Unlike Theora which is now lagging behind, it is a very close competitor to H264, both in terms of quality and video size.

The switch to VP8 allowed us to release the videos in their original full HD resolution (we now have three full HD camcorders to shoot conference videos), with video files of about the same size.

You will probably need a recent GNU/Linux distribution (such as Ubuntu 10.10) to watch these videos. As this codec released by Google is taking off quickly, you should also find solutions to watch videos on Windows and MacOS X. Don’t hesitate to post comments here about your experience playing these files. You can even watch them on the Panda board, which can decode VP8 with its hardware video decoder.

As usual, these videos are released under the terms of the Creative Commons Attribution – ShareAlike Licence version 3.0.

As often in conferences, the videos were unfortunately shot is tough lighting conditions. The organizers usually turn off the lights to make it easier for the audience to read the screen. The consequence is a high contrast between the speaker and the screen, causing the speaker to appear very dark when we film her or him together with the screen. In a number of videos, we tried to solve this by using a beach mode provided by our camcorders. While the speaker now looks great, this unfortunately blurred the screen, causing more inconvenience than benefits. We gave up this mode in the last videos and will shoot ELC 2011 is the standard way, even if the speaker looks dark again. At least, with full HD videos, you will be able to read the slides directly on the screen.

The videos from the 2010 GStreamer conference will also be available in the next days, and to help you produce your own videos, we will release our new video processing scripts soon too.

Ruud DerwigVideo capture
Welcome speech
Video (15 minutes):
full HD (228M), 450×800 (71M)

Wolfram SangVideo capture
Pengutronix
Developer’s Diary: Supporting Maintainers
Slides
Video (46 minutes):
full HD (888M)
Rekha Kumar and Nipuna GunasekeraVideo capture
Texas Instruments
Panda board demonstration
Video (14 minutes):
full HD (373M), 450×800 (85M)

Robert SchusterVideo capture
OpenJDK
OpenJDK for Embedded Linux Devices
Slides
Video (39 minutes):
full HD (947M), 450×800 (225M)
Philippe RobinVideo capture
Linaro
Facilitating Open Source Development and Collaboration
Slides
Video (46 minutes):
full HD (548M), 450×800 (160M)
Tim BirdVideo capture
Sony
Android System Programming – Tips and Tricks
Slides
Video (40 minutes):
full HD (471M), 450×800 (142M)
Mischa Jonker and Ruud DerwigVideo capture
Synopsys
Portability is for People Who Cannot Write New Programs – GNU/Linux/OS on ARC
Slides
Video (34 minutes):
full HD (517M), 450×800 (148M)
Leif LindholmVideo capture
ARM
Software Considerations When Using High-Performance Memory Systems
Slides
Video (46 minutes):
full HD (511M), 450×800 (153M)
Ravi Sankar GunturVideo capture
Samsung
A Simple Method to Detect Memory Leaks and Buffer Overruns
Slides
Video (17 minutes):
full HD (171M), 450×800 (55M)
Will NewtonVideo capture
Imagination Technologies
Exploiting On-chip Memories in Embedded Linux Applications
Slides
Video (20 minutes):
full HD (255M), 450×800 (68M)
Andrey FedotovVideo capture
AFSoft
Linux Application in Safety-Critical Environment: A Real-Life Example
Video (39 minutes):
full HD (304M), 450×800 (111M)

Anna DushistovaVideo capture
Mentor Graphics
Eclipse and Embedded Linux Developers: What It Can and What It Cannot Do For You
Slides
Video (31 minutes):
full HD (338M), 450×800 (112M)
Yoshitake KobayashiVideo capture
Toshiba
Linux Kernel Acceleration for Long-term Testing
Slides
Video (30 minutes):
full HD (249M), 450×800 (89M)
Ralf BaechleVideo capture
Wind River
Embedded Linux – The State of the Nation
Video (40 minutes):
full HD (375M), 450×800 (128M)

Jim ZemlinVideo capture
Linux Foundation
The Linux Foundation and CELF
Video (21 minutes):
full HD (282M), 450×800 (71M)

Andrew MurrayVideo capture
MPC Data
The Right Approach to Minimal Boot Times
Slides
Video (41 minutes):
full HD (472M), 450×800 (149M)
Robert Schwebel and Sascha HauerVideo capture
Pengutronix
Barebox: Booting Linux Fast and Fancy
Slides
Video (45 minutes):
full HD (779M), 450×800 (192M)
Kevin HilmanVideo capture
Deep Root Systems
Runtime Power Management
Slides
Video (45 minutes):
full HD (780M), 450×800 (195M)
Michael OpdenackerVideo capture
Free Electrons
Flash Filesystem Benchmarks
Slides
Video (47 minutes):
full HD (937M), 450×800 (229M)
Ari RauchVideo capture
Texas Instruments
The Dynamic Role of Open Linux Architectures in Today’s Mobile Landscape
Slides
Video (34 minutes):
full HD (789M), 450×800 (203M)
Benjamin GaignardVideo capture
ST-Ericsson
Android and GStreamer
Slides
Video (42 minutes):
full HD (432M), 450×800 (133M)
Hans VerkuilVideo capture
Tandberg
Supporting SoC Video Subsystems in Video4linux
Slides
Video (45 minutes):
full HD (424M), 450×800 (139M)
Benjamin ZoresVideo capture
Alcatel-Lucent
State of Multimedia in 2010’s Embedded Linux Devices
Slides
Video (45 minutes):
full HD (784M), 450×800 (219M)
Iago Toral QuirogaVideo capture
Igalia/Grilo
Grilo: Integrating Multimedia Content in Applications
Slides
Video (32 minutes):
full HD (515M), 450×800 (149M)
Jean-Paul SamanVideo capture
M2X BV
Porting VLC to TI DaVinci
Slides
Video (46 minutes):
full HD (516M), 450×800 (167M)
Stefan KostVideo capture
Nokia
Meego Multimedia
Slides
Video (37 minutes):
full HD (316M), 450×800 (105M)
Vitaly WoolVideo capture
Porting Legacy Code to Linux Userspace Driver Framework
Video (26 minutes):
full HD (400M), 450×800 (108M)

Martin MichlmayrVideo capture
Debian
Adapting Debian Installer to NAS and Other Consumer Devices
Slides
Video (21 minutes):
full HD (196M), 450×800 (62M)
Frank ScholzVideo capture
Android and Its Impact On Home Entertainment and Home Automation
Video (28 minutes):
full HD (347M), 450×800 (101M)

WookeyVideo capture
Yaffs
Yaffs updates
Slides
Video (27 minutes):
full HD (312M), 450×800 (95M)
Yann E. MorinVideo capture
Crosstool-ng
Crosstool-NG, A Cross-Toolchain Generator
Slides
Video (41 minutes):
full HD (1.1G), 450×800 (185M)
Armijn HemelVideo capture
Loohuis Consulting
Introducing the Binary Analysis Tool
Slides
Video (47 minutes):
full HD (507M), 450×800 (155M)
Kees-Jan DijkzeulVideo capture
Sioux Embedded Systems
A Gentle Introduction to Autotools
Slides
Video (41 minutes):
full HD (371M), 450×800 (124M)
Klaas Van GendVideo capture
Montavista
Deflating the Virtualization Hype in 3 Simple Steps
Slides
Video (38 minutes):
full HD (507M), 450×800 (131M)
Peter KorsgaardVideo capture
Buildroot
Do More With Less – On Driver-less Interfacing with Embedded Devices
Slides
Video (48 minutes):
full HD (529M), 450×800 (173M)
Ray KinsellaVideo capture
Intel
Xen in Embedded Systems
Slides
Video (34 minutes):
full HD (380M), 450×800 (135M)
Arnout VandecappelleVideo capture
Mind
Practical Testing of Open Source Embedded Systems
Slides
Video (51 minutes):
full HD (364M), 450×800 (160M)
Carmelo Amoroso and Rosario ContarinoVideo capture
STMicroelectronics
Lightweight Prelinker for Kernel Modules
Slides
Video (45 minutes):
full HD (302M), 450×800 (129M)
Frank RowandVideo capture
Sony
Identifying Embedded Real-Time Latency Issues: I-Cache and Locks
Slides
Video (43 minutes):
full HD (272M), 450×800 (120M)
David AndersVideo capture
Texas Instruments
Board Bringup: Methods and Utilities
Slides
Video (34 minutes):
full HD (248M), 450×800 (99M)
John OgnessVideo capture
Linutronix
IPL+UBI: Flexible and Reliable with Linux as the Bootloader
Slides
Video (27 minutes):
full HD (232M), 450×800 (89M)
Vitaly WoolVideo capture
WLAN Chips in Embedded Linux Systems
Video (23 minutes):
full HD (264M), 450×800 (82M)

Grant LikelyVideo capture
Secret Lab Technologies
ARM Flattened Device Tree Status Report
Slides
Video (40 minutes):
full HD (542M), 450×800 (173M)
Koen KooiVideo capture
OpenEmbedded
The State of OpenEmbedded and Tooling to Make Life Easier
Slides
Video (44 minutes):
full HD (308M), 450×800 (122M)
Harald WelteVideo capture
OpenBSC
Running your own GSM+GPRS network using OpenBSC, OsmoSGSN and OpenGGSN
Slides
Video (49 minutes):
full HD (402M), 450×800 (163M)
Arun RaghavanVideo capture
Collabora
PulseAudio In The Embedded World
Slides
Video (30 minutes):
full HD (204M), 450×800 (88M)
Jake EdgeVideo capture
LWN.net
Understanding Threat Models for Embedded Devices
Slides
Video (29 minutes):
full HD (186M), 450×800 (80M)
Gustavo F. PadovanVideo capture
Profusion
The Linux Bluetooth Stack
Slides
Video (30 minutes):
full HD (213M), 450×800 (87M)
Klaas van GendVideo capture
Closing session
Video (62 minutes):
full HD (1.2G), 450×800 (285M)

Chris SimmondsVideo capture
2net
The Embedded Linux Quick Start Guide – Part 1
Slides
Video (52 minutes):
full HD (397M)
Chris SimmondsVideo capture
2net
The Embedded Linux Quick Start Guide – Part 2
Slides
Video (79 minutes):
full HD (660M)
Chris SimmondsVideo capture
2net
The Embedded Linux Quick Start Guide – Part 3
Slides
Video (67 minutes):
full HD (501M)
Chris SimmondsVideo capture
2net
What else can you do with Android? – Part 1
Slides
Video (49 minutes):
full HD (432M), 450×800 (144M)
Chris SimmondsVideo capture
2net
What else can you do with Android? – Part 2
Slides
Video (31 minutes):
full HD (293M), 450×800 (94M)
Chris SimmondsVideo capture
2net
What else can you do with Android? – Part 3
Slides
Video (59 minutes):
full HD (545M), 450×800 (180M)

Here are also videos of the Embedded Linux and Android tutorials by Chris Simmonds.

Linux Kernel Development, third edition

Linux Kernel Development, by Robert Love, 3rd edition

Linux Kernel Development is a book authored by Robert Love, a famous kernel developer. Contrary to the very famous Linux Device Drivers book, Linux Kernel Development is not oriented towards driver development, but instead covers how the core Linux kernel works.

Having this knowledge is not absolutely necessary to write Linux device drivers, but having a good overall understanding of the kernel always help to understand what’s going on in your system, even at the application level. In July this year, the third edition of Linux Kernel Development has been published, which upgrades the book contents to kernel version 2.6.34, a good opportunity to have a new look at the book that Free Electrons received a few weeks ago.

After a quick introduction to the kernel sources (configuring, building, organization of the source tree), the book immediately dives into kernel internals:

  • Process management: how the kernel represents processes and their state, how processes are created inside the kernel, how threads are handled, are processes are terminated.
  • Process scheduling: a full chapter dedicated to the Linux kernel process scheduler. The new CFS scheduler is of course covered in great detail, with large portion of commented source code, for those who want to understand the fine details of the scheduler. Topics such as process sleep/wake-up, preemption, real-time scheduling policies are also covered.
  • System calls are then covered: how they are implemented, how parameters are passed from userspace to the kernel, etc. The call path from your user-space application down to the kernel is well explained in this chapter.
  • Kernel data structures: a generic chapter which details the kernel API for linked lists, queues, maps, and binary trees. Those APIs are omni-present inside the kernel, and it’s therefore a good idea to know how they work, both for understand existing code and for writing new code.
  • Interrupts: how interrupts are handled and how one can write an interrupt handler. Unfortunately, the newly introduced threaded interrupt handlers are not covered, but it’s true that their usage is not yet very widespread inside the mainline kernel.
  • Bottom halves and deferring work, a topic closely related to interrupt handling. It covers bottom halves, softirqs, tasklets and workqueues.
  • Kernel synchronization: two chapters are dedicated to this topic. First a chapter detailing why synchronization is needed, what are the sources of concurrency and what should be protected against concurrent access. And then a chapter detailing the mechanisms provided by the kernel to implement proper synchronization: atomic operations, spin locks, reader-writer spin locks, semaphores, reader-writer semaphores, mutexes, completion variables, sequential locks, preemption disabling, ordering and barriers
  • Timers and time management details how the kernel manages time: ticks, jiffies counter, timers, delaying execution of code are covered in this chapter. There are unfortunately no details about the clocksource and clockevents infrastructure, and no details about how timers and high-resolution timers are implemented. Contrary to other chapters that go fairly deep into the implementation details, this one mostly only covers the API to time management rather than the internals.
  • Memory management is the topic of the following chapter: physical memory management with the page allocator and the physical zones, then the kmalloc, vmalloc and SLAB allocators are covered. High-memory mappings, a topic specific to 32 bits architectures having more than a gigabyte of RAM is also covered in detail. The per-cpu interface is also covered, and will help those who want to understand parts of the kernel that have been optimized for scalability on multiple CPUs.
  • The Virtual Filesystem, with its different objects: superblock, inode, dentry and file is covered in good detail.
  • The block layer is then covered, with a description of the role of the bio structure, the request queues, and the I/O schedulers.
  • Then, the book goes back to more details about the internals of memory management: the mm_struct memory descriptor, the virtual memory areas (so called VMAs) and how they relate with the mmap/munmap system calls. The next chapter continues with a detailed description of the page cache implementation.
  • A fairly strange chapter called “Devices and modules” gives some information about kernel modules (how to build them, how to use module parameters, how dependencies are handled), then covers the internal of the device model (kobjects, ktypes, ksets, krefs) and finally sysfs. Just like the chapter covering the device model in the third edition of Linux Device Drivers, I think it totally misses the point. All the kobject, ktypes, ksets and krefs stuff is very low-level plumbing used by the Linux device model, but it is not exactly what the driver developer needs to interact with in the first place. In my opinion, a good description of the device model should rather explain what struct bus_type, struct driver and struct device are, how they are specialized for the different bus types in pci_driver, pci_device, usb_driver, usb_device, platform_driver, platform_device, and how the registration/probing of drivers and devices is done. I’ve recently given a talk about this topic, the video is in French, but the slides are in English.
  • Debugging is then covered: printk of course, but also oopses, debugging-related kernel options, the magic SysRq key, kernel debuggers, etc.
  • A rather generic chapter about Portability is then proposed, and finally a chapter about Patches, Hacking and the community that details the kernel community, the kernel coding style, how to generate and submit patches, etc.

All in all, Linux Kernel Development remains very good reading. I particularly appreciate the writing style of Robert Love, who manages to make a deeply-technical book interesting and easy to read. Of course, there are some topics in the kernel in which I had to dive myself and for which I’d expect to see more details in this book, but giving every possible detail about a huge beast such as the Linux kernel in just 400 pages is not possible!

Videos from FOSDEM 2010

Peter Korsgaard presenting Buildroot in the Cross build systems workshop at FOSDEM 2010

Like every year, the Free and Open Source Developer European Meeting took place early February in Brussels, and Thomas Petazzoni, from Free Electrons, attended and recorded a few talks from the embedded session. However, contrary to previous years, I haven’t been able to record all talks from the embedded session, since I attended talks from other sessions which were already being recorded by others.

Gian-Carlo Pascutto presenting Embedded software development best practices at FOSDEM 2010

We also attended talks from the X.org and Coreboot developer roooms : videos for the X.org developer room can be found at http://video.fosdem.org/2010/devrooms/xorg/ and videos for the Coreboot developer room can be found at http://video.fosdem.org/2010/devrooms/coreboot/.

ELC 2010 videos

Videos from the Embedded Linux Conference in San Francisco, April 12-14, 2010.

The 2010 edition of the Embedded Linux Conference was once again a very interesting event. For embedded Linux developers, the Embedded Linux Conference is a perfect place to learn about new technologies, profit from the experience of other developers, and to meet key software developers.

For people who couldn’t attend this conference, and for single core people who didn’t manage to attend two or three talks at the same time, here are the videos that we managed to shoot. As usual, the videos are released with a Creative Commons Attribution – ShareAlike 3.0 license.

We hope it makes you feel like joining the next edition of the conference. If you can’t wait, what about going to ELC Europe in Cambridge (UK) in late October? It has a very interesting program too. Of course, the sessions will also be recorded. I hope to see you there!

Recruiting in Toulouse, France

Penguin worksFor the French speaking readers, we are looking for a graduate engineer to open a new office in Toulouse, France.

All the details are available on our French blog.

This job is not only open to French applicants. Everyone ready to relocate in Toulouse is welcome, but we need someone with a good command of the French language. This will be needed to serve local customers.