Tag: embedded

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 Bootlin, 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!

ELC Europe 2010 sessions announced

List of sessions and speakers at ELC Europe in Cambridge, UK

Cambridge, UKBeing a member of the organization committee of the Embedded Linux Conference Europe, I get access to fresh news about this yearly conference. The call for presentations is now over and we have just announced the list of sessions.

Note that this list is not the final one yet. Some speakers haven’t confirmed their participation or haven’t sent their biographies yet. There are also two or three speakers added at the last minute who are not listed yet.

The conference will happen in Cambridge, UK, on October 27-28, 2010. Keep an eye on the website (or on our blog). Registration should open in a few days from now, and all practical details will be given then.

See also the agenda of the GStreamer conference which will happen at the same location on the day before.

Location of Embedded Linux Conference Europe 2010 announced

Cambridge, UKWhile the American Embedded Linux Conference always takes place in the San Francisco area in California, the European Embedded Linux Conference Europe travels each year in a different country across Europe: it took place in Austria in 2007, in the Netherlands in 2008 and in France in 2009. The location for the 2010 edition of ELCE has been announced recently: it will take place on October 27th and 28th in Cambridge, United Kingdom. As usual there will be many talks, Bird-of-a-Feather sessions, technical demonstrations and more. If you’re an embedded Linux developer in Europe, you should definitely ask your employer to send you to this conference!

Presentations on the following topics are encouraged: audio, video, and graphics systems for embedded products, security, system size, boot-up time, meeting real-time constraints, power management, streaming media, flash memory devices and filesystems, technologies related to cell phones, digital set top boxes, handheld devices, or other CE products, development tools for embedded users, use of Linux in actual products, practical experience and war stories, standards for CE products. The proposal must be received by June, 30th. My colleague Michael Opdenacker, founder of Bootlin, is a member of the program committee.

On the day before, note that there will also be an interesting event: GStreamer Conference 2010. As GStreamer is a key component of today’s multimedia systems based on embedded Linux. Staying in Cambridge for three days instead of two could then make a lot of sense.

Crosstool-NG 1.7.0, Bootlin contributed basic Blackfin support

Yann E. Morin, maintainer of Crosstool-NG, has just announced version 1.7.0 of his toolchain building tool we like so much at Bootlin. For the record, Crosstool-NG allows to build cross-compiling toolchains for a wide-range of architectures, using either glibc, uClibc, eglibc or newlib, and everything is configured through a menuconfig interface, familiar to all embedded Linux developers.

Blackfin architectureBootlin has contributed to this release, by adding some support for the Blackfin architecture, on which we have been working recently. Crosstool-NG is now capable of generating a FDPIC cross-compiling toolchain for Blackfin. FDPIC allows to use shared libraries even on no-MMU architectures like the Blackfin. This support of Blackfin in Crosstool-NG is only the beginning, a lot of work remains to be done to make sure that the toolchain works really well, and to support FLAT binaries and bare-metal as well.

Here are the patches that Bootlin has contributed for this release :

The other major changes for this release are :

  • two new architectures have been added: Blackfin and mips64
  • building canadian-crosses has been enhanced
  • experimental support for gcc-4.5 has been added
  • eglibc can be optimized for size (instead of speed)
  • companion libraries can be built statically, removing the need for a wrapper
  • many components versions have been added, and associated patchsets updated
  • some less important new features, or enhancements for stability and usability
  • a lot of bug-fixes, of which some to help on Darwin & *BSD

The 1.7.0 release can be downloaded at http://ymorin.is-a-geek.org/download/crosstool-ng/crosstool-ng-1.7.0.tar.bz2 and the homepage of the Crosstool-NG project is http://ymorin.is-a-geek.org/projects/crosstool. Enjoy !

New jobs at Bootlin

Penguin worksLooking for kernel and embedded Linux experts

Bootlin is looking for experienced members of the Free Software community to satisfy increasing demand for development, consulting and training on embedded Linux and on the Linux kernel.

One thing that distinguishes our positions from others is that contributing to the community will be part of your objectives.

All the details can be found on our careers page.

ELCE 2009 videos

Videos from the Embedded Linux Conference Europe, Grenoble, October 2009

ELCE 2009Just 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 were shot by Satoru Ueda and Tim Bird (Sony), Ruud Derwig (NXP) and by Thomas Petazzoni and Michael Opdenacker (Bootlin). As usual, they are released under the terms of the Creative Commons Attribution – ShareAlike Licence version 3.0.

Ruud DerwigIf you have never been to an Embedded Linux Conference yet, these videos should show you how useful this conference is for embedded Linux system developers. This is the place where you can discover new development tools and technologies that will change your working life, benefit from the experience from your peers, get the opportunity to talk to the fantastic people who implement the Free and Open Source software that makes your system run, and win cool penguin goodies. So, don’t miss next next edition in San Francisco.

ELC 2010 program announced

Japantown, San FranciscoThe program of talks and BOFs of the 2010 edition of the Embedded Linux Conference has been published a few days ago, an opportunity to look at the most important and interesting conference for embedded Linux developers. For the record, ELC 2010 will take place from April, 12th to April, 14th in San Francisco, CA, USA, in the same place as the 2009 edition.

A nice set of talks

  • A set of real-time related talks: Real-Time Linux Failure, by Frank Rowand (works for Sony, well known for his preempt-rt related talks at various ELC conferences), Effective Use of RT-Preempt, by Kevin Dankwardt, Using Interrupt Threads to Prioritize Interrupts, by Mike Anderson (also well known for his very interactive talks, he will also be giving his traditional Using JTAG to debug Linux device drivers tutorial), Measuring Responsiveness of Linux Kernel on Embedded System, by YungJoon Jung and DongHyouk Lim.
  • A talk by Grant Likely about Flattened Device Tree ARM support update, an effort to convert the ARM architecture to the same organization used in PowerPC, with a device tree file describing the hardware details instead of platform_device definitions in plain C. An important change for anyone doing ARM kernel development.
  • Several power-management related talks: Runtime Power Management: Overview and Platform Implementation, by Kevin Hillman (who works for Deep Root Systems and has done a huge amount of work in the OMAP power management area). Runtime Power Management is probably the most important change done recently to the power management infrastructure of the Linux kernel, so this talk is certainly worth a look, all the more as Kevin is a very good speaker. On power manegement, there will also be other talks : DVFS for the Embedded Linux, by Yong Bon Koo and Youngbin Seo, Wake-ups effect on idle power for Intel’s Moorestown MID and smartphone platform, by German Monroy (Intel), Workload based aggressive Power Management on the Intel Moorestown MID and future Intel MID/Smartphone Platforms, by Sujith Thomas (from Intel).
  • Japan Town, San FranciscoThe usual tracing-related talks, with Using the LTTng tracer for system-wide performance analysis and debugging by Mathieu Desnoyers and Ftrace – embedded edition, by Steven Rostedt. A talk on debugging Linux toolchain overview with advanced debugging and tracing features, by Dominique Toupin.
  • Talks about platforms: a keynote by Greg Kroah Hartmann on Android: a case study of an embedded Linux project (during which Greg will probably explain why the Android kernel modifications are not mainlined), Experiences in Android Porting, Lessons learned, tips and tricks, by Mark Gross and Understanding and Developing Applications for the Maemo Platform, by Leandro Melo de Sales, even though the recent merge of Maemo and Moblin to create MeeGo is likely to change some technical aspects of application development for this platform.
  • The question of multi-core now also seems to be present in embedded conferences: Strategies for Migrating Uniprocessor Code to Multi-Core, by Mike Anderson, Embedded Multi-core with Adeos, Dan Malek, Lock-free algorithm for Multi-core architecture, Hiromasa Kanda. Multi-core Scheduling optimizations for soft real-time multi-threaded applications – A cooperation aware approach, Lucas Martins De Marchi.
  • Some security talks, with Mike Anderson (again !) talking about Creating a Secure Router Using SELinux and Jake Edge about Understanding threat models for embedded devices
  • Some more-or-less multimedia-oriented talks: Supporting SoC video subsystems in video4linux, by Hans Verkuil, An Introduction to the Qt Development Framework, by Jeremy Katz, GeeXboX Enna: embedded Media Center, by Benjamin Zores, Case Study – Embedded Linux in a digital television STB, by Melanie Rhianna Lewis
  • In the other talks, I’ve noted the Small Business Owners BOF by Grant Likely, Evaluation of Data Reliability on Linux File Systems by Yoshitake Kobayashi, Porting the Linux Kernel to x86 MID platforms, by Jacob Pan, Linux without a bootloader? by Greg Ungerer, Kexec – Ready for Embedded Linux by Magnus Damn, Custom hardware modeling for FPGAs and Embedded Linux Platforms with QEMU, by John Williams, Edgar Iglesias.

Both Michael Opdenacker and I will be there at ELC. We hope to meet you during this conference!

Linux 2.6.33 features for embedded systems

Interesting features for embedded Linux system developers

Penguin workerLinux 2.6.33 was out on Feb. 24, 2010, and to incite you to try this new kernel in your embedded Linux products, here are features you could be interested in.

The first news is the availability of the LZO algorithm for kernel and initramfs compression. Linux 2.6.30 already introduced LZMA and BZIP2 compression options, which could significantly reduce the size of the kernel and initramfs images, but at the cost of much increased decompression time. LZO compression is a nice alternative. Though its compression rate is not as good as that of ZLIB (10 to 15% larger files), decompression time is much faster than with other algorithms. See our benchmarks. We reduced boot time by 200 ms on our at91 arm system, and the savings could even increase with bigger kernels.

This feature was implemented by my colleague Albin Tonnerre. It is currently available on x86 and arm (commit, commit, commit, commit), and according to Russell King, the arm maintainer, it should become the default compression option on this platform. This compressor can also be used on mips, thanks to Wu Zhangjin (commit).

For systems lacking RAM resources, a new useful feature is Compcache, which allows to swap application memory to a compressed cache in RAM. In practise, this technique increases the amount of RAM that applications can use. This could allow your embedded system or your netbook to run applications or environments it couldn’t execute before. This technique can also be a worthy alternative to on-disk swap in servers or desktops which do need a swap partition, as access performance is much improved. See this LWN.net article for details.

This new kernel also carries lots of improvements on embedded platforms, especially on the popular TI OMAP platform. In particular, we noticed early support to the IGEPv2 board, a very attractive platform based on the TI OMAP 3530 processor, much better than the Beagle Board for a very similar price. We have started to use it in customer projects, and we hope to contribute to its full support in the mainline kernel.

Another interesting feature of Linux 2.6.33 is the improvements in the capabilities of the perf tool. In particular, perf probe allows to insert Kprobes probes through the command line. Instead of SystemTap, which relied on kernel modules, perf probe now relies on a sysfs interface to pass probes to the kernel. This means that you no longer need a compiler and kernel headers to produce your probes. This made it difficult to port SystemTap to embedded platforms. The arm architecture doesn’t have performance counters in the mainline kernel yet (other architectures do), but patches are available. This carries the promise to be able to use probe tools like SystemTap at last on embedded architectures, all the more if SystemTap gets ported to this new infrastructure.

Other noticeable improvements in this release are the ability to mount ext3 and ext2 filesystems with just an ext4 driver, a lightweight RCU implementation, as well as the ability to change the default blinking cursor that is shown at boot time.

Unfortunately, each kernel release doesn’t only carry good news. Android patches got dropped from this release, because of a lack of interest from Google to maintain them. These are sad news and a threat for Android users who may end up without the ability to use newer kernel features and releases. Let’s hope that Google will once more realize the value of converging with the mainline Linux community. I hope that key contributors that this company employs (Andrew Morton in particular) will help to solve this issue.

As usual, this was just a selection. You will probably find many other interesting features on the Linux Changes page for Linux 2.6.33.

Embedded Linux practical labs with the Beagle Board

Note: the materials for training with the Beagle Board are no longer available, and would be significantly out of date anyway. We advise you to check our Embedded Linux System Development and Linux Kernel and Driver Development training courses for up-to-date instructions that work on cheaper boards, which are still available on the market today. And if you still have an old Beagle board, it will be an interesting exercise to adapt our current labs to run them on such hardware.

We were asked to customize our embedded Linux training session with specific labs on OMAP 3530 hardware. After a successful delivery on the customer site, using Beagle boards, here are our training materials, released as usual under the terms of the Creative Commons Attribution-ShareAlike 3.0 license:

If you are the happy owner of such a board (both attractive and cheap), or are interested in getting one, you can get valuable embedded Linux experience by reading our lecture materials and by taking our practical labs.

Here’s what you would practise with if you decide to take our labs:

  • Build a cross-compiling toolchain with crosstool-NG
  • Compile U-boot and the X-loader and install it on MMC and flash storage.
  • Manipulate Linux kernel sources and apply source patches
  • Configure, compile and boot a Linux kernel for an emulated PC target
  • Configure, cross-compile and boot a Linux kernel on your Beagle Board
  • Build a tiny filesystem from scratch, based on BusyBox, and with a web server interface. Practice with NFS booting.
  • Put your filesystem on MMC storage, replacing NFS. Practice with SquashFS.
  • Put your filesystem on internal NAND flash storage. Practice with JFFS2 too.
  • Manually cross-compile libraries (zlib, libpng, libjpeg, FreeType and DirectFB) and a DirectFB examples, getting familiar with the tricks required to cross-compile components provided by the community.
  • Build the same kind of graphical system automatically with Buildroot.
  • Compile your own application against existing libraries. Debug a target application with strace, ltrace and gdbserver running on the target.
  • Do experiments with the rt-preempt patches. Measure scheduling latency improvements.
  • Implement hotplugging with mdev, BusyBox’s lightweight alternative to udev.

Note that the labs were tested with Rev. C boards, but are also supposed to work fine with Rev. B ones. You may also be able to reuse some of our instructions with other boards with a TI OMAP3 processor.

Of course, if you like the materials, you can also ask your company to order such a training session from us. We will be delighted to come to your place and spend time with you and your colleagues.