Embedded Linux Conference Europe 2009

The 2009 edition of the Embedded Linux Conference Europe (ELCE) was held recently in Grenoble, France. This event, sponsored by the CE Linux Forum (CELF), brought together developers and companies interested in embedded Linux, from throughout Europe and from around the world. Last year's edition was held in the Netherlands, but the conference moves around, and this year the event was held in France. The city of Grenoble is in an impressive setting, surrounded by tall mountains, and is a hub of technical development (locally called the "scientific polygon").

This report describes a few of the talks this year. It's impossible to describe all the different talks at the event in a short summary, but the presentations are being gathered on the CELF wiki. There were presentations on a range of topics, including distributions and build systems, kernel subsystems, features and tools, licensing, power management, bootup time, and many more. Most presentations are already available on the wiki, and the few stragglers should show up within a week or two. I should mention that I'm one of the conference organizers, so you can expect some bias about the event, but overall I think the conference turned out very well.

Jon Masters, a developer at RedHat, started off the conference with a talk about porting Linux to different architectures and platforms. He spoke about the technical challenges involved, and the surprising addition of 2 new architectures to the mainline kernel source tree just this year. He reported that Arnd Bergmann is in the process of writing a new set of asm-generic include files, and trying to rework and clean up a lot of existing architecture code in the kernel (the source files of which have often been copied for new architectures from pre-existing architectures, sometimes correctly and sometimes with bugs.) This work has the potential to make it much easier and less error prone to add new architecture support to the kernel going forward.

Matt Porter, who has been in the embedded Linux domain for many years, gave a very interesting talk about Android. (In fact, his talk was voted by attendees as the best one at the conference.) He titled his talk "Mythbusters: Android", and Matt said he intended to show some of the realities about the system that developers may not expect. He described a lot of the difficulties that he and his team of developers at Mentor Graphics had in porting Android to other processors, and also in supporting existing Linux applications. Android replaces many parts of the system with its own, newly-written software. Things like the init system, the Dalvik virtual machine, and many class libraries are new, and appear to have been written hastily to get the phone products out the door. Also, there are numerous examples of ARM-specific and endian-specific code in the system that were painful to find and fix. Matt said Google needs to do a much better job of interacting with the rest of the open source community.

The next session was another on Android by Nina Wilner of IBM. She works for Power.org, and her talk was on porting Android to PowerPC. She started, however, by talking about the possible upsides of Android, helping to explain why this platform has raised people's expectations. Among other things, she observed that Android might just be to Linux, what Linux was to Unix. In the embedded space, Linux distributions are horribly fragmented, so a strongly supported platform might create a rallying point to unite around and be used to compete against other commercial embedded offerings.

Nina remarked that when Linux arrived on the Unix scene, many people looked at the relatively immature system and asked "why make a new OS?" Although Android may be a bit rough around the edges right now, it is possible that things like marketing clout may overcome its coding quality, and create a common Linux platform that can be used in a variety of embedded products. We'll have to wait to see if that's how things play out in the market or not.

On Thursday evening, there was a social event at the "Bastille", an 18th century fort in the mountains above Grenoble, that now has a cable car, restaurants, and other touristy stuff. The trip in the cable cars was quite interesting, as they consist of "bubbles", which are clear on all sides. This, combined with the steepness of the ascent, was a little more thrilling than most cable car rides. See Wikipedia for more information.

On Friday, the keynote was offered by Philip Gerum, who is the lead maintainer for the Xenomai (realtime framework for Linux) project. He gave a thorough talk about the current state of Xenomai, and realtime support in Linux in general.

Another talk on Friday that I found quite interesting was by Vitaly Wool about recent work on adding "device tree" support for the ARM architecture. The device tree is a structure used to describe platform hardware to the kernel, which can be integrated into a compiled kernel or passed by the bootloader. It was developed for the PowerPC architecture, but has since been used in other architectures as well. There may be some value in pushing it throughout the different kernel architectures in order to simplify device drivers and unify the methods of passing data between firmware and the kernel on bootup. He reported on the different discussions that were held on the kernel mailing list, and the points made by different developers in favor or against adopting this for the ARM architecture.

The conference closed with a game designed to show the "Butterfly Effect of CELF". It was really an excuse for the primary sponsor to talk a little about itself, and a way to hand out prizes to attendees. The game consisted of a physics engine where, in some levels, you added objects and removed obstacles to allow a butterfly to reach its goal. Some humorous moments developed when contestants figured out that the controls allowed manipulating pre-existing level elements (including deleting the obstacles directly). The game is open source, and is still under development, but it is currently available for download at SourceForge.

Free Electrons videotaped all the sessions, and will make them available shortly — once they have time to do some video processing. This is a really nice service to the embedded Linux community. The videos from this event should be available in 4 to 6 weeks, and will be announced when they are ready.

Overall the conference provided a good opportunity for embedded Linux developers in Europe to convene and connect with each other. CELF is planning a similar conference for Europe next year (in addition to its "regular" Embedded Linux Conference which is usually held in the spring in the US.)