Videos of XDC2014 and Kernel Recipes 2014

Recently, two interesting conferences took place in France: the X.org developer conference (in Bordeaux, October 8th-10th) and the Kernel Recipes conference (in Paris, September 25th-26th).

X.org Foundation logo

Kernel Recipes logo

Both conferences have now published videos and slides of the different talks:

  • for the XDC 2014 conference, they are available in the program page
  • for the Kernel Recipes conference, they are available from the schedule page

It also means that the video of the talk given by Bootlin engineer Maxime Ripard about the support for Allwinner processors in the kernel is now available: video, slides.

https://www.youtube.com/watch?v=yJmZkzq651Q

Call for participation for the Embedded Linux Conference 2015

San Jose, CaliforniaThe Embedded Linux Conference Europe is just over that it’s already time to think about the Embedded Linux Conference 2015, which will take place on March 23-25 in San Jose, California.

The call for participation has been published recently, and interested speakers are invited to submit their proposals before January, 9th 2015. The notifications of whether your talk is accepted or not will be sent on January, 16th and the final schedule is planned to be published on January, 23th.

At Bootlin, we really would like to encourage developers who are working on interesting embedded Linux related projects to submit a talk about what they are doing: talking about a specific open-source project, feedback on some experience doing an embedded Linux based product, etc. The scope of topics covered by the Embedded Linux Conference is fairly broad, so do not hesitate to submit a proposal. Giving a talk at this conference is really a great way of getting feedback about what you’re doing, raising awareness about a particular project or issue, and generally meeting other developers interested in similar topics.

It is worth mentioning that for those people whose talk is accepted, the entrance ticket is free. For hobbyists working on their own on open-source projects, the Linux Foundation also has the possibility of funding travel to the conference.

Bootlin team back from ELCE and Linux Plumbers

As we announced in an earlier blog post, the entire Bootlin engineering team was at the Embedded Linux Conference Europe and Linux Plumbers Conference last week in Düsseldorf.

Bootlin engineering team at the Embedded Linux Conference Europe 2014
Bootlin engineering team at the Embedded Linux Conference Europe 2014. From left to right, Grégory Clement, Alexandre Belloni, Maxime Ripard, Antoine Ténart, Thomas Petazzoni, Boris Brezillon and Michael Opdenacker.

In addition to attending many talks, meeting developers of the embedded Linux community and therefore keeping us up-to-date with the most recent developments in this domain, we also gave a number of talks, for which the slides are now available:

Boris Brezillon giving his DRM/KMS talk
Boris Brezillon giving his DRM/KMS talk
Maxime Ripard giving his Allwinner kernel talk
Maxime Ripard giving his Allwinner kernel talk
Thomas Petazzoni giving his Buildroot talk
Thomas Petazzoni giving his Buildroot talk
At the social event, from left to right: Grégory Clement (Bootlin), Kevin Hilman (Linaro), Boris Brezillon (Bootlin), Maxime Ripard (Bootlin)
At the social event, from left to right: Grégory Clement (Bootlin), Kevin Hilman (Linaro), Boris Brezillon (Bootlin), Maxime Ripard (Bootlin)

All the slides of the conference are also available on the event site of the Linux Foundation, and all talks have been video-recorded by the Linux Foundation so hopefully videos should become available in the near future.

Linux 3.17 released, Bootlin 14th contributing company

PenguinLinux 3.17 has been released a few days ago. One can read the coverage of the 3.17 merge window by LWN (part 1 and part 2) to get some details about the new features brought by this kernel release.

As usual, Bootlin has continued to contribute a significant number of patches to this kernel release, even though with 147 patches, our contribution has been less important than for the 3.16 release for which we contributed 388 patches. With 147 patches merged, Bootlin is the 14th contributing company by the number of patches, according to the statistics.

Our contributions remain mainly focused on support for various families of ARM processors:

  • For the Atmel processors
    • Switched to use the generic PWM framework instead of custom PWM drivers. This allowed to remove three obsolete drivers (a backlight driver, a LED driver and a misc driver). This work was done by Alexandre Belloni.
    • Continue the migration to the common clock framework, by adding clock information to a large number of Atmel boards. Done by Alexandre Belloni.
    • Migration of the interrupt controller driver from arch/arm/mach-at91 to drivers/irqchip. Done by Boris Brezillon.
  • For the Marvell EBU processors (Armada 370, 375, 38x, XP)
    • Addition of the mvpp2 network driver, which is used on the Armada 375 SoC. This work was done by Marcin Wojtas from Semihalf, with a lot of review, help and debugging done by Ezequiel Garcia.
    • Addition of cpuidle support for Armada 370 and Armada 38x. This work was done by Grégory Clement and Thomas Petazzoni.
    • Preparation work to enable cpufreq on Armada XP was merged. However the feature cannot be enabled yet due to missing features in the cpufreq-cpu0 driver. Done by Thomas Petazzoni.
  • For Marvell Berlin processors
    • SMP support has been added. Done by Antoine Ténart.
    • Description of the I2C controller has been added to the Device Tree. Done by Antoine Ténart.
    • Support for AHCI has been added. Also done by Antoine Ténart.
  • For Allwinner processors
    • New DMA controller driver for the DMA engine of the Allwinner A31 SoC. Done by Maxime Ripard.
    • A number of fixes and improvements to the pin-muxing driver for Allwinner platforms. Done by Maxime Ripard.
    • Support for the Merrii A31 Hummingbird board has been added. Done by Maxime Ripard.
  • Other changes
    • Addition of a helper function to convert an ONFI timing mode into the according NAND timings. Done by Boris Brezillon.
    • Addition of a driver for the Foxlink FL500WVR00-A0T panel. Done by Boris Brezillon.

The detailed list of our contributions:

Xenomai 2.6.4 released, with Atmel SAMA5D3 support

XenomaiAt the end of September, the Xenomai project has announced the release of version 2.6.4. For the record, Xenomai is a hard real-time extension to the Linux kernel.

Amongst a number of bug fixes and improvements, this new release brings an interesting new feature to which Bootlin contributed: the support for the Atmel SAMA5D3. This means that Xenomai can now be used on platforms such as the Xplained SAMA5D3 and any other SAMA5D3 based platform. This work was done by Xenomai ARM maintainer Gilles Chanteperdrix, thanks to the testing and insights of Bootlin engineer Maxime Ripard.

Mainly, the change needed was to support the AIC5 interrupt controller used in SAMA5D3, which is different from the interrupt controller used on earlier AT91 processors. This change should also provide compatibility with the recently released SAMA5D4, though we haven’t tested this at this time, and Xenomai only provides its patch up to kernel 3.14, while SAMA5D4 support was only recently added to the mainline kernel.

This 2.6.4 Xenomai release also brings support for the 3.14 kernel version, through the corresponding I-Pipe patch.

There are also some other interesting Xenomai news: in early October, they have released the first release candidate of Xenomai 3, the next generation Xenomai architecture. And they also have a brand new and more modern website at xenomai.org.

Bootlin at Kernel Recipes 2014

Kernel RecipesThe Kernel Recipes conference is holding its third edition next week in Paris, on September 25th and 26th. With speakers like Greg Kroah-Hartmann, Hans Peter Anvin, Martin Peres, Hans Verkuil or Jean Delvare and many others, it is going to be a very interesting kernel-oriented conference.

Bootlin will participate to this conference, as our engineer Maxime Ripard will give a talk about Supporting a new ARM platform: the Allwinner example, and Maxime will be attending the event on both days.

Also, Bootlin’sCEO Michael Opdenacker will be attending the conference as well.

A good opportunity to meet Bootlin folks, and discuss business or career opportunities! We are always interested in getting to know more engineers with embedded Linux or Linux kernel knowledge to join our engineering team, so do not hesitate to meet us during the conference, or contact us ahead of time to plan a discussion. If you don’t have a seat yet, unfortunately the conference is fully booked, but meeting in the area is possible too.

Slides from the LinuxCon North America 2014 conference

The LinuxCon North America conference was held a few days ago in Chicago.

LinuxCon North America 2014

A number of slides from the conference have been published. While the conference is a general purpose Linux conference, there were quite a few talks discussed kernel or low-level related topics that may be of interest to embedded Linux developers. Amongst them, we noted:

Not all the slides have been posted yet, so be sure to check the slides page regularly for updates!

Bootlin at the Embedded Linux Conference Europe

DüsseldorfThe Embedded Linux Conference Europe will take place on October 13-15 in Düsseldorf, Germany. As usual, a large part of the Bootlin engineering team will participate to the conference, with no less than 7 engineers: Alexandre Belloni, Boris Brezillon, Grégory Clement, Michael Opdenacker, Thomas Petazzoni, Maxime Ripard and Antoine Ténart.

Several of our talk proposals have been accepted, so we’ll be presenting about the following topics:

In addition to this participation to the Embedded Linux Conference Europe:

  • Many of us will also participate to the Linux Plumbers conference, on October 15-17. It’s another great opportunity to talk about topics around real-time, power management, storage, multimedia, and more.
  • Thomas Petazzoni will participate to the next Buildroot Developers Meeting.

As usual, we’re looking forward to this event! Do not hesitate to get in touch with us if you’re interested in meeting us during these events for specific discussions.

Embedded Linux training update: Atmel Xplained, and more!

Atmel SAMA5D3 Xplained boardWe are happy to announce that we have published a significant update of our Embedded Linux training course. As all our training materials, this update is freely available for everyone, under a Creative Commons (CC-BY-SA) license.

This update brings the following major improvements to the training session:

  • The hardware platform used for all the practical labs is the Atmel SAMA5D3 Xplained platform, a popular platform that features the ARMv7 compatible Atmel SAMA5D3 processor on a board with expansion headers compatible with Arduino shields. The fact that the platform is very well supported by the mainline Linux kernel, and the easy access to a wide range of Arduino shields makes it a very useful prototyping platform for many projects. Of course, as usual, participants to our public training sessions keep their board after the end of the course! Note we continue to support the IGEPv2 board from ISEE for customers who prefer this option.
  • The practical labs that consist in Cross-compiling third party libraries and applications and Working with Buildroot now use a USB audio device connected to the Xplained board on the hardware side, and various audio libraries/applications on the software side. This replaces our previous labs which were using DirectFB as an example of a graphical library used in a system emulated under QEMU. We indeed believe that practical labs on real hardware are much more interesting and exciting.
  • Many updates were made to various software components used in the training session: the toolchain components were all updated and we now use a hard float toolchain, more recent U-Boot and Linux kernel versions are used, etc.

The training materials are available as pre-compiled PDF (slides, labs, agenda), but their source code in also available in our Git repository.

If you are interested in this training session, see the dates of our public training sessions, or order one to be held at your location. Do not hesitate to contact us at training@bootlin.com for further details!

It is worth mentioning that for the purpose of the development of this training session, we did a few contributions to open-source projects:

Thanks a lot to our engineers Maxime Ripard and Alexandre Belloni, who worked on this major update of our training session.

Linux 3.16 released, Bootlin 7th contributing company

Linus Torvalds has released the 3.16 kernel a few weeks ago. Unfortunately, the KernelNewbies LinuxChanges page has not been updated, but LWN.net summaries of the merge window (part 1, part 2 and final part) give a good summary of the important changes available in Linux 3.16.

On Bootlin’sside, 3.16 has been our most active kernel cycle ever: we have merged 388 patches in this cycle, making Bootlin the 7th company contributing to the Linux kernel by number of patches according to the statistics. Bootlin is ranked right after Texas Instruments, and before Novell, Renesas or Google. (Note that the statistics rank Bootlin as 9th, but this includes the “Unknown” and “Hobbyists” categories which are not companies). This strong participation clearly shows Bootlin’sability to get code merged in the mainline Linux kernel, as we’ve progressively done since kernel 3.6 over the last two years.

We are therefore available to help companies willing to add support for their hardware (processor, system-on-chip, module, or board) to the mainline Linux kernel. Do not hesitate to contact to get the discussion started.

Our major contributions have again been focused on the support of various ARM processor families:

  • On the Atmel SoC family
    • Conversion of the SAM9RL processor to the Device Tree. Done by Alexandre Belloni.
    • Huge cleanup of ADC/touchscreen handling: improvements in the IIO at91_adc driver to support more SoC families, and conversions of several Atmel platforms to use this driver, and then finally removal of the old atmel_tsadcc driver. Done by Alexandre Belloni.
    • Numerous fixes to the clock handling on various SoCs, following their conversion to the Common Clock Framework. Done by Alexandre Belloni.
    • Conversion of the SAM9RL, SAM9x5 and SAM9n12 SoCs to the Common Clock Framework. Done by Boris Brezillon.
    • Boris Brezillon is now one of the official maintainers for AT91 clock support.
  • On the Allwinner SoC family
    • Addition of PWM support to sun4i and sun7i. Done by Alexandre Belloni.
    • Addition of SMBus support to the regmap subsystem. This was needed to support the P2WI bus of Allwinner A31. Done by Boris Brezillon.
    • New I2C driver for the P2WI bus of Allwinner A31, used to communicate with the PMIC. Done by Boris Brezillon.
    • Improvements to the Allwinner pinctrl driver needed to support the P2WI bus. Done by Boris Brezillon.
    • Addition of a driver for the PRCM (Power, Reset and Clock Management) unit of the Allwinner A31. Done by Boris Brezillon.
    • Numerous cleanups of the pinctrl driver for Allwinner. Done by Maxime Ripard.
    • Addition of the ARM PMU description in the Device Tree of Allwinner platforms. Done by Maxime Ripard.
    • Add USB support for Allwinner A31. Done by Maxime Ripard, with some help from Boris Brezillon.
    • Various improvements to Allwinner clock drivers. Done by Maxime Ripard.
  • On the Marvell Berlin SoC family
    • Addition of basic Device Tree descriptions for several Marvell Berlin processors and boards. Done by Antoine Ténart.
    • Addition of clock drivers and DT clock descriptions of the Marvell Berlin processors. Done by Alexandre Belloni.
    • Addition of the pinctrl drivers for the Marvell Berlin processors. Done by Antoine Ténart.
    • Enabling of SDHCI and GPIO support on Marvell Berlin. Done by Antoine Ténart.
  • On the Marvell EBU SoC family
    • Addition of watchdog support for Armada 375 and Armada 38x, which required some changes to the existing watchdog driver. Done by Ezequiel Garcia.
    • Addition of thermal support for Armada 375 and Armada 38x, which required some changes in the existing armada_thermal driver. Done by Ezequiel Garcia.
    • Improvements of the pxa3xx_nand driver used for NAND support on Armada 370/375/38x/XP to use the newly introduced ECC strength and step size Device Tree bindings, which allows from the Device Tree to override the ECC constraints described by ONFI, when needed to match the bootloader constraints. Done by Ezequiel Garcia.
    • Addition of a generic software TSO (TCP Segmentation Offload) layer, and the corresponding changes to enable this feature in the mv643xx_eth and mvneta network drivers. This gives a huge performance boost in transmit operations! Done by Ezequiel Garcia.
    • SMP support for Armada 375 and Armada 38x has been added. Done by Grégory Clement.
    • cpuidle support for Armada XP has been added. Done by Grégory Clement.
    • USB support (USB2 and USB3) for Armada 375 and Armada 38x has been added. Done by Grégory Clement.
    • Hardware I/O coherency support for Armada 375 and Armada 38x. Done by Thomas Petazzoni.
    • Enabling of the SDHCI and AHCI interfaces on Armada 38x. Done by Thomas Petazzoni.
    • Major clean-up of Marvell Orion5x support. This is an older ARMv5 family of processors from Marvell, having a lot of similarities with Kirkwood and more recent Armada. This cleanup include many Device Tree conversions, up to the point where a few Marvell Orion5x platforms can now be fully described using a Device Tree, with no board file. Done by Thomas Petazzoni.
    • Addition of a new Device Tree binding for fixed network links, i.e links that do not use a MDIO-controlled PHY. This involved both some generic PHY layer improvements, and corresponding changes in the Marvell-specific mvneta network driver. Done by Thomas Petazzoni.
    • Addition of a work-around for a relatively complex PCIe/L2 errata affecting Armada 375/38x, which fixes heavy PCIe traffic when the system is running with hardware I/O coherency enabled. Done by Thomas Petazzoni.

Here is the complete list of patches from Bootlin merged into the 3.16 kernel: