Tag: contribution

Linux 4.2 released, Bootlin contributions inside

Adelie Penguin
Linus Torvalds has released last sunday the 4.2 release of the Linux kernel. LWN.net covered the merge window of this 4.2 release cycle in 3 parts (part 1, part 2 and part 3), giving a lot of details about the new features and important changes.

In a more recent article, LWN.net published some statistics about the 4.2 development cycle. In those statistics, Bootlin appears as the 10th contributing company by number of patches with 203 patches integrated, and Bootlin engineer Maxime Ripard is in the list of most active developers by changed lines, with 6000+ lines changed. See also this page for more kernel contribution statistics.

This time around, the most important contributions of Bootlin where:

  • Support for Atmel ARM processors:
    • The effort to clean-up the arch/arm/mach-at91/ continued, now that the conversion to the Device Tree and multiplatform is completed. This was mainly done by Alexandre Belloni.
    • Support for the ACME Systems Arietta G25 was added by Alexandre Belloni.
    • Support for the RTC on at91sam9rlek was also added by Alexandre Belloni.
    • Significant improvements were brought to the dmaengine xdmac and hdmac drivers (used on Atmel SAMA5D3 and SAMA5D4), bringing interleaved support, memset support, and better performance for certain use cases. This was done by Maxime Ripard.
  • Support for Marvell Berlin ARM processors:
    • In preparation to the addition of a driver for the ADC, an important refactoring of the reset, clock and pinctrl driver was done by using a regmap and the syscon mechanism to more easily share the common registers used by those drivers. Worked done by Antoine Ténart.
    • An IIO driver for the ADC was contributed, which relies on the syscon and regmap mentioned above, as the ADC uses registers that are mixed with the clock, reset and pinctrl ones.
    • The Device Tree files were relicensed under GPLv2 and X11 licenses.
  • Support for Marvell EBU ARM processors:
    • A completely new driver for the CESA cryptographic engine was contributed by Boris Brezillon. This driver aims at replacing the old mv_cesa drivers, by supporting the newer features of the cryptographic engine available in recent Marvell EBU SoCs (DMA, new ciphers, etc.). The driver is backward compatible with the older processors, so it will be a full replacement for mv_cesa.
    • A big cleanup/verification work was done on the pinctrl drivers for Armada 370, 375, 38x, 39x and XP, leading to a number of fixes to pin definitions. This was done by Thomas Petazzoni.
    • Various fixes were made (suspend/resume improvements, big endian usage, SPI, etc.).
  • Support for the Allwinner ARM processors:
    • Support for the AXP22x PMIC was added by Boris Brezillon, including the support for the regulators provided by this PMIC. This PMIC is used on a significant number of Allwinner designs.
    • A small number of Device Tree files were relicensed under GPLv2 and X11 licenses.
    • A big cleanup of the Device Tree files was done by using more aggressively the “DT label based syntax”
    • A new driver, sunxi_sram, was added to support the SRAM memories available in some Allwinner processors.
  • RTC subsystem:
    • As was announced recently, Bootlin engineer Alexandre Belloni is now the co-maintainer of the RTC subsystem. He has set up a Git repository at https://git.kernel.org/cgit/linux/kernel/git/abelloni/linux.git/ to maintain this subsystem. During the 4.2 release cycle, 46 patches were merged in the drivers/rtc/ directory: 7 were authored by Alexandre, and all other patches (with the exception of two) were merged by Alexandre, and pushed to Linus.

The full details of our contributions:

Linux 4.1 released, Bootlin 17th contributing company

TuxLinus Torvalds recently released the 4.1 Linux kernel, for which LWN.net gave a good description of the major new features: 4.1 Merge window, part 1, 4.1 Merge window, part 2, The 4.1 merge window closes.

As usual, Bootlin engineers contributed to the Linux kernel during this development cycle, though this time with a smaller number of patches: we contributed 118 patches. This time around, Bootlin is the 17th company contributing to this kernel release, by number of patches.

Our major contributions this time around have been:

  • On support for Atmel platforms
    • Alexandre Belloni did a good number of improvements to Atmel SoC support: converting some remaining SoCs to the SoC detection infrastructure, cleaning up the timer driver to use a syscon/regmap, removing a lot of unused headers in arch/arm/mach-at91/, etc. The final and very important change is that the AT91 ARM platform is now part of the multiplatform mechanism: you can build a single zImage for ARMv5 or for ARMv7 which will include support for the ARMv5 or ARMv7 Atmel platforms.
    • Boris Brezillon improved the Atmel DRM/KMS driver for the display controller by switching to atomic mode-setting. He also added Device Tree definitions for the Atmel display controller on Atmel SAMA5D3 and Atmel SAMA5D4.
  • On support for Marvell EBU platforms
    • Ezequiel Garcia enabled the Performance Monitor Unit on Armada 375 and Armada 38x, which allows to use perf on those platforms.
    • Gregory Clement did a number of fixes and minor improvements to support for Marvell EBU platforms.
    • Maxime Ripard enabled the Performance Monitoring Unit on Armada 370/XP, enabling the use of perf on these platforms. He also improved support for the Armada 385 AP board by enabling NAND and USB3 support.
    • Thomas Petazzoni added initial support for the new Marvell Armada 39x platform (clock driver, pinctrl driver, Device Tree). He did some cleanup and fixes in many Device Tree of Marvell EBU platforms and added suspend/resume support in the PCI and pinctrl drivers for these platforms.
  • Other contributions
    • As we posted recently, Alexandre Belloni also became in this release cycle a co-maintainer for the RTC subsystem.
    • Alexandre Belloni added bq27510 support for the bq27x00_battery driver.
    • Maxime Ripard did some small contributions to the dmaengine subsystem, improved the of_touchscreen code and the edt-ft5x06 touchscreen driver, and did some cleanup in the Allwinner sun5i clocksource driver.

For the upcoming 4.2 version, we have 198 patches in linux-next, of which 191 have already been pulled by Linus as part of the 4.2 merge window.

Our complete list of contributions follows:

Buildroot 2015.05 release, Bootlin contributions inside

Buildroot LogoThe Buildroot project has recently released a new version, 2015.05. With exactly 1800 patches, it’s the largest release cycle ever, with patches from more than 100 different contributors. It’s an impressive number, showing the growing popularity of Buildroot as an embedded Linux build system.

The CHANGES file summarizes the most important improvements of this release.

Amongst those 1800 patches, 143 patches were contributed by Bootlin. Our most significant contributions for this release have been:

  • Addition of a package for the wf111 WiFi drivers. They allow to use a WiFi chip from Bluegiga, which is being used in one of our customer projects.
  • Addition of the support for using uClibc-ng. uClibc-ng is a “collaborative” fork of the uClibc project, which aims at doing more regular releases and have better testing. Maintained by Waldemar Brodkorb, the project has already seen several releases since its initial 1.0 release. Waldemar is merging patches from the original uClibc regularly, and adding more fixes. It allows Buildroot and other uClibc users to have well-identified uClibc stable versions instead of a 3 years old 0.9.33.2 version with dozens of patches on top of it. uClibc-ng is not currently used as the default uClibc version as of 2015.05, but it might very well be the case in 2015.08.
  • Important internal changes to the core infrastructure. Until this release, the make legal-info, make source, make external-deps and make source-check logic was relying only on the Buildroot configuration file. This was giving correct results for target packages which all have a corresponding Buildroot configuration option, but not for host packages (which for most of them don’t have Buildroot configuration options). Only a manual two-level dependency handling was done for the host packages for the above mentioned commands. With our work, the handling of those features has been moved to be part of the package infrastructure itself, so it’s using proper make recursivity to resolve the entire dependency tree. Due to this, the results of make legal-info or make external-deps may be longer following this release, but it’s because it’s now actually correct and complete. You can look at the patches for more details, but these changes are very deep into the core Buildroot infrastructure.
  • Large number of build fixes. We contributed 52 patches fixing issues detected by the autobuild infrastructure.
  • Addition of the imx-usb-loader package, which can be used to load over USB a new bootloader on i.MX6 platforms, even if the platform has no bootloader or a broken bootloader. We also use it as part of one of our customer projects.

With 142 patches, Bootlin engineer Thomas Petazzoni is the third contributor to this release by number of patches:

git shortlog -s -n 2015.02..

   397	Bernd Kuhls
   393	Gustavo Zacarias
   142	Thomas Petazzoni

But by far, our most important contribution by far for this release is Thomas acting as the interim maintainer: on the total of 1800 patches merged for this release, Thomas has been the committer of 1446 patches. He has therefore been very active in merging the patches contributed by the Buildroot community.

There are already some very interesting goals set for the Buildroot 2015.08 release, as you can see on the Buildroot release goals page.

Also, if you want to learn Buildroot in details, do not hesitate to look at our Buildroot training course!

Bootlin working on the $9 C.H.I.P. computer

C.H.I.P computer

If you’re following the news about embedded Linux and new cool development platforms, you for sure couldn’t miss the announcement on the world’s first $9 computer. This computer, called C.H.I.P., was started through a crowd-funding campaign on Kickstarter and reception in the Free Software and Open Source community has been very positive. Out of an initial funding goal of $50,000, NextThing Co, the Oakland, California based company creating this product eventually managed to raise more $2,000,000 of funding.

NextThing Co announced their intention to support the platform in the most open way possible: the schematics will be made available, and it will be supported in the mainline Linux kernel.

It turns out that the processor NextThing Co has chosen for this platform is an Allwinner R8 processor. Bootlin has been working since several years on supporting Allwinner processors in the mainline Linux kernel: our engineer Maxime Ripard is the maintainer of the Allwinner SoC support.

Thanks to this long term involvement, Bootlin has been asked by NextThing Co to work with them to support the C.H.I.P. computer in the mainline Linux kernel, and in the process bring some significant improvements to the support of Allwinner processors in the kernel.

C.H.I.P, world first $9 computer

NextThing Co announced recently our collaboration in a blog post on Kickstarter:

We’re incredibly excited to announce that we’ve partnered with one of the premier contributors to ARM Linux: Bootlin! We will be collaborating with their amazing team of ARM Linux engineers, and of course our Kernel Hacker backers to help us test and mainline C.H.I.P.’s kernel modifications as we move forward.

Bootlin is also very excited to be working with NextThing Co on this project! Thanks to this, over the next months, we will have a very substantial amount of time dedicated to this project, and we will regularly push code to support the missing hardware Allwinner SoC hardware blocks in the mainline Linux kernel and to support the C.H.I.P. board.

Pocket C.H.I.P

More details about the C.H.I.P:

  • Availability planned for 2016 for the general public. A selection of 1000 kernel hackers who backed on Kickstarter will have the platform earlier.
  • Very small platform: 40mm x 60mm, making is even smaller than a Raspberry Pi or BeagleBone.
  • Allwinner R8 processor, clocked at 1 Ghz, and offering OpenGL/OpenVG acceleration through an ARM Mali GPU
  • 512 MB of RAM
  • 4GB of on-board NAND flash storage
  • WiFi and Bluetooth 4.0 to connect the system to the outside world
  • One USB host port
  • Powered through a micro USB connector which also supports USB OTG (either USB host or device).
  • Jack connector for composite video out, headphones and microphone input.
  • Many headers to connect external devices (SPI, I2C, UART + 8 GPIOs)
  • Integrated circuit for charging a LiPo battery and being powered by it
  • Additional HDMI or VGA add-on boards will be needed to connect to displays with the corresponding connectivity.

New training course on Buildroot: materials freely available

Buildroot LogoLast year, Bootlin launched a new training course on using the Yocto Project and OpenEmbedded to develop embedded Linux systems. In the selection of build system tools available in the embedded Linux ecosystem, another very popular choice is Buildroot, and we are happy to announce today that we are releasing a new 3 days training course on Buildroot!

Bootlin is a major contributor to the Buildroot upstream project, with more than 2800 patches merged as of May 2015 (including the ones contributed with our previous name). Our engineer Thomas Petazzoni alone has contributed more than 2700 patches. He has gathered an extensive knowledge of Buildroot and its internals, being one of the primary authors of the core infrastructures of Buildroot. He is a major participant to the Buildroot community, organizing the regular Buildroot Developer Days, supporting users through the mailing list and on IRC. Last but not least, Thomas acts as an interim maintainer when the main Buildroot maintainer is not available, an indication of Thomas strong involvement in the Buildroot project.

In addition, Bootlin has used and is using Buildroot in a significant number of customer projects, giving us an excellent view of Buildroot usage for real projects. This feedback has been driving some of our Buildroot contributions over the last years.

The 3 days training we have developed covers all the aspects of Buildroot: basic usage and configuration, understanding the source and build trees, creating new packages including advanced aspects, analyzing the build, tips for organizing your Buildroot work, using Buildroot for application development and more. See the detailed agenda.

buildroot-slidesWe can deliver this training course anywhere in the world, at your location (see our rates and related details). We have also scheduled a first public session in English in Toulouse, France, on November 30 to December 2. Contact us at training@bootlin.com if you are interested.

And finally, last but not least, like we do for all our training sessions, we are making the training materials freely available under a Creative Commons BY-SA license, at the time of the training announcement: the first session of this course is being given this week. For the Buildroot training, the available materials are:

Our materials have already been reviewed by some of the most prominent contributors to Buildroot: Peter Korsgaard (Buildroot maintainer), Yann E. Morin, Thomas De Schampheleire, Gustavo Zacarias and Arnout Vandecappelle. We would like to take this opportunity to thank them for their useful comments and suggestions in the development of this new training course.

2015 Q1 newsletter

The Bootlin team wishes you a Happy New Year for 2015, with plenty of optimism and energy!

Bootlin is happy to take this opportunity to share some news about the latest training and contribution activities of the company.

Kernel contributions

We continue to work significantly on support for various ARM processors in the Linux kernel. Our contributions to the latest kernel releases:

  • 147 patches from Bootlin merged in Linux 3.17, making Bootlin the 14th contributing company for this release by number of patches. See our blog post about this release.
  • 155 patches from Bootlin merged in Linux 3.18, making Bootlin the 14th contributing company. See our blog post for more details.
  • For the upcoming 3.19 release, we already have 196 patches merged.

One of the highlights was that we added support for the Atmel SAMA5D4 SoC to the Linux kernel even before the new chip was announced by Atmel! That’s a very positive sign for customers when an SoC is supported in the mainline Linux kernel sources right at product launch, instead of having to wait for months or years before the community developers can catch up.

Note that we also added Atmel SAMA5D3 SoC support to Xenomai, a hard real-time extension for the Linux kernel. Thanks to this, the Atmel SAMA5D3 Xplained board can now run with the 2.6.x release of Xenomai.

Besides those highlights, most of our kernel contributions were as usual centered around support for specific families of ARM processors: CPUs from Marvell EBU and Marvell Berlin, from Atmel and from Allwinner. We added a new network driver for some Marvell EBU processors, added SMP support for Marvell Berlin processors, added a DMA controller driver for Allwinner processors, and did a lot of maintenance work to support these processors in the mainline kernel.

Buildroot contributions

Our involvement into the Buildroot project, a popular embedded Linux build system, is going on. Our engineer Thomas Petazzoni contributed 136 patches to the 2014.11 release, making him the second contributor by number of patches. Thomas is also taking care of the maintenance of the project on a more regular basis, reviewing and merging patches from contributors.

OpenWRT contributions

We have recently started contributing to the OpenWRT project: improve the kernel support to use defconfig, introduce a notion of board to support different NAND configurations for each platform. We will soon to be pushing support for the Marvell Armada 385 platform, and improved support for the Marvell Armada 370 and XP platforms.

Recent projects

Besides our publicly visible kernel contributions, we do also work on customer-specific projects. Among the latest projects we have done:

  • Develop a complete Board Support Package for a custom TI AM335x based platform: U-Boot porting, Linux kernel porting, and development of a Yocto-generated system. Qt5 and OpenGL are used for the graphical application, a fairly complex audio setup had to be supported, and many traditional interfaces as well (USB Host and Device, CAN, display, etc.)
  • Develop a Board Support Package for a custom Marvell Armada 375 based platform for a telephony system. Not only did we port a Linux kernel on this platform, but we also wrote several DAHDI drivers to interface the telephony hardware of the platform with Asterisk.
  • NAND and UBI stress-testing for a customer-specific Freescale i.MX28 based platform. We improved the NAND controller driver, added a new MTD tool to generate bitflips, and did some long term power-cut stress-testing of the UBIFS setup to ensure the reliability of the platform. See our kernel driver improvements and the new nandflipbits tool.
  • Adapt an existing ADC driver for a customer-specific platform to the modern Industrial Input Output (IIO) subsystem of the kernel.

Conferences: FOSDEM, Embedded World and Embedded Linux Conference

Several Bootlin engineers will participate to the FOSDEM conference, taking place on January 30 and February 1 in Brussels. In addition, Thomas Petazzoni will be participating to the Buildroot Developers Meeting that takes place right after FOSDEM in the Google offices in Brussels.

Bootlin will participate to the Embedded World trade show on February 24-26 in Nuremberg, Germany. We will be present at Atmel’s booth and visiting exhibitor booths too. For people in Europe, this will be a good opportunity to ask your questions about our embedded Linux training and engineering services. In particular, you will be able meet our engineers Alexandre Belloni, Thomas Petazzoni (CTO), Michael Opdenacker (CEO) and Anja Roubin as well, the new person in charge of our training services.

This year again, most of the Bootlin engineering team (7 engineers) will participate to the 2015 edition of the Embedded Linux Conference on March 23-25 in San Jose, California. We submitted several talk proposals, but our presence won’t depend on the number of talks that are eventually accepted. Participating to this conference, and to its European edition in the fall too, is very important for us to make sure we do not miss any of the interesting developments in the technical community, and above all to strengthen our ties with the community developers. This helps us to be good technical trainers with valuable experience and information to share. The strong relationships with other community developers (and in particular with project maintainers) also help us when our customers contract us to add hardware support or features to official versions of community projects such as the Linux kernel.

Free technical documentation resources

Since the latest edition of this newsletter, we started running our new Yocto Project and OpenEmbedded course, and we released all training materials for this course. As usual, such materials are meant to be used by people learning by themselves too. All you have to do is get your hands on a Beaglebone Black board, read the slides and try to do the labs!

Our engineer Maxime Ripard also contributed documentation about the DMAEngine subsystem in the Linux kernel.

Upcoming training sessions – Now in Paris too!

The news is that we will run new public sessions in Paris, in addition to the ones we usually organize in Toulouse, Avignon and Lyon in France. We are starting with our embedded Linux and our Yocto courses, but other topics will follow too.

So, here are our next session dates:

See sessions and dates for more details. Of course, we can also deliver our training courses at your location, anywhere in the world. Feel free to contact us for a quote.

If you are interested in more frequent news about Bootlin, you can follow us on Twitter, Google+ and LinkedIn.

Linux 3.18 released, Bootlin 13th contributing company

PenguinLinus Torvalds has recently released the 3.18 version of the Linux kernel. As usual, LWN.net made an excellent coverage of the merge window: part 1, part 2 and part 3.

As of 3.18-rc6, LWN.net gathered some statistics about the 3.18 kernel contributions, and Bootlin is ranked as the 13th contributing company for this release in number of patches (see the statistics), right after MEV Limited and before Qualcomm.

A quick summary of our contributions:

  • Improvements to the support of Atmel ARM processors: addition of a memory driver for the RAM controller (Alexandre Belloni), improvements to the irqchip driver to support the new SAMA5D4 processor (Alexandre Belloni), updates to the defconfigs (Alexandre Belloni), new clock driver for the SAMA5D4 processor (Alexandre Belloni), preparation work for multi-platform (Boris Brezillon), numerous fixes to clock drivers (Boris Brezillon), NAND driver improvements (Boris Brezillon), new reset and poweroff drivers and moved all the corresponding logic to a Device Tree based description (Maxime Ripard), refactoring of the clocksource driver and move to the proper drivers/clocksource directory (Maxime Ripard).
  • Improvements to the support of Marvell EBU ARM processors: XOR driver improvements (Ezequiel Garcia), pin-muxing description in Device Tree for more platforms (Ezequiel Garcia), support for the RTC on Armada 375 (Grégory Clement), support for the Spread Sprectrum Generator on Armada 370 (Grégory Clement), improvements to the support of the Armada 370 RD platform (Thomas Petazzoni), extensions to the cpufreq-dt driver to support platforms with independent clocks for each CPU, various fixes.
  • Improvements to the support of Marvell Berlin ARM processors: add support for the Ethernet controller by re-using the existing pxa168_eth driver (Antoine Ténart).
  • Improvements to the support of Allwinner ARM processors: addition of the support for a phase property to the Common Clock Framework, and usage in the context of the MMC clock on Allwinner processors (Maxime Ripard).
  • Various small UBI improvements (Ezequiel Garcia).
  • A number of trivial fixes: removal of IRQF_DISABLED, typo fixes, etc. (Michael Opdenacker).

The detailed list of the patches we have contributed:

DMAEngine Documentation: Work (finally) in Progress

While developping a DMA controller driver for the Allwinner A31 SoCs (that eventually got merged in the 3.17 kernel), I’ve realised how under-documented the DMAEngine kernel subsystem was, especially for a newcomer like I was.

After discussing this with a few other kernel developers in the same situation, I finally started to work on such a documentation during the summer, and ended up submitting it at the end of July. As you might expect, it triggered a lot of questions, comments and discussions that enhanced a lot the documentation itself but also pointed out some inconsistencies in the API, obscure areas or just enhancements.

This also triggered an effort to clean up these areas, and hopefully, a lot more will follow, allowing to eventually clean up the framework as a whole.

And the good thing is that this documentation has been merged by the DMAEngine maintainer and is visible in linux-next, feel free to read it, and enhance it!

Yocto Project and OpenEmbedded training materials published

Yocto Project and OpenEmbedded trainingAs we announced in out latest newsletter, we recently launched a new Yocto Project and OpenEmbedded development training course.

The first public session will take place in Toulouse, France on November 18-20 and we still have a few seats available. We can also deliver on-site sessions at the location of your choice, see our Training cost and registration page for more details.

However, what brings us here today is that we are happy to announce the release of all the training materials of this new course: like all Bootlin training materials, they are available under the Creative Commons Attribution Share-Alike license.

Fully committed to its knowledge sharing principles, Bootlin has chosen to publish those materials even before the first session has taken place.

The materials available are:

We of course welcome reviews, feedback and comments about these materials, in order to improve them where needed. Send us your comments!

Bootlin registered as Yocto Project Participant.

Yocto_Project_Badge_Participant_Web_RGB
Earlier this month, Bootlin applied and was elected Yocto Project Participant by the Yocto Project Advisory Board. This badge is awarded to people and companies actively participating to the Yocto Project and promoting it.

We have mainly contributed to the meta-fsl-arm and meta-fsl-arm-extra layers but we also have some contributions in OpenEmbedded Core and in the meta-ti layer.

Bootlin offers a Yocto Project and OpenEmbedded training course that we can deliver at your location, or that you can attend by joining one of our public sessions. Our engineers are also available to provide consulting and development services around the Yocto Project, to help you use this tool for your embedded Linux projects. Do not hesitate to contact us!