Thomas Petazzoni – Page 23

Bootlin working on the $9 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.

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.

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.

Bootlin engineer Alexandre Belloni co-maintainer of Linux Atmel processor support

After becoming the co-maintainer of the Linux RTC subsystem, Bootlin engineer Alexandre Belloni also recently became a co-maintainer for the support of Atmel ARM processors in the Linux kernel.

Bootlin has been working since early 2014 with Atmel to improve support for their processors in the mainline kernel. Since this date, our work has mainly consisted in:

Modernizing existing code for Atmel processors: complete the switch to the Device Tree and the common clock framework for all platforms, rework all that was needed to make Atmel processor support compatible with the ARM multiplatform kernel, and do a lot of related driver and platform refactoring.
Implement a complete DRM/KMS driver for the display subsystem of the most recent Atmel processors.
Upstream support for the Atmel SAMA5D4, the latest Cortex-A5 based SoC from Atmel.

Thanks to this long-term involvement from Alexandre Belloni and Boris Brezillon, Alexandre was appointed as a co-maintainer of Atmel support, replacing Andrew Victor who hasn’t been active in kernel development since quite some time. He is joining Nicolas Ferre and Jean-Christophe Plagniol-Villard in the team of maintainers for the Atmel platform.

Alexandre has sent his first pull request as an Atmel co-maintainer on May 22, sending 9 patches to the ARM SoC maintainers, planned for the 4.2 kernel release. His pull request was quickly merged by ARM SoC maintainer Arnd Bergmann.

Bootlin is proud to have one of its engineers as the maintainer of one very popular embedded Linux platform, which has had since many years a strong commitment of upstream Linux kernel support. Alexandre is the third Bootlin engineer to become an ARM platform maintainer: Maxime Ripard is the maintainer of Allwinner ARM processor support, and Gregory Clement is the co-maintainer of Marvell EBU ARM processor support.

New training course on Buildroot: materials freely available

Last 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.

We 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.

ELC 2015 videos available

The videos from the last Embedded Linux Conference that took place late March in San Jose, California, are now available on Youtube! This represents a lot of interesting and useful content about embedded Linux topics.

You’ll find below the videos of the three talks given by Bootlin engineers at this Embedded Linux Conference.

An Overview of the kernel DMAEngine subsystem, Maxime Ripard

MLC/TLC NAND Support: Challenges for MTD/NAND Subsystem, Boris Brezillon

The Device Tree as a Stable ABI: A Fairy Tale?, Thomas Petazzoni

Bootlin contributes U-Boot support for SECO i.MX6 uQ7 board

Amongst the multiple customer projects we are currently working on that rely on i.MX6 based platforms, one of them is using the SECO i.MX6 µQ7 System on Module as its heart. Unfortunately, the SECO Linux BSP relies on old U-Boot and Linux kernel releases, which we didn’t want to use for this project.

Therefore, Bootlin engineer Boris Brezillon has ported the mainline U-Boot bootloader on this platform, and contributed the corresponding patches. These patches have been merged, and the support for this platform is now part of the 2015.04 U-Boot release. To build it, simply use the secomx6quq7_defconfig configuration.

The work behind these patches was funded by ECA Group.

Bootlin engineer Alexandre Belloni co-maintainer of the Linux RTC subsystem

The Linux RTC subsystem supports the Real Time Clock drivers for a large number of platforms and I2C or SPI based Real Time Clocks: it contains about 140 different device drivers, plus the RTC core itself. The current maintainer, Alessandro Zummo, had unfortunately very little time to address all the patches that were sent, and many of them where usually handled by Andrew Morton, acting as a fallback for various parts of the kernel that are not enough actively maintained.

To address this lack of maintainer time, Bootlin engineer Alexandre Belloni recently became a co-maintainer of the RTC subsystem, as can be seen in this patch to the MAINTAINERS file. Alexandre has already started his work by cleaning up the patchwork instance listing all the pending RTC patches, reducing the number of pending patches from 2843 to 436, actively applying new patches being posted, and reviving old patches that never got any attention.

Up to the 4.1 release included, RTC patches will flow to Linus Torvalds through Andrew Morton, but starting from Linux 4.2, Alexandre will start sending his pull requests directly to Linus.

Linux 4.0 released, Bootlin #7 contributing company

Linus Torvalds has released 4.0 a few days ago, deciding to increment the major number version just because he cannot count up to 20 with his fingers and toes. As usual, LWN gave an excellent coverage of the merge window for 4.0 (which at the time was expected to be called 3.20): first part, second part and third part. LWN also published an article with development statistics about the 4.0 cycle.

According to the statistics, Bootlin is the 7th contributing company in number of patches for the 4.0 cycle.

Here is in detail, all our commits to the Linux 4.0 release:

Embedded Linux Conference 2015 slides from Bootlin

The Bootlin engineering team is back from a busy week at the Embedded Linux Conference 2015 in San Jose, California, last week. During this conference, we presented several talks, a BoF, and participated to the technical showcase with a Buildroot related demo:

Maxime Ripard gave a presentation about the DMAengine subsystem, and his slides are available as PDF.
Thomas Petazzoni gave a talk about The Device Tree as a stable ABI: a fairy tale?, and the slides are available as PDF.
Boris Brezillon gave a talk about MLC/TLC NAND support: (new ?) challenges for the MTD/NAND subsystem, the slides are available as PDF.

Our three talks were all given in front of fully packed rooms, even with a number of people standing in the room for some of them! We were glad to see that the topics we proposed did interest the ELC audience.

Boris Brezillon about support for MLC NAND in MTD

Thomas Petazzoni about Device Tree bindings as a stable ABI. Photo by Drew Fustini.

In addition to the talk, Thomas Petazzoni organized on Tuesday last week a BoF (Birds of a feather) session on Buildroot, during which approximately 15 persons showed up even though it wasn’t announced in the official schedule. This session was useful to get some feedback from Buildroot users, and meet users and developers in person.

Finally, on Tuesday evening, during the technical show-case, we demo-ed the Buildroot capabilities using a setup that consisted in two platforms running Buildroot-generated systems: a Raspberry Pi 2 system that runs the Kodi media player software, and a Marvell Armada XP based OpenBlocks AX3 system that runs as a NAS providing contents for the media player. This demo was prepared by Buildroot contributor Yann E. Morin, and Bootlin engineer Thomas Petazzoni. The poster presented is available as PDF or SVG, and all the instructions to rebuild the two systems are documented at http://elinux.org/Buildroot:TechShowcase2015_Demo.

Buildroot demonstration at ELC 2015 technical show case

In addition, it is worth mentioning that all the slides from the Embedded Linux Conference are available at https://events.linuxfoundation.org/events/archive/2015/embedded-linux-conference/program/schedule and http://elinux.org/ELC_2015_Presentations. The talks have been video recorded by the Linux Foundation, and hopefully unlike to what happened to the ELCE 2014 videos, the ELC 2015 videos will really appear online at some point in the future.

The location of the next Embedded Linux Conference was also announced, and it will take place in San Diego next year. It is the first time that the Embedded Linux Conference US edition moves outside of the Silicon Valley!

Linux 3.19 released, overview of Bootlin contributions

It’s been a while that Linus Torvalds has released Linux 3.19 and we already know that the next version of Linux will be called 4.0. It’s not too late though to learn more about the 3.19 release, by reading the following three LWN articles: part 1, part 2 and part 3. KernelNewbies has also updated its page about 3.19.

In terms of statistics for the 3.19 release cycle, LWN has published an article which ranks Bootlin the 13th contributing company, with 205 patches merged. We have been in the top 30th contributing company by number of patches for all kernel releases since Linux 3.8, a sign of our continuous involvement in the upstream kernel community.

Our most important contributions in this kernel release are:

For the Atmel ARM processors, numerous cleanup patches from Alexandre Belloni to prepare the platform for ARM multiplatform compliance (the possibility of building the support for Atmel ARM processors together with the support of other ARM processors in a single kernel image). From Boris Brezillon, addition of Device Tree support in the AT91 RTC driver, improvements to the AT91 irqchip driver, addition of a PWM driver for the PWM built into the Atmel HLCDC display controller, addition of Device Tree support for the AT91 hardware random number generator driver, addition of an MFD driver for the Atmel HLCDC display controller, and many other Device Tree fixes and improvements.
For the Marvell Berlin ARM processors, addition of USB, SATA and reset controller support. The USB support required numerous core improvements to the USB subsystem, and the addition of a specific USB PHY driver.
For the Marvell EBU ARM processors, Gregory Clement added USB PHY support for Armada 375, and CPU hotplug support for Armada 38x as well as several other fixes and improvements. Thomas Petazzoni added suspend to RAM support for Armada XP, fixed a serious problem in the I2C driver that required some major refactoring, and did some HW I/O coherency related fixes.
For the Allwinner ARM processors, Maxime Ripard did the relicensing of many Device Tree files from GPL only to GPL+X11 licenses. He also added pinctrl support on Allwinner A80.
After writing a dmaengine driver which was merged in 3.17, Maxime Ripard started to get involved in the dmaengine subsystem itself. He contributed a documentation for this subsystem, which was merged in Linux 3.19, as well as several fixes for dmaengine drivers.
Addition of a generic linux/media-bus-format.h header file, containing definitions of the various possible pixel formats. This header file was until then specific to the Video4Linux subsystem, but will start being used by the DRM/KMS subsystem. This addition was done in preparation of the introduction of a DRM/KMS driver for the AT91 HLCDC display controller (to come in Linux 4.0).
A few small improvements to the core DRM/KMS subsystem, also preparation work for the AT91 HLCDC display controller driver.
Fixes for the i.MX28 NAND flash controller driver, the gpmi-nand to properly support the raw access operations, which allow to use the userspace MTD testing utilities to validate the MTD setup. This was part of a customer project we did to assess the quality of the MTD and UBI setup on a Freescale i.MX28 custom platform.

The details of our contributions are:

Embedded Linux Conference schedule announced, several talks from Bootlin

The schedule for the upcoming Embedded Linux Conference, which takes place on March 23-25 in San Jose, has been announced and is available publicly at http://elcabs2015.sched.org/, together with the Android Builders Summit schedule. As usual, there are lots of talks that look very interesting, so we can expect a very useful conference once again.

This time around, there will be three talks given by Bootlin engineers:

Maxime Ripard will give an Overview of the Kernel DMAEngine Subsystem, to which he made some contributions recently, especially the writing of a documentation for it.
Boris Brezillon will talk about MLC/TLC NAND Support: (New?) Challenges for the MTD/NAND Subsystem. Boris is Bootlin MTD and NAND expert. He has recently contributed to the official Linux kernel a driver for the NAND controller available in Allwinner processors, and made some improvements to the NAND controller driver for Freescale i.MX28 processors.
Thomas Petazzoni will talk about The Device Tree as a Stable ABI: A Fairy Tale?, a thought on whether giving the Device Tree the position of a stable ABI is a realistic and useful thing.

So, book your tickets, and join us for the Embedded Linux Conference at the end of March!