Tag: linux

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!

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:

Atmel SAMA5D4 support in the mainline Linux kernel

Atmel SAMA5D4Atmel announced its new ARM Cortex-A5-based SoC on October 1, the SAMA5D4. Compared to the previous Cortex-A5 SoC from Atmel, the SAMA5D3, this new version brings a L2 cache, NEON, a slightly different clock tree, a hardware video decoder, and Trustzone support.

Bootlin engineers have worked since several months with Atmel engineers to prepare and submit the support for this new SoC to the mainline Linux kernel. We have actually submitted the patches on September, 11th, almost a month before the official release of the new chip! This means that most of the support for this new SoC will already be part of the upcoming 3.18 kernel release. Meanwhile, it is already possible to test it out by using the linux-next repository.

There are however a few pieces missing pieces to support all aspects of the chip:

  • A few patches are needed to get proper NAND flash controller support.
  • The DMA controller is brand new in this SAMA5D4 SoC, and the DMA controller driver has not yet been merged, even though the patches have been posted a long time ago, and are currently in their sixth iteration.
  • Display support, through a DRM/KMS driver, is also being reviewed. The driver, written by Bootlin engineer Boris Brezillon, was initially designed for the sam9x5 and sam5d3, but will be compatible with sama5d4 as well. The patch series is currently in its seventh iteration.

The last big missing part is support for non-secure mode: for the moment, the system always runs in secure mode. Running the kernel in non-secure mode will require some more work but an initial version will probably be pushed during the next development cycle.

Besides this work on SAMA5D4 support ahead of its public release, Bootlin is also doing a lot of maintenance work on all the Atmel ARM platforms in the Linux kernel: migration to the Device Tree, to the clock framework, to several other new subsystems, etc. See the summary of our kernel contributions to 3.16, 3.15 and 3.14.

Through this work, the Bootlin engineering team has a very deep knowledge of the Linux support for Atmel ARM processors. Do not hesitate to contact us if you need help to bring up the bootloader or kernel on your custom Atmel ARM platform! It is also worth mentioning that Free-Electrons is part of the Atmel partner ecosystem.

2014 Q3 newsletter

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

Kernel contributions

Since our last newsletter, our engineering team continued to make significant contributions to the Linux kernel, especially in the area of supporting ARM processors and platforms:

  • 218 patches from Bootlin were merged into Linux 3.15, making Bootlin the 12th contributing company for this release by number of patches. See our blog post.
  • 388 patches from Bootlin were merged into Linux 3.16, making Bootlin the 7th contributing company for this release, by number of patches. See our blog post.
  • For the upcoming 3.17 release, we already have 146 patches merged, and we have a lot more work being done for future kernel releases.

The major areas of our contributions were:

  • The addition of an ubiblk driver, which allows traditional block filesystems to be used on top of UBI devices, and therefore on NAND flash storage. Only read-only support is available, but it already allows to make use of the super efficient SquashFS filesystem on top of NAND flash in a safe way.
  • Another major addition is support for the new Marvell Armada 375 and Armada 38x processors. In just two releases (3.15 and 3.16) we almost pushed entire support for these new processors. The network driver for Armada 375 is one missing piece, coming in 3.17.
  • Our maintenance work on the Atmel AT91 and SAMA5 processors has continued, with more conversion to the Device Tree, the common clock framework, and other modern kernel mechanisms. We have also developed the DRM/KMS (graphics) driver for the SAMA5D3 SoC, which has already been posted and should hopefully be merged soon.
  • Our work to support the Marvell Berlin processor has started to be merged in 3.16. This processor is used in various TVs, set-top boxes or devices like the Google Chromecast. Basic support was merged including Device Trees, clock drivers, pin-muxing driver, GPIO and SDHCI support. AHCI support will be in 3.17, and USB and network support should be in 3.18.
  • Additional work was done on support for Allwinner ARM SoCs, especially the A31 processor: SPI and I2C support, drivers for the P2WI bus and the PRCM controller, and support for USB.

We now have broad experience in writing kernel drivers and getting code merged into the mainline tree. Do not hesitate to contact us if you need help to develop Linux kernel drivers, or to support a new board or processor.

Buildroot contributions

Our involvement into the Buildroot project, a popular embedded Linux build system, is going on. We have merged 159 patches in the 2014.05 release of the project (total of 1293 patches), and 129 patches in the 2014.08 release of the project (total of 1353 patches). Moreover, our engineer Thomas Petazzoni is regularly an interim maintainer of the project, when the official maintainer Peter Korsgaard is not available. Some of the major features we contributed: major improvements to Python 3 support, addition of EFI bootloaders, addition of support for the Musl C library.

Regular embedded Linux projects

Of course, we also conducted embedded Linux development and boot time optimization projects for various embedded system makers, with less visible impact on community projects. However, we will try to share generic technical experience from such projects through future blog posts.

New training course: Yocto Project and OpenEmbedded

A large number of embedded Linux projects use embedded Linux build systems to integrate the various software components of the system into a working root filesystem image. Among the solutions available to achieve this, the Yocto Project and OpenEmbedded are very popular.

We have therefore launched a new 3 day Yocto Project and OpenEmbedded training course to help engineers and companies who are using, or are interested in using these solutions for their embedded Linux projects. Starting from the basics of understanding the core principles of Yocto, the training course goes into the details of writing package recipes, integrating support for a board into Yocto, creating custom images, and more.

The detailed agenda of the training course is available. You can order this training course at your location, or participate to the first public session organized on November 18-20 in France.

Embedded Linux training course updated

The embedded Linux ecosystem is evolving very quickly, and therefore we are continuously updating our training courses to match the latest developments. As part of this effort, we have recently conducted a major update to our Embedded Linux course: the hardware platform used for the practical labs has been changed to the popular and very interesting Atmel Xplained SAMA5D3, and many practical labs have been improved to provide a more useful learning experience. See our blog post for more details.

Mailing list for training participants

We have launched a new service for the participants to our training sessions: a mailing list dedicated to them, and through which they can ask additional questions after the course, share their experience, get in touch with other training participants and Bootlin engineers. Of course, all Bootlin engineers are on the mailing list and participate to the discussions. Another useful service offered by our training courses!

This resource is no longer available, but participants to our training sessions are still welcome to contact us by e-mail.

Conferences: ELC, ELCE, Kernel Recipes

The Bootlin engineering team will participate to the Embedded Linux Conference Europe and Linux Plumbers, next month in Düsseldorf, Germany. Several Bootlin engineers will also be giving talks during ELCE:

In addition, Thomas will participate to the Buildroot Developers Day, taking place right before the Embedded Linux Conference Europe in Düsseldorf.

See also our blog post about ELCE for more details.

Maxime Ripard and Michael Opdenacker will participate to the Kernel Recipes 2014 conference, on September 25-26 in Paris. Maxime will be giving his Allwinner kernel talk at this conference. See our blog post for more details.

Last but not least, we have recently published the videos of a number of talks from the previous Embedded Linux Conference, held earlier this year in San Jose. A lot of interesting material about embedded Linux! Check out our blog post for more details.

Upcoming training sessions

We have a number of public training sessions dates, with seats available:

Sessions and dates

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.

Videos from Embedded Linux Conference 2014

San Jose, CaliforniaAs the summer is coming to an end, we finally managed to publish the videos we recorded during the last Embedded Linux Conference, held earlier this year in San Jose, California.

This year, the Linux Foundation was only recording the audio of the talks, and we’ve been recording the video only for a few talks. Sorry to all the speakers that won’t be able to see their footage, but we were not able to attend (and record) all of the talks this year. Still, we include below the links to all the talks, slides and their audio recording, in order to cover all of this year’s schedule.

Our videos

Alan OttVideo capture
Signal 11 Software
USB and the Real World
Slides
Audio Recording
Video (49 minutes):
full HD (365M), 800×450 (224M)

Alexandre BelloniVideo capture
Bootlin
Using Yocto for Modules Manufacturers
Slides
Audio Recording
Video (56 minutes):
full HD (421M), 800×450 (224M)

David Anders, Matt RanostayVideo capture
CircuitCo, Intel
Hardware Debugging Tools, Sigrok: Using Logic to Debug Logic
Slides
Audio Recording
Video (42 minutes):
full HD (314M), 800×450 (223M)

David Anders, Matt Porter, Matt Ranostay, Karim YaghmourVideo capture
CircuitCo, Linaro, Intel, Opersys
Debugging – Panel Discussion
Audio Recording
Video (43 minutes):
full HD (322M), 800×450 (228M)

Gregory ClementVideo capture
Bootlin
SMP Bring Up On ARM SOCs
Slides
Audio Recording
Video (48 minutes):
full HD (359M), 800×450 (253M)

Linus WalleijVideo capture
Linaro
Fear and Loathing in the Media Transfer Protocol
Slides
Audio Recording
Video (55 minutes):
full HD (414M), 800×450 (224M)

Martti PiirainenVideo capture
Tieto
Productizing Telephony and Audio in a GNU/Linux (Sailfish OS) Smartphone
Slides
Audio Recording
Video (46 minutes):
full HD (343M), 800×450 (204M)

Matt PorterVideo capture
Linaro
Debugging – Linux Kernel Testing
Audio Recording
Video (47 minutes):
full HD (357M), 800×450 (254M)

Matt PorterVideo capture
Linaro
Kernel USB Gadget Configfs Interface
Slides
Audio Recording
Video (42 minutes):
full HD (317M), 800×450 (224M)

Maxime RipardVideo capture
Bootlin
Supporting a New ARM Platform: The Allwinner SoCs Example
Slides
Audio Recording
Video (48 minutes):
full HD (364M), 800×450 (203M)

Micheal E AndersonVideo capture
The PTR Group, Inc.
Extending Linux using Arduinos
Slides
Audio Recording
Video (57 minutes):
full HD (430M), 800×450 (230M)

Michael OpdenackerVideo capture
Bootlin
Update on Boot Time Reduction Techniques with Figures
Slides
Audio Recording
Video (45 minutes):
full HD (340M), 800×450 (198M)

Thomas PetazzoniVideo capture
Bootlin
Buildroot: What’s New?
Slides
Audio Recording
Video (52 minutes):
full HD (392M), 800×450 (278M)

Thomas PetazzoniVideo capture
Bootlin
Two Years of ARM SoC Support mainlining: Lessons Learned
Slides
Audio Recording
Video (52 minutes):
full HD (388M), 800×450 (221M)

Tomasz FigaVideo capture
Samsung R&D Institute
Trees need care: A Solution to Device Tree Validation Problem
Slides
Audio Recording
Video (50 minutes):
full HD (377M), 800×450 (234M)

Tristan LelongVideo capture
Adeneo Embedded
Linux Quickboot
Slides
Audio Recording
Video (54 minutes):
full HD (406M), 800×450 (288M)

Other talks

Adrian Perez de Castro
Igalia
Improving Performance Of A WebKit Port MIPS Platform
Slides
Audio Recording

Adrien Verge
Ecole Polytechnique Montreal
Hardware-Assisted Software Tracing
Slides
Audio Recording

Behan Webster
Converse in Code Inc.
LLVMLinux: Embracing the Dragon
Slides
Audio Recording

Belen Barros Pena
Intel’s Open Source Technology Center
Building Tools From the Outside In: Bringing User-Centered Design to Embedded Linux
Slides
Audio Recording

Bradley M. Kuhn
Software Freedom Conservancy
Collaborative GPL Enforcement Through Non-Profit Entities
Slides
Audio Recording

Joe Kontur
Panasonic
CE Workgroup (BoFs)
Audio Recording

Chase Maupin
Texas Instruments
Using Agile Development Practices For Kernel Development
Audio Recording

Chris Simmonds
2net
A Timeline For Embedded Linux
Audio Recording

David Anders, Tim Bird, Matt Porter, Benjamin Zores, Karim Yaghmour
CircuitCo, Sony Mobile, Linaro, Alcatel-Lucent, OperSys
Keynote Panel: IoT and the Role of Embedded Linux and Android
Audio Recording

David Greaves
Mer Project
The #qt/#wayland/#systemd/#btrfs-phone … the Jolla phone
Slides
Audio Recording

Denys Dmytriyenko
Texas Instruments
Qt5 & Yocto – adding SDK and easy app migration from Qt4
Slides
Audio Recording

Gabriel Huau
Adeneo Embedded
Hardware Accelerated Video Streaming with V4L2
Slides
Audio Recording

Geert Uytterhoeven
Glider bvba
Engaging Device Trees
Slides
Audio Recording

Hans Verkuil
Cisco Systems Norway
An Introduction to the Video4Linux Framework
Slides
Audio Recording

Hisao Munakata, Tsugikazu Shibata
Renesas Electronics, NEC
LTSI Project Update for 3.10 Kernel and Future Plan
Audio Recording

Insop Song
Gainspeed
Can A Board Bringing Up Be Less Painful, if with Yocto and Linux?
Slides
Audio Recording

Iyad Qumei
LG Electronics
webOS, An Openembedded Use Case
Slides
Audio Recording

Jeff Osier-Mixon
Intel Corporation
Yocto Project / OpenEmbedded BoF
Audio Recording

Josh Cartwright
Qualcomm Innovation Center
System Power Management Interface (SPMI)
Audio Recording

Khem Raj
Juniper Networks
(Tutorial) Some GCC Optimizations for Embedded Software
Slides
Audio Recording

Laurent Pinchart
Renesas Linux Kernel Team
Mastering the DMA and IOMMU APIs
Slides
Audio Recording

John ‘Warthog9’ Hawley, Nitin Kamble
Intel
Making a Splash: Digital Signage Powered by MinnowBoard and the Yocto Project
Slides
Audio Recording

Mark Brown
Linaro
What’s going on with SPI
Audio Recording

Mark Skarpness
Intel
Keynote: Scaling Android at the Speed of Mobility
Audio Recording

Marta Rybczynska
Kalray
Porting Linux to a New Architecture
Slides
Audio Recording

Michael Christofferson
Enea
User Space Drivers in Linux ? Pros, Cons, and Implementation Issues
Audio Recording

Michael E Anderson
The PTR Group, Inc.
How to Build a Linux-Based Robot
Slides
Audio Recording

Minchan Kim
LG Electronics
Volatile Ranges
Audio Recording

Tim Bird
Sony Mobile
(BoFs) QCOM SoC Mainlining
Audio Recording

Patrick Titiano
BayLibre
Use-Case Power Management Optimization: Identifying & Tracking Key Power Indicators
Slides
Audio Recording

Philip Balister
OpenSDR
Open-Source Tools for Software-Defined Radio on Multicore ARM+DSP
Slides
Audio Recording

Ricardo Salveti de Araujo
Ubuntu Touch low level stack
Ubuntu Touch Internals
Slides
Audio Recording

Thomas Petazzoni
Bootlin
Device Tree for Dummies
Slides
Audio Recording

Tim Bird
Sony Mobile
Keynote: The Paradox of embedded and Open Source
Slides
Audio Recording

Tom Zanussi
Intel’s Open Source Technology Center
MicroYocto and the ‘Internet of Tiny’
Slides
Audio Recording

Victor Rodriguez
Intel
Introducing Embedded Linux to Universities
Slides
Audio Recording

Vitaly Wool
Softprise Consulting OU
Linux for Microcontrollers: Spreading the Disease
Slides
Audio Recording

Wolfgang Mauerer
Siemens
Understanding the Embedded Linux Ecosystem with Codeface
Slides
Audio Recording

Yoshitake Kobayashi
Toshiba
Using Real-Time Patch with LTSI Kernel
Slides
Audio Recording

Embedded Linux Development with Yocto Project

Embedded Linux Development with Yocto Project Cover

We were kindly provided a copy of Embedded Linux Development with Yocto Project, written by Otavio Salvador and Daiane Angolini. It is available at Packt Publishing, either in an electronic format (DRM free) or printed.

This book will help you start with your embedded system development and integration using the Yocto Project or OpenEmbedded.

The first chapter sheds some light on the meaning of commonly misused names: Yocto Project, Poky, OpenEmbedded, BitBake. Then, it doesn’t waste time and explains how to install and use Poky to build and then run an image. The entire book is full of examples that can easily be tested, providing useful hands-on experience, using Yocto Project 1.6 (Poky 11).

The following chapters cover:

  • Hob: a user friendly interface, however, it will soon be deprecated and replaced by Toaster.
  • BitBake and Metadata: how to use BitBake, how to write recipes for packages or images, how to extend existing recipes, how to write new classes, how to create a layer, where to find existing layers and use them.
  • The build directory layout: what the generated files are, and what their use is.
  • Packaging: how to generate different package formats, how to handle a package feed and the package versions.
  • The various SDKs that can be generated and their integration in Eclipse.
  • Debugging the metadata: what the common issues are, how to find what is going wrong, and solving these issues.
  • Debugging the applications on the target: how to generate an image with debugging tools installed.
  • Available tools to help achieve copyleft compliance: in particular, how to cope with the GPL requirements.

Finally, there is a chapter dedicated to explaining how to generate and run an image on the Wandboard, an i.MX6 based community board.

The book is easy to read, with plenty of examples and useful tips. It requires some knowledge about generic embedded Linux system development (see our training) as only the Yocto Project specifics are covered. I would recommend it both for beginners wanting to learn about the Yocto Project and for developers wanting to improve their current knowledge and their recipes and also understand the BitBake internals.

Speaking of the Yocto Project, it is worth noting that Bootlin is now offering a Yocto Project and OpenEmbedded training course (detailed agenda). If you’re interested, join one of the upcoming public training sessions, or order a session at your location!