Tag: development

Covid-19: Bootlin proposes online sessions for all its courses

Tux working on embedded Linux on a couchLike most of us, due to the Covid-19 epidemic, you may be forced to work from home. To take advantage from this time confined at home, we are now proposing all our training courses as online seminars. You can then benefit from the contents and quality of Bootlin training sessions, without leaving the comfort and safety of your home. During our online seminars, our instructors will alternate between presentations and practical demonstrations, executing the instructions of our practical labs.

At any time, participants will be able to ask questions.

We can propose such remote training both through public online sessions, open to individual registration, as well as dedicated online sessions, for participants from the same company.

Public online sessions

We’re trying to propose time slots that should be manageable from Europe, Middle East, Africa and at least for the East Coast of North America. All such sessions will be taught in English. As usual with all our sessions, all our training materials (lectures and lab instructions) are freely available from the pages describing our courses.

Our Embedded Linux and Linux kernel courses are delivered over 7 half days of 4 hours each, while our Yocto Project, Buildroot and Linux Graphics courses are delivered over 4 half days. For our embedded Linux and Yocto Project courses, we propose an additional date in case some extra time is needed to complete the agenda.

Here are all the available sessions. If the situation lasts longer, we will create new sessions as needed:

Type Dates Time Duration Expected trainer Cost and registration
Embedded Linux (agenda) Sep. 28, 29, 30, Oct. 1, 2, 5, 6 2020. 17:00 – 21:00 (Paris), 8:00 – 12:00 (San Francisco) 28 h Michael Opdenacker 829 EUR + VAT* (register)
Embedded Linux (agenda) Nov. 2, 3, 4, 5, 6, 9, 10, 12, 2020. 14:00 – 18:00 (Paris), 8:00 – 12:00 (New York) 28 h Michael Opdenacker 829 EUR + VAT* (register)
Linux kernel (agenda) Nov. 16, 17, 18, 19, 23, 24, 25, 26 14:00 – 18:00 (Paris time) 28 h Alexandre Belloni 829 EUR + VAT* (register)
Yocto Project (agenda) Nov. 30, Dec. 1, 2, 3, 4, 2020 14:00 – 18:00 (Paris time) 16 h Maxime Chevallier 519 EUR + VAT* (register)
Buildroot (agenda) Dec. 7, 8, 9, 10, and 11, 2020 14:00 – 18:00 (Paris time) 16 h Thomas Petazzoni 519 EUR + VAT* (register)
Linux Graphics (agenda) Dec. 1, 2, 3, 4, 2020 14:00 – 18:00 (Paris time) 16 h Paul Kocialkowski 519 EUR + VAT* (register

* VAT: applies to businesses in France and to individuals from all countries. Businesses in the European Union won’t be charged VAT only if they provide valid company information and VAT number to Evenbrite at registration time. For businesses in other countries, we should be able to grant them a VAT refund, provided they send us a proof of company incorporation before the end of the session.

Each public session will be confirmed once there are at least 6 participants. If the minimum number of participants is not reached, Bootlin will propose new dates or a full refund (including Eventbrite fees) if no new date works for the participant.

We guarantee that the maximum number of participants will be 12.

Dedicated online sessions

If you have enough people to train, such dedicated sessions can be a worthy alternative to public ones:

  • Flexible dates and daily durations, corresponding to the availability of your teams.
  • Confidentiality: freedom to ask questions that are related to your company’s projects and plans.
  • If time left, possibility to have knowledge sharing time with the instructor, that could go beyond the scope of the training course.
  • Language: possibility to have a session in French instead of in English.

Online seminar details

Each session will be given through Jitsi Meet, a Free Software solution that we are trying to promote. As a backup solution, we will also be able to Google Hangouts Meet. Each participant should have her or his own connection and computer (with webcam and microphone) and if possible headsets, to avoid echo issues between audio input and output. This is probably the best solution to allow each participant to ask questions and write comments in the chat window. We also support people connecting from the same conference room with suitable equipment.

Each participant is asked to connect 15 minutes before the session starts, to make sure her or his setup works (instructions will be sent before the event).

How to register

For online public sessions, use the EventBrite links in the above list of sessions to register one or several individuals.

To register an entire group (for dedicated sessions), please contact training@bootlin.com and tell us the type of session you are interested in. We will then send you a registration form to collect all the details we need to send you a quote.

You can also ask all your questions by calling +33 484 258 097.

Questions and answers

Q : Should I order hardware in advance, our hardware included in the training cost?
R : No, practical labs are replaced by technical demonstrations, so you will be able to follow the course without any hardware. However, you can still order the hardware by checking the “Shopping list” pages of presentation materials for each session. This way, between each session, you will be able to replay by yourself the labs demonstrated by your trainer, ask all your questions, and get help between sessions through our dedicated Matrix channel to reach your goals.

Q: Why just demos instead of practicing with real hardware?
A: We are not ready to support a sufficient number of participants doing practical labs remotely with real hardware. This is more complicated and time consuming than in real life. Hence, what we we’re proposing is to replace practical labs with practical demonstrations shown by the instructor. The instructor will go through the normal practical labs with the standard hardware that we’re using.

Q: Would it be possible to run practical labs on the QEMU emulator?
R: Yes, it’s coming. In the embedded Linux course, we are already offering instructions to run most practical labs on QEMU between the sessions, before the practical demos performed by the trainer. We should also be able to propose such instructions for our Yocto Project and Buildroot training courses in the next months. Such work is likely to take more time for our Linux kernel course, practical labs being closer to the hardware that we use.

Q: Why proposing half days instead of full days?
A: From our experience, it’s very difficult to stay focused on a new technical topic for an entire day without having periodic moments when you are active (which happens in our public and on-site sessions, in which we interleave lectures and practical labs). Hence, we believe that daily slots of 4 hours (with a small break in the middle) is a good solution, also leaving extra time for following up your normal work.

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

Atmel SAMA5After 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.

Embedded Linux Projects Using Yocto Project Cookbook

Embedded Linux Projects Using Yocto Project Cookbook Cover

We were kindly provided a copy of Embedded Linux Projects Using Yocto Project Cookbook, written by Alex González. It is available at Packt Publishing, either in an electronic format (DRM free) or printed.

It is written as a cookbook so it is a set of recipes that you can refer to and solve your immediate problems instead of reading it from cover to cover. While, as indicated by the title, the main topic is embedded development using Yocto Project, the book also includes generic embedded Linux tips, like debugging the kernel with ftrace or debugging a device tree from U-Boot.

The chapters cover the following topics:

  • The Build System: an introduction to Yocto Project.
  • The BSP Layer: how to build and customize the bootloader and the Linux kernel, plenty of tips on how to debug kernel related issues.
  • The Software layer: covers adding a package and its configuration, selecting the initialization manager and making a release while complying with the various licenses.
  • Application development: using the SDK, various IDEs (Eclipse, Qt creator), build systems (make, CMake, SCons).
  • Debugging, Tracing and Profiling: great examples and tips for the usage of gdb, strace, perf, systemtap, OProfile, LTTng and blktrace.

The structure of the book makes it is easy to find the answers you are looking for and also explains the underlying concepts of the solution. It is definitively of good value once you start using Yocto Project.

Bootlin is also offering a Yocto Project and OpenEmbedded training course (detailed agenda) to help you start with your projects. If you’re interested, join one of the upcoming public training sessions, or order a session at your location!

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!

ELCE 2012 slides: porting Linux to new ARM SoC

We are just returning from Barcelona, Spain, after participating to the 2012 edition of the Embedded Linux Conference Europe. My colleague Thomas Petazzoni has delivered the below presentation:

Your New ARM SoC Linux Support Check-List

Since Linus Torvalds raised warnings about the state of the ARM architecture support in the Linux kernel, a huge amount of effort and reorganization has happened in the way Linux supports ARM SoCs. From the addition of the device tree to the pinctrl subsystem, from the new clock framework to the new rules in code organization and design, the changes have been significant over the last one and half year in theARM Linux kernel world.

Based on the speaker’s experience on getting the new Marvell Armada 370 and Armada XP SoC supported in the mainline Linux kernel, we will give an overview of those changes and summarize the new rules for ARM Linux support. We aim at helping developers willing to add suppot for new ARM SoCs in the Linux kernel by providing a check-list of things to do.

Thomas Petazzoni is an embedded Linux engineer and trainer at Bootlin since 2008. He has been involved with multiple projects around the Linux kernel, especially the mainlining of Marvell Armada 370/XP SoCs support. He is also a major contributor to the Buildroot embedded Linux build system with more than 1100 patches merged.

The presentation slides and their sources are now available here. We have also shot a video of Thomas’ talk and it should be available in the next weeks. Stay tuned!

Do not hesitate to contact us if you are looking for engineers to port Linux to new hardware.

Buildroot Developer Day, Brussels edition

BuildrootAround each FOSDEM conference and Embedded Linux Conference Europe event, we have been organizing a Buildroot Developer Day for a few years, in order to gather some developers and users of the Buildroot build system, in order to discuss the development of Buildroot, its features, development process, design, and more.

In Prague at the last Embedded Linux Conference Europe in October 2011, we had a very interesting meeting that gathered developers from other build systems (OE-lite, OpenBricks and PXTdist), and we published a report of this meeting.

The next Buildroot Developer Day will take place on Friday, 3rd February, just before the FOSDEM conference, in Brussels. This is the first meeting that will gather such a number of Buildroot developers: Peter Korsgaard (Buildroot maintainer), Arnout Vandecapelle (developer from Essensium/Mind, who has been contributing a lot to Buildroot lately), Thomas De Schampheleire (also a big contributor in the last year or so), Luca Ceresoli, Yann E. Morin (developer of Crosstool-NG), my colleague Maxime Ripard (who contributed package enhancements and improvements of the package infrastructure) and myself.

This meeting is open to all Buildroot developers and users, and will take place in a location easily accessible in the center of Brussels. Do not hesitate to contact me at thomas.petazzoni@bootlin.com if you want to take part to this meeting.

Buildroot 2010.08 released!

Buildroot logoOn the last day of August, just in time, the 2010.08 version of Buildroot has been released. For the record, Buildroot is an easy-to-use embedded Linux build system: it can build your toolchain, your root filesystem with all its components (Busybox, libraries, applications, etc.), your kernel and your bootloaders, or any combination of these components.

Amongst the interesting changes in this version :

  • Complete rewrite of the bootloader build code. It contained a lot of legacy, unused and unclear stuff, it is now much easier to use and extend. We’ve removed support for Yaboot and added support for the new Barebox bootloader, and all the code to support AT91Bootstrap, AT91DataFlashBoot, U-Boot, Grub and Grub 2 has been rewritten.
  • Complete rewrite of the Linux kernel build code. It was also complicated to use, with an horribly complicated kernel version selection mechanism, the new code is much easier to configure and use.
  • The configuration file .config is now located in the out-of-tree directory when the O= option is used. So typically, for an out-of-tree build (which are very convenient when using the same Buildroot source tree for different projects/tests), you could do : mkdir ~/myoutput ; make O=~/myoutput menuconfig ; make O=~/myoutput
  • Support for building NPTL toolchains with uClibc, using the latest uClibc snapshots.
  • Support for the gconfig Gtk-based configurator, in addition to the already available menuconfig and xconfig
  • A particular effort has been put on fixing many of the bugs in our Bugzilla, improving robustness thanks to automated random builds, and converting even more packages to the generic and autotools infrastructure
  • Various things have also been deprecated: support for the CRIS, IA64, Sparc64 and Alpha architectures, support for Gtk over DirectFB (which is at the moment not supported upstream), Java support (no maintainer has volunteered to maintain this in Buildroot)
  • Many components have been bumped to newer versions
  • The shared configuration cache, which allowed to speed up the configuration of different packages, has been disabled by default, since it was causing a lot of problems with certain package configurations

I’ve again contributed to a significant portion of this release, being the author of the bootloader build code cleanup, the Linux kernel build code rewrite, leading an effort to reduce the number of outstanding bugs in our Bugzilla and many other little things. The contributors for this release are shown below :

   175  Peter Korsgaard
   168  Thomas Petazzoni
    38  Gustavo Zacarias
    18  cmchao
     8  Luca Ceresoli
     7  Paul Jones
     6  Lionel Landwerlin
     6  Malte Starostik
     5  Yann E. MORIN
     3  Julien Boibessot
     3  Khem Raj
     2  Dmytro Milinevskyy
     2  Francois Perrad
     2  Nick Leverton
     2  Peter Huewe
     2  Stanislav Bogatyrev
     1  Baruch Siach
     1  Bjørn Forsman
     1  Daniel Hobi
     1  Darcy Watkins
     1  Darius Augulis
     1  H Hartley Sweeten
     1  Karl Krach
     1  Kelvin Cheung
     1  Ossy
     1  Sagaert Johan
     1  Simon Pasch
     1  Slava Zanko
     1  Thiago A. Correa
     1  Will Wagner
     1  Yegor Yefremov

For the next release, there are already a few things in the pipeline :

  • Cleanup of all the board support code in Buildroot, in order to cleanly add support for more boards like BeagleBoard, Qemu boards, Calao boards, etc. We’ll use the new minimal defconfig mechanism used by the kernel. I’ve already started working on this
  • Cleanup of the package download process, to support Git and SVN download. The code has already been written by Maxime Petazzoni, reviewed on the list, so I expect it to be included fairly soon
  • Rewrite of libtool handling code, to remove some of our ugly libtool hacks. The code is currently being worked on by Lionel Landwerlin
  • Support for compiling toolchain using Crosstool-NG as a backend. The code is currently being finalized by Yann E. Morin, the author of Crosstool-NG
  • Further work on package uninstallation, clean partial rebuild. Some work has been started by Lionel Landwerlin, but it needs some discussion
  • Continue the conversion of packages to the generic and autotools infrastructures
  • I have also a ton of other things on my TODO-list : rework gdb/gdbserver support with external toolchains, rework the configuration of IPv6/RPC/locale/etc. with external toolchains, set up a Wiki-based Buildroot website with tutorials and better documentation, clean up the toolchain build process, reduce the number of “enhancement” bugs waiting in our Bugzilla, etc.

As Peter Korsgaard, Buildroot maintainer, said in the 2010.08 announcement: The next release is going to be 2010.11. Expect the first release candidate in late October and the final release at the end of November..

It is worth noting that we will be having a Buildroot Developer Day, on Friday 29th October, right after Embedded Linux Conference Europe. At least Peter Korsgaard, Lionel Landwerlin, Yann E. Morin and myself should be there.

Buildroot 2010.02 released, contributions from Bootlin!

Buildroot logoBuildroot is a embedded Linux system build system. It automates the process of downloading, configuring, compiling and installating all the components of an embedded Linux system, from Busybox to more complicated software stacks using Gtk, Qt, X.org, Gstreamer, etc. Buildroot is easy to use and extend, making it a nice choice for small to medium-sized embedded Linux systems.

As promised by the fixed-release schedule, a 2010.02 release has been published on Friday, with numerous improvements over the previous version 2009.11, many of which are part of the general cleanup process that the project is doing since the beginning of 2009. These improvements are detailed in the project CHANGES file.

Thomas Petazzoni, from Bootlin, implemented several of these improvements :

  • Creation of a package infrastructure for non-autotools packages. Buildroot had for a long time an infrastructure to factorize the code needed to build packages based on the autotools build systems. But all other packages were using hand-made Makefiles, which were hard to write and generated a lot of code duplication. Therefore, we have introduced an infrastructure that makes adding new packages much easier, and which allows us to cleanup the existing codebase significantly by factorizing a lot of common code. The autotools infrastructure has also been reworked on top of the generic infrastructure to avoid code duplication as well. At the same time, we have significantly improved the documentation on how to add new packages. This infrastructure is a building block that will allow us to easily add more features to all packages in Buildroot (such as package generation).
  • Removal of the external toolchain source mechanism, which was merged with the normal toolchain building procedure. This special casing was implemented to allow the compilation of AVR32 toolchains, but such an additional complexity wasn’t needed. Now, Buildroot continues to build AVR32 toolchains as it used to do, but the code is much cleaner. Another illustration of our large cleanup effort.
  • Many, many, many fixes to different packages, many of them to ensure that we do not depend on development packages being installed on the host. This is very important to ensure that our build procedure is as independent as possible from the development machine configuration.

From the list of contributors, ordered by the number of patches, Thomas Petazzoni of Bootlin has been the first Buildroot contributor for this last release :

$ git shortlog -e -n -s 2009.11..2010.02  (removed e-mail addresses)
139 Thomas Petazzoni
124 Peter Korsgaard
26  Lionel Landwerlin
23  Gustavo Zacarias
7   Julien Boibessot
4   Nigel Kukard
4   Sven Neumann
2   Anders Darander
2   Chris Packham
2   Daniel Mack
2   H Hartley Sweeten
2   Richard van Paasen
2   Will Wagner
2   William Wagner
2   Yann E. MORIN
1   Cameron Hutchison
1   Clark Rawlins
1   Francisco Gonzalez
1   Francisco Gonzalez Morell
1   Hans-Christian Egtvedt
1   Lionel Landwerlin
1   Ormund Williams
1   Rob Alley
1   Sagaert Johan
1   grante

For the next release, we will work on additional cleanup of Buildroot and particularly the target/ directory, which contains the code to build the Linux kernel, different bootloaders, and to generate the final root filesystem image in various formats. Improving support for external toolchains is also on our TODO list : supporting multilib toolchains such as the CodeSoucery toolchain, and fixing a long-standing issue with libtool.

Don’t hesitate to try Buildroot, and to report your successes and failures on the mailing-list, in our bug tracker, or on our IRC channel, #uclibc on Freenode.

Buildroot simplified for users!

Buildroot logoYesterday, a set of patches I’ve authored that aims at simplifying Buildroot for users has been merged into the official version of the project, and will therefore be part of the next stable release (scheduled for November, according to our 3 months release cycle). This work is probably my major contribution to Buildroot, outside of external toolchain support and various fixes here and there. Here are quick details about the improvements brought by these patches :

  • Remove the “project” feature. The project feature removal was the main point of this patch set. This feature, that allows to compile a system for different, but very similar platforms, without recompiling everything from scratch, was rarely used and introduced a lot of complexity in the usage of Buildroot for newcomers. Who hasn’t been confused by this project_build_arm directory? This thing is gone now.
  • Remove the BOARD/LOCAL feature, which duplicates another way of adding support for new targets in Buildroot. This is the kind of feature that has been added at the time Buildroot was basically unmaintained, when nobody was able to say « Hey, but you’re just trying to-reimplement something that already exists »
  • Move all output directories in an output directory. By default, when Buildroot is compiled, it generates several directories in the middle of its source code. Now, with this patch, everything is grouped into an output directory, unless out-of-tree compilation is used, of course (with O=)
  • Remove TOPDIR_PREFIX and TOPDIR_SUFFIX since the same effect could already be done using out-of-tree compilation with O=. Another duplicated feature that should never have reached the tree.
  • Rename the output directories. Now that everything is properly stored in an output directory, it was time to rename the subdirectories to make them more meaningful. So now, we have build where all packages are built, images that contains the final binary images of the root filesystem and the kernel, staging which contains the staging directory (all packages installed with their development headers and libraries), target that contains the root filesystem for the target (without the device files), host that contains the installation of the host tools that Buildroot requires for its execution, stamps that contains the stamp files used by Buildroot to keep track of the compilation progress. Therefore, all directories such as build_ARCH or toolchain_build_ARCH have disappeared.
  • Major documentation update, to of course make sure that our documentation is up-to-date with the latest changes.

Getting all these changes mainlined is really a nice thing. I also have tons of other ideas to improve Buildroot infrastructure, and I’m sure the coming Buildroot Developer Day will be a great opportunity to discuss these.