Linux 5.8 released: Bootlin contributions

Linux 5.8 was released recently. See our usual resources for a good coverage of the highlights of this new release: KernelNewbies page, article on the first part of the merge window, article on the second part of the merge window.

On our side, we contributed a total of 155 commits to Linux 5.8, which makes Bootlin the 19th contributing company by number of commits according to Linux Kernel Patch Statistic. The highlights of our contributions are:

  • Miquèl Raynal contributed a completely new NAND controller driver: the arasan-nand-controller driver, used on Xilinx platforms.
  • In the MTD subsystem, Miquèl Raynal, as one of the co-maintainers, made a substantial number of contributions: cleanups in the nandsim driver, drop of the nand_release() API, support in the NAND core for the specificities of the arasan-nand-controller driver in terms of ECC handling (we will soon publish a blog post on this topic!)
  • On the support of Atmel/Microchip platforms
    • Alexandre Belloni migrated the SAMA5D3, AT91SAM9N12, AT91RM9200 and AT91SAM9G45 Device Tree files to use the new clock DT bindings
    • Grégory Clement modified the atmel_usba_udc USB device controller driver to no longer require describing all USB endpoints in the Device Tree, since they are always the same for a given SoC.
  • Grégory Clement contributed a number of improvements and fixes for the n_gsm line discipline driver, which allows to multiplex an UART used to communicate with a GSM modem. These improvements and fixes allowed the n_gsm driver to be fully stable for one of our customers.
  • In the RTC subsystem, Alexandre Belloni (maintainer of that subsystem) did a number of small improvements to various RTC drivers.
  • Antoine Ténart has done a number of improvements in the support for Microchip/Microsemi networking products: improvements to the mscc-miim MDIO driver, improvements to the MSCC Ocelot Ethernet switch driver, improvements to the MSCC Ethernet PHY Driver.

Also, several Bootlin engineers are maintainers of various areas of the Linux kernel:

  • Miquèl Raynal, as the NAND maintainer and MTD co-maintainer, reviewed and merged 57 patches from other contributors
  • Alexandre Belloni, as the RTC maintainer and Microchip platform support co-maintainer, reviewed and merged 54 patches from other contributors
  • Grégory Clement, as the Marvell EBU platform support co-maintainer, reviewed and merged 13 patches from other contributors

Here is the complete list of our contributions:

Online training courses in September/October 2020

Following the success of our online training courses in Spring/Summer, we now have scheduled additional online training courses in September/October, for all our 5 training courses.

Those courses are delivered live, online, by a Bootlin instructor: the entire contents of our training lectures are covered, and the training practical labs are demonstrated live by the instructor. All you need to register is a Chrome-based web browser, an audio headset, and you’re all set to learn about embedded Linux, Linux kernel driver development, Yocto, Buildroot or Linux graphics!

Registration is open for the following 5 sessions, make sure to book your seat before the sessions fill up!

Type Dates Time Duration Expected trainer Cost and registration
Linux kernel (agenda) Sep. 14, 15, 16, 17, 18, 21 and 22, 2020 13:30 – 17:30 (Paris time) 28 h Gregory Clement 829 EUR + VAT* (register)
Linux Graphics (agenda) Sep. 22, 23, 24 and 25, 2020 14:00 – 18:00 (Paris time) 16 h Paul Kocialkowski 519 EUR + VAT* (register)
Yocto Project (agenda) Sep. 28, 29, 30, Oct. 1, 2, 2020 14:00 – 18:00 (Paris time) 20 h Maxime Chevallier 625 EUR + VAT* (register)
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)
Buildroot (agenda) Oct. 1, 2, 5, 6, and 8, 2020 14:00 – 18:00 (Paris time) 16 h Thomas Petazzoni 519 EUR + VAT* (register)

Linux 5.7 released, Bootlin contributions

We’re late to the party as Linux 5.8 is going to be released in a few weeks, but we never published about our contribution to the current Linux stable release, Linux 5.7, so here is our usual summary! For an overview of the major changes in 5.7, KernelNewbies has a nice summary, as well as LWN, in two parts: part 1 and part 2.

Bootlin contributed 92 commits to this release, a small number of contributions compared to past releases, but nevertheless with some significant work:

  • Antoine Ténart contributed support for offloading the MACsec encryption/decryption to a PHY in the networking stack, as well as the corresponding offloading support for some specific Microchip/Vitesse Ethernet PHYs. See our blog post for more details about this feature.
  • Alexandre Belloni continued converting the Atmel/Microchip platforms to the new clock representation, with this time AT91SAM9G45, SAMA5D3, AT91SAM9N12 and AT91RM9200.
  • Alexandre Belloni, as the RTC subsystem maintainer, again did a lot of cleanup and improvements in multiple RTC drivers.
  • Kamel Bouhara contributed support for I2C recovery for the Atmel/Microchip platforms.

In terms of maintainers activity: Miquèl Raynal, as the MTD co-maintainer, merged 62 patches from other contributors, Alexandre Belloni, the RTC maintainer and Atmel/Microchip platform co-maintainer merged 49 patches from other contributors, while Grégory Clement, as the Marvell EBU platforms co-maintainer, merged 11 patches from other contributors.

Here is the detail of our contributions for 5.7:

Bootlin at the Embedded Linux Conference 2020

Bootlin has been a participant at the Embedded Linux Conference for many years, and despite the special conditions this year, we will again be participating to this online event, from June 29 to July 1.

More specifically:

  • Bootlin engineer Alexandre Belloni and Bootlin’s audio expert will give a talk ASoC: supporting Audio on an Embedded Board, which presents how audio complex in embedded devices are typically supported by the Linux kernel ALSA System-on-Chip framework. This talk takes place on June 29 at 2:05 PM UTC-5.
  • Bootlin engineer and CTO Thomas Petazzoni will give his usual Buildroot: what’s new ? talk, giving an update on the latest developments and improvements of the Buildroot project. This talk takes place on July 1 at 11:15 AM UTC-5.
  • The vast majority of the Bootlin engineering team will be attending many of talks proposed during the event. Bootlin has been offering to all its engineers the participation to two conferences a year: with the Embedded Linux Conference going virtual, we’ve simply allowed all our engineers to participate, with no restriction. This is part of Bootlin’s policy to ensure our engineers stay as up to date as possible with embedded Linux technologies.
  • Bootlin CTO Thomas Petazzoni was once again part of the program committee for this edition of the Embedded Linux Conference, as part of this committee he reviewed and selected the different talks that were submitted.

We are interested in seeing how this virtual version of the Embedded Linux Conference will compare to the traditional physical event. For many old timers to these conferences, the most useful part of a conference is the hallway track and all the side discussions, meetings and dinners with members of the embedded Linux community, and a virtual version makes such interactions more challenging.

In any case, we hope you’ll enjoy the conference! Don’t hesitate to join us in the Q&A session after our talks, or on the 2-track-embedded-linux room of the Slack workspace set up for the event by the Linux Foundation.

Bootlin toolchains updated, edition 2020.02

Bootlin provides a large number of ready-to-use pre-built cross-compilation toolchains at We announced the service in June 2017, and released multiple versions of the toolchains up to 2018.11.

After a long pause, we are happy to announce that we have released a new set of toolchains, built using Buildroot 2020.02, and therefore labelled as 2020.02, even though they have been published in April. They are available for 38 CPU architectures or architecture variants, supporting the glibc, uclibc-ng and musl C libraries when possible.

For each toolchain, we offer two variants: one called stable which uses “proven” versions of gcc, binutils and gdb, and one called bleeding edge which uses the latest version of gcc, binutils and gdb.

Overall, these 2020.02 toolchains use:

  • gcc 8.4.0 for stable, 9.3.0 for bleeding edge
  • binutils 2.32 for stable, 2.33.1 for bleeding edge
  • gdb 8.2.1 for stable, 8.3 for bleeding edge
  • linux headers 4.4.215 for stable, 4.19.107 for bleeding edge
  • glibc 2.30
  • uclibc-ng 1.0.32
  • musl 1.1.24

2020.02 toolchains

In total, that’s 154 different toolchains that we are providing! If you are using these toolchains and face any issue, or want to request some additional change of feature, do not hesitate to contact us through the corresponding Github project. Also, I’d like to thank Romain Naour, from Smile for his contributions to this project.