Author: Thomas Petazzoni

Thomas Petazzoni is Bootlin's co-owner and CEO. Thomas joined Bootlin in 2008 as a kernel and embedded Linux engineer, became CTO in 2013, and co-owner/CEO in 2021. More details...

Feedback from ELCE 2023: selection of talks #2

As we reported in previous blog post, almost the entire Bootlin engineering team was at the Embedded Linux Conference Europe in Prague in June. In order to share with our readers more about what happened at this conference, we have asked all engineers at Bootlin to select one talk they found interesting and useful and share a short summary of it. We will share this feedback in a series of blog post: first post, this one being the second post.

Continue reading “Feedback from ELCE 2023: selection of talks #2”

Bootlin toolchains 2023.08 released

Bootlin toolchains 2023.08We are happy to announce that we have just published a new update of our freely available toolchains at toolchains.bootlin.com, version 2023.08.

For the record, we provide pre-built cross-compilation toolchains that work on x86-64 Linux machines, and targeting 43 different CPU architecture variants, with support for all 3 major C libraries: glibc, musl and uClibc-ng. For each toolchain, we provide two versions: a stable one that uses GCC/binutils/GDB versions next to the last, and a bleeding-edge one that uses the very latest GCC/binutils/GDB versions.

In this 2023.08 release, we have:

  • Updated the bleeding-edge toolchains to gcc 13.2, binutils 2.41, gdb 13.2, kernel headers 5.10, glibc 2.37, musl 1.2.4 or uclibc-ng 1.0.43
  • Updated the stable toolchains to gcc 12.3, binutils 2.40, gdb 12.1, kernel headers 4.14, glibc 2.37, musl 1.2.4 or uclibc-ng 1.0.43
  • Marked the sparcv8 toolchain as obsolete as sparc support in GCC has been broken for several releases, and the last working version of GCC for sparc has been dropped from Buildroot

A special thanks to Romain Naour from Smile who helped investigate and resolve some of the issues encountered in the preparation of those 2023.08 toolchains.

If you encounter any issue in the usage of those toolchains, or miss the support for a specific feature or architecture variant, let us know through the issue tracker. We hope those toolchains will continue to be useful to the community.

Bootlin collaborates with DENT to upstream ONIE NVMEM support in Linux

DENT project logoThe DENT project is a project from the Linux Foundation which aims at utilizing the Linux Kernel, Switchdev, and other Linux based projects as the basis for building a new standardized network operating system without abstractions or overhead.

Recently, Bootlin collaborated with the DENT project to work on a specific topic: extending the Linux kernel NVMEM subsystem to be able to support the ONIE TLV storage format which is used on ONIE-compliant network equipment to store in an EEPROM various information about the device: serial number, model, MAC addresses, and more.

This work, lead by Bootlin engineer Miquèl Raynal has now landed in Linux 6.4 as the drivers/nvmem/layouts/onie-tlv.c driver, together with the underlying new NVMEM layout infrastructure, which Miquèl helped to upstream in collaboration with Michael Walle.

We have written and published a longer blog post on the DENT website to explain the motivation for this effort and the results.

Feedback from ELCE 2023: selection of talks #1

As we reported in previous blog post, almost the entire Bootlin engineering team was at the Embedded Linux Conference Europe in Prague in June. In order to share with our readers more about what happened at this conference, we have asked all engineers at Bootlin to select one talk they found interesting and useful and share a short summary of it. We will share this feedback in a series of blog post, this one being the first of this series.

Continue reading “Feedback from ELCE 2023: selection of talks #1”

Back from the Embedded Linux Conference Europe 2023

From June 28 to June 30, Bootlin participated to the Embedded Linux Conference Europe, which was organized as part of the new and larger Embedded Open Source Summit.

In addition, the day before the conference, on June 27, our team had a great team building event, spending the day visiting Prague, having lunch in a traditional restaurant, enjoying a boat tour on the Vltava river, and an evening with a traditional dinner and folklore music. As our team is distributed, conferences are a great opportunity to meet each other and Prague was for several members of our team their first in-person meeting.

With 14 Bootlin engineers at the conference, almost our entire engineering team participated. Indeed, we have a policy at Bootlin to offer to all our engineers, regardless of their seniority level, the chance of attending 2 technical conferences each year.

Continue reading “Back from the Embedded Linux Conference Europe 2023”

Welcome to Thomas Richard

Welcome on board!Bootlin is really happy to welcome another engineer in its team: Thomas Richard, who joined us on July 3, 2023 (missing a participation to the Embedded Linux Conference Europe by just one week!).

Thomas graduated from INSA Toulouse in 2015, and then started his embedded software engineer career at Kontron, where he worked on numerous aspects of embedded Linux system development:

  • Thomas developed an OpenWRT based embedded Linux OS for railway systems, including virtualization support and security features such as TPM-based secret sealing, Host Intrusion Detection System (HIDS), and Linux Security Modules (LSM)
  • Thomas used both Yocto and Buildroot as build systems to create custom embedded Linux systems, in particular to support VME/VPX boards.
  • Thomas has developed several Linux kernel drivers, for GPIOs, HDLC, UART, watchdog, and more, to address the needs of several Kontron products
  • Thomas has also worked on cyber-security challenges, by creating a streamlined process to merge results from different vulnerability scanners and generate comprehensive reports for customers, to allow them to keep their embedded Linux systems updated in terms of security fixes.

Thomas is joining our team located in Lyon, France, where he will work at our office with Alexandre Belloni, Grégory Clement, Théo Lebrun and Kamel Bouhara, and of course with the rest of our team in Toulouse and remote.

For more details, see Thomas’ page on Bootlin.com or his LinkedIn profile.

Linux 6.4 released, Bootlin contributions inside

Linux 6.4 was released on June 25, just before the start of the Embedded Open Source Summit in Prague. As usual, lots of changes in Linux 6.4, and we recommend reading LWN coverage of the merge window (part 1, part 2). Sadly, the usual KernelNewbies page hasn’t received a lot of attention, contributions are probably welcome to revive this useful resource.

With 59 commits from Bootlin engineers, Bootlin is ranked as the #28 contributing company by number of commits for this 6.4 release, according to contribution statistics. Our main contributions have been:

  • Alexis Lothoré and Clément Léger contributed a few fixes to the Renesas RZ/N1 A5PSW Ethernet switch driver
  • Hervé Codina contributed a number of new drivers needed to support complex audio setups on some relatively old Freescale PowerPC 32-bit platforms: a driver for the Time Slot Assigner (TSA), a driver for the QUICC Multichannel Controller (QMC), and an ALSA driver that provides audio support over QMC. We have more contributions coming in this area, most notably to support HDLC network traffic over QMC.
  • Kamel Bouhara added support for the TI TAS5733 audio codec in the existing tas571x driver
  • Luca Ceresoli improved the fsl-ldb driver, used on NXP i.MX8MP and i.MX93 for the built-in DPI-to-LVDS encoder. Luca’s improvement allows to use LVDS channel 1 only, while the driver initially supported using either LVDS channel 0, or LVDS channel 0 and 1 combined.
  • Maxime Chevallier contributed an improvement to the regmap code, which allows upshifting register addresses before performing operations
  • Maxime Chevallier also contributed some small fixes to the phylink code related to previous work on QUSGMII support
  • Miquèl Raynal contributed the support for Real-While-Write in the MTD SPI-NOR subsystem. This allows to perform read operations while erase/program operations are on-going, which helps to reduce read latencies. This of course only works on SPI NOR chips that support this feature.
  • Miquèl Raynal contributed several improvements to the NVMEM subsystem. First, a brand new NVMEM driver capable of parsing the ONIE TLV information, as defined by the ONIE spec used on network equipment. Second, he contributed changes that allow NVMEM layout drivers to be compiled as kernel modules rather than being built-in

And the full details of our contributions:

New training course: Embedded Linux Audio

Embedded Linux Audio training course
Image from flaticon.com
We are very happy to announce the availability of a new training course in our portfolio: Embedded Linux audio.

Over the past years, Bootlin has helped more and more of its customers with numerous audio aspects on embedded Linux systems: development of Linux kernel drivers for audio components, description of audio hardware in Device Tree, support of unusual audio hardware setups, integration of user-space audio frameworks and servers such as PipeWire, and more. We have seen an interest from our customers and the broader community in getting trained on those topics, so we have built a brand new training course covering the following:

  • Digital Audio Representation
  • Audio hardware
  • Linux kernel ASoC subsystem
  • Linux kernel helpers for audio
  • Audio routing
  • More kernel audio components
  • Audio troubleshooting and debugging
  • User-space configuration for audio hardware
  • User-space configuration for audio controls
  • User-space APIs to play and capture audio
  • PipeWire
  • GStreamer

The detailed agenda of course is available for on-line sessions (4 half-days of 4 hours each) and on-site sessions (2 days). As usual with Bootlin, our training materials will be published for free under an open-source license in the next few weeks.

This course has been developed and is taught by Bootlin expert Alexandre Belloni.

We have a first public on-line session scheduled on September 11-14 2023, with a possible extra session on September 15. Sessions take place from 2 PM to 6 PM UTC+2 on each day. Seats are offered at 619 EUR per participant, with a discount at 519 EUR per participant under conditions. You can book your seat now, beware that only 12 seats are available.

This new training course is the 9th training course we offer in our portfolio, with all courses centered around embedded Linux development. We aim at developing more of those specific courses in the next few years, to continue to help engineers working on embedded Linux grow their skills and expertise.

Bootlin at Embedded Open Source Summit 2023 in Prague, June 28-30

Embedded Open Source Summit logoIn the Embedded Linux ecosystem, the Embedded Linux Conference is the most important event, covering all topics related to the usage of Linux in embedded systems, and probably gathering the largest audience of embedded Linux developers and maintainers.

After several years where it was combined in the much larger Open Source Summit, mixed with conferences on largely unrelated topics, the Embedded Linux Conference is this year grouped only with other embedded-related conferences under an umbrella event called the Embedded Open Source Summit.

Like every year, Bootlin will have a strong participation to the event: no less than 14 engineers of our team will be at the conference, which is almost our entire team. At Bootlin, we strongly believe that participating to conferences is a key aspect of an engineer’s job, in order to stay up-to-date with the latest developments in our field, but also to make or strengthen connections with other members of the embedded Linux community.

Overall, Alexandre Belloni, Kamel Bouhara, Luca Ceresoli, Maxime Chevallier, Hervé Codina, Jérémie Dautheribes, Paul Kocialkowski, Théo Lebrun, Alexis Lothoré, Köry Maincent, Michael Opdenacker, Thomas Perrot and Thomas Petazzoni will participate to the conference.

In addition, we also have 3 talks that have been accepted at the conference, which are visible in the schedule:

Finally it is worth mentioning that Bootlin has already started contributing to the conference: as a member of the Embedded Linux Conference program committee, Bootlin CEO Thomas Petazzoni has already reviewed and participated to the selection of talks that made it to the schedule of this year’s conference.

We look forward to seeing you all in Prague!

Linux 6.3 released, Bootlin contributions inside

Linux 6.3 has been released yesterday, right on schedule. As usual, see the LWN.net articles that covered the 6.3 merge window (part 1 and part 2) as well as the KernelNewbies page.

For this release, Bootlin engineers contributed a total of 66 commits, with the following highlights:

  • Alexandre Belloni, as the RTC subsystem maintainer, contributed a number of patches to RTC drivers: add support for ACPI-based probing to two RTC drivers, convert a number of RTC drivers to use the fwnode API to retrieve IRQ flags
  • Alexis Lothoré contributed a fix for a regression in the FPGA subsystem
  • Clément Léger contributed a fix for a reference count issue found while testing Device Tree overlays and also contributed a minor cleanup to the pcs-rzn1-miic he contributed sometime ago.
  • Hervé Codina contributed a full new driver to support the USB Device controller found in Renesas RZ/N1 processors: renesas_usbf, together with the corresponding Device Tree binding description, Device Tree files updates, as well as an update to the Renesas clock driver
  • Hervé Codina also contributed two new audio codec drivers: one for the Renesas IDT821034 codec and one for the Infineon PEB2466 codec
  • Miquèl Raynal contributed a significant number of updates to the IEEE 802.15.4 stack of the Linux kernel, most notably implementing passive scanning support as well as beaconing support.
  • Paul Kocialkowski contributed a number of fixes for the Allwinner sun6i-csi camera interface driver, the Allwinner MIPI CSI2 bridge driver as well as the Allwinner sun6i-isp ISP driver, following previous contributions he made on all those multimedia drivers

Here are the details of our contributions, commit by commit: