Back from the Embededded Linux Conference: selection of talks #3

After a first and a second episode, our series of blog posts with our selection of talks we liked at the latest Embedded Linux Conference continues. Read on to discover the last 3 talks that we enjoyed and decided to summarize and highlight for you.

Continue reading “Back from the Embededded Linux Conference: selection of talks #3”

Back from the Embededded Linux Conference: selection of talks #2

After a first episode, our series of blog posts with our selection of talks we liked at the latest Embedded Linux Conference continues. Read on to discover 4 more talks that we enjoyed, and decided to summarize and highlight for you.

Continue reading “Back from the Embededded Linux Conference: selection of talks #2”

Back from the Embededded Linux Conference: selection of talks #1

As we wrote in a previous blog post, 11 engineers from Bootlin attended the Embedded Linux Conference in Seattle in April. We have a tradition after such an event to share with you a selection of talks that we have found useful. In order to achieve this, we ask each of our engineers who participated to the conference to pick one talk they would like to highlight, and write a short summary/feedback about the talk. In this first installment of this series of blog posts, we’ll share our selection of 4 first talks.

Continue reading “Back from the Embededded Linux Conference: selection of talks #1”

Our talks at Embedded Open Source Summit 2024

The Embedded Open Source Summit 2024 took place on Apr 16-18 in Seattle, with many talks on a wide range of embedded Linux topics. 11 engineers from Bootlin participated to this conference and four of us gave talks, for which we are happy to publish the slides and videos in this blog post.

Bootlin team at Embedded Open Source Summit 2024
Bootlin team at Embedded Open Source Summit 2024

Continue reading “Our talks at Embedded Open Source Summit 2024”

Bootlin at Embedded Open Source Summit North America, Apr 16-18: 4 talks, 11 engineers

Embedded Open Source SummitThe Embedded Open Source Summit will take place on April 16-18 in Seattle (Washington, US), with a wide range of events, including the Embedded Linux Conference which is of particular interest to Bootlin considering our core expertise.

As usual, a significant fraction of the Bootlin team will attend the event, with no less than 11 engineers from our team going to Seattle: Alexandre Belloni, Bastien Curutchet, Grégory Clement, Jérémie Dautheribes, João Marcos Costa, Köry Maincent, Louis Chauvet, Luca Ceresoli, Maxime Chevallier, Thomas Petazzoni and an additional engineer who will join us at the beginning of April. At Bootlin, all engineers, regardless of their seniority level, are offered the possibility of attending up to 2 conferences per year, to expand their knowledge on embedded Linux topics, to create connections with the community and therefore provide better services to our customers.

In addition to participating, we will also be delivering no less than 4 talks at the conference:

  • In the Kernel Trenches: Mastering Ethernet Drivers on Linux – Maxime Chevallier, Bootlin
    An Ethernet Controller driver in linux is a complex piece of software, with many entrypoints and callbacks, even for a basic Ethernet Controller we can find in Embedded Systems. In this talk, we’ll take a tour of what’s inside a typical Ethernet driver. We’ll start with the base of what every network driver provides, even non-Ethernet ones, a net_device. We will discuss the various required steps to get a basic driver working, ranging from simple initialization, queue setup, DMA mappings, before diving into more advances topics such as the NAPI loop implementation, memory-management through the page-pool API and finally XDP, which is now getting implemented in more and more drivers. We’ll continue the tour through the ethernet-specific bits, such as the ethtool operations, and phylink support to interact with a potential Ethernet PHY, and discuss a little bit about the specifics of embedded Ethernet Controllers, where low-level configuration for a PCS or some Serdes lanes might be required. Finally, we’ll discuss about testing and debugging tools that can be useful to help you in your driver development, but also in debugging and optimizing existing drivers.
  • Introduction to DAPM, Linux Power Management for Embedded Audio Devices – Luca Ceresoli, Bootlin
    DAPM (Digital Audio Power Management) is the part of ASoC (Alsa for System-on-Chips) that dynamically turns on and off power to various parts of the audio hardware in embedded Linux systems. DAPM is very useful, but not well known and documented. After introducing the motivations for DAPM and how it models the hardware, Luca will present some user space tools to understand how DAPM works at runtime. He will then show what DAPM practically means for developers, with code examples of how to add DAPM support to device drivers. Finally he will mention some improvements to the DAPM tooling and documentation.
  • Unlocking the Potential of Suspend to RAM Using Linux in a Multi-Core, Multi-Firmware Automotive SoC – Grégory Clement, Bootlin
    Fast booting in modern, complex System-on-Chips (SoCs) demands innovative solutions. This talk delves into the intricacies of implementing Suspend to RAM (S2R) on a sophisticated SoC featuring diverse CPU cores—high-performance A72, real-time R5, and low-power M3—as well as multiple firmware components, including open-source ones like TF-A, U-Boot, and OP-TEE. We begin with a hardware overview of the TI DRA821 SoC from the Jacinto family, emphasizing the open-source firmware utilized in the boot process. The focus then shifts to presenting a practical approach for integrating S2R into this multifaceted platform. Notably, our implementation poses a unique challenge: the SoC is entirely powered off during S2R, adding an extra layer of complexity. Join us as we share insights into the hurdles encountered and resolved during the implementation, along with a discussion on the outstanding challenges for which we’ve devised viable solutions. This session offers a comprehensive exploration into the software, including bootloaders and the Linux kernel, as well as the hardware aspects, showcasing a real-world approach to bringing Suspend to RAM to life on a cutting-edge automotive SoC.
  • Adding Support for Power Over Ethernet (PoE or IEEE Clause 33) to Linux Network Stack – Köry Maincent, Bootlin
    Power over Ethernet (PoE) is a technology that combines electrical power and data transmission over a single Ethernet cable. It eliminates the need for separate power sources, simplifying installations for devices like IP cameras, and VoIP phones. In this presentation, we’ll initially delve into Power over Ethernet (PoE), It debuted in IEEE Clause 33 without explicit reference to the PoE nomenclature. We will look at what currently exists in the Linux kernel and user space to support PoE. We’ll continue our discussion with some details of the Linux implementation currently in development and the PSE core changes brought by this new support. The PSE framework core and bindings happen to need modification as it was not prepared for the PoE specificities. In parallel to these extensions of the PSE framework, we developed Linux kernel drivers for two distinct PoE controllers: the Microchip PD692x0 and the Texas Instruments TPS23881. Finally, we will look into the mainline status, the things that still need to be merged and the future features that need development. This PoE Linux support is sponsored and funded by DENT Project.

See the full schedule of talks.

The Embedded Open Source Summit isn’t just about the presentations—it’s about forging connections, sharing ideas, and exploring opportunities. Join us for insightful conversations with the Bootlin team, where you can discuss your projects, ambitions, and maybe even discover new career pathways.

And mark your calendars because following the summit, our CEO Thomas Petazzoni will be in the Bay Area until April 24, ready to delve deeper into your embedded Linux needs.

So, whether you’re a seasoned veteran or a curious newcomer, don’t miss out on the Embedded Open Source Summit 2024. We’ll see you there!

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”

Embedded Linux Conference Europe 2022: a selection of talks by Bootlin engineers

Almost the entire engineering team of Bootlin attended the Embedded Linux Conference Europe 2022 in Dublin mid-september, an important event for Bootlin as it helps everyone in the team stay up to date with the latest developments in the Embedded Linux ecosystem, and connect with members of the community.

All the slides and videos are available at https://elinux.org/ELC_Europe_2022_Presentations, which is one of the great things about the Embedded Linux Conference.

After such conferences, we have a tradition at Bootlin: share with our readers a selection of talks that we found interesting. Several members of our engineering team were asked to select one of their favorite talks, and highlight it with a short summary.

Continue reading “Embedded Linux Conference Europe 2022: a selection of talks by Bootlin engineers”

Bootlin at the Embedded Linux Conference North America 2022

Bootlin CEO Thomas Petazzoni and COO Alexandre Belloni will both be attending the next Embedded Linux Conference North America, on June 21-24 in Austin, Texas.

In addition, both Thomas and Alexandre will be speaking at the event:

  • Thomas Petazzoni will give a talk Buildroot: what’s new?, providing an update on the improvements and new features in the Buildroot build system that have been integrated over the past two years
  • Alexandre Belloni will give a talk Yocto Project Autobuilders and the SWAT Team, during which he will explain what’s happening behind in the scenes in the Yocto Project to review and validate contributions before they are integrated.

Thomas and Alexandre will also naturally be available during the event to discuss business or career opportunities, so do not hesitate to get in touch if you’re interested.

Finally, prior to the event, Thomas Petazzoni will be in the Bay Area on June 13-15, also available for meetings or discussions.

Embedded Linux Conference 2021 schedule published, 4 talks from Bootlin

The schedule for the Embedded Linux Conference 2021 has been published and features 4 talks proposed by Bootlin !

This year, the ELC will take place in Seatle but will be organised as a hybrid virtual/physical event  due to the pandemic.  As usual the ELC will have a really interesting schedule with 46 talks covering a wide range of topics: build system, kernel graphics, boot process, security, etc.

See below the details of Bootlin talks that will be presented as virtual talks.

Advanced Camera Support on Allwinner SoCs with Mainline Linux – Paul Kocialkowski, Bootlin

Capturing pixels with a camera involves a number of steps, from the ADC reading the photosites in the image sensor to the final pixel values that are ready for encode/display, with various processing and transmission taking place along the way. While simple cases put most of the heavy lifting on the image sensor’s side (through its embedded processor) and use a simple parallel bus for transmission, advanced cases require more work to be done outside of the sensor. In addition, modern high-speed transmission buses also bring-in more complexity. This talk will present how support for such an advanced use case was integrated into the mainline Linux kernel, using the Media and V4L2 APIs. It involves supporting a sensor using the raw Bayer RGB format, transmission over the MIPI CSI-2 bus as well as support for the Image Signal Processor (ISP) found on Allwinner platforms. A specific focus will be set on this ISP, with details about the features it implements as well as the internal and userspace APIs that are used to support it. The integration between all of the involved components will also be highlighted.

Talk given by Paul Kocialkowski, at 4:50 PM PDT on September 27, 2021. See this talk in the schedule.

Embedded Linux Nuggets found in Buildroot Package Eldorado

To this date, Buildroot supports more than 2,500 packages, selected for the ability to run them on embedded Linux systems. We’ve gone exploring this Eldorado, and came back with multiple nuggets of all shapes and colors. Join this playful presentation and as if you were still a new comer to the embedded Linux community, discover lesser known tools and resources that can add to the functionality of your systems or make your life as a developer easier and more fun. Whenever possible, each resource will be shown through a quick demonstration or video capture. During this talk, I’ll also open an Etherpad for all participants to share their favorite solutions with the rest of the audience, especially the ones that deserve to be better known, and could be worth supporting in Buildroot too. We will close the session by an open review and discussion based on the nuggets shared by the audience.

Michael Opdenacker

Talk given by Michael Opdenacker, at 12:00 PM PDT on September 28, 2021. See this talk in the schedule.

I3C in Tomorrow’s Design

I3C is the new bus specification by the MIPI Alliance. While being compatible with I2C devices, this bus brings a colorful set of new features such as dynamic address assignment, in-band interrupts, hot-join, master handover and many others. It was improved once again recently with the 1.1 version of the specification which brought timer based sampling synchronization and targeted reset. All this make the I3C bus a good candidate for a number of new situations compared to its I2C cousin. It is then more and more being included in new hardware designs. With this talk we would like to propose a reminder of the various components and concepts of this relatively new bus. We will then detail how it is implemented in the Linux kernel with a short guided tour in the I3C core. Since the previous talk on I3C in 2018 by Boris Brezillon, I3C has now become a reality and starts to become available in real hardware designs. This talk will recap the basics of I3C as well as add details of the 1.1 specification and improvements in the Linux support.

Miquèl Raynal

Talk given by Miquèl Raynal, at 4:00 PM PDT on September 28, 2021. See this talk in the schedule.

OP-TEE: When Linux Loses Control

OP-TEE is an open-source Trusted Execution Environment designed to be executed in a secure context as a companion to a non secure Linux system. But what happens to the peripherals control since OP-TEE can forbid the non-secure OS to access them ? When running with a TEE, Linux isn’t in charge anymore of some critical peripherals and relies on the TEE to access and configure them. There are multiple protocols and methods to access these peripherals that are supported by Linux (SCMI, PSCI, SMC). Supporting them for a SoC requires understanding the various interactions between the systems and how to modify them to fit that new control scheme. Additionally, the configuration must be passed from OP-TEE to Linux to allow a seamless integration. This talk will cover the boot process to start a secure system and the modifications needed to run Linux when OP-TEE is in charge of some peripherals. The work that has been done for a specific SoC will be described to have a tangible real-world use-case.

Clément Léger

Talk given by Clément Léger, at 12:00 PM PDT on September 29, 2021. See this talk in the schedule.

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.