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.

Slides and videos of Bootlin talks at Live Embedded Event #2

The second edition of Live Embedded Event took place on June 3rd, exactly 6 months after the first edition. Even though there were a few issues with the online platform, it was once again great to learn new things about embedded, and share some of the work we’ve been doing at Bootlin on various topics. For the next edition, we plan to switch to a different online platform, hopefully providing a better experience.

But in the mean time, all videos of the event have been posted on the Youtube Channel of the event. The talks from Bootlin have been posted on Bootlin’s Youtube Channel.

Indeed, in addition to being part of the organization committee, Bootlin prepared and delivered 5 talks as part of Live Embedded Event, covering different topics we have worked on in the recent months for our customers.

Understanding U-Boot Falcon Mode and adding support for new boards, Michael Opdenacker

Slides [PDF]

Introduction to RAUC, Kamel Bouhara

Slides [PDF]

Security vulnerability tracking tools in Buildroot, Thomas Petazzoni

Slides [PDF]

Secure boot in embedded Linux systems, Thomas Perrot

Slides [PDF]

Device Tree overlays and U-boot extension board management, Köry Maincent

Slides [PDF]

CFP for the Embedded Linux Conference 2021 ends June 13th

Initially planned to take place in Dublin, Ireland, the unique edition this year of the Embedded Linux Conference will take place in Seattle, US and virtually from September 27 to September 30, 2021. See also the conference website. Bootlin CEO Thomas Petazzoni is again a member of the program committee for this edition of ELC.

Embedded Linux Conference 2021

This kind of event is only possible thanks to the talks proposed by its participants! As detailed on the Call For Papers, the last date to submit your proposals is June 13, 2021. There is really a wide range of suggested topics, and ELC is an excellent place to talk about advancements in the Linux kernel for embedded platforms, in user-space libraries and stacks relevant to embedded, about practical experiences in using Linux in embedded devices, about real-time, boot time, power management, build systems, open hardware, and more.

We look forward to seeing your proposals for ELC!

CFP open for Live Embedded Event #2

Back in December 2020, together with Smile, Logilin and Theoris, Bootlin organized and participated to the first edition of Live Embedded Event, a new 1-day online conference focused on embedded systems topics. Following the success of this first edition, we are now organizing a second edition of Live Embedded Event, which will take place on June 3rd, 2021. Like the previous edition, this event is free.

Live Embedded Event #2

The call for papers is open, and we are looking for talk proposals on a wide range of topics:

  • Software update and provisioning
  • Network connectivity (Long range / Short range)
  • Edge Computing / ML-AI
  • Security & Safety
  • RTOS and Embedded frameworks
  • Firmware, BSP and Bootloader
  • Internet Of Things / Cyber Physical Systems
  • Hardware: system-on-chips, interfaces, FPGA, open hardware
  • Linux kernel
  • Build systems: Yocto, OpenWrt, Buildroot
  • Development process, methods and tools
  • Embedded Linux
  • Real time

Two talk formats are proposed: 45 minutes talk + 15 minutes of questions, or 25 minutes talk + 5 minutes of questions. If you want to get a feeling of the talks that were accepted for the first edition, look at the Youtube channel of the event.

We look forward to your proposals for Live Embedded Event #2, and of course, to your participation!

Videos and slides of Bootlin presentations at FOSDEM 2021

The videos from Bootlin’s presentations earlier this month at FOSDEM 2021 are now publicly available. Once again, FOSDEM was a busy event, even if it was online for once. As in most technical conferences, Bootlin engineers volunteered to share their experience and research by giving two talks.

Maxime Chevallier – Network Performance in the Linux Kernel, Getting the most out of the Hardware

Abstract: The networking stack is one of the most complex and optimized subsystems in the Linux kernel, and for a good reason. Between the wild range of applications, the complexity and variety of the networking hardware, getting good performance while keeping the stack easily usable from userspace has been a long-standing challenge.

Nowadays, complex Network Interface Controllers (NICs) can be found even on small embedded systems, bringing powerful features that were previously found only in the server world closest to day to day users.

This is a good opportunity to dive into the Linux Networking stack, to discover what is used to make networking as fast as possible, both by using all the features of the hardware and by implementing some clever software tricks.

In this talk, we cover these various techniques, ranging from simple batch processing with NAPI, queue management with RSS, RPS, XPS and so on, flow steering and filtering with ethool and TC, to finish with the newest big change that is XDP.

We dive into these various techniques and see how to configure them to squeeze the most out of your hardware, and discover that what was previously in the realm of datacenters and huge computers can now also be applied to embedded linux development.

Here are PDF slides for this presentation.

Michael Opdenacker – Embedded Linux from Scratch in 45 minutes, on RISC-V

Abstract: Discover how to build your own embedded Linux system completely from scratch. In this presentation and tutorial, we show how to build a custom toolchain (Buildroot), bootloader (opensbi / U-Boot) and kernel (Linux), that one can run on a system with the new RISV-V open Instruction Set Architecture emulated by QEMU. We also show how one can build a minimal root filesystem by oneself thanks to the BusyBox project. The presentation ends by showing how to control the system remotely through a tiny webserver. The approach is to provide only the files that are strictly necessary. That’s all the interest of embedded Linux: one can really control and understand everything that runs on the system, and see how simple the system can be. That’s much easier than trying to understand how a GNU/Linux system works from a distribution as complex as Debian!

The presentation also shares details about what’s specific to the RISC-V architecture, in particular about the various stages of the boot process. This presentation shares all the hardware (!), source code build instructions and demo binaries needed to reproduce everything at home, and add specific improvements. Most of the details are also useful to people using other hardware architectures (in particular arm and arm64).

It’s probably the first time a tutorial manages to show so many aspects of embedded Linux in less than an hour. See by yourself! At least, that’s for sure the first one demonstrating how to boot Linux from U-Boot in a RISC-V system emulated by QEMU.

Here are PDF slides for this presentation.