Technical – Bootlin

Cyber Resilience Act (CRA) – Obligations for manufacturers

The EU’s new Cyber Resilience Act (CRA) sets out a comprehensive framework of cybersecurity requirements for products with digital elements. While most of its provisions will apply starting December 11, 2027, certain obligations—most notably, reporting duties for manufacturers—will kick in earlier, on September 11, 2026.

In a previous blog post, we offered an overview of the CRA and its broader context. In this article, we’re narrowing the focus to a key actor in the CRA’s ecosystem: the manufacturer. We’ll explore what qualifies someone as a manufacturer under the regulation, and what responsibilities that role carries under the new law.

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Demystifying the Kernel Boot Sequence: From ‘Starting Kernel…’ to Userspace”

Board booting

As kernel developers, we often find ourselves writing device drivers—pieces of code that are typically registered using module_init() in the Linux kernel. But have you ever paused to wonder: just how late in the boot process does this happen? What exactly takes place between the moment we see the famous "Starting kernel..." message and the point where drivers are finally registered and devices probed?

If you’re curious about the intricate steps that occur before the system even reaches a working init process, you’re in the right place. Join us as we explore the fascinating journey of the Linux kernel boot sequence—step by step.

Throughout this article, you’ll find clickable links to our Elixir source code browser. We encourage you to dive in and follow along!

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Zephyr: making a driver for the Nunchuk joystick

This post is the fifth blog post in our series of blog posts about Zephyr. You can find the previous episodes below:

In this 5th blog post, we are going to implement a driver for the Nunchuk joystick from Nintendo. The Nunchuk is a simple joystick, which has the advantage of having a very simple interface that relies on the I²C bus.

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Back from Netdev 0x19

Around mid-March, Bootlin engineers Köry Maincent and Romain Gantois had the chance to attend edition 0x19 of the Netdev conference, where developers from the Linux kernel networking community assemble for four days of technical presentations and discussions.

They were generally very much impressed by the quality and detail of the talks given during this conference, and they have selected two of the talks that they found the most interesting, which they summarized below. We expect the slides and videos to be published at some point in the future, but they don’t seem to be available at the moment.

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Linux 6.14 released, Bootlin contributions inside

Penguin coding, AI generated Linux 6.14 was released last week, and as usual, we recommend checking out the LWN articles covering the 6.14 merge window (part 1, part 2) to get a good sense of the main new features and updates in this release.

Bootlin engineers have once again been busy contributing to this kernel release, with 125 commits authored by Bootlin engineers, and 60 patches reviewed and merged by Bootlin engineers who are maintainers of specific parts of the Linux kernel.

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Improving the eBPF tests in the kernel

As part of a partnership with the eBPF Foundation, Bootlin engineers Bastien Curutchet and Alexis Lothoré are working with the kernel community in order to improve eBPF support in the kernel on different aspects. This post is the first one of a series highlighting this effort. For those who need to catch up with the eBPF technology, you can take a look at our “Linux Debugging, tracing and profiling” training course which has been recently updated with eBPF basics !

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The NIST’s new plan for digital signatures: impact on secure boot

In October 2024, the National Institute of Standards and Technology (NIST) published an initial public draft of Special Publication 800 – 131A, with the title “Transitioning the Use of Cryptographic Algorithms and Key Lengths”.
It details how the NIST expects the requirements for use of cryptography to protect non-classified information to evolve.

There are several key points, such as abandoning ECB and SHA-1, but the main one this post will investigate is digital signatures.

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Integrating ST7789H2 Display Support on STM32L562E-DK with Zephyr: A Step-by-Step Guide

This blog post is a continuation of our series of blog posts on Zephyr, in which we already discussed Getting started with Zephyr, Understanding Zephyr’s Blinky Sample, and Zephyr: implementing a device driver for a sensor.

In this fourth blog post in our series, we will see how to add support in Zephyr for the display panel available on the STM32L562E-DK board.

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Linux 6.13 released, Bootlin contributions inside

Penguin coding, AI generated Linux 6.13 has been released last Sunday and a few lucky kernel developers won some guitar pedals assembled by Linus Torvalds himself! As usual, we recommend looking at the excellent coverage from LWN.net of the 6.13 merge window to get a high-level overview of the main changes and new features: part 1 and part 2. KernelNewbies also has a nice thoroughly documented page about the Linux 6.13 updates.

On our side, we contributed a total of 96 patches to this release, making Bootlin the 22nd contributing company by number of commits. In addition to those direct contributions, Bootlin engineers also reviewed/merged 77 patches from other contributors, as part of their role of being kernel maintainers. Most notably, Alexandre Belloni reviewed/merged 53 patches from other contributors as the RTC and I3C subsystems maintainer, while Miquèl Raynal merged 17 patches from other contributors as an MTD subsystem co-maintainer.

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Updated Buildroot support for STM32MP1 and STM32MP2 platforms, ST BSP v6.0

Bootlin is an authorized partner of ST The buildroot-external-st project is an extension of the Buildroot build system with ready-to-use configurations for the STMicroelectronics STM32MP1 and STM32MP2 platforms.

More specifically, this project is a BR2_EXTERNAL repository for Buildroot, with a number of defconfigs that allow to quickly build embedded Linux systems for the STM32MPU Discovery Kit platforms and Evaluation board. It’s a great way to get started with Buildroot on those platforms.

Today, we are happy to announce an updated version of this project, published under the branch st/2024.02.9 at https://github.com/bootlin/buildroot-external-st.

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