Linux on Rootcommit WIP

Board Bring-Up: Radxa Dragon Q6A with Mainline Linux and Yocto

Sat, 18 Apr 2026 00:00:00 +0000

Radxa Dragon 6A

The Radxa Dragon Q6A is a credit card-sized single-board computer built around Qualcomm’s QCS6490 — the same silicon family found in the Fairphone 5 and Qualcomm’s own RB3gen2 reference platform. It packs an octa-core Kryo 670 CPU, an Adreno 643 GPU, and a 12 TOPS Hexagon NPU into a board with Gigabit Ethernet, WiFi 6, HDMI, triple camera connectors, and an M.2 NVMe slot. Starting at around $60, it sits in an interesting spot — significantly more compute per dollar than a Raspberry Pi 5, with a genuine ML inference pipeline that doesn’t require an external accelerator. Qualcomm provides Yocto builds for RB3Gen2 boards and Radxa mentions this in their documentation but doesn’t provide any how-to. In this article, we shall explore the steps taken to get Yocto running with Mainline Linux Kernel.

Mainline Linux 7.0 running on Arduino Q

Mon, 13 Apr 2026 00:00:00 +0000

Here are steps to reproduce it by yourself, if you are the happy owner of this board, currently priced at 48 EUR on the Arduino shop for the 2 GB version. This is done without removing the original kernel. Your board will still boot such kernel by default.

Setup and prerequisites

To do this by yourself, you will need:

An Arduino Q board
A USB-C hub with external power, to power the board and to connect external devices such as USB mass storage or USB-Ethernet.

Contributions to Linux 6.19

Tue, 10 Feb 2026 00:00:00 +0000

Root Commit’s contributions to Linux 6.19

Linux 6.19 is out with 7 contributions from Root Commit:

Using Yocto to build images for Orange Pi 3B

Tue, 25 Nov 2025 00:00:00 +0000

Introduction

Orange PI 3B is a cheap and attractive Raspberry Pi sized single board computer based on the Rockchip RK3566:

Rockchip RK3566 (4x ARM Cortex-A55 @ 1.6GHz)
ARM Mali-G52-2EE GPU (OpenGL ES 1.1/2.0/3.0/3.1/3.2, Vulkan 1.1, OpenCL 2.0)
LPDDR4 RAM (2/4/8 GB)
Micro-SD card slot
SPI flash (16/32 MB)
Optional eMMC pluggable module (16/32/64/128/256 GB)
Wi-Fi5 + Bluetooth 5.0, BLE
1x USB 2.0 Type A OTG, 2x USB 2.0 Type A HOST, 1x USB 3.0 Type A Host

Orange Pi RV2 RISC-V board running Linux 6.18-rc1

Thu, 16 Oct 2025 00:00:00 +0000

Introduction

Five days ago, I received the Orange Pi RV2 board I ordered. For about 54 EUR / 64 USD (+ shipping), this board has very attractive features, in particular:

Top view - Source Orange Pi

8 GB of LPDDR4X RAM (2 and 4 GB options exist)

Yocto security: Kernel Hardening

Tue, 07 Oct 2025 00:00:00 +0000

This is another blog post about securing your Yocto built systems:

Introduction

The Linux kernel is the cornerstone and stronghold of a Linux based system. Unlike user-space applications which run with limited privileges, if it’s compromised, there is almost no limit to what an attacker can do.

While nothing is unbreakable, there are two types of settings you can change to make your kernel harder to compromise:

Yocto bookmark and new training dates

Wed, 01 Oct 2025 00:00:00 +0000

Bookmark

After a brief announcement two weeks ago, here is the new Yocto command reference bookmark, in a format you can print and modify, according to the terms of the Creative Commons Attribution-ShareAlike license.

In particular, the PDF version is ready to be printed. This way you will get 5 bookmarks on double-sided A4 paper.

The documents were created with the Scribus open-source publishing application. It’s a great program to create leaflets, brochures and any professional looking documents. Sources are available in our GitLab repository.

Linux 6.17 is out and already running at Root Commit

Mon, 29 Sep 2025 00:00:00 +0000

Linux 6.17 has just been released, and it’s already running here at Root Commit.

The first system it’s been running on is this Toradex Verdin iMX8M Mini SOM (below the heat sink!) on the Dahlia Carrier board. I’m using this board for a medical device project at the moment.

Here are my notes for building Linux 6.17 for this device:

Get the Linux 6.17 sources (through git or tarball)

Yocto Security: Production and Development Images

Thu, 04 Sep 2025 00:00:00 +0000

This blog post is part of a series about securing your Yocto built systems:

What to avoid

So, you use Yocto to build an image for your embedded device. You tweak the image and distribution settings to get the features you need, and other developers use the SDK built by Yocto to create and build the User Interface and other applications.

"Securing Yocto Built Systems" presentation slides

Wed, 03 Sep 2025 00:00:00 +0000

Last week, I gave a “Making Yocto Built Images More Secure” presentation at the Embedded Linux Conference in Amsterdam.

The main goal was to share the research I’ve done so far for a customer project, and gather feedback from the audience.

See how U-Boot modifies your board device tree

Mon, 21 Jul 2025 00:00:00 +0000

If you compare the device tree as loaded by Linux, available in /sys/firmware/fdt, you will see that it differs from the one that you loaded in U-Boot. Taking the time to make the comparison is quite instructive.

Let’s do this on my Toradex Verdin iMX8M Mini SoM on the Dahlia carrier board.

Decompiling the DTB

It’s easy to decompile any Device Tree Binary (DTB) file using dtc, the Device Tree Compiler.

Copy /sys/firmware/fdt from your live Linux system to external storage (assuming your external storage is mounted on /mnt/usb)
cp /sys/firmware/fdt /mnt/usb/linux.dtb

Seven steps to grow your embedded Linux skills

Sun, 20 Jul 2025 00:00:00 +0000

A variant of this article also exists as a conference presentation.

Do you already have a job in embedded Linux but wish to be given more challenging goals? Or are you in IT, already using Linux on your own laptop, and dreaming about landing an embedded Linux job, possibly starting as your own boss? Follow my advice in a patient and consistent way, and you will achieve your goals in less than 12 months.

Virtual Packages in Yocto Project / OpenEmbedded

Thu, 03 Jul 2025 00:00:00 +0000

Understanding Virtual Packages in Yocto Project / OpenEmbedded

If you are using Yocto, this post will help you learn about Virtual Packages: how they work, why they are useful, and how to create them step by step.

We assume you are already familiar with:

Yocto Project setup
Basic command of BitBake and recipe syntax

What is a Virtual Package?

Imagine you have multiple implementations of the same functionality (for example, different kernels such as a real-time kernel, a boot-time optimized kernel, and a kernel without loadable modules). Of course, your final image will include only one kernel, but you may want to keep several implementations in your project, so you can switch between them easily whenever you like.

Yocto: variable overrides tricks

Tue, 18 Mar 2025 00:00:00 +0000

Kernel Recipes conference in Paris
One of the best for Linux kernel topics 😉.
Recommended by Root Commit!

I discovered a intriguing phenomenon while preparing my How to test the latest mainline Linux kernel or bootloader presentation at OpenEmbedded Workshop 2025. It turned out there was something incomplete in my understanding of BitBake variable overrides.

Introducing Yocto Project Overview Seminars

Thu, 27 Feb 2025 00:00:00 +0000

Following discussions with a customer, and as a teaser for our Yocto Project and OpenEmbedded course, we are now offering a 1-day overview seminar on this topic.

The main goal is to give you a clear view of the Yocto Project and the value it can bring to your embedded Linux device projects. You will have a guided view of its main features and quick demos, all done in an engaging and interactive way.

Build and run the mainline Linux kernel on your PC

Wed, 26 Feb 2025 00:00:00 +0000

Last week, I gave a “How to test a specific version of Linux on PC hardware” talk at the Alposs conference in Echirolles near Grenoble, France.

This was a very nice technical conference, with 330 participants (+110 compared to last year), organized in the city hall of Echirolles near Grenoble and by Belledonne Communications (the editors of Linphone) and OW2, an international association of Free Software professionals. Echirolles has a very dynamic orientation, deploying Free and Open Source Software in many of its services, thus improving the services offered to its citizens.

Booting the Raspberry Pi 5 with the Mainline Linux Kernel

Wed, 19 Feb 2025 00:00:00 +0000

If you have other boards, read on, these instructions support multiple other Raspberry Pi boards.

Hardware

In this tutorial, we assume you have the Raspberry Pi Debug Probe to access the board’s serial port. You could use the GPIO UARTs too, but they are neither enabled by default at the bootloader level nor as a kernel console. Enabling them for serial console access would slightly complicate these instructions.

Video replay: Yocto Project devtool hands-on

Wed, 15 Jan 2025 00:00:00 +0000

I’ve just produced a 4K video replay of my Devtool Hands-on Class at Yocto Project Summit 2024.12.

Here are the main reasons for shooting such a video:

Compared to the official recording, this video is shorter without the pauses waiting for participants to complete their instructions.
The video can be recorded at a better quality, both in terms of video and audio.
The issues found during the presentation have been corrected.
It’s possible to show presentation slides and command line terminals on the same screen.

First public training sessions

Mon, 06 Jan 2025 00:00:00 +0000

The first sessions announced in 2024 are coming. We are opening in-person and online sessions open to individual registration, for our Embedded Linux and Yocto Project and OpenEmbedded training courses:

Yocto Project and OpenEmbedded
In-person – Feb. 25-28 2025, Avignon, France
Online – Mar 18-20, 25-27, 2025

Embedded Linux
Online, Apr. 14-17, 22-25, 2025
In-person, May 5-9, 2025, Avignon, France

Shared features

Both courses, online and in-person, share the same key features:

75% of active learning time through practical labs and activities. You won’t get more than 25% of the time going through theory.

Yocto Binary Distributions presentation

Mon, 30 Sep 2024 00:00:00 +0000

Here are the slides of the “Building and Maintaining Binary Distributions with the Yocto Project” presentation I gave at the Embedded Linux Conference in Vienna.

The abstract I submitted is a good way to describe my presentation:

Imagine a world in which you can try the Yocto Project without even using it. This was possible in the past with the Ångström distribution, offering ready-made images which could be extended through binary package feeds. Though Ångström is long gone, the Yocto Project still has the ability to generate such images and package feeds. While system makers are still using this feature, the Yocto Project itself has never published such binaries.

The Yocto Project, thanks to funding from the Sovereign Tech Fund, has recently developed its abilities to support binary distributions, by creating tooling to verify the ability to upgrade the images built for its releases through package feeds, and to support managing a “local” distribution that can customize packages offered by an “upstream” distribution.

Since Yocto is about recipes, I will first present a cookbook for building your own images so that they can be updated through package feeds. I will then describe the recently developed features related to binary distributions and what possibilities they open for the Yocto Project and its users.

Writing a new story

Mon, 27 May 2024 00:00:00 +0000

LinkedIn posts quickly fade out from view and may not last forever. Here is a copy of my most successful post in 2024.

Last Friday was my last day at Bootlin, the company which I created 20 years ago.

Bootlin is in good hands now, and has become a great contributor to many Open Source projects. I stayed there for three more years after selling it in 2021 to two of its engineers, Thomas Petazzoni and Alexandre Belloni. This was a very good experience to get back to engineering, especially contributing to the Yocto Project, teaching training sessions and sharing experience through speaking at international conferences. Bootlin has also managed to hire incredibly talented engineers over the years. However, working as an employee didn’t leave enough time to explore as many new techniques and resources as I was interested in.

Kernel Panic QR Code

Mon, 01 Jan 0001 00:00:00 +0000

Building and Simulating Linux Kernel Panic QR with DRM/KMS in QEMU

When a Linux system runs into a serious error that it can’t recover from, it triggers a kernel panic. This fills the system console with complex information, including registers, call stacks, and error codes. When the system console is on a serial line on terminal, such information is easy to copy to another machine for analysis. Retrieving all the data becomes much more difficult when the panic is displayed on a graphical console. You can take a picture with a smartphone but then getting the corresponding text back is tedious.