Bootlin has recently contributed to the Kas project by adding support for Yocto Project’s Buildtools. In this blog post, we will give an overview of what Kas is, what Buildtools are, why an integration of Buildtools was deemed useful and relevant, and how to use it.
Continue reading “Support for Yocto buildtools added to upstream Kas”
Bootlin is happy to share that our engineer Luca Ceresoli will be speaking at Linux Day 2025 in Bergamo, Italy, on Saturday, October 25, 2025.
Luca’s talk, titled “Software updates on embedded Linux devices” (“Aggiornamenti software su dispositivi embedded Linux”), will take place from 14:00 to 15:00.
Many of the electronic products we use every day are powered by Linux, even when we don’t see it. Like PCs, these embedded devices also need software updates to fix bugs and improve functionality. However, unlike PCs, they must perform these updates automatically and reliably, without any user intervention.
In his presentation, Luca will explain one of the most widely used techniques for achieving this: A/B updates. He will describe what they are, how they work, and the most common tools used to implement them in embedded Linux systems.
This talk is a great opportunity for developers and engineers interested in the practical challenges of maintaining and updating Linux-based devices in the field.
Linux Day is an annual, nationwide event organized across Italy to promote the use and understanding of free and open-source software. Many cities host talks, workshops, and meetups aimed at both newcomers and experienced developers. The Bergamo edition continues this tradition with a full day of technical sessions, community engagement and an install party.
If you’re attending Linux Day Bergamo 2025, don’t miss Luca’s session! Don’t hesitate to meet Luca to talk about what we do at Bootlin and open job positions!
Among all activities I’ve been doing at Bootlin during the past few months, one has been to add support for the Maxim MAX7360 Key-Switch Controller and LED Driver/GPIOs chip to the Linux kernel. Together with my colleague Kamel Bouhara, we developed Linux kernel device drivers to support it and upstreamed them to the mainline kernel. The full set of drivers have been merged in the upstream Linux kernel, and will be available in the upcoming Linux 6.18 release.
In this blog post, we will share some details on how this hardware works, and how it is now supported by the Linux kernel.
Continue reading “Adding support for the MAX7360 keypad controller in the Linux kernel”
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/2025.02.5 at https://github.com/bootlin/buildroot-external-st.
Continue reading “Updated Buildroot support for STM32MPU platforms, ST BSP v6.1”
This blog post is the third installment in our eBPF blog post series, following our posts about eBPF selftests and eBPF trampolines.
In the previous blog post, we discussed how eBPF trampolines are dynamically generated to allow hooking tracing programs to functions’ entry and/or exit. Each trampoline is tailored specifically for the target function on which we want to hook programs: it is then able to read the function context (e.g. function arguments and return value) and to pass those to the hooked programs. However there is one detail that we did not address: how does the trampoline generator know exactly about the function layout ? To be able to generate trampolines that can read and store the function arguments, the trampoline generator needs many details about each argument: the location (a register ? If so, which one ? Or maybe it is on the stack ? And if so, at which offset ?) and its size. Parsing the function machine code is not enough to learn about those, and even if it was, compiler optimizations would obfuscate this kind of info even more. What if besides the actual executable code, the kernel image could be bearing some data about its internal functions ? In this post, we will dive into the DWARF debug information format, and the BPF Type Format (BTF) derived from it to support such a purpose.
Continue reading “The Dwarves Beneath the Kernel: Forging BTF for eBPF”
Linux 6.17 was released a bit over a week ago, and as usual LWN.net gave the best summary of the new features and important changes in this release: part 1, part 2.
As usual, Bootlin contributed to this kernel, with a total of 98 patches authored by Bootlin engineers, but also another 94 patches that were reviewed/merged by Bootlin engineers, mostly by Alexandre Belloni (RTC and I3C maintainer, reviewed/merged 58 patches), Miquèl Raynal (MTD co-maintainer, reviewed/merged 20 patches) and Grégory Clement (Marvell EBU platform maintainer, reviewed/merged 8 patches).
Continue reading “Linux 6.17 released, Bootlin contributions inside”
The X.Org Developer’s Conference (XDC) is the key annual event for developers shaping the future of Open Graphics technologies, including the Linux kernel, Mesa, DRM, Wayland, and X11. It is taking place on Sep 29, Sep 30 and Oct 1 in Vienna, Austria.
Bootlin engineer and Linux graphics specialist Louis Chauvet will be attending and giving a talk on Display Testing without Hardware: Discovering the Power of VKMS!. In this session, he will introduce VKMS, demonstrate its testing capabilities with real examples, and share details on the new features that Bootlin is actively driving upstream.
After participating in the Display Next Hackfest earlier this year, this second graphics-focused event confirms Bootlin’s involvement in the Linux graphics ecosystem. It reflects our commitment not only to staying at the cutting edge of graphics technologies, but also to contributing improvements that benefit the entire community.
If your projects involve Linux graphics and you are looking for expertise, feel free to get in touch with us to see how Bootlin can help.
Bootlin had a very strong presence at the recent Open Source Summit Europe, with 26 members of our team attending the event, 8 talks given by our engineers, and a booth at the technical showcase.
As the Linux Foundation just posted the videos of all talks from the event, now is a good time to publish the slides of our talks, alongside with the videos.
Continue reading “Back from Open Source Summit Europe 2025: talks from Bootlin”
We are excited to announce the release of a new version of our freely available, pre-compiled cross-compilation toolchains, hosted at toolchains.bootlin.com.
This update covers a range of 43 CPU architecture variants, including: aarch64, aarch64be, arcle-750d, arcle-hs38, armv5-eabi, armv6-eabihf, armv7-eabihf, armebv7-eabihf, armv7m, m68k-68xxx, m68k-coldfire, microblazebe, microblazeel, mips32, mips32el, mips32r5el, mips32r6el, mips64-n32, mips64el-n32, mips64r6el-n32, openrisc, powerpc-440fp, powerpc-e300c3, powerpc-e500mc, powerpc64-e5500, powerpc64-e6500, powerpc64-power8, powerpc64le-power8, riscv32-ilp32d, riscv64-lp64d, s390x-z13, sh-sh4, sh-sh4aeb, sparc64, sparcv8, x86-64, x86-64-v2, x86-64-v3, x86-64-v4, x86-64-core-i7, x86-core2, x86-i686, xtensa-lx60.
As with previous releases, we provide two editions of each toolchain: a stable version based on the N-1 releases of GCC, binutils, GDB, and slightly older kernel headers, and a bleeding edge version featuring the latest available components. For the 2025.08 release, the versions are:
All toolchains are built for x86-64 Linux hosts and are compatible even with relatively old Linux distributions. We welcome bug reports and feedback through our project issue tracker.
Congatec’s x86 System-on-Modules (SoM) include a Board Controller component connected to the processor via an eSPI bus, and providing various features such as I²C buses, GPIOs, a watchdog timer, and various sensors for monitoring voltage, fan speed, and more.
For their x86 System-on-Modules (SoMs), Congatec provides a Yocto meta-layer: meta-congatec-x86. This meta-layer includes, among other components, a driver, a library, and tools for interfacing with the Board Controller.
The primary issue with the provided driver is its deviation from standard Linux APIs. It exposes a custom character device and relies on custom ioctl() for communication with userspace. This non-standard approach leads to compatibility and portability challenges. For example, an application using the standard Linux GPIO API would need to be adapted to access the GPIOs from Congatec’s Board Controller. Similarly, software designed specifically for the Board Controller’s GPIOs would require changes to work with GPIOs on other platforms.
Additionally, because the driver is out-of-tree, it raises concerns about long-term support and maintainability. Questions naturally arise—will the driver be regularly updated to remain compatible with future Linux kernel versions, given the instability of internal APIs? Will bugs and security vulnerabilities be addressed in a timely manner?
One of our customers, planning to use the Conga-SA7 board in a commercial product, recognized these challenges early on. As a result, they asked us to integrate support for the Congatec Board Controller directly into the mainline Linux kernel. Upstreaming the driver into the kernel would eliminate these issues by ensuring better portability, long-term maintenance, and community support.
Continue reading “Congatec Board Controller support into the upstream Linux Kernel”
