Marcus Folkesson

Route priorities - metric values Brief It's not an uncommon scenario that a Linux system has several network interfaces that are all up and routeable.

Lund Linux Conference 2023 The conference Lund Linux Conference (LLC) [1] is a "half-open" conference located in Lund.

TIL - Split streams with boost::tee_device TIL, Today I Learned, is more of a "I just figured this out: here are my notes, you may find them useful too" rather than a full blog post Split streams could be useful if you want the same output to appear in mo…

TIL - NFS UDP Support TIL, Today I Learned, is more of a "I just figured this out: here are my notes, you may find them useful too" rather than a full blog post Today I was trying to bring up an really old board (v2.6.32 kernel) that used to mount its root

Write a device driver for Zephyr - Part 1 This is the first post in this series.

Write a device driver for Zephyr - Part 2 This is the second post in this series.

Write a device driver for Zephyr - Part 3 This is the third post in this series.

Write a device driver for Zephyr - Part 4 This is the fourth post in this series.

Encrypted storage on i.MX Brief Many embedded Linux systems have some kind of sensitive information on a file storage.

TIL - Buildroot & BR_NO_CHECK_HASH_FOR TIL, Today I Learned, is more of a "I just figured this out: here are my notes, you may find them useful too" rather than a full blog post In Buildroot [1], the integrity of (almost) all downloaded packages is verifi…

Bug in the iMX8MP ECSPI module?

Capture an image with V4L2 Brief As we have seen before, cameras in Linux could be a complex [1] story and you have to watch every step you take to get it right. libcamera [2] does a great job to simplify this in a platform independent way and should be u…

TIL - Git jump TIL, Today I Learned, is more of a "I just figured this out: here are my notes, you may find them useful too" rather than a full blog post The Git v2.40.0 was released [1] yesterday (2023-03-13) and one of the release notes that caught my e…

Service of a pocket watch Mechanical watches is fascinating.

Razor Leather Case My safety razor broke during usage last week, so I sadly had to order a new one.

Route traffic with NAT Long time ago I wrote a blog post [1] about how to use NAT to route traffic to your embedded device via your host computer.

Leather watch strap keeper My watch was missing the strap keeper, so I had to make one.

Contiguous Memory Allocator Introduction I do find memory management as one of the most fascinating subsystems in the Linux kernel, and I take every chance I see to talk about it.

TIL - U-Boot support for HTTP TIL, Today I Learned, is more of a "I just figured this out: here are my notes, you may find them useful too" rather than a full blog post Until now, U-Boot did only support UDP and were limited to protocols that are based on…

Use custom EDID in Linux Extended Display Identification Data (EDID) is a metadata format for display devices to describe their capabilities such as resolution, display size, timing, bit depth and update frequency.

Audio and Embedded Linux Brief Last time I wrote kernel drivers for the ASoC (ALSA System on Chip) subsystem, the functionality was split up into these parts: Platform class driver that defines the SoC audio interface for the actual CPU itself.

Debug kernel with KGDB What is KGDB?

TIL - Virtual CAN interfaces TIL, Today I Learned, is more of a "I just figured this out: here are my notes, you may find them useful too" rather than a full blog post There are many scenarios where a virtual Controller Area Network(CAN) interface could be

Raspberry Pi and QEMU What is QEMU?

TIL - Debug FindBoost in CMake TIL, Today I Learned, is more of a "I just figured this out: here are my notes, you may find them useful too" rather than a full blog post When you use find_package for a Boost component in CMake it will end up with the Find…

Crosscompile libcamera for RPi Goal The goal is to cross-compile libcamera [1] and libcamera-apps [2] for Raspberry Pi using the latest Raspbian [3] (Bullseye) release.

What is libcamera and why should you use it Read out a picture from camera Once in a time, video devices were not that complex.

TIL - Yocto bitbake-getvar TIL, Today I Learned, is more of a "I just figured this out: here are my notes, you may find them useful too" rather than a full blog post Writing recipes for Yocto has recently become something I do several times a week.

TIL - SystemD and $MAINPID TIL, Today I Learned, is more of a "I just figured this out: here are my notes, you may find them useful too" rather than a full blog post A special environmnent variable, $MAINPID, is set and is available for the .service file.

HID report descriptors and Linux HID Devices USB HID (Human Interface Device) device class is the type of computer peripherals that human interacts with, such as keyboards, mice, game controllers and touchscreens.

Industrial I/O and triggers I've maintained a couple of IIO-drivers (MCP3911 [4] and LTC1660 [5]) for some time now and it's time to give at least the MCP3911 a face-lift.

Mounting with systemd and udev Systemd hasn't always been my first choice as init system for embedded system, but I cannot ignore that it has many good and handy things that other init systems don't.

Open Source "Free as in freedom - not as in free beer".

Forge a hoof scratch In this project I made a hoof scratch as a gift to a friend - made out of a horse shoe of course.

This website setup This post is more for my own good if I have to setup my website once again.

Leather sewing machine I have worked with leather for some time which I enjoyed a lot.

Leather penguin A Linux guy needs his penguin, right?

Player's handbook, Dungeon Master's Guide and Monster Manual These three books are the "core books" for Dungeons and Dragons 5e.

Dungeons and dragons - My confession I have always been fascinated about fantasy.

V4L2 and media controller The media infrastructure in the kernel is a giant beast handling many different types of devices involving different busses and electrical interfaces.

Parsing command line options Parsing command line options is something almost every command or applications needs to handle in some way, and there are too many home-made argument parsers out there.

Embedded Linux Conference 2019 Here we go again!

libsegfault.so The dynamic linker [1] in a Linux system is using several environment variables to customize it's behavior.

Embedded Linux Conference 2018 OK, time for another conference.

Oppigård Amarillo, third batch This recipe is also from the book [1] and the third batch of this beer and it is one of my favorite hopier beer.

Green fingers This year I have engaged more than usual in growing vegetables.

St Eriks Pale Ale, second batch The book "Klona öl" [1] ("Clone beers" in English) has collected recipes from many Swedish breweries.

BEER2RST - my first attempt with golang I'm using Beersmith [1] a (non-free...) software to create my beer recipes.

Lund Linux Conference 2018 It's just two weeks from now til the Lund Linux Conference (LLC) [1] begins!

ath10k QCA6584 and Wireless network stack ATH10K is the mac80211 wireless driver for Qualcomm Atheros QCA988x family of chips, and I'm currently working [1] with the QCA6584 chip which is an automotive graded radio chip with PHY support for the abgn+ac mo…