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.

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.

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.

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.

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.