Embear's Journal

Accessing a DRM Framebuffer to display an image

19 Jul 2021

To test if a display interface works we often don't want to use a huge framework like GTK or Qt. This article shows an easy way on how we can use a framebuffer directly on a DRM graphics driver under Linux.

Booting RAM disk images over Ethernet

08 Jun 2021

To boot a system for the first time, it is often necessary to boot Linux using a RAM disk image. Here are some examples on how to use Ethernet to load and boot RAM disk images.

Why did my remote device reboot?

03 May 2021

When dealing with remote systems it is helpful to know why a system was restarting. Some possible reasons for a reboot are power-cycle, soft-reboot, kernel panic and watchdog. This article shows a concept of how we detect such scenarios by using reserved memory.

Use ramoops for logging under Linux

07 Apr 2021

Store the kernel log, console output and user messages persistent between reboots

Using the parent child relation in a kernel module

08 Mar 2021

This article shows based on an LED how we can gain access to a device, which isn't exposed direclty, by using the parent child relation of Linux kernel drivers

Cross compiling a kernel module

07 Mar 2021

This article shows how we can cross compile a kernel module for an embedded device without replacing the kernel

Deferred Interrupts

10 Feb 2021

Masking interrupts can defer the time when they trigger

Containers and PIDs

17 Jan 2021

Processes inside a container have different numbers than processes outside a container