<![CDATA[warning using eglfs on a raspberry pi 4 with a yocto distro & performance issue]]>Hi all. I'm getting my head around using a custom yocto build of linux with QT. I'm playing around, learning how I'd develop a QT gui application for a device. I've added QT to the yocto image, and have used the generated SDK to compile some simple qt terminal and gui applications. I created a test gui with some sliders and knobs, but I get the following warnings on execution:

XDG_RUNTIME_DIR not set, defaulting to 'tmp/runtime-root' ( thought this was because I ran as admin, so added my user to video group so I didn't need admin, but the warning persists)

Couldn't get V3D INDENT0: no such device (couldn't find anything about this error at all!)

Setting Framebuffer is only avalible with DRN atomic API

Attribute QT::AA_ShareOpenGLContexts must be set before QCoreApplication is created.

app seems to run fine anyway, but the performance is terrible. Moving a slider or knob at all pins the cpu at 100% and takes about a second to complete the frame update. Could this be related to some of the warnings?

]]>https://forum.qt.io/topic/114453/warning-using-eglfs-on-a-raspberry-pi-4-with-a-yocto-distro-performance-issueRSS for NodeSun, 16 Aug 2026 10:11:33 GMTTue, 05 May 2020 08:50:16 GMT60