No video at first, Pi2 and Pi3


Testing my new Pyro build on the Pi, currently at version 0.3.2, X fails to start and it stays at the commandline. Then, I type "xwin" and X starts.

So, what's the problem? I found from /var/log/Xorg.0.log, that '/dev/dri/card0' is missing. Or rather it takes awhile to appear.
I put a wait-loop at the end of /etc/rc.d/rc.sysinit, and found that it takes 4 seconds for /dev/dri/card0 to appear!!!!

I discovered why, not the delay, but why we have this new issue. Pyro is compiled in OpenEmbedded with support for VC4 video acceleration. Read about it here:
https://wiki.gentoo.org/wiki/Raspberry_Pi_VC4

In 'config.txt':
# Enable VC4 Graphics
dtoverlay=vc4-kms-v3d,cma-256


So, looks like I need to put in a permanent wait-loop somewhere, before starting X.


Comments:

vc4 configuration   Posted on 4 Jul 2017, 10:33 by admin
Useful info here:

https://github.com/anholt/linux/wiki/VC4-configuration