I am setting up a beaglebone black with HDMI output.
startx reports “(EE) no screens found(EE)”
I should have installed all required packages when comparing to a previous setup running with HDMI output on another system.
When running, /opt/scripts/tools/update_kernel.sh this was updated to 4.19.94-ti-r71 .
Then without any further change, the graphical application started on the screen, but as soon as the mouse was moved, the system crashed resulting in a reboot. Then again, when moving the mouse, the system crashed.
That’s not practicle and supposing that the -r71 is not actually stable, or needs other updates that are not proposed through “apt upgrade” so I decided to avoid it.
So I reverted to the original kernel version, to verify that it was indeed the kernel that was responsible for making the HDMI output work.
After:
apt purge '*-ti-71'
and
apt reinstall libpruio-modules-4.19.94-ti-r42 linux-image-4.19.94-ti-r42 rtl8723bu-modules-4.19.94-ti-r42 rtl8821cu-modules-4.19.94-ti-r42 ti-cmem-4.16.00.00-modules-4.19.94-ti-r42
I could reboot to a system with the initial kernel, and there was no HDMI output, startx reports it can not find the screen.
So these are the installed kernel modules:
i libpruio-modules-4.19.94-ti-r42 - libpruio modules
i linux-image-4.19.94-ti-r42 - Linux kernel, version 4.19.94-ti-r42
i rtl8723bu-modules-4.19.94-ti-r42 - rtl8723bu modules
i rtl8821cu-modules-4.19.94-ti-r42 - rtl8821cu modules
i ti-cmem-4.16.00.00-modules-4.19.94-ti-r42 - ti-cmem modules
After that I tried adding the following because that was recommended in some posts, but that did not help:
apt install xserver-xorg-video-fbdev x11-utils
The working system uses a version that the update_kernel.sh script does not even propose to update:
info: you are running: [4.1.12-ti-r29], latest is: updating…
Here are the outputs from /opt/scripts/tools/version.sh - I had to copy that script to the older system because it did not even exist there:
nonworkingVersion.txt (3,2 Ko)
workingVersion.txt (6,9 Ko)