bb black - enable framebuffer on console image

General Discussion
1

Can anybody provide info or links to enabling the framebuffer on the headless ‘console’ image on the beaglebone black?
I’m porting a kiosk application to the bbb and I need to be able to draw directly to the framebuffer with no window manager, GUI or any other graphic layers. This is something I’ve done in the past on other hardware, but google has turned up nothing for the BBB.
I could use the full iot image then disable all the X stuff but that seems a bit hackish.
Thanks Paul

2

@bbbpaul Check this out Linux Framebuffer
Of course it will only work if you have the framebuffer device in /dev

3

What interface does your app use? directFB, DRM, xorg, or wayland…

All image console, iot, xfce/lxqt have the hdmi enabled…

Regards,

4

Sorry, a correction - it’s the iot image, not console. My bad.

However further investigation appears to show something odd happening.
I flashed a clean image onto an SD card (debian-10.3-iot-armhf-2020-04-06) and the board came up just fine - /dev/fb0 existed and I could write to it just as I would expect. However after an ‘apt upgrade’ and reboot, the monitor would not wake up and there was no /dev/fb*.
I havn’t been able to get the monitor to fire up at all (just the same as in my earlier tests, which is why I thought I needed to somehow enable the framebuffer).
I’ll try with a different board.

In reply to RobertCNelson, I’m just writing directly to /dev/fb*, so I’m not sure what interface that would be - xorg?. It appears that this should just work. I need to track down why /dev/fb* is not appearing. I’ll do some more work and let you know how I get on.
Thanks for the responses so far.

Thanks.

5

That’s very weird… i’d retest with the latest snapshot, encase something broke that old image on update.

https://forum.beagleboard.org/tag/latest-images

Regards,

6

Ok, Ive confirmed it:

Flash bone-debian-10.3-iot-armhf-2020-04-06-4gb.img to an sd card.
Boot bbb.
→ video works
sudo apt update
sudo apt upgrade
reboot
→ no video output.

Flashing the latest image (bone-debian-10.12-iot-armhf-2022-08-01-4gb.img) works just fine - video works and /dev/fb0 exists as expected after updates and upgrades.

Thanks Robert and Benedict (those ioctls could be usefull, I didnt know about those).

Paul