@YFZdude @mitu @dankcushions

It was the freaking port.

I connected it to the second port and booted it up, then started playing around with the config again. Lo and behold, hdmi_group=1 didn't cause a catastrophic error! The rest was cake, thanks to you guys.

Very much appreciated, thank you so much for all your help!

@IceRook88 see https://retropie.org.uk/docs/First-Installation/ - we only support the images referred to here (ie https://retropie.org.uk/docs/First-Installation/#download)

The naming depends on the device-tree settings, doesn't affect the actual capability of the GPU. Running the same command on a recent Raspbian OS yields

Graphics: Device-1: bcm2711-vc5 driver: vc4_drm v: N/A bus ID: N/A chip ID: brcm:gpu

RetroPie doesn't support Manjaro OS on the Pi, btw.

You didn't mention how installed RetroPie.

@mitu - Ok, that sounds good, I appreciate the information.

@mitu That's unfortunate. I was about to nag him for a retropie tutorial with his mesa drivers.