I have an AMD 2400G APU and I have connected a monitor using HDMI. I am using the amdgpu kernel driver to get a framebuffer. When the driver loads, black becomes dark grey on my screen. The reason is most likely, that the driver thinks, that my screen is a TV and the driver thinks, that 16-240 is the RGB range to use, instead of the full 0-255.
I had this issue before on an intel gpu with X11. The solution was to call
xrandr --output HDMI1 --set "Broadcast RGB" "Full"
But now I want to accomplish the same without X11 directly on the framebuffer on amd graphics. I have tried some things with fbset, but that didn't work out for me.
I have seen some tutorials on hacking/patching EDID for the display, but I would rather avoid that. I would really prefer just switching things on the running system, like I was able to do in X11.
