I wanted to share my workaround of setting the proper resolution on both, console and Xorg:
Display: Generic 5 inch 800x480 HDMI "Waveshare V2" clone
Kernel: mainline
Proper/usual way of doing it:
1. Edit uboot/dtb display variable -> does not work currently because only a few resolutions are supported (848x480 is the closest).
2. Add a new mode with "xrandr" and "gtf or cvt" -> but "cvt 800 480 60" does yield a modeline which totally glitches out the display.
Possible workaround:
1. Set linux console to 800x480: "sudo fbset -g 800 480 800 480 32"
2. Edit or create something similar to "/etc/X11/xorg.conf.d/01-armbian-defaults.conf" and add:
Section "Device"
Identifier "fbdev device"
Driver "fbdev"
EndSection
3. Start the Xserver.
For me this effectively disables the Xserver's self-configuration and thus it looks for the resolution that was set prior by fbset. Since that is set to 800x480, Xserver picks it up.
This however also breaks the "randr" extension, so no live screen rotation and stuff, which is a pity.
If you want to rotate the screen you have to add the following instead:
Section "Device"
Identifier "fbdev device"
Driver "fbdev"
Option "ShadowFB" "true"
Option "Rotate" "CW" #Clockwise
EndSection
So yeah, to conclude - its a pretty hacky solution and someone might hopefully find a more suitable one.
Regards
