I have Rock64 board with latest Armbian Focal flashed on it. I want to use it with this HDMI display by Waveshare: https://www.waveshare.com/wiki/7inch_HDMI_LCD_(H)_(with_case)
Now, when I connect it to Rock64 it runs as 1080p downscaled by HDMI controller on display, resulted image is garbage, even though it is present. As was discussed here: https://forum.armbian.com/topic/10071-tinker-board-hdmi-resolutions-do-not-all-work/ current kernel/u-boot doesn't have required video mode to run this display properly.
I tried to set required mode with xrandr but with no success.
Can anyone help me to figure out how to patch kernel/u-boot to get this thing work properly? And what exactly is setting video mode kernel or u-boot? I've found where video modes are set in u-boot source, but I suspect that adding required video mode there won't be enough, am I right?
