More xorg mischief on Rpi3B, failed to open /dev/io

[Yuri Pankov]

bob prohaska wrote:
> Enabling amdgpu in llvm80 solved the problem of compiling xorg
> on a Pi3b, but now that it's built and installed it still fails
> to run.

Probably stupid question, but as you didn't mention it, is the actual 
drm module loaded? Also you don't need the 'configure' step, how about a 
simple 'startx' from normal user?