Weston

If Weston fails to start double check :
/etc/xdg/weston/weston.ini
and verify that the output name and screen resolution matches the configured U-Boot environment.
For example on Renesas Porter board rev 1.0 with screen resolution 1024x768:

[core]
shell=desktop-shell.so
backend=drm-backend.so

[shell]
locking=true
# Uncomment below to hide panel
#panel-location=none

[output]
name=HDMI-A-1
mode=1024x768
#mode=1920x1080
#mode=173.00  1920 2048 2248 2576  1080 1083 1088 1120 -hsync +vsync