Try to use outputs on all cards

Normally weston uses card0 only. In dual-GPU setup, it may not be the
one with monitor connected, and when it doesn't find any connector
monitor, it fails to startup. Look also at outputs connected to other
cards too. There doesn't seems to be any option to
check all connected devices, so enumerate them via sysfs manually.

Author: marmarek

scripts/run-gui-backend.guiweston

@@ -29,7 +29,13 @@ if [ -n "$XDG_VTNR" ]; then
     chvt "${XDG_VTNR}"
 fi
 
-weston --config=${CONFIG_FILE} --socket=wl-firstboot-0
+cards=$(ls -d /sys/class/drm/card*| grep -v -- -| cut -d / -f 5)
+primary_card=$(echo "$cards" | head -1 )
+secondary_cards=$(echo "$cards"|
+                  tail -n +2|
+                  xargs printf "%s,")
+
+weston --config=${CONFIG_FILE} --socket=wl-firstboot-0 --drm-device="$primary_card" --additional-devices="$secondary_cards"
 exit_code=$(< ${EXIT_CODE_SAVE})
 
 rm ${CONFIG_FILE} ${RUN_SCRIPT} ${EXIT_CODE_SAVE}