add sanity check

scripts/build_distro

@@ -22,6 +22,17 @@ then
   PKG_CLEAN+=" ${CLEAN_EMU_32BIT}"
 fi
 
+# Device RK3566-X55 needs a built RK3466 root
+if [ "${DEVICE}" = "RK3566-X55" ]
+then
+    if [ ! -d "build.${DISTRO}-RK3566.${ARCH}" ]
+    then
+        echo "ERROR: Can't find build root build.${DISTRO}-RK3566.${ARCH}"
+        echo "You need to build RK3566 before RK3566-X55"
+        exit 1
+    fi
+fi
+
 # If DEVICE_ROOT is defined and not the device being built, make sure that the
 # build folder is a link to root rather than a folder.