diff --git a/ROMFS/Makefile b/ROMFS/Makefile
index ec4221b93a..3b024de06d 100644
--- a/ROMFS/Makefile
+++ b/ROMFS/Makefile
@@ -35,6 +35,10 @@ ROMFS_FSSPEC	:= $(SRCROOT)/scripts/rcS~init.d/rcS \
 		   $(SRCROOT)/mixers/FMU_octo_+.mix~mixers/FMU_octo_+.mix \
 		   $(SRCROOT)/logging/logconv.m~logging/logconv.m
 
+# the EXTERNAL_SCRIPTS variable is used to add out of tree scripts
+# to ROMFS. 
+ROMFS_FSSPEC += $(EXTERNAL_SCRIPTS)
+
 #
 # Add the PX4IO firmware to the spec if someone has dropped it into the
 # source directory, or otherwise specified its location.
diff --git a/ROMFS/scripts/rcS b/ROMFS/scripts/rcS
index 69d791da52..660bf61e9d 100755
--- a/ROMFS/scripts/rcS
+++ b/ROMFS/scripts/rcS
@@ -69,6 +69,16 @@ else
 	fi
 fi
 
+# if this is an APM build then there will be a rc.APM script
+# from an EXTERNAL_SCRIPTS build option
+if [ -f /etc/init.d/rc.APM ]
+then
+	echo Running rc.APM
+	# if APM startup is successful then nsh will exit
+	sh /etc/init.d/rc.APM
+fi
+
+
 #
 # If we are still in flight mode, work out what airframe 
 # configuration we have and start up accordingly.