SITL: add multi-vehicle support to rcS

This also removes the HIGHRES_IMU mavlink stream to the GCS. I don't see
why it's needed and it adds noticeable CPU load.

Tools/sitl_multiple_run.sh

@@ -2,21 +2,16 @@
 # run multiple instances of the 'px4' binary, but w/o starting the simulator.
 # It assumes px4 is already built, with 'make posix_sitl_default'
 
+# The simulator is expected to send to UDP port 14560+i for i in [0, N-1]
+# For example jmavsim can be run like this:
+#./Tools/jmavsim_run.sh -p 14561
+
 sitl_num=2
-
-sim_port=15019
-mav_port=15010
-mav_port2=15011
-
-mav_oport=15015
-mav_oport2=15016
-
-port_step=10
+[ -n "$1" ] && sitl_num="$1"
 
 SCRIPT_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
 src_path="$SCRIPT_DIR/.."
 
-rc_script="posix-configs/SITL/init/ekf2/multiple_iris"
 build_path=${src_path}/build/posix_sitl_default
 
 echo "killing running instances"
@@ -24,32 +19,17 @@ pkill -x px4 || true
 
 sleep 1
 
-cd $build_path
+export PX4_SIM_MODEL=iris
 
-user=`whoami`
-n=1
-while [ $n -le $sitl_num ]; do
-	working_dir="instance_$n"
-	if [ ! -d $working_dir ]; then
-		mkdir -p "$working_dir"
-		pushd "$working_dir" &>/dev/null
-
-		# replace template config with configured ports of current instance
-		cat ${src_path}/${rc_script} | sed s/_SIMPORT_/${sim_port}/ | \
-			sed s/_MAVPORT_/${mav_port}/g | sed s/_MAVOPORT_/${mav_oport}/ | \
-			sed s/_MAVPORT2_/${mav_port2}/ | sed s/_MAVOPORT2_/${mav_oport2}/ > rcS
-		popd &>/dev/null
-	fi
+n=0
+while [ $n -lt $sitl_num ]; do
+	working_dir="$build_path/instance_$n"
+	[ ! -d "$working_dir" ] && mkdir -p "$working_dir"
 
 	pushd "$working_dir" &>/dev/null
 	echo "starting instance $n in $(pwd)"
-	sudo -b -u $user ../bin/px4 -i $n -d "$src_path" -s rcS >out.log 2>err.log
+	../bin/px4 -i $n -d "$src_path/ROMFS/px4fmu_common" -s etc/init.d-posix/rcS >out.log 2>err.log &
 	popd &>/dev/null
 
 	n=$(($n + 1))
-	sim_port=$(($sim_port + $port_step))
-	mav_port=$(($mav_port + $port_step))
-	mav_port2=$(($mav_port2 + $port_step))
-	mav_oport=$(($mav_oport + $port_step))
-	mav_oport2=$(($mav_oport2 + $port_step))
 done