posix: add option to use the startup config directory and name for th…

…e working directory

launch/single_vehicle_spawn.launch

@@ -19,7 +19,7 @@
     <arg name="cmd" default="$(find xacro)/xacro $(find px4)/Tools/sitl_gazebo/models/rotors_description/urdf/$(arg vehicle)_base.xacro rotors_description_dir:=$(find px4)/Tools/sitl_gazebo/models/rotors_description mavlink_udp_port:=$(arg mavlink_udp_port) --inorder"/>
     <param command="$(arg cmd)" name="rotors_description"/>
     <!-- PX4 SITL -->
-    <node name="sitl_$(arg ID)" pkg="px4" type="px4" output="screen" args="$(find px4) $(arg rcS)">
+    <node name="sitl_$(arg ID)" pkg="px4" type="px4" output="screen" args="-w $(find px4) $(arg rcS)">
     </node>
     <!-- spawn vehicle -->
     <node name="$(arg vehicle)_$(arg ID)_spawn" output="screen" pkg="gazebo_ros" type="spawn_model" args="-urdf -param rotors_description -model $(arg vehicle)_$(arg ID) -package_to_model -x $(arg x) -y $(arg y) -z $(arg z) -R $(arg R) -P $(arg P) -Y $(arg Y)"/>

platforms/posix/src/main.cpp

@@ -241,8 +241,10 @@ static void run_cmd(const vector<string> &appargs, bool exit_on_fail, bool silen
 static void usage()
 {
 
-	cout << "./px4 [-d] [data_directory] startup_config [-h]" << endl;
-	cout << "   -d            - Optional flag to run the app in daemon mode and does not listen for user input." <<
+	cout << "./px4 [-d] [-w] [data_directory] startup_config [-h]" << endl;
+	cout << "   -d            - Optional flag to run the app in daemon mode and does not listen for user input" <<
+	     endl;
+	cout << "   -w            - Use the startup_config location and name as the working directory for rootfs" <<
 	     endl;
 	cout << "                   This is needed if px4 is intended to be run as a upstart job on linux" << endl;
 	cout << "<data_directory> - directory where ROMFS and posix-configs are located (if not given, CWD is used)" << endl;
@@ -296,6 +298,7 @@ int main(int argc, char **argv)
 {
 	bool daemon_mode = false;
 	bool chroot_on = false;
+	bool change_working_dir = false;
 
 	tcgetattr(0, &orig_term);
 	atexit(restore_term);
@@ -331,6 +334,9 @@ int main(int argc, char **argv)
 			if (strncmp(argv[index], "-d", 2) == 0) {
 				daemon_mode = true;
 
+			} else if (strncmp(argv[index], "-w", 2) == 0) {
+				change_working_dir = true;
+
 			} else if (strncmp(argv[index], "-h", 2) == 0) {
 				usage();
 				return 0;
@@ -397,6 +403,29 @@ int main(int argc, char **argv)
 		return -1;
 	}
 
+	if (change_working_dir) {
+		char rootfs_path[path_max_len];
+
+		strcpy(rootfs_path, commands_file.c_str());
+		strcat(rootfs_path, "_wd");
+
+		// check if there is an existing path to working directory, or make it
+		if (!dirExists(rootfs_path)) {
+			if (mkpath(rootfs_path, S_IRUSR | S_IWUSR | S_IXUSR) == -1) {
+				PX4_ERR("Error making rootfs path %s", rootfs_path);
+				return -1;
+			}
+		}
+
+		// change current working directory
+		if (chdir(rootfs_path) == -1) {
+			PX4_ERR("Error changing to rootfs path %s", rootfs_path);
+			return -1;
+		}
+
+		cout << "working directory: " << pwd() << endl;
+	}
+
 	// create sym-links
 	if (symlinks_needed) {
 		vector<string> path_sym_links;