Rebase changes on upstream master

This brings in many of the changes from the PX4 fork on ATLFLight.

Signed-off-by: Mark Charlebois <charlebm@gmail.com>

cmake/common/px4_base.cmake

@@ -90,7 +90,7 @@ include(CMakeParseArguments)
 #		endfunction()
 #
 #		test(NAME "hello" LIST a b c)
-#		
+#
 #		OUTPUT:
 #			name: hello
 #			list: a b c
@@ -349,11 +349,11 @@ function(px4_generate_messages)
 		list(APPEND msg_files_out ${msg_out_path}/${msg}.h)
 	endforeach()
 	add_custom_command(OUTPUT ${msg_files_out}
-		COMMAND ${PYTHON_EXECUTABLE} 
+		COMMAND ${PYTHON_EXECUTABLE}
 			Tools/px_generate_uorb_topic_headers.py
 			${QUIET}
 			-d msg
-			-o ${msg_out_path} 
+			-o ${msg_out_path}
 			-e msg/templates/uorb
 			-t ${CMAKE_BINARY_DIR}/topics_temporary
 		DEPENDS ${DEPENDS} ${MSG_FILES}
@@ -370,11 +370,11 @@ function(px4_generate_messages)
 		list(APPEND msg_multi_files_out ${msg_multi_out_path}/px4_${msg}.h)
 	endforeach()
 	add_custom_command(OUTPUT ${msg_multi_files_out}
-		COMMAND ${PYTHON_EXECUTABLE} 
+		COMMAND ${PYTHON_EXECUTABLE}
 			Tools/px_generate_uorb_topic_headers.py
 			${QUIET}
 			-d msg
-			-o ${msg_multi_out_path} 
+			-o ${msg_multi_out_path}
 			-e msg/templates/px4/uorb
 			-t ${CMAKE_BINARY_DIR}/multi_topics_temporary/${OS}
 			-p "px4_"
@@ -556,6 +556,7 @@ function(px4_add_common_flags)
 			-funsafe-math-optimizations
 			-ffunction-sections
 			-fdata-sections
+			-fPIC
 			)
 	endif()
 
@@ -685,7 +686,7 @@ endfunction()
 #	Input:
 #		dirname					: path to module dir
 #
-#	Output: 
+#	Output:
 #		newname					: module name
 #
 #	Example:
@@ -716,8 +717,8 @@ endfunction()
 function(px4_create_git_hash_header)
 	px4_parse_function_args(
 		NAME px4_create_git_hash_header
-		ONE_VALUE HEADER 
-		REQUIRED HEADER 
+		ONE_VALUE HEADER
+		REQUIRED HEADER
 		ARGN ${ARGN})
 	execute_process(
 		COMMAND git rev-parse HEAD