initial minimal PX4_ROS2 platform and px4_ros2_default build (#20689)

- new ROS2 platform in PX4 intended for creating configs that build and run entirely in ROS2
 - PX4_CONFIG defaults to px4_ros2_default if no config specified and in a colcon workspace with ROS_VERSION=2
 - currently doesn't do much other than allow you to build px4 msgs interface package

platforms/nuttx/cmake/px4_impl_os.cmake

@@ -64,10 +64,19 @@ function(px4_os_add_flags)
 		${PX4_SOURCE_DIR}/platforms/nuttx/NuttX/apps/include
 	)
 
-	# prevent using the toolchain's std c++ library
-	add_compile_options($<$<COMPILE_LANGUAGE:CXX>:-nostdinc++>)
 
-	add_compile_options($<$<COMPILE_LANGUAGE:CXX>:-fno-sized-deallocation>)
+	set(cxx_flags)
+	list(APPEND cxx_flags
+		-fno-exceptions
+		-fno-rtti
+		-fno-sized-deallocation
+		-fno-threadsafe-statics
+		-nostdinc++ # prevent using the toolchain's std c++ library
+	)
+
+	foreach(flag ${cxx_flags})
+		add_compile_options($<$<COMPILE_LANGUAGE:CXX>:${flag}>)
+	endforeach()
 
 	add_compile_options($<$<COMPILE_LANGUAGE:C>:-Wbad-function-cast>)
 

platforms/nuttx/src/canbootloader/arch/nxp/s32k14x/drivers/can/driver.c

@@ -53,7 +53,7 @@
 #include <arch/board/board.h>
 #include "flexcan.h"
 
-#include <lib/systemlib/crc.h>
+#include <lib/crc/crc.h>
 
 
 #define CAN_TX_TIMEOUT_MS     (200 /(1000/(1000000/CONFIG_USEC_PER_TICK)))

platforms/nuttx/src/canbootloader/arch/stm/stm32f4/drivers/can/driver.c

@@ -55,7 +55,7 @@
 
 #include <arch/board/board.h>
 
-#include <lib/systemlib/crc.h>
+#include <lib/crc/crc.h>
 
 #define INAK_TIMEOUT          65535
 

platforms/nuttx/src/canbootloader/arch/stm/stm32f7/drivers/can/driver.c

@@ -54,7 +54,7 @@
 
 #include <arch/board/board.h>
 
-#include <lib/systemlib/crc.h>
+#include <lib/crc/crc.h>
 
 #define INAK_TIMEOUT          65535
 

platforms/nuttx/src/canbootloader/protocol/uavcan.c

@@ -49,7 +49,7 @@
 #include "uavcan.h"
 #include "can.h"
 
-#include <lib/systemlib/crc.h>
+#include <lib/crc/crc.h>
 
 #define CAN_REQUEST_TIMEOUT 1000
 #define ANY_NODE_ID 0

platforms/nuttx/src/canbootloader/uavcan/main.c

@@ -58,7 +58,7 @@
 #include <drivers/bootloaders/boot_app_shared.h>
 #include <drivers/bootloaders/boot_alt_app_shared.h>
 #include <drivers/drv_watchdog.h>
-#include <lib/systemlib/crc.h>
+#include <lib/crc/crc.h>
 
 //#define DEBUG_APPLICATION_INPLACE    1 /* Never leave defined */
 #define DEBUG_NO_FW_UPDATE           1 /* With DEBUG_APPLICATION_INPLACE

platforms/nuttx/src/px4/stm/stm32_common/board_hw_info/CMakeLists.txt

@@ -34,4 +34,4 @@
 px4_add_library(arch_board_hw_info
 	board_hw_rev_ver.c
 )
-target_link_libraries(arch_board_hw_info PRIVATE arch_adc systemlib)
+target_link_libraries(arch_board_hw_info PRIVATE arch_adc crc)

platforms/nuttx/src/px4/stm/stm32_common/board_hw_info/board_hw_rev_ver.c

@@ -48,8 +48,8 @@
 #include <fcntl.h>
 #include <board_config.h>
 
-#include <systemlib/crc.h>
-#include <systemlib/px4_macros.h>
+#include <lib/crc/crc.h>
+#include <lib/systemlib/px4_macros.h>
 
 #if defined(BOARD_HAS_HW_VERSIONING)