Add support for compiling modules into kernel side

Define __KERNEL__ macro during compilation and place the module in separate library

Remove default library linking to m or libc on NuttX. Add these in platform layer instead, since
they are different on kernel and user side

Signed-off-by: Jukka Laitinen <jukkax@ssrc.tii.ae>

CMakeLists.txt

@@ -125,6 +125,11 @@ define_property(GLOBAL PROPERTY PX4_MODULE_LIBRARIES
                  FULL_DOCS "List of all PX4 module libraries"
                  )
 
+define_property(GLOBAL PROPERTY PX4_KERNEL_MODULE_LIBRARIES
+                 BRIEF_DOCS "PX4 kernel side module libs"
+                 FULL_DOCS "List of all PX4 kernel module libraries"
+                 )
+
 define_property(GLOBAL PROPERTY PX4_MODULE_PATHS
                  BRIEF_DOCS "PX4 module paths"
                  FULL_DOCS "List of paths to all PX4 modules"
@@ -142,6 +147,7 @@ set(CONFIG "px4_sitl_default" CACHE STRING "desired configuration")
 
 include(px4_add_module)
 set(config_module_list)
+set(config_kernel_list)
 
 # Find Python
 # If using catkin, Python 2 is found since it points

Kconfig

@@ -118,6 +118,11 @@ config BOARD_CRYPTO
     help
         Enable PX4 Crypto Support. Select the implementation under drivers
 
+config BOARD_PROTECTED
+    bool "Memory protection"
+    help
+        Enable memory protection via MPU/MMU
+
 menu "Serial ports"
 
     config BOARD_SERIAL_URT6

cmake/kconfig.cmake

@@ -26,6 +26,8 @@ set(COMMON_KCONFIG_ENV_SETTINGS
 	ROMFSROOT=${config_romfs_root}
 )
 
+set(config_user_list)
+
 if(EXISTS ${BOARD_DEFCONFIG})
 
     # Depend on BOARD_DEFCONFIG so that we reconfigure on config change
@@ -79,6 +81,17 @@ if(EXISTS ${BOARD_DEFCONFIG})
             endif()
         endif()
 
+        # Find variable name
+        string(REGEX MATCH "^CONFIG_USER[^=]+" Userspace ${NameAndValue})
+
+        if(Userspace)
+            # Find the value
+            string(REPLACE "${Name}=" "" Value ${NameAndValue})
+            string(REPLACE "CONFIG_USER_" "" module ${Name})
+            string(TOLOWER ${module} module)
+            list(APPEND config_user_list ${module})
+        endif()
+
         # Find variable name
         string(REGEX MATCH "^CONFIG_DRIVERS[^=]+" Drivers ${NameAndValue})
 
@@ -171,6 +184,16 @@ if(EXISTS ${BOARD_DEFCONFIG})
 
     endforeach()
 
+    # Put every module not in userspace also to kernel list
+    foreach(modpath ${config_module_list})
+        get_filename_component(module ${modpath} NAME)
+        list(FIND config_user_list ${module} _index)
+
+        if (${_index} EQUAL -1)
+            list(APPEND config_kernel_list ${modpath})
+        endif()
+    endforeach()
+
     if(PLATFORM)
         # set OS, and append specific platform module path
         set(PX4_PLATFORM ${PLATFORM} CACHE STRING "PX4 board OS" FORCE)
@@ -336,6 +359,7 @@ if(EXISTS ${BOARD_DEFCONFIG})
 	list(APPEND config_module_list ${board_support_src_rel}/src)
 
 	set(config_module_list ${config_module_list})
+	set(config_kernel_list ${config_kernel_list})
 
 endif()
 

cmake/px4_add_library.cmake

@@ -44,8 +44,8 @@ function(px4_add_library target)
 	target_compile_definitions(${target} PRIVATE MODULE_NAME="${target}")
 
 	# all PX4 libraries have access to parameters and uORB
-	add_dependencies(${target} uorb_headers)
-	target_link_libraries(${target} PRIVATE prebuild_targets parameters_interface px4_platform)
+	add_dependencies(${target} uorb_headers parameters)
+	target_link_libraries(${target} PRIVATE prebuild_targets)
 
 	set_property(GLOBAL APPEND PROPERTY PX4_MODULE_PATHS ${CMAKE_CURRENT_SOURCE_DIR})
 	px4_list_make_absolute(ABS_SRCS ${CMAKE_CURRENT_SOURCE_DIR} ${ARGN})

cmake/px4_add_module.cmake

@@ -154,9 +154,29 @@ function(px4_add_module)
 	# all modules can potentially use parameters and uORB
 	add_dependencies(${MODULE} uorb_headers)
 
+	# Check if the modules source dir exists in config_kernel_list
+	# in this case, treat is as a kernel side component for
+	# protected build
+	get_target_property(MODULE_SOURCE_DIR ${MODULE} SOURCE_DIR)
+	file(RELATIVE_PATH module ${PROJECT_SOURCE_DIR}/src ${MODULE_SOURCE_DIR})
+
+	list (FIND config_kernel_list ${module} _index)
+	if (${_index} GREATER -1)
+		set (KERNEL TRUE)
+	endif()
+
 	if(NOT DYNAMIC)
-		target_link_libraries(${MODULE} PRIVATE prebuild_targets parameters_interface px4_layer px4_platform systemlib)
-		set_property(GLOBAL APPEND PROPERTY PX4_MODULE_LIBRARIES ${MODULE})
+		target_link_libraries(${MODULE} PRIVATE prebuild_targets parameters_interface px4_platform systemlib perf)
+		if (${PX4_PLATFORM} STREQUAL "nuttx" AND NOT CONFIG_BUILD_FLAT AND KERNEL)
+			target_link_libraries(${MODULE} PRIVATE px4_kernel_layer uORB_kernel)
+			set_property(GLOBAL APPEND PROPERTY PX4_KERNEL_MODULE_LIBRARIES ${MODULE})
+		else()
+			target_link_libraries(${MODULE} PRIVATE px4_layer uORB)
+			set_property(GLOBAL APPEND PROPERTY PX4_MODULE_LIBRARIES ${MODULE})
+		endif()
+		set_property(GLOBAL APPEND PROPERTY PX4_MODULE_PATHS ${CMAKE_CURRENT_SOURCE_DIR})
+		px4_list_make_absolute(ABS_SRCS ${CMAKE_CURRENT_SOURCE_DIR} ${SRCS})
+		set_property(GLOBAL APPEND PROPERTY PX4_SRC_FILES ${ABS_SRCS})
 	endif()
 
 	set_property(GLOBAL APPEND PROPERTY PX4_MODULE_PATHS ${CMAKE_CURRENT_SOURCE_DIR})
@@ -197,6 +217,10 @@ function(px4_add_module)
 		target_compile_options(${MODULE} PRIVATE ${COMPILE_FLAGS})
 	endif()
 
+	if (KERNEL)
+		target_compile_options(${MODULE} PRIVATE -D__KERNEL__)
+	endif()
+
 	if(INCLUDES)
 		target_include_directories(${MODULE} PRIVATE ${INCLUDES})
 	endif()