CROWN_MAIN_SRC defined in root cmake file

CMakeLists.txt

@@ -61,7 +61,9 @@ set (CROWN_THIRD_LIBS
 
 # detect operating system
 if (${CMAKE_SYSTEM_NAME} MATCHES "Linux")
-	set(LINUX 1)
+	set (LINUX 1)
+
+	set (CROWN_MAIN_SRC ${CMAKE_SOURCE_DIR}/src/os/linux/main.cpp)
 
 	list (APPEND CROWN_INCLUDES
 		${CMAKE_SOURCE_DIR}/src/os/linux
@@ -72,6 +74,8 @@ endif (${CMAKE_SYSTEM_NAME} MATCHES "Linux")
 if (${CMAKE_SYSTEM_NAME} MATCHES "Windows")
 	set(WINDOWS 1)
 
+	set (CROWN_MAIN_SRC ${CMAKE_SOURCE_DIR}/src/os/win/main.cpp)
+
 	list (APPEND CROWN_INCLUDES
 		${CMAKE_SOURCE_DIR}/src/os/win
 		${CMAKE_SOURCE_DIR}/src/renderers/gl/wgl