cmake: changes required for qurt build

Fixed CMakeLists.txt to be consistent with module.mk
Converted PX4_TICKS_PER_SEC to define for QURT to get around relocation error
Added stubs for QURT so building a full executable can be tested. This will
enable CI testing without the full Hexagon SDK.

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

src/firmware/posix/CMakeLists.txt

@@ -7,9 +7,6 @@ message(STATUS "module list: ${module_dir_list}")
 
 include_directories(${CMAKE_CURRENT_BINARY_DIR})
 
-#add_custom_command(OUTPUT apps.h
-#	COMMAND ${PYTHON_EXECUTABLE} ${CMAKE_SOURCE_DIR}/Tools/posix_apps.py > apps.h)
-
 foreach(directory ${module_dir_list})
 	message(STATUS "directory: ${directory}")
 	px4_mangle_name(${directory} mangled_name)

src/firmware/qurt/CMakeLists.txt

@@ -15,8 +15,9 @@ foreach(directory ${module_dir_list})
 	list(APPEND module_list
 		${mangled_name})
 endforeach()
+
 px4_qurt_generate_builtin_commands(
-	OUT apps.h
+	OUT ${CMAKE_BINARY_DIR}/apps.h
 	MODULE_LIST ${module_list})
 
 # FIXME @jgoppert - how to work around issues like this?
@@ -25,9 +26,22 @@ px4_qurt_generate_builtin_commands(
 set(CMAKE_SHARED_LIBRARY_LINK_C_FLAGS "")
 set(CMAKE_SHARED_LIBRARY_LINK_CXX_FLAGS "")
 
-add_library(mainapp 
-	${CMAKE_SOURCE_DIR}/src/platforms/qurt/px4_layer/main.cpp
-	apps.h)
+# Enable build without HexagonSDK to check link dependencies
+if ("${QURT_ENABLE_STUBS}" STREQUAL "1")
+	add_executable(mainapp 
+		${CMAKE_SOURCE_DIR}/src/platforms/qurt/dspal/dspal_stub.c
+		${CMAKE_BINARY_DIR}/apps.h)
+else("${QURT_ENABLE_STUBS}" STREQUAL "1")
+	add_library(mainapp 
+		${CMAKE_SOURCE_DIR}/src/platforms/qurt/dspal/dspal_stub.c
+		${CMAKE_BINARY_DIR}/apps.h)
+endif()
+
+set(main_link_flags
+	"-T${CMAKE_SOURCE_DIR}/cmake/posix/ld.script"
+	)
+px4_join(OUT main_link_flags LIST ${main_link_flags} GLUE " ")
+set_target_properties(mainapp PROPERTIES LINK_FLAGS ${main_link_flags})
 
 target_link_libraries(mainapp
 	-Wl,--whole-archive