fix #74; list possible bindings

CMakeLists.txt

@@ -7,9 +7,11 @@ project(lib_bluetoe CXX)
 
 option(BLUETOE_BUILD_UNIT_TESTS "If true, unit test targets are added are build.")
 
+# Libray required by everything in Bluetoe. If there is need to add build options,
+# add them on bluetoe::iface.
 add_library(bluetoe_iface INTERFACE)
-target_compile_features(bluetoe_iface INTERFACE cxx_std_11)
 add_library(bluetoe::iface ALIAS bluetoe_iface)
+target_compile_features(bluetoe_iface INTERFACE cxx_std_11)
 target_include_directories(bluetoe_iface INTERFACE ${CMAKE_CURRENT_SOURCE_DIR})
 
 # Link Layer implementation based on radio hardware

examples/CMakeLists.txt

@@ -10,8 +10,13 @@ if (NOT CMAKE_CROSSCOMPILING)
     message(FATAL_ERROR " examples can only be cross compiled to arm cortex-m, missing -Dtoolchain_file on cmake invocation?")
 endif()
 
+set(AVAILABLE_BINDINGS nrf51 nrf52)
+
+set(BINDING nrf52 CACHE STRING "Microcontroller target to build for")
+set_property(CACHE BINDING PROPERTY STRINGS ${AVAILABLE_BINDINGS})
+
 if (NOT BINDING)
-    message(FATAL_ERROR " A binding must be defined. Use -DBINDING=nrf51. Current available bindings are nrf51, nrf52")
+    message(FATAL_ERROR " A binding must be defined. Use -DBINDING=nrf51. Current available bindings are ${AVAILABLE_BINDINGS}")
 endif()
 
 # include hardware specific compile options and definitions that must be apllied to the whole project
@@ -50,6 +55,9 @@ add_subdirectory(assert)
 # bluetoe library
 add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/.. ${CMAKE_CURRENT_BINARY_DIR}/bluetoe)
 
+# Additional settings for the Bluetoe library itself:
+target_link_libraries(bluetoe_iface INTERFACE assert::arm)
+
 function(add_bluetoe_example target_name)
     add_executable(${target_name} ${target_name}.cpp runtime.cpp)
     set_target_properties(${target_name}