if (NOT TARGET pico_stdio) pico_add_library(pico_stdio) target_include_directories(pico_stdio_headers SYSTEM INTERFACE ${CMAKE_CURRENT_LIST_DIR}/include) target_sources(pico_stdio INTERFACE ${CMAKE_CURRENT_LIST_DIR}/stdio.c ) pico_add_library(pico_stdio_usb) pico_add_library(pico_stdio_uart) pico_add_library(pico_stdio_semihosting) function(pico_enable_stdio_uart) endfunction() function(pico_enable_stdio_usb) endfunction() function(pico_enable_stdio_semihosting) endfunction() function(pico_enable_stdio_rtt) endfunction() endif()