chore(pycardium): Make (defunct) open() available

pycardium/mpconfigport.h

@@ -39,6 +39,10 @@ typedef unsigned mp_uint_t; /* must be pointer size */
 
 typedef long mp_off_t;
 
+/* extra built in names to add to the global namespace */
+#define MICROPY_PORT_BUILTINS \
+    { MP_ROM_QSTR(MP_QSTR_open), MP_ROM_PTR(&mp_builtin_open_obj) },
+
 /*
  * Make a pointer to RAM callable (eg set lower bit for Thumb code)
  * (This scheme won't work if we want to mix Thumb and normal ARM code.)

pycardium/mphalport.c

@@ -116,6 +116,7 @@ mp_import_stat_t mp_import_stat(const char *path)
 mp_obj_t mp_builtin_open(size_t n_args, const mp_obj_t *args, mp_map_t *kwargs)
 {
 	/* TODO: Once fs is implemented, get this working as well */
+	mp_raise_NotImplementedError ("FS is not yet implemented");
 	return mp_const_none;
 }
 MP_DEFINE_CONST_FUN_OBJ_KW(mp_builtin_open_obj, 1, mp_builtin_open);