+/**
+ * @defgroup fosa FOSA Private Interfaces
+ *
+ * FOSA is an OS adaption layer that encapsulates all POSIX types and
+ * functions into neutral names so that FRSH can compile and be used in
+ * non-POSIX operating systems such as OSE.
+ *
+ * It is divided in two parts:
+ * - FRSH_FOSA: Types visible to the application via FRSH_API and
+ * the functions to manage them (thread, signals).
+ * - FOSA: Types and functions only used within FRSH.
+ *
+ * The former reside in the FRSH subversion directory and the latter
+ * have their own. They need to be separated because the application
+ * must not see FOSA itself.
+ *
+ * For simplicity, we have chosen to hide the operation function on
+ * signals and mutexes with the assumption that a direct mapping
+ * exists for frsh_signal_t, frsh_signal_info_t and frsh_mutext_t in
+ * the native OS.
+ *
+ * Since there are some parts which are platform dependent a define
+ * has been introduced for each platform. Currently the supported
+ * defines are:
+ *
+ * -DRT_LINUX
+ * -DOSE
+ * -DMARTE_OS
+ *
+ * This module contains all other modules that are internal to the
+ * FRSH implementation.
+ *
+ * Note that to compile FOSA objects an include path towards FRSH is
+ * needed: -I<frsh_include_directory>.
+ **/
+