+/**
+ * \brief Registers a file in the SysFS tree
+ * \param Path Path relative to the SysFS root (no .. or .)
+ * \param Data File buffer address
+ * \param Length Length of the file buffer
+ * \return An ID number to refer to the file, or -1 on error
+ * \note \a Data must be maintained until ::SysFS_UpdateFile is called
+ * with a different buffer, or ::SysFS_RemoveFile is called.
+ */