Updater: Add safety memory to updater

stm-firmware/include/reflow-controller/updater/updater.h

@@ -25,7 +25,14 @@
 
 /**
  * @brief Start the RAM Code of the updater. This function will never return!
+ *
+ * This function is called at startup when the controller detects, that an update should
+ * be performed.
+ *
+ * @note You prabably want to call @ref start_updater function to update.
  */
+void __attribute__((noreturn)) start_updater_ram_code(void);
+
 void __attribute__((noreturn)) start_updater(void);
 
 #endif /* __UPDATER_UPDATER_H__ */