Merge pull request #5109 from thinkyhead/rc_eeprom_M218_tool_offset

Save hotend_offset array (M218) in EEPROM

Marlin/Marlin.h

 extern float position_shift[XYZ];
 extern float home_offset[XYZ];
 
+#if HOTENDS > 1
+  extern float hotend_offset[XYZ][HOTENDS];
+#endif
+
 // Software Endstops
 void update_software_endstops(AxisEnum axis);
 #if ENABLED(min_software_endstops) || ENABLED(max_software_endstops)

Marlin/Marlin_main.cpp

 
 // Extruder offsets
 #if HOTENDS > 1
-  float hotend_offset[][HOTENDS] = {
-    HOTEND_OFFSET_X,
-    HOTEND_OFFSET_Y
-    #ifdef HOTEND_OFFSET_Z
-      , HOTEND_OFFSET_Z
-    #endif
-  };
+  float hotend_offset[XYZ][HOTENDS];
 #endif
 
 #if HAS_Z_SERVO_ENDSTOP
    *   Z<zoffset> - Available with DUAL_X_CARRIAGE and SWITCHING_EXTRUDER
    */
   inline void gcode_M218() {
-    if (get_target_extruder_from_command(218)) return;
+    if (get_target_extruder_from_command(218) || target_extruder == 0) return;
 
     if (code_seen('X')) hotend_offset[X_AXIS][target_extruder] = code_value_axis_units(X_AXIS);
     if (code_seen('Y')) hotend_offset[Y_AXIS][target_extruder] = code_value_axis_units(Y_AXIS);

Marlin/configuration_store.h

 #include "MarlinConfig.h"
 
 void Config_ResetDefault();
+void Config_StoreSettings();
 
 #if DISABLED(DISABLE_M503)
   void Config_PrintSettings(bool forReplay=false);
 #endif
 
 #if ENABLED(EEPROM_SETTINGS)
-  void Config_StoreSettings();
   void Config_RetrieveSettings();
 #else
-  FORCE_INLINE void Config_StoreSettings() {}
   FORCE_INLINE void Config_RetrieveSettings() { Config_ResetDefault(); Config_PrintSettings(); }
 #endif