weak standby callback

firmware/controllers/algo/engine_configuration.cpp

@@ -1044,5 +1044,7 @@ void commonFrankensoAnalogInputs() {
 __attribute__((weak)) void setBoardDefaultConfiguration() { }
 __attribute__((weak)) void setBoardConfigOverrides() { }
 
+__attribute__((weak)) void onBoardStandBy() { }
+
 __attribute__((weak)) int getBoardMetaOutputsCount() { return 0; }
 __attribute__((weak)) Gpio* getBoardMetaOutputs() { return nullptr; }

firmware/controllers/algo/engine_configuration.h

@@ -60,8 +60,9 @@ void resetConfigurationExt(engine_type_e engineType);
 void rememberCurrentConfiguration();
 #endif /* __cplusplus */
 
-void setBoardDefaultConfiguration(void);
-void setBoardConfigOverrides(void);
+void setBoardDefaultConfiguration();
+void setBoardConfigOverrides();
+void onBoardStandBy();
 void boardOnConfigurationChange(engine_configuration_s *previousConfiguration);
 
 #if !EFI_UNIT_TEST

firmware/controllers/lua/lua_hooks_util.cpp

@@ -82,6 +82,7 @@ void configureRusefiLuaUtilHooks(lua_State* l) {
 
 #if defined(STM32F4) || defined(STM32F7)
 	lua_register(l, "mcu_standby", [](lua_State*) {
+	    onBoardStandBy();
 		stm32_standby();
 		return 0;
 	});