Backup EEPROM before performing OTA (#1808, #1809)

* [Fix] Backing up EEPROM before performing OTA.For fixing - [#1808]

* Guard ArduinoOTA, different handler for async

code/espurna/eeprom.ino

@@ -23,6 +23,9 @@ void eepromRotate(bool value) {
             DEBUG_MSG_P(PSTR("[EEPROM] Disabling EEPROM rotation\n"));
         }
         EEPROMr.rotate(value);
+
+        // Because .rotate(false) marks EEPROM as dirty, this is equivalent to the .backup(0)
+        eepromCommit();
     }
 }
 
@@ -54,6 +57,10 @@ void eepromCommit() {
     _eeprom_commit = true;
 }
 
+void eepromBackup(uint32_t index){
+    EEPROMr.backup(index);
+}
+
 #if TERMINAL_SUPPORT
 
 void _eepromInitCommands() {

code/espurna/nofuss.ino

@@ -122,6 +122,9 @@ void nofussSetup() {
 
             // Disabling EEPROM rotation to prevent writing to EEPROM after the upgrade
             eepromRotate(false);
+
+            // Force backup right now, because NoFUSS library will immediatly reset on success
+            eepromBackup(0);
         }
 
         if (code == NOFUSS_FILESYSTEM_UPDATE_ERROR) {
@@ -145,6 +148,8 @@ void nofussSetup() {
             #if WEB_SUPPORT
                 wsSend_P(PSTR("{\"action\": \"reload\"}"));
             #endif
+            // TODO: NoFUSS will reset the board after this callback returns.
+            //       Maybe this should be optional
             nice_delay(100);
         }
 

code/espurna/ota.ino

@@ -251,6 +251,9 @@ void otaSetup() {
         // Disabling EEPROM rotation to prevent writing to EEPROM after the upgrade
         eepromRotate(false);
 
+        // Because ArduinoOTA is synchronous, force backup right now instead of waiting for the next loop()
+        eepromBackup(0);
+
         DEBUG_MSG_P(PSTR("[OTA] Start\n"));
 
         #if WEB_SUPPORT