Add partition label argument to Update and ArduinoOTA classThe UpdateClass in the Updater component has the ability to update data toa SPIFFS partition. It selects the first available partition using theESP-IDF esp_partition_find_first() function.That behaviour is problematic if one has multiple SPIFFS partitions.This change allows a user to pass the label argument (defaults to NULL)to UpdateClass::begin() so a specific SPIFFS partition can be updated.Additionally, ArduinoOTA can set this partition label using thenew method ArduinoOTAClass::setPartitionLabel which is optional.This change does not break compatibility. (#4442)

The UpdateClass in the Updater component has the ability to update data to
a SPIFFS partition. It selects the first available partition using the
ESP-IDF esp_partition_find_first() function.
That behaviour is problematic if one has multiple SPIFFS partitions.

This change allows a user to pass the label argument (defaults to NULL)
to UpdateClass::begin() so a specific SPIFFS partition can be updated.

Additionally, ArduinoOTA can set this partition label using the
new method ArduinoOTAClass::setPartitionLabel which is optional.

This change does not break compatibility.

libraries/ArduinoOTA/src/ArduinoOTA.cpp

@@ -88,6 +88,17 @@ ArduinoOTAClass& ArduinoOTAClass::setPasswordHash(const char * password) {
     return *this;
 }
 
+ArduinoOTAClass& ArduinoOTAClass::setPartitionLabel(const char * partition_label) {
+    if (!_initialized && !_partition_label.length() && partition_label) {
+        _partition_label = partition_label;
+    }
+    return *this;
+}
+
+String ArduinoOTAClass::getPartitionLabel() {
+    return _partition_label;
+}
+
 ArduinoOTAClass& ArduinoOTAClass::setRebootOnSuccess(bool reboot){
     _rebootOnSuccess = reboot;
     return *this;
@@ -235,7 +246,8 @@ void ArduinoOTAClass::_onRx(){
 }
 
 void ArduinoOTAClass::_runUpdate() {
-    if (!Update.begin(_size, _cmd)) {
+    const char *partition_label = _partition_label.length() ? _partition_label.c_str() : NULL;
+    if (!Update.begin(_size, _cmd, -1, LOW, partition_label)) {
 
         log_e("Begin ERROR: %s", Update.errorString());
 
@@ -358,7 +370,7 @@ void ArduinoOTAClass::end() {
 
 void ArduinoOTAClass::handle() {
     if (!_initialized) {
-        return; 
+        return;
     }
     if (_state == OTA_RUNUPDATE) {
         _runUpdate();

libraries/ArduinoOTA/src/ArduinoOTA.h

@@ -44,6 +44,10 @@ class ArduinoOTAClass
     //Sets the password as above but in the form MD5(password). Default NULL
     ArduinoOTAClass& setPasswordHash(const char *password);
 
+    //Sets the partition label to write to when updating SPIFFS. Default NULL
+    ArduinoOTAClass &setPartitionLabel(const char *partition_label);
+    String getPartitionLabel();
+
     //Sets if the device should be rebooted after successful update. Default true
     ArduinoOTAClass& setRebootOnSuccess(bool reboot);
 
@@ -80,6 +84,7 @@ class ArduinoOTAClass
     int _port;
     String _password;
     String _hostname;
+    String _partition_label;
     String _nonce;
     WiFiUDP _udp_ota;
     bool _initialized;

libraries/Update/src/Update.h

@@ -43,7 +43,7 @@ class UpdateClass {
       Call this to check the space needed for the update
       Will return false if there is not enough space
     */
-    bool begin(size_t size=UPDATE_SIZE_UNKNOWN, int command = U_FLASH, int ledPin = -1, uint8_t ledOn = LOW);
+    bool begin(size_t size=UPDATE_SIZE_UNKNOWN, int command = U_FLASH, int ledPin = -1, uint8_t ledOn = LOW, const char *label = NULL);
 
     /*
       Writes a buffer to the flash and increments the address

libraries/Update/src/Updater.cpp

@@ -104,7 +104,7 @@ bool UpdateClass::rollBack(){
     return _partitionIsBootable(partition) && !esp_ota_set_boot_partition(partition);
 }
 
-bool UpdateClass::begin(size_t size, int command, int ledPin, uint8_t ledOn) {
+bool UpdateClass::begin(size_t size, int command, int ledPin, uint8_t ledOn, const char *label) {
     if(_size > 0){
         log_w("already running");
         return false;
@@ -132,7 +132,7 @@ bool UpdateClass::begin(size_t size, int command, int ledPin, uint8_t ledOn) {
         log_d("OTA Partition: %s", _partition->label);
     }
     else if (command == U_SPIFFS) {
-        _partition = esp_partition_find_first(ESP_PARTITION_TYPE_DATA, ESP_PARTITION_SUBTYPE_DATA_SPIFFS, NULL);
+        _partition = esp_partition_find_first(ESP_PARTITION_TYPE_DATA, ESP_PARTITION_SUBTYPE_DATA_SPIFFS, label);
         if(!_partition){
             _error = UPDATE_ERROR_NO_PARTITION;
             return false;