Fixed Persistent Storage Issue for RP2040 with Arduino Pico Framework (…

…#868)

RP2040 does not have an EEPROM but always uses the last 4K chunk of the flash for a software EEPROM - if used. It is exactly handled as ESP32 "SoftEEPROMs", meaning it does copy the "flashEEPROM" to memory on .begin(); and does need to commit(); to write it back. We saw in the past that a node could successfully get an OTAA on an RP2040, but could never join - due to the missing commit and wrong init, this was the reason. As the "SoftEEPROM" is always written at the end of the flash, it also survives an Arduino Sketch reflash if not wiped afterwards by node.wipe(); More info and documentation here: https://arduino-pico.readthedocs.io/en/latest/eeprom.html

src/ArduinoHal.cpp

@@ -104,31 +104,31 @@ void inline ArduinoHal::spiEnd() {
 
 void ArduinoHal::readPersistentStorage(uint32_t addr, uint8_t* buff, size_t len) {
   #if !defined(RADIOLIB_EEPROM_UNSUPPORTED)
-    #if defined(RADIOLIB_ESP32)
+    #if defined(RADIOLIB_ESP32) || defined(ARDUINO_ARCH_RP2040)
       EEPROM.begin(RADIOLIB_HAL_PERSISTENT_STORAGE_SIZE);
     #elif defined(ARDUINO_ARCH_APOLLO3)
       EEPROM.init();
     #endif
     for(size_t i = 0; i < len; i++) {
       buff[i] = EEPROM.read(addr + i);
     }
-    #if defined(RADIOLIB_ESP32)
+    #if defined(RADIOLIB_ESP32) || defined(ARDUINO_ARCH_RP2040)
       EEPROM.end();
     #endif
   #endif
 }
 
 void ArduinoHal::writePersistentStorage(uint32_t addr, uint8_t* buff, size_t len) {
   #if !defined(RADIOLIB_EEPROM_UNSUPPORTED)
-    #if defined(RADIOLIB_ESP32)
+    #if defined(RADIOLIB_ESP32) || defined(ARDUINO_ARCH_RP2040)
       EEPROM.begin(RADIOLIB_HAL_PERSISTENT_STORAGE_SIZE);
     #elif defined(ARDUINO_ARCH_APOLLO3)
       EEPROM.init();
     #endif
     for(size_t i = 0; i < len; i++) {
       EEPROM.write(addr + i, buff[i]);
     }
-    #if defined(RADIOLIB_ESP32)
+    #if defined(RADIOLIB_ESP32) || defined(ARDUINO_ARCH_RP2040)
       EEPROM.commit();
       EEPROM.end();
     #endif