bootoptions: use NVRAM instead of wearing out flash for crash detection in esp32

src/BootOptions.cpp

@@ -1,9 +1,11 @@
 #include "BootOptions.h"
+#include "Config.h"
+
+#include <EEPROM.h>
+
 #ifdef BOARD_ESP8266
 #include <ESP8266WiFi.h>
 #endif
-#include <EEPROM.h>
-#include "Config.h"
 
 #ifdef PLATFORM_PHOTON
 LEDStatus serialStatus = LEDStatus(RGB_COLOR_ORANGE, LED_PATTERN_FADE, LED_SPEED_FAST, LED_PRIORITY_BACKGROUND);
@@ -12,6 +14,10 @@ retained bool LAST_BOOT_WAS_FLASH;
 retained bool LAST_BOOT_WAS_SERIAL;
 #endif
 
+#ifdef BOARD_ESP32
+__NOINIT_ATTR uint8_t s_rebootCount = 0;
+#endif
+
 void
 BootOptions::initPins()
 {
@@ -36,9 +42,24 @@ BootOptions::BootOptions()
     configStatus.setActive(isSetup);
     serialStatus.setActive(isSerial);
 #endif
+#ifdef BOARD_ESP32
+    resetReason = esp_reset_reason();
+    crashCount = s_rebootCount;
+    if (resetReason >= 4) { // TODO: These values are defined in
+                            // esp32/rom/rtc.h, but not sure if that's included
+                            // on platformio builds
+      if (crashCount++ >= 3) {
+        // Boot into safe mode if the watchdog reset us three times in a row.
+        isSafeMode = true;
+      }
+    } else {
+      crashCount = 0;
+    }
+    s_rebootCount = crashCount;
+#endif
 #ifdef BOARD_ESP8266
     struct rst_info resetInfo = *ESP.getResetInfoPtr();
-    uint8_t crashCount;
+    resetReason = resetInfo.reason;
     EEPROM.begin(sizeof(crashCount));
     EEPROM.get(sizeof(HardwareConfig) + 32, crashCount);
     EEPROM.end();

src/BootOptions.h

@@ -1,4 +1,5 @@
 #pragma once
+#include <Arduino.h>
 
 struct BootOptions {
     static void initPins();
@@ -12,4 +13,6 @@ struct BootOptions {
     bool isFlash = false;
     bool lastBootWasFlash = false;
     bool isSafeMode = false;
+    uint8_t crashCount = 0;
+    uint8_t resetReason = 0;
 };