Battery, EPD, and SD support for m5paper

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lib/hal/HalGPIO.cpp

@@ -192,7 +192,13 @@ HalGPIO::DeviceType detectDeviceTypeWithFingerprint() {
 
 void HalGPIO::begin() {
   inputMgr.begin();
+#if !(defined(FREEINK_DEVICE_M5PAPER) && FREEINK_DEVICE_M5PAPER)
+  // Claim the shared SPI bus with the X4/X3 display+SD pins. On M5Paper the SDK's
+  // IT8951 driver and SDCardManager each bring up SPI from BoardConfig::ACTIVE
+  // pins; pre-claiming VSPI here would stick (SPIClass::begin early-returns if the
+  // bus is already started) and leave the SD card on the wrong pins.
   SPI.begin(EPD_SCLK, SPI_MISO, EPD_MOSI, EPD_CS);
+#endif
 
   _deviceType = detectDeviceTypeWithFingerprint();
 
@@ -232,12 +238,29 @@ void HalGPIO::startDeepSleep() {
     inputMgr.update();
   }
   // Arm the wakeup trigger *after* the button is released
+#if SOC_PM_SUPPORT_EXT1_WAKEUP
+  // Xtensa (classic ESP32 / S3): GPIO deep-sleep wake is via RTC ext1.
+  esp_sleep_enable_ext1_wakeup(1ULL << InputManager::POWER_BUTTON_PIN, ESP_EXT1_WAKEUP_ALL_LOW);
+#else
+  // RISC-V (C3): direct GPIO deep-sleep wakeup source.
   esp_deep_sleep_enable_gpio_wakeup(1ULL << InputManager::POWER_BUTTON_PIN, ESP_GPIO_WAKEUP_GPIO_LOW);
+#endif
   // Enter Deep Sleep
   esp_deep_sleep_start();
 }
 
 void HalGPIO::verifyPowerButtonWakeup(uint16_t requiredDurationMs, bool shortPressAllowed) {
+  if (BoardConfig::ACTIVE.input.power < 0) {
+    // No readable power-button input pin: can't verify a hold, so don't sleep.
+    return;
+  }
+#if defined(FREEINK_DEVICE_M5PAPER) && FREEINK_DEVICE_M5PAPER
+  // M5Paper: power-on is a hardware latch and the "power button" is the rotary
+  // push (G38), shared with Confirm. A USB/flash cold boot is indistinguishable
+  // from an intentional power-on hold here, so skip the X4-style anti-accidental-
+  // wake check and always boot. G38 still serves as the deep-sleep wake source.
+  return;
+#endif
   if (shortPressAllowed) {
     // Fast path - no duration check needed
     return;

lib/hal/HalPowerManager.cpp

@@ -18,7 +18,9 @@ void HalPowerManager::begin() {
     Wire.setTimeOut(4);
     _batteryUseI2C = true;
   } else {
-    pinMode(BAT_GPIO0, INPUT);
+    // Battery ADC pin from the active board profile (X4: GPIO0, M5Paper: GPIO35),
+    // not a hardcoded X4 pin.
+    pinMode(BoardConfig::ACTIVE.batteryAdc, INPUT);
   }
   normalFreq = getCpuFrequencyMhz();
   modeMutex = xSemaphoreCreateMutex();
@@ -76,8 +78,10 @@ void HalPowerManager::startDeepSleep(HalGPIO& gpio) const {
 #endif
 
   // Pre-sleep routines from the original firmware
+#if !SOC_PM_SUPPORT_EXT1_WAKEUP  // RISC-V (C3 / X4)
   // GPIO13 is connected to battery latch MOSFET, we need to make sure it's low during sleep
   // Note that this means the MCU will be completely powered off during sleep, including RTC
+  // (X4-specific: on classic ESP32/M5Paper GPIO13 is SD MISO, so this is skipped.)
   constexpr gpio_num_t GPIO_SPIWP = GPIO_NUM_13;
   gpio_set_direction(GPIO_SPIWP, GPIO_MODE_OUTPUT);
   gpio_set_level(GPIO_SPIWP, 0);
@@ -90,6 +94,10 @@ void HalPowerManager::startDeepSleep(HalGPIO& gpio) const {
   // power button is hard-wired to briefly provide power to the MCU, waking it up regardless of the wakeup source
   // configuration
   esp_deep_sleep_enable_gpio_wakeup(1ULL << InputManager::POWER_BUTTON_PIN, ESP_GPIO_WAKEUP_GPIO_LOW);
+#else  // Xtensa (classic ESP32 / S3): RTC ext1 GPIO wake
+  pinMode(InputManager::POWER_BUTTON_PIN, INPUT_PULLUP);
+  esp_sleep_enable_ext1_wakeup(1ULL << InputManager::POWER_BUTTON_PIN, ESP_EXT1_WAKEUP_ALL_LOW);
+#endif
   // Enter Deep Sleep
   esp_deep_sleep_start();
 }
@@ -121,7 +129,8 @@ uint16_t HalPowerManager::getBatteryPercentage() const {
     _batteryLastPollMs = now;
     return _batteryCachedPercent;
   }
-  static const BatteryMonitor battery = BatteryMonitor(BAT_GPIO0);
+  // ADC pin from the active profile (X4 GPIO0 / M5Paper GPIO35); default 2:1 divider.
+  static const BatteryMonitor battery = BatteryMonitor(BoardConfig::ACTIVE.batteryAdc);
 
   // smooth the battery %.
   if (_batteryCachedPercent == 0) {

lib/hal/HalSystem.cpp

@@ -38,6 +38,13 @@ void IRAM_ATTR __wrap_panic_print_backtrace(const void* frame, int core) {
     __real_panic_print_backtrace(frame, core);
     return;
   }
+#if !__riscv
+  // RvExcFrame and the flat SP scan below are RISC-V-only (C3). On Xtensa
+  // (classic ESP32 / S3) the exception frame is XtExcFrame with windowed-register
+  // unwinding, so fall back to the default backtrace.
+  __real_panic_print_backtrace(frame, core);
+  return;
+#else
   for (size_t i = 0; i < MAX_PANIC_STACK_DEPTH; i++) {
     panicStack[i].sp = 0;
   }
@@ -65,6 +72,7 @@ void IRAM_ATTR __wrap_panic_print_backtrace(const void* frame, int core) {
   }
 
   __real_panic_print_backtrace(frame, core);
+#endif  // __riscv
 }
 }