SD-card firmware update + X3 bootloader compatibility (#1786)

src/activities/settings/SdFirmwareUpdateActivity.h

@@ -0,0 +1,56 @@
+#pragma once
+
+#include <string>
+
+#include "activities/Activity.h"
+
+/**
+ * SD-card based firmware update activity.
+ *
+ * Flow:
+ *  1) onEnter -> push FileBrowserActivity in PickFirmware mode (only .bin files visible).
+ *  2) On result: validate the .bin (header magic, size fits OTA partition).
+ *  3) Push ConfirmationActivity ("Update firmware?").
+ *  4) On confirm: stream the file into the OTA partition via raw esp_partition APIs,
+ *     drawing a progress bar; on success ESP.restart().
+ *
+ * Used both from Settings -> System -> "SD Card Firmware Update", and as the only
+ * activity launched in boot recovery mode (left side button + power on X3).
+ */
+class SdFirmwareUpdateActivity : public Activity {
+ public:
+  enum class State {
+    PICKING,
+    VALIDATING,
+    CONFIRMING,
+    UPDATING,
+    SUCCESS,
+    FAILED,
+  };
+
+  explicit SdFirmwareUpdateActivity(GfxRenderer& renderer, MappedInputManager& mappedInput, bool recoveryMode = false)
+      : Activity("SdFirmwareUpdate", renderer, mappedInput), recoveryMode(recoveryMode) {}
+
+  void onEnter() override;
+  void loop() override;
+  void render(RenderLock&&) override;
+  bool preventAutoSleep() override { return state == State::UPDATING || state == State::VALIDATING; }
+  bool skipLoopDelay() override { return state == State::UPDATING; }
+
+ private:
+  State state = State::PICKING;
+  bool recoveryMode = false;
+
+  std::string firmwarePath;
+  size_t firmwareSize = 0;
+  size_t writtenBytes = 0;
+  unsigned int lastRenderedPercent = 101;
+  std::string errorMessage;
+
+  void launchPicker();
+  void onPickerResult(const ActivityResult& result);
+  bool validateFirmware();
+  void promptConfirmation();
+  void onConfirmationResult(const ActivityResult& result);
+  void performUpdate();
+};