Implement silent reboot

src/SilentRestart.h

@@ -0,0 +1,10 @@
+#pragma once
+
+// ESP.restart() with an RTC_NOINIT flag that survives the reboot, so setup()
+// skips the boot splash and routes straight to a destination. Used to clear
+// heap fragmentation accumulated during a wifi session — WiFi/LWIP/netif
+// teardown scatters long-lived allocations across the heap, leaving ~50KB of
+// contiguous space unrecoverable without a reboot.
+
+void silentRestart();          // home screen
+void silentRestartToReader();  // currently-open EPUB (APP_STATE.openEpubPath)

src/activities/browser/OpdsBookBrowserActivity.cpp

@@ -2,7 +2,6 @@
 
 #include <Epub.h>
 #include <GfxRenderer.h>
-#include <HalClock.h>
 #include <HalStorage.h>
 #include <I18n.h>
 #include <Logging.h>
@@ -17,6 +16,7 @@
 
 #include "MappedInputManager.h"
 #include "OpdsFormatLabel.h"
+#include "SilentRestart.h"
 #include "activities/network/WifiSelectionActivity.h"
 #include "activities/util/KeyboardEntryActivity.h"
 #include "components/UITheme.h"
@@ -133,12 +133,16 @@ void OpdsBookBrowserActivity::onEnter() {
 void OpdsBookBrowserActivity::onExit() {
   Activity::onExit();
 
-  HalClock::wifiOff();
-
   entryOffsets.clear();
   navigationHistory.clear();
   formatSelectionLabels.clear();
   Storage.remove("/.tmp_opds_cache.dat");
+
+  if (WiFi.getMode() != WIFI_MODE_NULL) {
+    WiFi.disconnect(false);
+    delay(30);
+    silentRestart();
+  }
 }
 
 void OpdsBookBrowserActivity::loop() {
@@ -701,8 +705,7 @@ void OpdsBookBrowserActivity::onWifiSelectionComplete(const bool connected) {
     requestUpdate(true);
     fetchFeed(currentPath);
   } else {
-    WiFi.disconnect();
+    // Leave WiFi up; onExit's silent reboot handles teardown without further fragmenting.
-    WiFi.mode(WIFI_OFF);
     state = BrowserState::ERROR;
     errorMessage = tr(STR_WIFI_CONN_FAILED);
     requestUpdate();

src/activities/network/CalibreConnectActivity.cpp

@@ -7,6 +7,7 @@
 #include <esp_task_wdt.h>
 
 #include "MappedInputManager.h"
+#include "SilentRestart.h"
 #include "WifiSelectionActivity.h"
 #include "activities/network/SignalStrengthWidget.h"
 #include "components/UITheme.h"
@@ -54,14 +55,11 @@ void CalibreConnectActivity::onEnter() {
 void CalibreConnectActivity::onExit() {
   Activity::onExit();
 
-  stopWebServer();
+  if (WiFi.getMode() != WIFI_MODE_NULL) {
-  MDNS.end();
-
-  delay(50);
     WiFi.disconnect(false);
     delay(30);
-  WiFi.mode(WIFI_OFF);
+    silentRestart();
-  delay(30);
+  }
 }
 
 void CalibreConnectActivity::onWifiSelectionComplete(const bool connected) {

src/activities/network/CrossPointWebServerActivity.cpp

@@ -3,7 +3,6 @@
 #include <DNSServer.h>
 #include <ESPmDNS.h>
 #include <GfxRenderer.h>
-#include <HalClock.h>
 #include <I18n.h>
 #include <WiFi.h>
 #include <esp_task_wdt.h>
@@ -12,6 +11,7 @@
 
 #include "MappedInputManager.h"
 #include "NetworkModeSelectionActivity.h"
+#include "SilentRestart.h"
 #include "WifiSelectionActivity.h"
 #include "activities/network/CalibreConnectActivity.h"
 #include "activities/network/SignalStrengthWidget.h"
@@ -64,45 +64,17 @@ void CrossPointWebServerActivity::onEnter() {
 void CrossPointWebServerActivity::onExit() {
   Activity::onExit();
 
-  LOG_DBG("WEBACT", "Free heap at onExit start: %d bytes", ESP.getFreeHeap());
-
   state = WebServerActivityState::SHUTTING_DOWN;
 
-  // Stop the web server first (before disconnecting WiFi)
+  // Skip reboot if WiFi was never activated (e.g. user backed out of mode selection).
-  stopWebServer();
+  if (WiFi.getMode() != WIFI_MODE_NULL) {
-
-  // Stop mDNS
-  MDNS.end();
-
-  // Stop DNS server if running (AP mode)
-  if (dnsServer) {
-    LOG_DBG("WEBACT", "Stopping DNS server...");
-    dnsServer->stop();
-    delete dnsServer;
-    dnsServer = nullptr;
-  }
-
-  // Brief wait for LWIP stack to flush pending packets
-  delay(50);
-
-  // Disconnect WiFi gracefully
     if (isApMode) {
-    LOG_DBG("WEBACT", "Stopping WiFi AP...");
       WiFi.softAPdisconnect(true);
-    delay(30);
-    WiFi.mode(WIFI_OFF);
-    delay(30);
     } else {
-    HalClock::wifiOff();
+      WiFi.disconnect(false);
     }
-
+    delay(30);
-  LOG_DBG("WEBACT", "Free heap at onExit end: %d bytes", ESP.getFreeHeap());
+    silentRestart();
-  requestUpdate();
-
-  if (webServerStarted) {
-    GUI.drawPopup(renderer, tr(STR_RESTART_DEVICE));
-    LOG_DBG("WEBACT", "Restarting device after webserver exit to regain heap...");
-    ESP.restart();
   }
 }
 
@@ -271,15 +243,6 @@ void CrossPointWebServerActivity::startWebServer() {
   }
 }
 
-void CrossPointWebServerActivity::stopWebServer() {
-  if (webServer && webServer->isRunning()) {
-    LOG_DBG("WEBACT", "Stopping web server...");
-    webServer->stop();
-    LOG_DBG("WEBACT", "Web server stopped");
-  }
-  webServer.reset();
-}
-
 void CrossPointWebServerActivity::loop() {
   // Handle different states
   if (state == WebServerActivityState::SERVER_RUNNING) {

src/activities/network/CrossPointWebServerActivity.h

@@ -55,7 +55,6 @@ class CrossPointWebServerActivity final : public Activity {
   void onWifiSelectionComplete(bool connected);
   void startAccessPoint();
   void startWebServer();
-  void stopWebServer();
 
  public:
   explicit CrossPointWebServerActivity(GfxRenderer& renderer, MappedInputManager& mappedInput)

src/activities/reader/KOReaderSyncActivity.cpp

@@ -8,10 +8,12 @@
 #include <WiFi.h>
 #include <esp_heap_caps.h>
 #include <esp_system.h>
+#include <esp_wifi.h>
 
 #include "KOReaderCredentialStore.h"
 #include "KOReaderDocumentId.h"
 #include "MappedInputManager.h"
+#include "SilentRestart.h"
 #include "activities/network/WifiSelectionActivity.h"
 #include "components/UITheme.h"
 #include "fontIds.h"
@@ -140,7 +142,8 @@ bool KOReaderSyncActivity::handleAutoPushPreflight() {
     LOG_DBG("KOSync", "AUTO_PUSH skipped: remote %.4f >= local %.4f", warmupProgress.percentage,
             localProgress.percentage);
     KOReaderSyncClient::endPersistentSession();
-    HalClock::wifiOff(true);
+    // Drop the radio while user reads the result; full teardown happens at silent reboot.
+    esp_wifi_stop();
     APP_STATE.koReaderSyncSession.outcome = KOReaderSyncOutcomeState::UPLOAD_COMPLETE;
     APP_STATE.saveToFile();
     resumeReader(KOReaderSyncOutcomeState::UPLOAD_COMPLETE);
@@ -180,7 +183,7 @@ void KOReaderSyncActivity::performFetchAndCompare() {
     if (syncIntent == KOReaderSyncIntentState::AUTO_PULL) {
       // Auto-pull at book open: nothing to apply, just open the book with local progress.
       KOReaderSyncClient::endPersistentSession();
-      HalClock::wifiOff(true);
+      esp_wifi_stop();
       resumeReader(KOReaderSyncOutcomeState::CANCELLED);
       return;
     }
@@ -230,7 +233,7 @@ void KOReaderSyncActivity::performFetchAndCompare() {
     if (!ensureRemotePositionMapped()) {
       if (syncIntent == KOReaderSyncIntentState::AUTO_PULL) {
         // Auto-pull was best-effort. Fail silently and just open the book.
-        HalClock::wifiOff(true);
+        esp_wifi_stop();
         resumeReader(KOReaderSyncOutcomeState::CANCELLED);
         return;
       }
@@ -258,7 +261,7 @@ void KOReaderSyncActivity::performFetchAndCompare() {
     if (syncIntent == KOReaderSyncIntentState::AUTO_PULL) {
       // Auto-pull skips the success-screen dwell — the reader will render the new
       // position immediately, which is the only visible feedback the user needs.
-      HalClock::wifiOff(true);
+      esp_wifi_stop();
       resumeReader(KOReaderSyncOutcomeState::APPLIED_REMOTE);
       return;
     }
@@ -418,7 +421,8 @@ void KOReaderSyncActivity::performUpload() {
   logSyncMemSnapshot("after_updateProgress");
 
   if (result != KOReaderSyncClient::OK) {
-    HalClock::wifiOff(true);
+    // Drop the radio while user reads the result; full teardown happens at silent reboot.
+    esp_wifi_stop();
     {
       RenderLock lock(*this);
       state = SYNC_FAILED;
@@ -435,7 +439,8 @@ void KOReaderSyncActivity::performUpload() {
     return;
   }
 
-  HalClock::wifiOff(true);
+  // Drop the radio while user reads the success screen; full teardown happens at silent reboot.
+  esp_wifi_stop();
   APP_STATE.koReaderSyncSession.outcome = KOReaderSyncOutcomeState::UPLOAD_COMPLETE;
   APP_STATE.saveToFile();
   if (syncIntent == KOReaderSyncIntentState::AUTO_PUSH) {
@@ -465,6 +470,9 @@ void KOReaderSyncActivity::onEnter() {
     return;
   }
 
+  // Past this point every path uses WiFi.
+  wifiActivated = true;
+
   // Check if already connected (e.g. from settings page auth)
   if (WiFi.status() == WL_CONNECTED) {
     LOG_DBG("KOSync", "Already connected to WiFi");
@@ -483,9 +491,18 @@ void KOReaderSyncActivity::onExit() {
 
   logSyncMemSnapshot("onExit_before_cleanup");
   KOReaderSyncClient::endPersistentSession();
-  HalClock::wifiOff(true);
   releaseEpubForMapping();
   logSyncMemSnapshot("onExit_after_cleanup");
+
+  if (wifiActivated) {
+    WiFi.disconnect(false);
+    delay(30);
+    if (exitToHomeAfterSync) {
+      silentRestart();
+    } else {
+      silentRestartToReader();
+    }
+  }
 }
 
 void KOReaderSyncActivity::closeCancelled() {
@@ -526,6 +543,7 @@ void KOReaderSyncActivity::resumeReader(const KOReaderSyncOutcomeState outcome,
   // the user just left would be jarring. The session state is consumed and cleared by the
   // home destination's normal flow (no reader to apply it to in this case).
   const bool exitToHome = sync.exitToHomeAfterSync;
+  exitToHomeAfterSync = exitToHome;
   if (exitToHome) {
     sync.clear();
   }

src/activities/reader/KOReaderSyncActivity.h

@@ -102,6 +102,16 @@ class KOReaderSyncActivity final : public Activity {
   unsigned long uploadCompleteTime = 0;
   bool closeRequested = false;
 
+  // Tracks whether this session activated WiFi. Set in onEnter past the credentials
+  // check; checked in onExit to decide whether to silent-reboot. Can't rely on
+  // WiFi.getMode() because intermediate paths call esp_wifi_stop() to drop the
+  // radio while user reads the result, which makes WiFi.getMode() return WIFI_MODE_NULL.
+  bool wifiActivated = false;
+
+  // Captured from sync.exitToHomeAfterSync in resumeReader() so onExit can route the
+  // silent reboot to home instead of the reader when reader-close auto-sync triggered.
+  bool exitToHomeAfterSync = false;
+
   void onWifiSelectionComplete(bool success);
   void performSync();
   bool calculateDocumentHash();

src/activities/settings/FontDownloadActivity.cpp

@@ -12,6 +12,7 @@
 
 #include "MappedInputManager.h"
 #include "SdCardFontGlobals.h"
+#include "SilentRestart.h"
 #include "activities/network/WifiSelectionActivity.h"
 #include "activities/util/ConfirmationActivity.h"
 #include "components/UITheme.h"
@@ -32,10 +33,12 @@ void FontDownloadActivity::onEnter() {
 
 void FontDownloadActivity::onExit() {
   Activity::onExit();
+
+  if (WiFi.getMode() != WIFI_MODE_NULL) {
     WiFi.disconnect(false);
-  delay(100);
+    delay(30);
-  WiFi.mode(WIFI_OFF);
+    silentRestart();
-  delay(100);
+  }
 }
 
 void FontDownloadActivity::onWifiSelectionComplete(const bool success) {

src/activities/settings/KOReaderAuthActivity.cpp

@@ -1,13 +1,13 @@
 #include "KOReaderAuthActivity.h"
 
 #include <GfxRenderer.h>
-#include <HalClock.h>
 #include <I18n.h>
 #include <WiFi.h>
 
 #include "KOReaderCredentialStore.h"
 #include "KOReaderSyncClient.h"
 #include "MappedInputManager.h"
+#include "SilentRestart.h"
 #include "activities/network/WifiSelectionActivity.h"
 #include "components/UITheme.h"
 #include "fontIds.h"
@@ -104,7 +104,11 @@ void KOReaderAuthActivity::onEnter() {
 void KOReaderAuthActivity::onExit() {
   Activity::onExit();
 
-  HalClock::wifiOff();
+  if (WiFi.getMode() != WIFI_MODE_NULL) {
+    WiFi.disconnect(false);
+    delay(30);
+    silentRestart();
+  }
 }
 
 void KOReaderAuthActivity::render(RenderLock&&) {

src/activities/settings/OtaUpdateActivity.cpp

@@ -1,11 +1,11 @@
 #include "OtaUpdateActivity.h"
 
 #include <GfxRenderer.h>
-#include <HalClock.h>
 #include <I18n.h>
 #include <WiFi.h>
 
 #include "MappedInputManager.h"
+#include "SilentRestart.h"
 #include "activities/network/WifiSelectionActivity.h"
 #include "components/UITheme.h"
 #include "fontIds.h"
@@ -68,7 +68,11 @@ void OtaUpdateActivity::onEnter() {
 void OtaUpdateActivity::onExit() {
   Activity::onExit();
 
-  HalClock::wifiOff();
+  if (WiFi.getMode() != WIFI_MODE_NULL) {
+    WiFi.disconnect(false);
+    delay(30);
+    silentRestart();
+  }
 }
 
 void OtaUpdateActivity::render(RenderLock&&) {

src/activities/weather/WeatherActivity.cpp

@@ -14,6 +14,7 @@
 #include <vector>
 
 #include "MappedInputManager.h"
+#include "SilentRestart.h"
 #include "WeatherSettingsActivity.h"
 #include "activities/network/WifiSelectionActivity.h"
 #include "components/UITheme.h"
@@ -222,7 +223,11 @@ void WeatherActivity::onExit() {
   // Weather screen is always landscape; restore app UI to portrait on exit.
   renderer.setOrientation(GfxRenderer::Orientation::Portrait);
 
-  WiFi.mode(WIFI_OFF);
+  if (WiFi.getMode() != WIFI_MODE_NULL) {
+    WiFi.disconnect(false);
+    delay(30);
+    silentRestart();
+  }
 }
 
 void WeatherActivity::loadAndDisplay() {
@@ -298,8 +303,7 @@ void WeatherActivity::onWifiSelectionComplete(bool connected) {
     LOG_DBG("WEA", "state -> CHECK_WIFI (waitStart=%lu)", (unsigned long)wifiWaitStartedAtMs);
     requestUpdate(true);
   } else {
-    WiFi.disconnect();
+    // Leave WiFi up; onExit's silent reboot handles teardown without further fragmenting.
-    WiFi.mode(WIFI_OFF);
     state = State::ERROR;
     errorMessage = tr(STR_WIFI_CONN_FAILED);
     requestUpdate();

src/main.cpp

@@ -29,6 +29,7 @@
 #include "OpdsServerStore.h"
 #include "RecentBooksStore.h"
 #include "SdCardFontSystem.h"
+#include "SilentRestart.h"
 #include "WeatherSettingsStore.h"
 #include "activities/Activity.h"
 #include "activities/ActivityManager.h"
@@ -124,6 +125,29 @@ EpdFont ui12RegularFont(&inter_ui_12_regular);
 EpdFont ui12BoldFont(&inter_ui_12_bold);
 EpdFontFamily ui12FontFamily(&ui12RegularFont, &ui12BoldFont);
 
+// SilentRestart.h definitions. RTC_NOINIT survives ESP.restart() but not power loss.
+RTC_NOINIT_ATTR uint32_t silentRebootMagic;
+RTC_NOINIT_ATTR uint32_t silentRebootTarget;
+constexpr uint32_t SILENT_REBOOT_MAGIC = 0xC1EAB007;
+constexpr uint32_t SILENT_REBOOT_TARGET_HOME = 0;
+constexpr uint32_t SILENT_REBOOT_TARGET_READER = 1;
+
+void silentRestart() {
+  silentRebootTarget = SILENT_REBOOT_TARGET_HOME;
+  silentRebootMagic = SILENT_REBOOT_MAGIC;
+  LOG_DBG("MAIN", "Silent restart (target=home)");
+  delay(50);
+  ESP.restart();
+}
+
+void silentRestartToReader() {
+  silentRebootTarget = SILENT_REBOOT_TARGET_READER;
+  silentRebootMagic = SILENT_REBOOT_MAGIC;
+  LOG_DBG("MAIN", "Silent restart (target=reader)");
+  delay(50);
+  ESP.restart();
+}
+
 // Enter deep sleep mode
 void enterDeepSleep() {
   LOG_DBG("MAIN", "enterDeepSleep called at millis=%lu, powerBtn isPressed=%d, rawPin=%d", millis(),
@@ -233,6 +257,15 @@ void setup() {
       esp_ota_mark_app_valid_cancel_rollback();
     }
   }
+
+  // Read-and-clear so a panic later in setup() doesn't loop into silent reboot.
+  // Bound the target range too — RTC_NOINIT memory is uninitialized on cold boot.
+  const bool isSilentReboot = (silentRebootMagic == SILENT_REBOOT_MAGIC);
+  const uint32_t silentRebootTargetSnapshot =
+      (isSilentReboot && silentRebootTarget <= SILENT_REBOOT_TARGET_READER) ? silentRebootTarget : 0;
+  silentRebootMagic = 0;
+  silentRebootTarget = 0;
+
   HalSystem::begin();
   gpio.begin();
   powerManager.begin();
@@ -330,7 +363,16 @@ void setup() {
 
   setupDisplayAndFonts();
 
+  if (!isSilentReboot) {
     activityManager.goToBoot();
+  } else {
+    // After a silent reboot the panel still shows the previous session's pixels but
+    // the SDK's RED-RAM diff buffer was cleared by begin(). A FAST refresh would only
+    // flip pixels the SDK *thinks* changed, leaving the old screen visible. Force the
+    // first paint to HALF_REFRESH so the panel cleanly repaints; subsequent paints
+    // resume FAST as normal.
+    renderer.setNextDisplayRefreshMode(HalDisplay::HALF_REFRESH);
+  }
 
   APP_STATE.loadFromFile();
   HalClock::restore();
@@ -341,6 +383,14 @@ void setup() {
     // Skip normal home/reader routing: jump straight into the SD firmware picker.
     activityManager.replaceActivity(
         std::make_unique<SdFirmwareUpdateActivity>(renderer, mappedInputManager, /*recoveryMode=*/true));
+  } else if (isSilentReboot && silentRebootTargetSnapshot == SILENT_REBOOT_TARGET_READER &&
+             !APP_STATE.openEpubPath.empty()) {
+    activityManager.goToReader(APP_STATE.openEpubPath);
+  } else if (isSilentReboot) {
+    // target == home (or reader with no open book): land on home — don't fall
+    // through to the sleep-wake "resume reader" logic, which fires on stale
+    // openEpubPath + lastSleepFromReader from a prior session.
+    activityManager.goHome();
   } else if (APP_STATE.openEpubPath.empty() || !APP_STATE.lastSleepFromReader ||
              mappedInputManager.isPressed(MappedInputManager::Button::Back) || APP_STATE.readerActivityLoadCount > 0) {
     activityManager.goHome();
@@ -353,9 +403,12 @@ void setup() {
     activityManager.goToReader(path);
   }
 
-  // Ensure we're not still holding the power button before leaving setup
+  // Ensure we're not still holding the power button before leaving setup.
   // waitForStablePowerRelease protects against switch bounce that might register as a false double-press.
+  // Skip on silent reboot: the firmware triggered the restart, so the button isn't held.
+  if (!isSilentReboot) {
     gpio.waitForStablePowerRelease();
+  }
   // Flush any pin state transitions that occurred during boot before entering the main loop
   mappedInputManager.update();
   buttonEventManager.drain();