Fix RF Log corrupting overlay apps on launch (issue #583)

App/app/rxtx_log.c

@@ -131,6 +131,7 @@ static uint16_t        gSessionChannel;
 static uint16_t        gSessionTicks500ms;
 static uint8_t         gSessionSMeter;
 static uint8_t         gSessionBattVolt;
+static bool            gSuspended;
 
 static uint16_t        gLogCursor;
 static uint8_t         gLogFilter;
@@ -922,7 +923,7 @@ uint32_t RXTX_LOG_SendK5ViewerHistoryPage(uint32_t beforeSeq, void (*send)(const
 
 static void RXTX_LOG_CaptureSession(uint8_t flags, const VFO_Info_t *vfo)
 {
-    if (!RXTX_LOG_IsEnabled() || vfo == NULL || gClearActive)
+    if (gSuspended || !RXTX_LOG_IsEnabled() || vfo == NULL || gClearActive)
         return;
 
     const uint32_t frequency = (flags & RXTX_LOG_FLAG_TX) ? vfo->pTX->Frequency : vfo->pRX->Frequency;
@@ -961,6 +962,7 @@ void RXTX_LOG_Init(void)
     gLogCursor        = 0;
     gLogFilter        = RXTX_LOG_FILTER_ALL;
     gSessionActive    = false;
+    gSuspended        = false;
     gSessionSMeter    = RXTX_LOG_SMETER_UNKNOWN;
     gSessionBattVolt  = RXTX_LOG_BATT_UNKNOWN;
     gClearActive        = false;
@@ -1060,6 +1062,17 @@ void RXTX_LOG_EndActive(void)
     RXTX_LOG_ResetActiveSession();
 }
 
+void RXTX_LOG_Suspend(void)
+{
+    RXTX_LOG_EndActive();
+    gSuspended = true;
+}
+
+void RXTX_LOG_Resume(void)
+{
+    gSuspended = false;
+}
+
 void RXTX_LOG_Tick500ms(void)
 {
     if (gSessionActive) {

App/app/rxtx_log.h

@@ -76,6 +76,8 @@ bool RXTX_LOG_IsEnabled(void);
 void RXTX_LOG_BeginRx(const VFO_Info_t *vfo, FUNCTION_Type_t function);
 void RXTX_LOG_BeginTx(const VFO_Info_t *vfo);
 void RXTX_LOG_EndActive(void);
+void RXTX_LOG_Suspend(void);
+void RXTX_LOG_Resume(void);
 void RXTX_LOG_Task10ms(void);
 void RXTX_LOG_Tick500ms(void);
 const char *RXTX_LOG_GetFilterName(void);

App/apps/app_overlay.c

@@ -38,6 +38,9 @@
 #include "k5viewer.h"
 #endif
 #include "app/app.h"
+#ifdef ENABLE_FEAT_F4HWN_RXTX_LOG
+#include "app/rxtx_log.h"
+#endif
 #include "ui/helper.h"
 #include "ui/main.h"
 #include "ui/status.h"
@@ -1105,6 +1108,13 @@ uint8_t APP_LaunchOverlay(uint8_t slot)
     if (h.link_vma != (uint32_t)ws)
         return APP_ERR_VMA;
 
+    /* Flush and suspend RF logging before the sector cache becomes executable
+     * app code. Both a pending RX and an app-owned TX could otherwise write a
+     * log entry through the same 4 KiB buffer and overwrite the running app. */
+#ifdef ENABLE_FEAT_F4HWN_RXTX_LOG
+    RXTX_LOG_Suspend();
+#endif
+
     /* Repurpose the sector cache: drop any cached config sector, load the code
      * straight in (ReadBuffer bypasses the cache), and verify it in RAM before
      * trusting it. Zeroing first leaves the app's .bss clean. */
@@ -1114,6 +1124,9 @@ uint8_t APP_LaunchOverlay(uint8_t slot)
 
     if (MB_Crc32Bytes(ws, h.code_size) != h.code_crc32) {
         PY25Q16_InvalidateCache();
+#ifdef ENABLE_FEAT_F4HWN_RXTX_LOG
+        RXTX_LOG_Resume();
+#endif
         return APP_ERR_CRC;
     }
 
@@ -1210,6 +1223,9 @@ uint8_t APP_LaunchOverlay(uint8_t slot)
         SETTINGS_SaveFM();
         PY25Q16_InvalidateCache();
     }
+#endif
+#ifdef ENABLE_FEAT_F4HWN_RXTX_LOG
+    RXTX_LOG_Resume();
 #endif
     return APP_OK;
 }