AP_HAL_ChibiOS: reset crash handler without watchdog

libraries/AP_HAL_ChibiOS/CrashDump.cpp

@@ -40,10 +40,6 @@
 static CrashCatcherInfo g_info;
 #endif
 
-#if AP_CRASHDUMP_FLASH_ENABLED
-CRASH_CATCHER_TEST_WRITEABLE CrashCatcherReturnCodes g_crashCatcherDumpEndReturn = CRASH_CATCHER_TRY_AGAIN;
-#endif
-
 #if AP_CRASHDUMP_FLASH_ENABLED
 static bool do_flash_crash_dump = true;
 #endif
@@ -52,6 +48,15 @@ static bool do_sd_crash_dump = false;
 static uint32_t sd_dump_size = 0;
 #endif
 
+static void wait_for_watchdog_or_reset() NORETURN;
+static void wait_for_watchdog_or_reset()
+{
+    if (!stm32_watchdog_enabled()) {
+        NVIC_SystemReset();
+    }
+    while (true) {}
+}
+
 const CrashCatcherMemoryRegion* CrashCatcher_GetMemoryRegions(void)
 {
 #if CRASHDUMP_SD_ENABLED || !AP_CRASHDUMP_FLASH_ENABLED
@@ -150,21 +155,19 @@ CrashCatcherReturnCodes CrashCatcher_DumpEnd(void)
             crashdump_sd_end(sd_dump_size);
         }
         do_sd_crash_dump = false;
-        // Let the watchdog reboot us so the saved watchdog state is restored.
-        while (true) {}
     }
 #endif
 #if AP_CRASHDUMP_FLASH_ENABLED
     if (do_flash_crash_dump) {
-        return crashdump_flash_end(g_crashCatcherDumpEndReturn, g_info.isBKPT);
+        crashdump_flash_end();
+        do_flash_crash_dump = false;
+    }
+    if (g_info.isBKPT) {
+        return CRASH_CATCHER_EXIT;
     }
-    do_flash_crash_dump = false;
-    return CRASH_CATCHER_TRY_AGAIN;
-#else
-    // No configured backend accepted the dump. Let the watchdog reboot us so
-    // the saved watchdog state is restored.
-    while (true) {}
 #endif
+    // Preserve watchdog-reset semantics when active; otherwise reset now.
+    wait_for_watchdog_or_reset();
 }
 
 #endif // AP_CRASHDUMP_ENABLED

libraries/AP_HAL_ChibiOS/CrashDump.h

@@ -108,8 +108,7 @@ const CrashCatcherMemoryRegion *crashdump_flash_memory_regions(bool active);
 void crashdump_flash_write(const void *memory,
                            CrashCatcherElementSizes element_size,
                            size_t element_count);
-CrashCatcherReturnCodes crashdump_flash_end(CrashCatcherReturnCodes return_code,
-        bool is_breakpoint);
+void crashdump_flash_end(void);
 #endif
 
 #ifdef __cplusplus

libraries/AP_HAL_ChibiOS/CrashDump_flash.cpp

@@ -266,8 +266,7 @@ void crashdump_flash_write(const void *memory,
     }
 }
 
-CrashCatcherReturnCodes crashdump_flash_end(CrashCatcherReturnCodes return_code,
-        bool is_breakpoint)
+void crashdump_flash_end(void)
 {
     if (dump_size + buf_off + sizeof(dump_size) >= stm32_crash_dump_max_size()) {
         memset(&dump_buffer[sizeof(dump_buffer) - sizeof(dump_size)],
@@ -299,10 +298,6 @@ CrashCatcherReturnCodes crashdump_flash_end(CrashCatcherReturnCodes return_code,
     }
 
     stm32_flash_keep_unlocked(false);
-    if (return_code == CRASH_CATCHER_TRY_AGAIN && is_breakpoint) {
-        return CRASH_CATCHER_EXIT;
-    }
-    return return_code;
 }
 
 #endif // AP_CRASHDUMP_ENABLED && AP_CRASHDUMP_FLASH_ENABLED

libraries/AP_HAL_ChibiOS/hwdef/common/watchdog.c

@@ -87,6 +87,14 @@ void stm32_watchdog_init(void)
     watchdog_enabled = true;
 }
 
+/*
+  return true if the watchdog has been started
+ */
+bool stm32_watchdog_enabled(void)
+{
+    return watchdog_enabled;
+}
+
 /*
   pat the dog, to prevent a reset. If not called for STM32_WDG_TIMEOUT_MS
   after stm32_watchdog_init() then MCU will reset

libraries/AP_HAL_ChibiOS/hwdef/common/watchdog.h

@@ -9,6 +9,11 @@ extern "C" {
  */
 void stm32_watchdog_init(void);
 
+/*
+  return true if the watchdog has been started
+ */
+bool stm32_watchdog_enabled(void);
+
 /*
   pat the dog, to prevent a reset. If not called for STM32_WDG_TIMEOUT_MS
   after stm32_watchdog_init() then MCU will reset