Indicate failure when CONFIG_IN_SDCARD is used and no SD card is

inserted.

src/main/drivers/system.h

@@ -42,6 +42,7 @@ typedef enum {
     FAILURE_SDCARD_READ_FAILED,
     FAILURE_SDCARD_WRITE_FAILED,
     FAILURE_SDCARD_INITIALISATION_FAILED,
+    FAILURE_SDCARD_REQUIRED,
 } failureMode_e;
 
 #define WARNING_FLASH_DURATION_MS 50

src/main/fc/init.c

@@ -374,6 +374,10 @@ void init(void)
     sdCardAndFSInit();
     initFlags |= SD_INIT_ATTEMPTED;
 
+    if (!sdcard_isInserted()) {
+        failureMode(FAILURE_SDCARD_REQUIRED);
+    }
+
     while (afatfs_getFilesystemState() != AFATFS_FILESYSTEM_STATE_READY) {
         afatfs_poll();