FS doesnt seem to work - FileOpen, DirOpen etc

[satellitecam]

Im trying to implement a data file, using FS, but have encountered a brick wall.

When using "F:/events.dat", I am constantly getting errors back - either -2 (no entry), or -84 (corrupt).
When using "/events.dat", the device just crashes.

The same things are happening for DirOpen, using "F:/" and "/" paths respectively.

Im trying to follow whats being done in built in services and controllers, like Settings, which seem to work without issue. Also, my code works fine on Infinisim.

Am I doing something wrong here?

debug_log is a function ive defined for logging to the screen, defined much like printf.

void TestService::SaveEventsLog() {
  debug_log("app", "SaveEventsLog");

  lfs_file_t saveFile;

  int file_operation_result = fs.FileOpen(&saveFile, "F:/events.dat", LFS_O_WRONLY | LFS_O_CREAT);
  if (file_operation_result < LFS_ERR_OK) {
    debug_log("app", "saveFile open failed: %d", file_operation_result);

    if (file_operation_result == LFS_ERR_CORRUPT) {
      fs.FileDelete("F:/events.dat");
      debug_log("app", "saveFile corrupt - deleting");
    }
    return;
  }

  debug_log("app", "saveFile opened");

  struct SaveData {
    uint8_t version = 1;
    std::vector<EventLogEntry> data;
  } saveData;

  saveData.data = eventLog;

  file_operation_result = fs.FileWrite(&saveFile, reinterpret_cast<uint8_t*>(&saveData), sizeof(saveData));
  if (file_operation_result < LFS_ERR_OK) {
    debug_log("app", "saveFile write failed: %d", file_operation_result);
  } else {
    debug_log("app", "saveFile saved");
  }

  file_operation_result = fs.FileClose(&saveFile);
  if (file_operation_result < LFS_ERR_OK) {
    debug_log("app", "saveFile close failed: %d", file_operation_result);
  } else {
    debug_log("app", "saveFile closed");
  }
}

[satellitecam]

New information. If I have file operation tests in a custom watch face from the constructor, then select that watch face, the tests run perfectly fine using "/events.dat", files are created and read, and directories listed.

Doing so from a custom BLE service loaded by NimbleController, even if the tests are called later on by a BLE characteristic write request, fails hard.

Is FS not intiialized properly at the point where NimbleController initializes its services?