Fix open flag bug

src/FatLib/ArduinoFiles.h

   }
   /** Opens the next file or folder in a directory.
    *
-   * \param[in] mode open mode flags.
+   * \param[in] oflag open oflag flags.
    * \return a File object.
    */
-  File openNextFile(uint8_t mode = O_RDONLY) {
+  File openNextFile(oflag_t oflag = O_RDONLY) {
     File tmpFile;
-    tmpFile.openNext(this, mode);
+    tmpFile.openNext(this, oflag);
     return tmpFile;
   }
   /** Read the next byte from a file.

src/FatLib/FatFile.cpp

     DBG_FAIL_MACRO;
     goto fail;
   }
-  if (!open(dirFile, path, O_CREAT | O_EXCL | O_RDWR)) {
+  if (!open(dirFile, path, O_RDWR | O_CREAT | O_EXCL)) {
     DBG_FAIL_MACRO;
     goto fail;
   }
     goto fail;
   }
   // create a normal file
-  if (!open(parent, fname, O_CREAT | O_EXCL | O_RDWR)) {
+  if (!open(parent, fname, O_RDWR | O_CREAT | O_EXCL)) {
     DBG_FAIL_MACRO;
     goto fail;
   }
   // convert file to directory
-  m_flags = O_RDONLY;
+  m_flags = F_READ;
   m_attr = FILE_ATTR_SUBDIR;
 
   // allocate and zero first cluster
     goto fail;
   }
   // seek to end of file if append flag
-  if ((m_flags & O_APPEND)) {
+  if ((m_flags & F_APPEND)) {
     if (!seekSet(m_fileSize)) {
       DBG_FAIL_MACRO;
       goto fail;
     m_flags |= F_FILE_DIR_DIRTY;
   }
 
-  if (m_flags & O_SYNC) {
+  if (m_flags & F_SYNC) {
     if (!sync()) {
       DBG_FAIL_MACRO;
       goto fail;

src/SpiDriver/SdSpiParticle.cpp

  */
 void SdSpiAltDriver::begin(uint8_t csPin) {
   m_csPin = csPin;
+  m_spi->begin(m_csPin);
+  // Next line is redundant - begin(m_csPin) sets csPin to output mode.
   pinMode(m_csPin, OUTPUT);
   digitalWrite(m_csPin, HIGH);
-  m_spi->begin();
 }
 //------------------------------------------------------------------------------
 /**
  */
 uint8_t SdSpiAltDriver::receive(uint8_t* buf, size_t n) {
   SPI_DMA_TransferCompleted = false;
-  m_spi->transfer(0, buf, n, SD_SPI_DMA_TransferComplete_Callback);
+  m_spi->transfer(nullptr, buf, n, SD_SPI_DMA_TransferComplete_Callback);
   while (!SPI_DMA_TransferCompleted) {}
-  return 0;  
+  return 0;
 }
 //------------------------------------------------------------------------------
 /** Send a byte.
 void SdSpiAltDriver::send(const uint8_t* buf , size_t n) {
   SPI_DMA_TransferCompleted = false;
 
-  m_spi->transfer(const_cast<uint8_t*>(buf), 0, n,
+  m_spi->transfer(const_cast<uint8_t*>(buf), nullptr, n,
                             SD_SPI_DMA_TransferComplete_Callback);
 
   while (!SPI_DMA_TransferCompleted) {}

src/SpiDriver/SdSpiSTM32.cpp

  */
 uint8_t SdSpiAltDriver::receive(uint8_t* buf, size_t n) {
 #if USE_STM32_DMA
-  return m_spi->dmaTransfer(0, buf, n);
+  return m_spi->dmaTransfer(nullptr, buf, n);
 #else  // USE_STM32_DMA
   m_spi->read(buf, n);
   return 0;
  */
 void SdSpiAltDriver::send(const uint8_t* buf , size_t n) {
 #if USE_STM32_DMA
-  m_spi->dmaTransfer(const_cast<uint8*>(buf), 0, n);
+  m_spi->dmaTransfer(const_cast<uint8*>(buf), nullptr, n);
 #else  // USE_STM32_DMA
   m_spi->write(const_cast<uint8*>(buf), n);
 #endif  // USE_STM32_DMA