add msc internal flash samd example

examples/MassStorage/msc_external_flash/msc_external_flash.ino

@@ -137,7 +137,7 @@ void loop()
     root.close();
 
     Serial.println();
-    delay(1000); // refresh every 0.5 second
+    delay(1000); // refresh every 1 second
   }
 }
 

examples/MassStorage/msc_internal_flash_samd/msc_internal_flash_samd.ino

@@ -0,0 +1,144 @@
+/*********************************************************************
+ Adafruit invests time and resources providing this open source code,
+ please support Adafruit and open-source hardware by purchasing
+ products from Adafruit!
+
+ MIT license, check LICENSE for more information
+ Copyright (c) 2019 Ha Thach for Adafruit Industries
+ All text above, and the splash screen below must be included in
+ any redistribution
+*********************************************************************/
+
+#include "SPI.h"
+#include "SdFat.h"
+#include "Adafruit_InternalFlash.h"
+#include "Adafruit_TinyUSB.h"
+
+// Start address and size should matches value in the CircuitPython (INTERNAL_FLASH_FILESYSTEM = 1)
+// to make it easier to switch between Arduino and CircuitPython
+#define INTERNAL_FLASH_FILESYSTEM_START_ADDR  (0x00040000 - 256 - 0 - INTERNAL_FLASH_FILESYSTEM_SIZE)
+#define INTERNAL_FLASH_FILESYSTEM_SIZE        (64*1024)
+
+// Internal Flash object
+Adafruit_InternalFlash flash(INTERNAL_FLASH_FILESYSTEM_START_ADDR, INTERNAL_FLASH_FILESYSTEM_SIZE);
+
+// file system object from SdFat
+FatFileSystem fatfs;
+
+FatFile root;
+FatFile file;
+
+// USB MSC object
+Adafruit_USBD_MSC usb_msc;
+
+// Set to true when PC write to flash
+bool fs_changed;
+
+// the setup function runs once when you press reset or power the board
+void setup()
+{
+  // Initialize internal flash
+  flash.begin();
+
+  // Set disk vendor id, product id and revision with string up to 8, 16, 4 characters respectively
+  usb_msc.setID("Adafruit", "Internal Flash", "1.0");
+
+  // Set callback
+  usb_msc.setReadWriteCallback(msc_read_callback, msc_write_callback, msc_flush_callback);
+  usb_msc.setWritableCallback(msc_writable_callback);
+
+  // Set disk size, block size should be 512 regardless of flash page size
+  usb_msc.setCapacity(flash.size()/512, 512);
+
+  // Set Lun ready
+  usb_msc.setUnitReady(true);
+
+  usb_msc.begin();
+
+  // Init file system on the flash
+  fatfs.begin(&flash);
+
+  Serial.begin(115200);
+  //while ( !Serial ) delay(10);   // wait for native usb
+
+  fs_changed = true; // to print contents initially
+}
+
+void loop()
+{
+  if ( fs_changed )
+  {
+    fs_changed = false;
+
+    if ( !root.open("/") )
+    {
+      Serial.println("open root failed");
+      return;
+    }
+
+    Serial.println("Flash contents:");
+
+    // Open next file in root.
+    // Warning, openNext starts at the current directory position
+    // so a rewind of the directory may be required.
+    while ( file.openNext(&root, O_RDONLY) )
+    {
+      file.printFileSize(&Serial);
+      Serial.write(' ');
+      file.printName(&Serial);
+      if ( file.isDir() )
+      {
+        // Indicate a directory.
+        Serial.write('/');
+      }
+      Serial.println();
+      file.close();
+    }
+
+    root.close();
+
+    Serial.println();
+    delay(1000); // refresh every 1 second
+  }
+}
+
+// Callback invoked when received READ10 command.
+// Copy disk's data to buffer (up to bufsize) and
+// return number of copied bytes (must be multiple of block size)
+int32_t msc_read_callback (uint32_t lba, void* buffer, uint32_t bufsize)
+{
+  // Note: InternalFlash Block API: readBlocks/writeBlocks/syncBlocks
+  // already include sector caching (if needed). We don't need to cache it, yahhhh!!
+  return flash.readBlocks(lba, (uint8_t*) buffer, bufsize/512) ? bufsize : -1;
+}
+
+// Callback invoked when received WRITE10 command.
+// Process data in buffer to disk's storage and
+// return number of written bytes (must be multiple of block size)
+int32_t msc_write_callback (uint32_t lba, uint8_t* buffer, uint32_t bufsize)
+{
+  // Note: InternalFlash Block API: readBlocks/writeBlocks/syncBlocks
+  // already include sector caching (if needed). We don't need to cache it, yahhhh!!
+  return flash.writeBlocks(lba, buffer, bufsize/512) ? bufsize : -1;
+}
+
+// Callback invoked when WRITE10 command is completed (status received and accepted by host).
+// used to flush any pending cache.
+void msc_flush_callback (void)
+{
+  // sync with flash
+  flash.syncBlocks();
+
+  // clear file system's cache to force refresh
+  fatfs.cacheClear();
+
+  fs_changed = true;
+}
+
+// Invoked to check if device is writable as part of SCSI WRITE10
+// Default mode is writable
+bool msc_writable_callback(void)
+{
+  // true for writable, false for read-only
+  return true;
+}