and now one step backwards :)

src/main/java/com/rusefi/dfu/DfuConnection.java

@@ -13,4 +13,6 @@ public interface DfuConnection {
     int receiveData(DfuCommmand command, short wValue, ByteBuffer data);
 
     int sendData(DfuCommmand command, short wValue, ByteBuffer data);
+
+    ByteBuffer allocateBuffer(int capacity);
 }

src/main/java/com/rusefi/dfu/DfuLogic.java

@@ -20,6 +20,7 @@ public class DfuLogic {
     }
 
     public static void actuallyUploadImage(Logger logger, DfuConnection device, BinaryImage image, FlashRange range) {
+        long enter = System.currentTimeMillis();
         List<Integer> erasePages = range.pagesForSize(image.getImageSize());
         // todo: smarted start address logic
         int eraseAddress = 0x08000000;
@@ -33,7 +34,7 @@ public class DfuLogic {
             DfuSeCommandSetAddress.execute(logger, device, device.getFlashRange().getBaseAddress() + offset);
             DfuConnectionUtil.waitStatus(logger, device);
 
-            ByteBuffer buffer = ByteBuffer.allocate(device.getTransferSize());
+            ByteBuffer buffer = device.allocateBuffer(device.getTransferSize());
             // last transfer would usually be smaller than transfer size
             int size = Math.min(device.getTransferSize(), image.getImage().length - offset);
             buffer.put(image.getImage(), offset, size);
@@ -42,13 +43,16 @@ public class DfuLogic {
             // "The Write memory operation is effectively executed only when a DFU_GETSTATUS request is issued by the host. "
             DfuConnectionUtil.waitStatus(logger, device);
         }
+        logger.info("Uploaded " + image.getImage().length + " bytes in " + (System.currentTimeMillis() - enter) + " ms");
     }
 
     public static void leaveDFU(Logger logger, DfuConnection device) {
-        device.sendData(DfuCommmand.DNLOAD, DfuSeCommand.W_DNLOAD, ByteBuffer.allocate(0));
+        logger.info("Leaving DFU");
+        device.sendData(DfuCommmand.DNLOAD, DfuSeCommand.W_DNLOAD, device.allocateBuffer(0));
         // The DFU Leave operation is effectively executed only when a DFU_GETSTATUS request is
         // issued by the host.
         DfuConnectionUtil.waitStatus(logger, device);
+        logger.info("DONE");
     }
 
     public static void startup(Logger logger, DfuConnection device) {

src/main/java/com/rusefi/dfu/android/AndroidDfuConnection.java

@@ -12,14 +12,14 @@ import static android.hardware.usb.UsbConstants.USB_DIR_OUT;
 
 public class AndroidDfuConnection implements DfuConnection {
     private final UsbDeviceConnection usbDeviceConnection;
-    private final byte interfaceNumber;
+    private final int interfaceNumber;
     private final int transferSize;
     private final FlashRange flashRange;
 
     private static final byte REQUEST_TYPE_CLASS = 32;
     private static final byte RECIPIENT_INTERFACE = 0x01;
 
-    public AndroidDfuConnection(UsbDeviceConnection usbDeviceConnection, byte interfaceNumber, int transferSize, FlashRange flashRange) {
+    public AndroidDfuConnection(UsbDeviceConnection usbDeviceConnection, int interfaceNumber, int transferSize, FlashRange flashRange) {
         this.usbDeviceConnection = usbDeviceConnection;
         this.interfaceNumber = interfaceNumber;
         this.transferSize = transferSize;
@@ -46,7 +46,15 @@ public class AndroidDfuConnection implements DfuConnection {
         return transfer(usbDeviceConnection, USB_DIR_OUT, command.getValue(), wValue, data);
     }
 
+    @Override
+    public ByteBuffer allocateBuffer(int capacity) {
+        // on Android direct buffer comes with arrayOffset which is just too much trouble
+        return ByteBuffer.allocate(capacity);
+    }
+
     private int transfer(UsbDeviceConnection connection, int direction, int request, short wValue, ByteBuffer byteBuffer) {
+        if (!byteBuffer.hasArray() || byteBuffer.arrayOffset() != 0)
+            throw new IllegalArgumentException("Need a simpler ByteArray");
         return connection.controlTransfer(REQUEST_TYPE_CLASS | RECIPIENT_INTERFACE | direction, request,
                 wValue, interfaceNumber, byteBuffer.array(), byteBuffer.limit(), DFU_TIMEOUT);
     }

src/main/java/com/rusefi/dfu/android/DfuDeviceLocator.java

@@ -42,7 +42,7 @@ public class DfuDeviceLocator {
                     throw new IllegalStateException("Unexpected USB_DT_DFU");
                 int transferSize = rawDescs[69] * 256 + rawDescs[68];
 
-                return new Result(connection, flashRange, transferSize);
+                return new Result(connection, interfaceIndex, flashRange, transferSize);
             }
         }
         return null;
@@ -50,11 +50,13 @@ public class DfuDeviceLocator {
 
     public static class Result {
         private final UsbDeviceConnection connection;
+        private final int interfaceIndex;
         private final FlashRange flashRange;
         private final int transferSize;
 
-        public Result(UsbDeviceConnection connection, FlashRange flashRange, int transferSize) {
+        public Result(UsbDeviceConnection connection, int interfaceIndex, FlashRange flashRange, int transferSize) {
             this.connection = connection;
+            this.interfaceIndex = interfaceIndex;
             this.flashRange = flashRange;
             this.transferSize = transferSize;
         }
@@ -67,6 +69,10 @@ public class DfuDeviceLocator {
             return flashRange;
         }
 
+        public int getInterfaceIndex() {
+            return interfaceIndex;
+        }
+
         public int getTransferSize() {
             return transferSize;
         }

src/main/java/com/rusefi/dfu/commands/DfuCommandAbort.java

@@ -6,8 +6,8 @@ import com.rusefi.dfu.DfuConnection;
 import java.nio.ByteBuffer;
 
 public class DfuCommandAbort {
-    public static void execute(DfuConnection session) {
-        ByteBuffer buffer = ByteBuffer.allocate(0);
-        session.sendData(DfuCommmand.ABORT, (short) 0, buffer);
+    public static void execute(DfuConnection connection) {
+        ByteBuffer buffer = connection.allocateBuffer(0);
+        connection.sendData(DfuCommmand.ABORT, (short) 0, buffer);
     }
 }

src/main/java/com/rusefi/dfu/commands/DfuCommandClearStatus.java

@@ -7,7 +7,7 @@ import java.nio.ByteBuffer;
 
 public class DfuCommandClearStatus {
     public static void execute(DfuConnection session) {
-        ByteBuffer buffer = ByteBuffer.allocate(0);
+        ByteBuffer buffer = session.allocateBuffer(0);
         session.sendData(DfuCommmand.CLRSTATUS, (short) 0, buffer);
     }
 }

src/main/java/com/rusefi/dfu/commands/DfuCommandGetStatus.java

@@ -13,9 +13,9 @@ public class DfuCommandGetStatus {
 
     private final static AtomicInteger STATUS_COUNTER = new AtomicInteger();
 
-    public static DeviceStatus read(DfuLogic.Logger logger, DfuConnection session) {
-        ByteBuffer buffer = ByteBuffer.allocate(PACKET_SIZE);
-        int count = session.receiveData(DfuCommmand.GETSTATUS, (short) 0, buffer);
+    public static DeviceStatus read(DfuLogic.Logger logger, DfuConnection connection) {
+        ByteBuffer buffer = connection.allocateBuffer(PACKET_SIZE);
+        int count = connection.receiveData(DfuCommmand.GETSTATUS, (short) 0, buffer);
         if (count != PACKET_SIZE)
             return new DeviceStatus(null, State.DFU_ERROR);
         buffer.rewind();

src/main/java/com/rusefi/dfu/commands/DfuSeCommandErasePage.java

@@ -5,10 +5,10 @@ import com.rusefi.dfu.*;
 import java.nio.ByteBuffer;
 
 public class DfuSeCommandErasePage {
-    public static void execute(DfuLogic.Logger logger, DfuConnection session, int address) {
+    public static void execute(DfuLogic.Logger logger, DfuConnection connection, int address) {
         logger.info(String.format("SetAddress %x", address));
-        ByteBuffer buffer = DfuSeCommandSetAddress.createSpecialCommandBuffer(DfuSeCommand.SE_ERASE_PAGE, address);
-        session.sendData(DfuCommmand.DNLOAD, DfuSeCommand.W_SPECIAL, buffer);
-        DfuConnectionUtil.waitStatus(logger, session);
+        ByteBuffer buffer = DfuSeCommandSetAddress.createSpecialCommandBuffer(connection, DfuSeCommand.SE_ERASE_PAGE, address);
+        connection.sendData(DfuCommmand.DNLOAD, DfuSeCommand.W_SPECIAL, buffer);
+        DfuConnectionUtil.waitStatus(logger, connection);
     }
 }

src/main/java/com/rusefi/dfu/commands/DfuSeCommandSetAddress.java

@@ -9,14 +9,14 @@ import java.nio.ByteBuffer;
 import java.nio.ByteOrder;
 
 public class DfuSeCommandSetAddress {
-    public static void execute(DfuLogic.Logger logger, DfuConnection session, int address) {
+    public static void execute(DfuLogic.Logger logger, DfuConnection connection, int address) {
         logger.info(String.format("SetAddress %x", address));
-        ByteBuffer buffer = createSpecialCommandBuffer(DfuSeCommand.SE_SET_ADDRESS, address);
-        session.sendData(DfuCommmand.DNLOAD, DfuSeCommand.W_SPECIAL, buffer);
+        ByteBuffer buffer = createSpecialCommandBuffer(connection, DfuSeCommand.SE_SET_ADDRESS, address);
+        connection.sendData(DfuCommmand.DNLOAD, DfuSeCommand.W_SPECIAL, buffer);
     }
 
-    protected static ByteBuffer createSpecialCommandBuffer(byte command, int address) {
-        ByteBuffer buffer = createBuffer(5);
+    protected static ByteBuffer createSpecialCommandBuffer(DfuConnection connection, byte command, int address) {
+        ByteBuffer buffer = createBuffer(connection, 5);
         buffer.put(command);
 //        buffer.rewind();
 //        byte[] t = new byte[4];
@@ -25,7 +25,7 @@ public class DfuSeCommandSetAddress {
         return buffer;
     }
 
-    protected static ByteBuffer createBuffer(int capacity) {
-        return ByteBuffer.allocate(capacity).order(ByteOrder.LITTLE_ENDIAN);
+    protected static ByteBuffer createBuffer(DfuConnection connection, int capacity) {
+        return connection.allocateBuffer(capacity).order(ByteOrder.LITTLE_ENDIAN);
     }
 }

src/main/java/com/rusefi/dfu/usb4java/USBDfuConnection.java

@@ -45,6 +45,12 @@ public class USBDfuConnection implements DfuConnection {
         return transfer(command, wValue, data, LibUsb.ENDPOINT_OUT);
     }
 
+    @Override
+    public ByteBuffer allocateBuffer(int capacity) {
+        // usb4java requires direct buffer
+        return ByteBuffer.allocateDirect(capacity);
+    }
+
     private int transfer(DfuCommmand command, short wValue, ByteBuffer data, byte mode) {
         return LibUsb.controlTransfer(
                 deviceHandle,

src/test/java/com/rusefi/dfu/DfuLogicTest.java

@@ -27,6 +27,11 @@ public class DfuLogicTest {
                 return data.limit();
             }
 
+            @Override
+            public ByteBuffer allocateBuffer(int capacity) {
+                return ByteBuffer.allocate(capacity);
+            }
+
             @Override
             public int sendData(DfuCommmand command, short wValue, ByteBuffer data) {
                 return data.limit();

src/test/java/com/rusefi/dfu/Sandbox.java

@@ -21,8 +21,9 @@ public class Sandbox {
             return;
         }
 
-        HexImage image = HexImage.loadHexToBuffer(new FileInputStream("rusefi.hex"), device.getFlashRange());
+        //HexImage image = HexImage.loadHexToBuffer(new FileInputStream("rusefi.hex"), device.getFlashRange());
 
+        DfuImage image = new DfuImage().read("rusefi_disco.dfu");
         DfuLogic.uploadImage(logger, device, image, device.getFlashRange());
 
         log.info("STM32 DFU " + device);