diff --git a/include/at91_udp.h b/include/at91_udp.h
index e667f91..235da43 100644
--- a/include/at91_udp.h
+++ b/include/at91_udp.h
@@ -1,6 +1,20 @@
 #ifndef AT91_UDP_H_
 #define AT91_UDP_H_
 
+#include <stdint.h>
+
+void ep_transfer_send(uint32_t ep,
+			char *data,
+			uint32_t length,
+			void (*complete_cb)(void));
+
+void ep_transfer_receive(uint32_t ep,
+			char *data,
+			uint32_t length,
+			void (*complete_cb)(void));
+
+void ep_send_stall(uint32_t ep);
+
 void at91_udp_init(void);
 
 #endif /*AT91_UDP_H_*/
diff --git a/src/at91_udp.c b/src/at91_udp.c
index 81a7e80..656b4b3 100644
--- a/src/at91_udp.c
+++ b/src/at91_udp.c
@@ -185,7 +185,16 @@ static const struct my_config cfg_descriptor = {
 },
 };
 
-static const struct dfu_status dfu_status = {
+/* not const! */
+static struct usb_cdc_line_coding cdc_line_coding = {
+	.dwDTERate		= 9600,
+	.bCharFormat		= USB_CDC_1_STOP_BITS,
+	.bParityType		= USB_CDC_NO_PARITY,
+	.bDataBits		= 8,
+};
+
+/* not const! */
+static struct dfu_status dfu_status = {
 	.bStatus		= DFU_STATUS_OK,
 	.bState			= DFU_STATE_appIDLE,
 };
@@ -389,6 +398,7 @@ static void ep_handle_ctrlrequest(struct usb_ctrlrequest *req)
 		// TODO: follow current_interface
 		switch (req->bRequest) {
 		case USB_REQ_DFU_DETACH: /* 0x00 */
+			dfu_status.bStatus = DFU_STATE_appDETACH;
 			ep_transfer_send(0, NULL, 0, NULL);
 			break;
 
@@ -397,7 +407,11 @@ static void ep_handle_ctrlrequest(struct usb_ctrlrequest *req)
 			break;
 
 		case USB_CDC_REQ_SET_LINE_CODING: /* 0x20 */
-			/* TODO: read 7 bytes to dummy buffer */
+			ep_transfer_receive(0, (char *)&cdc_line_coding, sizeof(cdc_line_coding), NULL);
+			break;
+
+		case USB_CDC_REQ_GET_LINE_CODING: /* 0x21 */
+			ep_transfer_send(0, (char *)&cdc_line_coding, sizeof(cdc_line_coding), NULL);
 			break;
 
 		case USB_CDC_REQ_SET_CONTROL_LINE_STATE: /* 0x22 */
@@ -511,9 +525,7 @@ static void udp_handle_ep(uint32_t ep)
 			/* test again */
 			if (transfer->length == transfer->curpos) {
 				ctx->flags &= ~CTX_OUT;
-
-				if (transfer->complete_cb)
-					transfer->complete_cb();
+				transfer_cb = transfer->complete_cb;
 			}
 		}
 
@@ -564,6 +576,12 @@ static void udp_isr(void)
 		udp->UDP_IDR = AT91C_UDP_EPINT1 | AT91C_UDP_EPINT2 | AT91C_UDP_EPINT3 |
 				AT91C_UDP_RXSUSP | AT91C_UDP_RXRSM | AT91C_UDP_SOFINT |
 				AT91C_UDP_WAKEUP;
+
+		if (dfu_status.bStatus == DFU_STATE_appDETACH) {
+			void (* bootloader)(void) = (void *)0x13c000;
+			bootloader();
+			while (1);
+		}
 	}
 
 	/* Handle Endpoint Interrupts */