diff --git a/src/platforms/common/cdcacm.c b/src/platforms/common/cdcacm.c
index 25c7f10..3b0d62a 100644
--- a/src/platforms/common/cdcacm.c
+++ b/src/platforms/common/cdcacm.c
@@ -45,24 +45,16 @@
 #	include "traceswo.h"
 #endif
 #include "usbuart.h"
-#include "serialno.h"
-#include "version.h"
 
-#include <libopencm3/cm3/nvic.h>
 #include <libopencm3/usb/cdc.h>
 #include <libopencm3/cm3/scb.h>
-
-#include "usb_descriptors.h"
-
-usbd_device * usbdev;
+#include <libopencm3/usb/dfu.h>
 
 static int configured;
 static int cdcacm_gdb_dtr = 1;
 
 static void cdcacm_set_modem_state(usbd_device *dev, int iface, bool dsr, bool dcd);
 
-char serial_no[DFU_SERIAL_LENGTH];
-
 static void dfu_detach_complete(usbd_device *dev, struct usb_setup_data *req)
 {
 	(void)dev;
@@ -165,7 +157,7 @@ static void cdcacm_set_modem_state(usbd_device *dev, int iface, bool dsr, bool d
 	usbd_ep_write_packet(dev, 0x82 + iface, buf, 10);
 }
 
-static void cdcacm_set_config(usbd_device *dev, uint16_t wValue)
+void cdcacm_set_config(usbd_device *dev, uint16_t wValue)
 {
 	configured = wValue;
 
@@ -208,19 +200,3 @@ static void cdcacm_set_config(usbd_device *dev, uint16_t wValue)
 	cdcacm_set_modem_state(dev, GDB_IF_NO, true, true);
 	cdcacm_set_modem_state(dev, UART_IF_NO, true, true);
 }
-
-/* We need a special large control buffer for this device: */
-static uint8_t usbd_control_buffer[256];
-
-void blackmagic_usb_init(void)
-{
-	serial_no_read(serial_no);
-
-	usbdev = usbd_init(&USB_DRIVER, &dev_desc, &config, usb_strings, sizeof(usb_strings) / sizeof(char *),
-		usbd_control_buffer, sizeof(usbd_control_buffer));
-
-	usbd_register_set_config_callback(usbdev, cdcacm_set_config);
-
-	nvic_set_priority(USB_IRQ, IRQ_PRI_USB);
-	nvic_enable_irq(USB_IRQ);
-}
diff --git a/src/platforms/common/cdcacm.h b/src/platforms/common/cdcacm.h
index c30c05c..e2e6bd1 100644
--- a/src/platforms/common/cdcacm.h
+++ b/src/platforms/common/cdcacm.h
@@ -31,6 +31,7 @@
 #include "usb.h"
 
 void blackmagic_usb_init(void);
+void cdcacm_set_config(usbd_device *dev, uint16_t wValue);
 /* Returns current usb configuration, or 0 if not configured. */
 int cdcacm_get_config(void);
 int cdcacm_get_dtr(void);
diff --git a/src/platforms/common/usb.c b/src/platforms/common/usb.c
index 441984e..8155b94 100644
--- a/src/platforms/common/usb.c
+++ b/src/platforms/common/usb.c
@@ -18,8 +18,32 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include <libopencm3/cm3/nvic.h>
+
 #include "general.h"
 #include "usb.h"
+#include "usb_descriptors.h"
+#include "cdcacm.h"
+#include "serialno.h"
+
+char serial_no[DFU_SERIAL_LENGTH];
+usbd_device *usbdev = NULL;
+
+/* We need a special large control buffer for this device: */
+static uint8_t usbd_control_buffer[256];
+
+void blackmagic_usb_init(void)
+{
+	serial_no_read(serial_no);
+
+	usbdev = usbd_init(&USB_DRIVER, &dev_desc, &config, usb_strings, sizeof(usb_strings) / sizeof(char *),
+		usbd_control_buffer, sizeof(usbd_control_buffer));
+
+	usbd_register_set_config_callback(usbdev, cdcacm_set_config);
+
+	nvic_set_priority(USB_IRQ, IRQ_PRI_USB);
+	nvic_enable_irq(USB_IRQ);
+}
 
 void USB_ISR(void)
 {
diff --git a/src/platforms/common/usb.h b/src/platforms/common/usb.h
index 8ea94fe..f706b00 100644
--- a/src/platforms/common/usb.h
+++ b/src/platforms/common/usb.h
@@ -31,4 +31,14 @@ extern usbd_device *usbdev;
 #define CDCACM_UART_ENDPOINT 3
 #define TRACE_ENDPOINT       5
 
+#define GDB_IF_NO  0
+#define UART_IF_NO 2
+#define DFU_IF_NO  4
+#ifdef PLATFORM_HAS_TRACESWO
+#define TRACE_IF_NO      5
+#define TOTAL_INTERFACES 6
+#else
+#define TOTAL_INTERFACES 5
+#endif
+
 #endif /*USB_H*/
diff --git a/src/platforms/common/usb_descriptors.h b/src/platforms/common/usb_descriptors.h
index 0e95702..370f4f5 100644
--- a/src/platforms/common/usb_descriptors.h
+++ b/src/platforms/common/usb_descriptors.h
@@ -26,19 +26,10 @@
 #include <libopencm3/usb/dfu.h>
 
 #include "usb.h"
+#include "version.h"
 
 #define BOARD_IDENT "Black Magic Probe " PLATFORM_IDENT FIRMWARE_VERSION
 
-#define GDB_IF_NO  0
-#define UART_IF_NO 2
-#define DFU_IF_NO  4
-#ifdef PLATFORM_HAS_TRACESWO
-#define TRACE_IF_NO      5
-#define TOTAL_INTERFACES 6
-#else
-#define TOTAL_INTERFACES 5
-#endif
-
 extern char serial_no[DFU_SERIAL_LENGTH];
 
 /* Top-level device descriptor */