diff --git a/ports/stm32f4/background.c b/ports/stm32f4/background.c
index e9872b0450..9c4f3ab27e 100644
--- a/ports/stm32f4/background.c
+++ b/ports/stm32f4/background.c
@@ -46,7 +46,7 @@ void run_background_tasks(void) {
     }
     running_background_tasks = true;
     filesystem_background();
-    //usb_background();
+    usb_background();
 
     #if CIRCUITPY_DISPLAYIO
     displayio_refresh_displays();
diff --git a/ports/stm32f4/boards/stm32f411re_discovery/mpconfigboard.h b/ports/stm32f4/boards/stm32f411re_discovery/mpconfigboard.h
index 6754432823..1b1410aea2 100644
--- a/ports/stm32f4/boards/stm32f411re_discovery/mpconfigboard.h
+++ b/ports/stm32f4/boards/stm32f411re_discovery/mpconfigboard.h
@@ -33,6 +33,8 @@
 #define FLASH_SIZE                  (0x7D000)
 #define FLASH_PAGE_SIZE             (0x4000)
 
+#define CIRCUITPY_AUTORELOAD_DELAY_MS 500
+
 #define CIRCUITPY_INTERNAL_NVM_SIZE (4096)
 #define AUTORESET_DELAY_MS 500
 #define BOARD_FLASH_SIZE (FLASH_SIZE - 0x4000 - CIRCUITPY_INTERNAL_NVM_SIZE)
\ No newline at end of file
diff --git a/supervisor/shared/usb/usb.c b/supervisor/shared/usb/usb.c
index bccdca622d..cfb39d4bb5 100644
--- a/supervisor/shared/usb/usb.c
+++ b/supervisor/shared/usb/usb.c
@@ -34,14 +34,19 @@
 
 #include "tusb.h"
 
+#define COMMON_HAL_MCU_PROCESSOR_UID_LENGTH 8
+
 // Serial number as hex characters. This writes directly to the USB
 // descriptor.
 extern uint16_t usb_serial_number[1 + COMMON_HAL_MCU_PROCESSOR_UID_LENGTH * 2];
 
 void load_serial_number(void) {
     // create serial number based on device unique id
-    uint8_t raw_id[COMMON_HAL_MCU_PROCESSOR_UID_LENGTH] = {1,2,3,4};
+    uint8_t raw_id[COMMON_HAL_MCU_PROCESSOR_UID_LENGTH];
     //common_hal_mcu_processor_get_uid(raw_id);
+    for (int i=0; i<2; i++) {
+        ((uint32_t*) raw_id)[i] = 0;
+    }
 
     static const char nibble_to_hex[16] = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
                                     'A', 'B', 'C', 'D', 'E', 'F'};
@@ -60,14 +65,10 @@ bool usb_enabled(void) {
 
 void usb_init(void) {
     init_usb_hardware();
-    //load_serial_number();
+    load_serial_number();
 
     tusb_init();
 
-    while(1) {
-        tud_task();
-    }
-
 #if MICROPY_KBD_EXCEPTION
     // Set Ctrl+C as wanted char, tud_cdc_rx_wanted_cb() callback will be invoked when Ctrl+C is received
     // This callback always got invoked regardless of mp_interrupt_char value since we only set it once here
diff --git a/supervisor/supervisor.mk b/supervisor/supervisor.mk
index 2d50e7a8b1..42a55243e0 100644
--- a/supervisor/supervisor.mk
+++ b/supervisor/supervisor.mk
@@ -78,6 +78,7 @@ else
 					  shared-module/usb_midi/PortIn.c \
 					  shared-module/usb_midi/PortOut.c \
 					  $(BUILD)/autogen_usb_descriptor.c
+
 	CFLAGS += -DUSB_AVAILABLE
 endif
 
diff --git a/tools/gen_usb_descriptor.py b/tools/gen_usb_descriptor.py
index 10bbf50663..db17c97666 100644
--- a/tools/gen_usb_descriptor.py
+++ b/tools/gen_usb_descriptor.py
@@ -273,17 +273,17 @@ cdc_iad = standard.InterfaceAssociationDescriptor(
 descriptor_list = []
 descriptor_list.append(cdc_iad)
 descriptor_list.extend(cdc_interfaces)
-descriptor_list.extend(msc_interfaces)
+# descriptor_list.extend(msc_interfaces)
 # Only add the control interface because other audio interfaces are managed by it to ensure the
 # correct ordering.
-descriptor_list.append(audio_control_interface)
+# descriptor_list.append(audio_control_interface)
 # Put the CDC IAD just before the CDC interfaces.
 # There appears to be a bug in the Windows composite USB driver that requests the
 # HID report descriptor with the wrong interface number if the HID interface is not given
 # first. However, it still fetches the descriptor anyway. We could reorder the interfaces but
 # the Windows 7 Adafruit_usbser.inf file thinks CDC is at Interface 0, so we'll leave it
 # there for backwards compatibility.
-descriptor_list.extend(hid_interfaces)
+# descriptor_list.extend(hid_interfaces)
 
 configuration = standard.ConfigurationDescriptor(
     description="Composite configuration",