diff --git a/ports/atmel-samd/common-hal/microcontroller/Processor.c b/ports/atmel-samd/common-hal/microcontroller/Processor.c
index 8c288a352e..44517f00c5 100644
--- a/ports/atmel-samd/common-hal/microcontroller/Processor.c
+++ b/ports/atmel-samd/common-hal/microcontroller/Processor.c
@@ -346,7 +346,7 @@ void common_hal_mcu_processor_get_uid(uint8_t raw_id[]) {
 
     for (int i=0; i<4; i++) {
         for (int k=0; k<4; k++) {
-            raw_id[4 * i + k] = (*(id_addresses[i]) >> k * 8) & 0xff;
+            raw_id[4 * i + (3 -k)] = (*(id_addresses[i]) >> k * 8) & 0xff;
         }
     }
 }
diff --git a/ports/atmel-samd/mpconfigport.mk b/ports/atmel-samd/mpconfigport.mk
index 7be9e203a8..559db97ca3 100644
--- a/ports/atmel-samd/mpconfigport.mk
+++ b/ports/atmel-samd/mpconfigport.mk
@@ -20,8 +20,6 @@ endif
 
 INTERNAL_LIBM = 1
 
-USB_SERIAL_NUMBER_LENGTH = 32
-
 # Number of USB endpoint pairs.
 USB_NUM_EP = 8
 
diff --git a/ports/cxd56/mpconfigport.mk b/ports/cxd56/mpconfigport.mk
index e767c6326f..a010f16778 100644
--- a/ports/cxd56/mpconfigport.mk
+++ b/ports/cxd56/mpconfigport.mk
@@ -1,4 +1,3 @@
-USB_SERIAL_NUMBER_LENGTH = 10
 USB_HIGHSPEED = 1
 USB_RENUMBER_ENDPOINTS = 0
 USB_CDC_EP_NUM_NOTIFICATION = 3
diff --git a/ports/esp32s2/mpconfigport.mk b/ports/esp32s2/mpconfigport.mk
index 5073d8812d..2671c30558 100644
--- a/ports/esp32s2/mpconfigport.mk
+++ b/ports/esp32s2/mpconfigport.mk
@@ -6,9 +6,6 @@ MPY_TOOL_LONGINT_IMPL = -mlongint-impl=mpz
 # Internal math library is substantially smaller than toolchain one
 INTERNAL_LIBM = 1
 
-# Chip supplied serial number, in bytes
-USB_SERIAL_NUMBER_LENGTH = 12
-
 # Longints can be implemented as mpz, as longlong, or not
 LONGINT_IMPL = MPZ
 
diff --git a/ports/litex/mpconfigport.mk b/ports/litex/mpconfigport.mk
index af6a94e64a..990b462dce 100644
--- a/ports/litex/mpconfigport.mk
+++ b/ports/litex/mpconfigport.mk
@@ -9,9 +9,6 @@ INTERNAL_LIBM = 1
 # Number of USB endpoint pairs.
 USB_NUM_EP = 16
 
-# Chip supplied serial number, in bytes
-USB_SERIAL_NUMBER_LENGTH = 30
-
 # Longints can be implemented as mpz, as longlong, or not
 LONGINT_IMPL = MPZ
 
diff --git a/ports/mimxrt10xx/mpconfigport.mk b/ports/mimxrt10xx/mpconfigport.mk
index 89c6d8c941..36d8f7deb8 100644
--- a/ports/mimxrt10xx/mpconfigport.mk
+++ b/ports/mimxrt10xx/mpconfigport.mk
@@ -14,7 +14,6 @@ endif
 
 INTERNAL_LIBM = 1
 
-USB_SERIAL_NUMBER_LENGTH = 32
 USB_HIGHSPEED = 1
 
 # Number of USB endpoint pairs.
diff --git a/ports/nrf/mpconfigport.mk b/ports/nrf/mpconfigport.mk
index 83924ff795..2bb7cca59f 100644
--- a/ports/nrf/mpconfigport.mk
+++ b/ports/nrf/mpconfigport.mk
@@ -9,8 +9,6 @@ MPY_TOOL_LONGINT_IMPL = -mlongint-impl=mpz
 
 INTERNAL_LIBM = 1
 
-USB_SERIAL_NUMBER_LENGTH = 16
-
 # Number of USB endpoint pairs.
 USB_NUM_EP = 8
 
diff --git a/ports/raspberrypi/mpconfigport.mk b/ports/raspberrypi/mpconfigport.mk
index ddbd0ec63b..b8d602e146 100644
--- a/ports/raspberrypi/mpconfigport.mk
+++ b/ports/raspberrypi/mpconfigport.mk
@@ -47,8 +47,6 @@ CIRCUITPY_AUDIOMIXER ?= 0
 
 INTERNAL_LIBM = 1
 
-USB_SERIAL_NUMBER_LENGTH = 16
-
 # Number of USB endpoint pairs.
 USB_NUM_EP = 8
 
diff --git a/ports/stm/mpconfigport.mk b/ports/stm/mpconfigport.mk
index a3216f2678..bfaff49274 100644
--- a/ports/stm/mpconfigport.mk
+++ b/ports/stm/mpconfigport.mk
@@ -1,7 +1,6 @@
 MPY_TOOL_LONGINT_IMPL ?= -mlongint-impl=mpz
 LONGINT_IMPL ?= MPZ
 INTERNAL_LIBM ?= 1
-USB_SERIAL_NUMBER_LENGTH ?= 24
 
 ifeq ($(MCU_VARIANT),$(filter $(MCU_VARIANT),STM32F405xx STM32F407xx))
 	CIRCUITPY_CANIO = 1
diff --git a/shared-module/storage/__init__.c b/shared-module/storage/__init__.c
index 786b72574c..368e30ac6d 100644
--- a/shared-module/storage/__init__.c
+++ b/shared-module/storage/__init__.c
@@ -58,7 +58,7 @@ static const uint8_t storage_usb_msc_descriptor_template[] = {
     // MSC Endpoint IN Descriptor
     0x07,        //  9 bLength
     0x05,        // 10 bDescriptorType (Endpoint)
-    0xFF,        // 11 bEndpointAddress (IN/D2H) [SET AT RUNTIME: 0x8 | number]
+    0xFF,        // 11 bEndpointAddress (IN/D2H) [SET AT RUNTIME: 0x80 | number]
 #define MSC_IN_ENDPOINT_INDEX 11
     0x02,        // 12 bmAttributes (Bulk)
     0x40, 0x00,  // 13,14 wMaxPacketSize 64
@@ -81,12 +81,21 @@ size_t storage_usb_descriptor_length(void) {
     return sizeof(usb_msc_descriptor);
 }
 
-size_t storage_usb_add_descriptor(uint8_t *descriptor_buf, uint8_t interface_number, uint8_t in_endpoint, uint8_t out_endpoint, uint8_t interface_string) {
+static const char[] storage_interface_name =  USB_INTERFACE_NAME " Mass Storage";
+
+size_t storage_usb_add_descriptor(uint8_t *descriptor_buf, uint8_t *current_interface, uint8_t *current_endpoint, uint8_t* current_interface_string) {
     memcpy(descriptor_buf, storage_usb_msc_descriptor_template, sizeof(storage_usb_msc_descriptor_template));
-    descriptor_buf[MSC_INTERFACE_INDEX] = interface_number;
-    descriptor_buf[MSC_INTERFACE_STRING_INDEX] = interface_string;
-    descriptor_buf[MSC_IN_ENDPOINT_INDEX] = in_endpoint_address;
-    descriptor_buf[MSC_OUT_ENDPOINT_INDEX] = 0x80 | out_endpoint_address;
+    descriptor_buf[MSC_INTERFACE_INDEX] = *current_interface;
+    (*current_interface)++;
+
+    descriptor_buf[MSC_IN_ENDPOINT_INDEX] = USB_MSC_EP_NUM_IN ? USB_MSC_EP_NUM_IN : *current_endpoint;
+    descriptor_buf[MSC_OUT_ENDPOINT_INDEX] = 0x80 | (USB_MSC_EP_NUM_OUT ? USB_MSC_EP_NUM_OUT : *current_endpoint);
+    (*current_endpoint)++:
+
+    usb_add_interface_string(*current_interface_string,);
+    descriptor_buf[MSC_INTERFACE_STRING_INDEX] = *current_interface_string;
+    (*current_interface_string)++;
+
     return sizeof(storage_usb_msc_descriptor_template);
 }
 
diff --git a/shared-module/storage/__init__.h b/shared-module/storage/__init__.h
index 2f38ed8b19..58ece345d1 100644
--- a/shared-module/storage/__init__.h
+++ b/shared-module/storage/__init__.h
@@ -31,6 +31,6 @@ extern bool storage_usb_enabled;
 
 void storage_init(void);
 size_t storage_usb_descriptor_length(void);
-size_t storage_usb_add_descriptor(uint8_t *descriptor_buf, uint8_t interface, uint8_t in_endpoint, uint8_t out_endpoint, uint8_tt interface_string);
+size_t storage_usb_add_descriptor(uint8_t *descriptor_buf, uint8_t *current_interface, uint8_t *current_endpoint, uint8_t* current_interface_string);
 
 #endif // SHARED_MODULE_STORAGE___INIT___H
diff --git a/shared-module/usb_cdc/__init__.c b/shared-module/usb_cdc/__init__.c
index 1a68148da6..307f0a8e68 100644
--- a/shared-module/usb_cdc/__init__.c
+++ b/shared-module/usb_cdc/__init__.c
@@ -140,21 +140,48 @@ size_t usb_cdc_descriptor_length(void) {
     return sizeof(usb_cdc_descriptor_template);
 }
 
-size_t usb_cdc_add_descriptor(uint8_t *descriptor_buf, uint8 comm_interface, uint8_t data_interface, uint8_t control_in_endpoint, uint8_t data_in_endpoint, uint8_t data_out_endpoint, uint8_t comm_interface_string, uint8_t data_interface_string) {
+static const char[] repl_cdc_comm_interface_name = USB_INTERFACE_NAME " CDC control";
+static const char[] data_cdc_comm_interface_name = USB_INTERFACE_NAME " CDC2 control";
+static const char[] repl_cdc_data_interface_name = USB_INTERFACE_NAME " CDC data";
+static const char[] data_cdc_data_interface_name = USB_INTERFACE_NAME " CDC2 data";
+
+size_t usb_cdc_add_descriptor(uint8_t *descriptor_buf, uint8_t *current_interface, uint8_t *current_endpoint, uint8_t* current_interface_string, bool repl) {
     memcpy(descriptor_buf, usb_midi_descriptor_template, sizeof(usb_midi_descriptor_template));
-    descriptor_buf[CDC_FIRST_INTERFACE_INDEX] = comm_interface;
-    descriptor_buf[CDC_COMM_INTERFACE_INDEX] = comm_interface;
-    descriptor_buf[CDC_CALL_MANAGEMENT_DATA_INTERFACE_INDEX] = data_interface;
-    descriptor_buf[CDC_UNION_MASTER_INTERFACE_INDEX] = comm_interface;
-    descriptor_buf[CDC_UNION_SLAVE_INTERFACE_INDEX] = data_interface;
-    descriptor_buf[CDC_DATA_INTERFACE_INDEX] = data_interface;
 
-    descriptor_buf[CDC_CONTROL_IN_ENDPOINT_INDEX] = control_in_endpoint;
-    descriptor_buf[CDC_DATA_OUT_ENDPOINT_INDEX] = data_out_endpoint;
-    descriptor_buf[CDC_DATA_IN_ENDPOINT_INDEX] = data_in_endpoint;
+    // Store comm interface number.
+    descriptor_buf[CDC_FIRST_INTERFACE_INDEX] = *current_interface;
+    descriptor_buf[CDC_COMM_INTERFACE_INDEX] = *current_interface;
+    descriptor_buf[CDC_UNION_MASTER_INTERFACE_INDEX] = *current_interface;
+    (*current_interface)++;
 
-    descriptor_buf[CDC_COMM_INTERFACE_STRING_INDEX] = comm_interface_string;
-    descriptor_buf[CDC_DATA_INTERFACE_STRING_INDEX] = data_interface_string;
+    // Now store data interface number.
+    descriptor_buf[CDC_CALL_MANAGEMENT_DATA_INTERFACE_INDEX] = *current_interface;
+    descriptor_buf[CDC_UNION_SLAVE_INTERFACE_INDEX] = *current_interface;
+    descriptor_buf[CDC_DATA_INTERFACE_INDEX] = *current_interface;
+
+    descriptor_buf[CDC_CONTROL_IN_ENDPOINT_INDEX] = repl
+        ? (USB_CDC_EP_NUM_NOTIFICATION ? USB_CDC_EP_NUM_NOTIFICATION : *current_endpoint)
+        : (USB_CDC2_EP_NUM_NOTIFICATION ? USB_CDC2_EP_NUM_NOTIFICATION : *current_endpoint);
+    (*current_endpoint)++;
+
+    descriptor_buf[CDC_DATA_OUT_ENDPOINT_INDEX] = repl
+        ? (USB_CDC_EP_NUM_DATA_OUT ? USB_CDC_EP_NUM_DATA_OUT : *current_endpoint)
+        : (USB_CDC2_EP_NUM_DATA_OUT ? USB_CDC2_EP_NUM_DATA_OUT : *current_endpoint);
+
+    descriptor_buf[CDC_DATA_IN_ENDPOINT_INDEX] = repl
+        ? (USB_CDC_EP_NUM_DATA_IN ? USB_CDC_EP_NUM_DATA_IN : *current_endpoint)
+        : (USB_CDC2_EP_NUM_DATA_IN ? USB_CDC2_EP_NUM_DATA_IN : *current_endpoint);
+    (*current_endpoint)++;
+
+    usb_add_interface_string(*current_interface_string,
+                             repl ? repl_cdc_comm_interface_name : data_cdc_comm_interface_name);
+    descriptor_buf[CDC_COMM_INTERFACE_STRING_INDEX] = *current_interface_string;
+    (*current_interface_string)++;
+
+    usb_add_interface_string(*current_interface_string,
+                             repl ? repl_cdc_data_interface_name : data_cdc_data_interface_name);
+    descriptor_buf[CDC_DATA_INTERFACE_STRING_INDEX] = *current_interface_string;
+    (*current_interface_string)++;
 
     return sizeof(usb_midi_descriptor_template);
 }
diff --git a/shared-module/usb_cdc/__init__.h b/shared-module/usb_cdc/__init__.h
index b7d635f49f..973569530f 100644
--- a/shared-module/usb_cdc/__init__.h
+++ b/shared-module/usb_cdc/__init__.h
@@ -34,6 +34,6 @@ extern bool usb_cdc_data_enabled;
 
 void usb_cdc_init(void);
 size_t usb_cdc_descriptor_length(void);
-size_t usb_cdc_add_descriptor(uint8_t *descriptor_buf, uint8 comm_interface, uint8_t data_interface, uint8_t control_in_endpoint, uint8_t data_in_endpoint, uint8_t data_out_endpoint, uint8_t comm_interface_string, uint8_t data_interface_string);
+size_t usb_cdc_add_descriptor(uint8_t *descriptor_buf, uint8_t *current_interface, uint8_t *current_endpoint, uint8_t* current_interface_string, bool repl);
 
 #endif /* SHARED_MODULE_USB_CDC___INIT___H */
diff --git a/shared-module/usb_hid/__init__.c b/shared-module/usb_hid/__init__.c
index d88f9787ac..5403b7fcef 100644
--- a/shared-module/usb_hid/__init__.c
+++ b/shared-module/usb_hid/__init__.c
@@ -24,4 +24,51 @@
  * THE SOFTWARE.
  */
 
-// Nothing needed here. Tables of HID devices are generated in autogen_usb_descriptor.c at compile-time.
+static const uint8_t usb_hid_descriptor_template[] = {
+    0x09,        //  0 bLength
+    0x21,        //  1 bDescriptorType (HID)
+    0x11, 0x01,  //  2 bcdHID 1.11
+    0x00,        //  3 bCountryCode
+    0x01,        //  4 bNumDescriptors
+    0x22,        //  5 bDescriptorType[0] (HID)
+    0xFF, 0xFF,  //  6,7 wDescriptorLength[0]   [SET AT RUNTIME: lo, hi]
+#define HID_DESCRIPTOR_LENGTH_INDEX 6
+
+    0x07,        //  8 bLength
+    0x05,        //  9 bDescriptorType (Endpoint)
+    0xFF,        // 10 bEndpointAddress (IN/D2H) [SET AT RUNTIME: 0x80 | endpoint]
+#define HID_IN_ENDPOINT_INDEX 10
+    0x03,        // 11 bmAttributes (Interrupt)
+    0x40, 0x00,  // 12,13  wMaxPacketSize 64
+    0x08,        // 14 bInterval 8 (unit depends on device speed)
+
+    0x07,        // 15 bLength
+    0x05,        // 16 bDescriptorType (Endpoint)
+    0xFF,        // 17 bEndpointAddress (OUT/H2D)  [SET AT RUNTIME]
+#define HID_OUT_ENDPOINT_INDEX 17
+    0x03,        // 18 bmAttributes (Interrupt)
+    0x40, 0x00,  // 19,20 wMaxPacketSize 64
+    0x08,        // 21 bInterval 8 (unit depends on device speed)
+};
+
+// Is the HID device enabled?
+bool usb_hid_enabled;
+
+size_t usb_hid_descriptor_length(void) {
+    return sizeof(usb_hid_descriptor);
+}
+
+static const char[] usb_hid_interface_name =  USB_INTERFACE_NAME " Mass Storage";
+
+size_t usb_hid_add_descriptor(uint8_t *descriptor_buf, uint8_t *current_interface, uint8_t *current_endpoint, uint8_t* current_interface_string, uint16_t report_descriptor_length) {
+    memcpy(descriptor_buf, usb_hid_descriptor_template, sizeof(usb_hid_descriptor_template));
+
+    descriptor_buf[HID_DESCRIPTOR_LENGTH_INDEX] = report_descriptor_length & 0xFF;
+    descriptor_buf[HID_DESCRIPTOR_LENGTH_INDEX + 1] = (report_descriptor_length >> 8);
+
+    descriptor_buf[HID_IN_ENDPOINT_INDEX] = USB_HID_EP_NUM_IN ? USB_HID_EP_NUM_IN : *current_endpoint;
+    descriptor_buf[HID_OUT_ENDPOINT_INDEX] = 0x80 | (USB_HID_EP_NUM_OUT ? USB_HID_EP_NUM_OUT : *current_endpoint);
+    (*current_endpoint)++:
+
+    return sizeof(usb_hid_descriptor_template);
+}
diff --git a/shared-module/usb_midi/__init__.c b/shared-module/usb_midi/__init__.c
index 9f78856836..9fa95dbe22 100644
--- a/shared-module/usb_midi/__init__.c
+++ b/shared-module/usb_midi/__init__.c
@@ -163,21 +163,41 @@ size_t usb_midi_descriptor_length(void) {
     return sizeof(usb_midi_descriptor_template);
 }
 
-size_t usb_midi_add_descriptor(uint8_t *descriptor_buf,
-                         uint8_t audio_control_interface, uint8_t midi_streaming_interface, uint8_t midi_streaming_in_endpoint, uint8_t midi_streaming_out_endpoint, uint8_t audio_control_interface_string, uint8_t midi_streaming_interface_string, uint8_t in_jack_string, uint8_t out_jack_string) {
+static const char[] midi_streaming_interface_name =  USB_INTERFACE_NAME " MIDI";
+static const char[] midi_audio_control_interface_name = USB_INTERFACE_NAME " Audio";
+static const char[] midi_in_jack_name =  USB_INTERFACE_NAME " usb_midi.ports[0]";
+static const char[] midi_out_jack_name =  USB_INTERFACE_NAME " usb_midi.ports[0]";
+
+size_t usb_midi_add_descriptor(uint8_t *descriptor_buf, uint8_t *current_interface, uint8_t *current_endpoint, uint8_t* current_interface_string) {
     memcpy(descriptor_buf, usb_midi_descriptor_template, sizeof(usb_midi_descriptor_template));
-    descriptor_buf[MIDI_AUDIO_CONTROL_INTERFACE_NUMBER_INDEX] = audio_control_interface_number;
-    descriptor_buf[MIDI_AUDIO_CONTROL_INTERFACE_STRING_INDEX] = audio_control_interface_string;
 
-    descriptor_buf[MSC_IN_ENDPOINT_INDEX] = midi_streaming_in_endpoint;
-    descriptor_buf[MSC_OUT_ENDPOINT_INDEX] = 0x80 | midi_streaming_out_endpoint;
+    descriptor_buf[MIDI_AUDIO_CONTROL_INTERFACE_NUMBER_INDEX] = *current_interface;
+    (*current_interface)++;
 
-    descriptor_buf[MIDI_STREAMING_INTERFACE_NUMBER_INDEX] = midi_streaming_interface_number;
-    descriptor_buf[MIDI_STREAMING_INTERFACE_NUMBER_INDEX_2] = midi_streaming_interface_number;
-    descriptor_buf[MIDI_STREAMING_INTERFACE_STRING_INDEX] = midi_streaming_interface_string;
+    descriptor_buf[MSC_IN_ENDPOINT_INDEX] = USB_MIDI_EP_NUM_IN ? USB_MIDI_EP_NUM_IN : *current_endpoint;
+    descriptor_buf[MSC_OUT_ENDPOINT_INDEX] =
+        0x80 | (USB_MIDI_EP_NUM_OUT ? USB_MIDI_EP_NUM_OUT : *current_endpoint);
+    (*current_endpoint)++;
 
-    descriptor_buf[MIDI_IN_JACK_STRING_INDEX] = in_jack_string;
-    descriptor_buf[MIDI_OUT_JACK_STRING_INDEX] = out_jack_string;
+    descriptor_buf[MIDI_STREAMING_INTERFACE_NUMBER_INDEX] = *current_interface;
+    descriptor_buf[MIDI_STREAMING_INTERFACE_NUMBER_INDEX_2] = *current_interface;
+    (*current_interface)++;
+
+    usb_add_interface_string(*current_interface, midi_streaming_interface_name);
+    descriptor_buf[MIDI_STREAMING_INTERFACE_STRING_INDEX] = *current_interface;
+    (*current_interface_string)++;
+
+    usb_add_interface_string(*current_interface, midi_audio_control_interface_name);
+    descriptor_buf[MIDI_AUDIO_CONTROL_INTERFACE_STRING_INDEX] = *current_interface;
+    (*current_interface_string)++;
+
+    usb_add_interface_string(*current_interface, midi_in_jack_name);
+    descriptor_buf[MIDI_IN_JACK_STRING_INDEX] = *current_interface;
+    (*current_interface_string)++;
+
+    usb_add_interface_string(*current_interface, midi_out_jack_name);
+    descriptor_buf[MIDI_OUT_JACK_STRING_INDEX] = *current_interface;
+    (*current_interface_string)++;
 
     return sizeof(usb_midi_descriptor_template);
 }
diff --git a/shared-module/usb_midi/__init__.h b/shared-module/usb_midi/__init__.h
index a57308e8b7..28871185cf 100644
--- a/shared-module/usb_midi/__init__.h
+++ b/shared-module/usb_midi/__init__.h
@@ -33,6 +33,6 @@ void usb_midi_init(void);
 void usb_midi_usb_init(void);
 
 size_t usb_midi_descriptor_length(void);
-size_t usb_midi_add_descriptor(uint8_t *descriptor_buf, uint8_t audio_control_interface, uint8_t midi_streaming_interface, uint8_t midi_streaming_in_endpoint, uint8_t midi_streaming_out_endpoint, uint8_t audio_control_interface_string, uint8_t midi_streaming_interface_string, uint8_t in_jack_string, uint8_t out_jack_string);
+size_t usb_midi_add_descriptor(uint8_t *descriptor_buf, uint8_t *current_interface, uint8_t *current_endpoint, uint8_t* current_interface_string);
 
 #endif /* SHARED_MODULE_USB_MIDI___INIT___H */
diff --git a/supervisor/shared/usb/usb.c b/supervisor/shared/usb/usb.c
index 9d48a512bd..0605b3fc93 100644
--- a/supervisor/shared/usb/usb.c
+++ b/supervisor/shared/usb/usb.c
@@ -51,27 +51,6 @@ extern const tusb_desc_webusb_url_t desc_webusb_url;
 static bool web_serial_connected = false;
 #endif
 
-
-
-// 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];
-    common_hal_mcu_processor_get_uid(raw_id);
-
-    usb_serial_number[0] = 0x300 | sizeof(usb_serial_number);
-    for (int i = 0; i < COMMON_HAL_MCU_PROCESSOR_UID_LENGTH; i++) {
-        for (int j = 0; j < 2; j++) {
-            uint8_t nibble = (raw_id[i] >> (j * 4)) & 0xf;
-            // Strings are UTF-16-LE encoded.
-            usb_serial_number[1 + i * 2 + j] = nibble_to_hex_upper[nibble];
-        }
-    }
-}
-
 bool usb_enabled(void) {
     return tusb_inited();
 }
@@ -80,8 +59,13 @@ MP_WEAK void post_usb_init(void) {
 }
 
 void usb_init(void) {
+    usb_build_device_descriptor();
+    usb_build_configuration_descriptor();
+    usb_build_hid_descriptor();
+    usb_build_string_descriptors();
+
+
     init_usb_hardware();
-    load_serial_number();
 
     tusb_init();
 
diff --git a/supervisor/shared/usb/usb_desc.c b/supervisor/shared/usb/usb_desc.c
index c894c8ab40..516c9d5e8b 100644
--- a/supervisor/shared/usb/usb_desc.c
+++ b/supervisor/shared/usb/usb_desc.c
@@ -46,9 +46,22 @@
 
 #include "genhdr/autogen_usb_descriptor.h"
 
+// ******* TODO PROTECT AGAINST GC.
 static uint8_t *device_descriptor;
 static uint8_t *config_descriptor;
 
+// Table for collecting interface strings (interface names) as descriptor is built.
+#define MAX_INTERFACE_STRINGS 16
+// slot 0 is not used.
+static char * collected_interface_strings[];
+static uint16_t current_interface_string;
+
+static const char[] manufacturer_name = USB_MANUFACTURER;
+static const char[] product_name = USB_PRODUCT;
+
+// Serial number string is UID length * 2 (2 nibbles per byte) + 1 byte for null termination.
+static char serial_number_hex_string[COMMON_HAL_MCU_PROCESSOR_UID_LENGTH * 2 + 1];
+
 static const uint8_t device_descriptor_template[] = {
     0x12,        //  0 bLength
     0x01,        //  1 bDescriptorType (Device)
@@ -87,8 +100,27 @@ static const uint8_t configuration_descriptor_template[] = {
     0x32,        // 8 bMaxPower 100mA
 };
 
-void build_usb_device_descriptor(uint16_t vid, uint16_t pid, uint8_t manufacturer_string_index, uint8_t product_string_index, uint8_t serial_number_string_index) {
+void usb_desc_init(void) {
+    uint8_t raw_id[COMMON_HAL_MCU_PROCESSOR_UID_LENGTH];
+    common_hal_mcu_processor_get_uid(raw_id);
 
+    for (int i = 0; i < COMMON_HAL_MCU_PROCESSOR_UID_LENGTH; i++) {
+        for (int j = 0; j < 2; j++) {
+            uint8_t nibble = (raw_id[i] >> (j * 4)) & 0xf;
+            serial_number_hex_string[i * 2 + (1 - j)] = nibble_to_hex_upper[nibble];
+        }
+    }
+
+    // Null-terminate the string.
+    serial_number_hex_string[sizeof(serial_number_hex_string)] = '\0';
+
+    // Set to zero when allocated; we depend on that.
+    collected_interface_strings = m_malloc(MAX_INTERFACE_STRINGS + 1, false);
+    current_interface_string = 1;
+}
+
+
+void usb_build_device_descriptor(uint16_t vid, uint16_t pid, uint8_t *current_interface_string) {
     device_descriptor = m_malloc(sizeof(device_descriptor_template), false);
     memcpy(device_descriptor, device_descriptor_template, sizeof(device_descriptor_template));
 
@@ -96,12 +128,21 @@ void build_usb_device_descriptor(uint16_t vid, uint16_t pid, uint8_t manufacture
     device_descriptor[DEVICE_VID_HI_INDEX] = vid >> 8;
     device_descriptor[DEVICE_PID_LO_INDEX] = pid & 0xFF;
     device_descriptor[DEVICE_PID_HI_INDEX] = pid >> 8;
-    device_descriptor[DEVICE_MANUFACTURER_STRING_INDEX] = manufacturer_string_index;
-    device_descriptor[DEVICE_PRODUCT_STRING_INDEX] = product_string_index;
-    device_descriptor[DEVICE_SERIAL_NUMBER_STRING_INDEX] = serial_number_string_index;
+
+    usb_add_interface_string(*current_interface_string, manufacturer_name);
+    device_descriptor[DEVICE_MANUFACTURER_STRING_INDEX] = *current_interface_string;
+    (*current_interface_string)++;
+
+    usb_add_interface_string(*current_interface_string, product_name);
+    device_descriptor[DEVICE_PRODUCT_STRING_INDEX] = *current_interface_string;
+    (*current_interface_string)++;
+
+    usb_add_interface_string(*current_interface_string, serial_number_hex_string);
+    device_descriptor[DEVICE_SERIAL_NUMBER_STRING_INDEX] = *current_interface_string;
+    (*current_interface_string)++;
 }
 
-void build_usb_configuration_descriptor(uint16_t total_length, uint8_t num_interfaces) {
+void usb_build_configuration_descriptor(uint16_t total_length, uint8_t num_interfaces) {
     size_t total_descriptor_length = sizeof(configuration_descriptor_template);
 
     // CDC should be first, for compatibility with Adafruit Windows 7 drivers.
@@ -143,19 +184,22 @@ void build_usb_configuration_descriptor(uint16_t total_length, uint8_t num_inter
     configuration_descriptor[CONFIG_TOTAL_LENGTH_HI_INDEX] = (total_descriptor_length >> 8) & 0xFF;
 
     // Number interfaces and endpoints.
-    // Endpoint 0 is already used for USB control.
+    // Endpoint 0 is already used for USB control, so start with 1.
     uint8_t current_interface = 0;
     uint8_t current_endpoint = 1;
-    uint16_t current_interface_string = 1;
 
     uint8_t *descriptor_buf_remaining = configuration_descriptor + sizeof(configuration_descriptor_template);
 
 #if CIRCUITPY_USB_CDC
     if (usb_cdc_repl_enabled) {
         // Concatenate and fix up the CDC REPL descriptor.
+        descriptor_buf_remaining += usb_cdc_add_descriptor(
+            descriptor_buf_remaining, *current_interface, *current_endpoint, *current_interface_string, true);
     }
     if (usb_cdc_data_enabled) {
         // Concatenate and fix up the CDC data descriptor.
+        descriptor_buf_remaining += usb_cdc_add_descriptor(
+            descriptor_buf_remaining, *current_interface, *current_endpoint, *current_interface_string, false);
     }
 #endif
 
@@ -163,13 +207,7 @@ void build_usb_configuration_descriptor(uint16_t total_length, uint8_t num_inter
     if (storage_usb_enabled) {
         // Concatenate and fix up the MSC descriptor.
         descriptor_buf_remaining += storage_usb_add_descriptor(
-            descriptor_buf_remaining, current_interface,
-            current_endpoint,  // in
-            current_endpoint,  // out
-            current_interface_string_index);
-        current_interface++;
-        current_endpoint++;
-        current_interface_string++;
+            descriptor_buf_remaining, *current_interface, *current_endpoint, *current_interface_string);
     }
 #endif
 
@@ -177,26 +215,14 @@ void build_usb_configuration_descriptor(uint16_t total_length, uint8_t num_inter
     if (usb_midi_enabled) {
         // Concatenate and fix up the MIDI descriptor.
         descriptor_buf_remaining += usb_midi_add_descriptor(
-            descriptor_buf_remaining,
-            current_interface,            // audio control
-            current_interface + 1,        // MIDI streaming
-            current_endpoint,             // in
-            current_endpoint,             // out
-            current_interface_string,     // audio control
-            current_interface_string + 1  // MIDI streaming
-            current_interface_string + 2  // in jack
-            current_interface_string + 3  // out jack
-            );
-        current_interface += 2;           // two interfaces: audio control and MIDI streaming
-        current_endpoint++;               // MIDI streaming only (no audio data)
-        current_interface_string += 4;    // two interface names: audio control and MIDI streaming
-
+            descriptor_buf_remaining, *current_interface, *current_endpoint, *current_interface_string);
     }
 #endif
 
 #if CIRCUITPY_USB_HID
     if (usb_hid_enabled) {
-        // Concatenate and fix up the HID descriptor (not the report descriptors).
+        descriptor_buf_remaining += usb_hid_add_descriptor(
+            descriptor_buf_remaining, *current_interface, *current_endpoint, *current_interface_string);
     }
 #endif
 
@@ -210,13 +236,33 @@ void build_usb_configuration_descriptor(uint16_t total_length, uint8_t num_inter
 
 }
 
-// Invoked when received GET DEVICE DESCRIPTOR
+void usb_add_interface_string(uint8_t interface_string_index, const char[] str) {
+    if (interface_string_index > MAX_INTERFACE_STRINGS) {
+        mp_raise_SystemError("Too many USB interface names");
+    }
+    // 2 bytes for String Descriptor header, then 2 bytes for each character
+    const size_t str_len = strlen(str);
+    uint8_t descriptor_size  = 2 + (str_len * 2);
+    uint16_t *string_descriptor = (uint16_t *) m_malloc(descriptor_size, false);
+    string_descriptor[0] = 0x0300 | descriptor_size;
+    // Convert to le16
+    for (i = 0; i <= str_len; i++) {
+        string_descriptor[i + 1] = str[i];
+    }
+
+    collected_interface_strings[interface_string_index] = string_descriptor;
+}
+
+
+void usb_
+
+// Invoked when GET DEVICE DESCRIPTOR is received.
 // Application return pointer to descriptor
 uint8_t const *tud_descriptor_device_cb(void) {
     return usb_descriptor_dev;
 }
 
-// Invoked when received GET CONFIGURATION DESCRIPTOR
+// Invoked when GET CONFIGURATION DESCRIPTOR is received.
 // Application return pointer to descriptor
 // Descriptor contents must exist long enough for transfer to complete
 uint8_t const *tud_descriptor_configuration_cb(uint8_t index) {
@@ -225,7 +271,7 @@ uint8_t const *tud_descriptor_configuration_cb(uint8_t index) {
 }
 
 #if CIRCUITPY_USB_HID
-// Invoked when received GET HID REPORT DESCRIPTOR
+// Invoked when GET HID REPORT DESCRIPTOR is received.
 // Application return pointer to descriptor
 // Descriptor contents must exist long enough for transfer to complete
 uint8_t const *tud_hid_descriptor_report_cb(uint8_t itf) {
@@ -234,9 +280,11 @@ uint8_t const *tud_hid_descriptor_report_cb(uint8_t itf) {
 }
 #endif
 
-// Invoked when received GET STRING DESCRIPTOR request
+// Invoked when GET STRING DESCRIPTOR request is received.
 // Application return pointer to descriptor, whose contents must exist long enough for transfer to complete
 uint16_t const *tud_descriptor_string_cb(uint8_t index, uint16_t langid) {
-    uint8_t const max_index = sizeof(string_descriptor_arr) / sizeof(string_descriptor_arr[0]);
-    return (index < max_index) ? string_descriptor_arr[index] : NULL;
+    if (index > MAX_INTERFACE_STRINGS) {
+        return NULL;
+    }
+    return collected_interface_strings[index];
 }
diff --git a/supervisor/supervisor.mk b/supervisor/supervisor.mk
index 7fab262f64..1210896c7f 100644
--- a/supervisor/supervisor.mk
+++ b/supervisor/supervisor.mk
@@ -76,7 +76,6 @@ else
     supervisor/usb.c \
     supervisor/shared/usb/usb_desc.c \
     supervisor/shared/usb/usb.c \
-    $(BUILD)/autogen_usb_descriptor.c \
 
   ifeq ($(CIRCUITPY_USB_CDC), 1)
     SRC_SUPERVISOR += \
@@ -159,61 +158,24 @@ USB_HIGHSPEED ?= 0
 USB_CDC_EP_NUM_NOTIFICATION ?= 0
 USB_CDC_EP_NUM_DATA_OUT ?= 0
 USB_CDC_EP_NUM_DATA_IN ?= 0
+
+USB_CDC2_EP_NUM_NOTIFICATION ?= 0
+USB_CDC2_EP_NUM_DATA_OUT ?= 0
+USB_CDC2_EP_NUM_DATA_IN ?= 0
+
 USB_MSC_EP_NUM_OUT ?= 0
 USB_MSC_EP_NUM_IN ?= 0
+
 USB_HID_EP_NUM_OUT ?= 0
 USB_HID_EP_NUM_IN ?= 0
+
 USB_MIDI_EP_NUM_OUT ?= 0
 USB_MIDI_EP_NUM_IN ?= 0
+
 USB_NUM_EP ?= 0
 
-USB_DESCRIPTOR_ARGS = \
-	--manufacturer $(USB_MANUFACTURER)\
-	--product $(USB_PRODUCT)\
-	--vid $(USB_VID)\
-	--pid $(USB_PID)\
-	--serial_number_length $(USB_SERIAL_NUMBER_LENGTH)\
-	--interface_name_prefix $(USB_INTERFACE_NAME)\
-	--devices "$(USB_DEVICES)"\
-	--hid_devices "$(USB_HID_DEVICES)"\
-	--max_ep $(USB_NUM_EP) \
-	--cdc_ep_num_notification $(USB_CDC_EP_NUM_NOTIFICATION)\
-	--cdc_ep_num_data_out $(USB_CDC_EP_NUM_DATA_OUT)\
-	--cdc_ep_num_data_in $(USB_CDC_EP_NUM_DATA_IN)\
-	--msc_ep_num_out $(USB_MSC_EP_NUM_OUT)\
-	--msc_ep_num_in $(USB_MSC_EP_NUM_IN)\
-	--hid_ep_num_out $(USB_HID_EP_NUM_OUT)\
-	--hid_ep_num_in $(USB_HID_EP_NUM_IN)\
-	--midi_ep_num_out $(USB_MIDI_EP_NUM_OUT)\
-	--midi_ep_num_in $(USB_MIDI_EP_NUM_IN)\
-	--output_c_file $(BUILD)/autogen_usb_descriptor.c\
-	--output_h_file $(BUILD)/genhdr/autogen_usb_descriptor.h
-
-ifeq ($(CIRCUITPY_USB_VENDOR), 1)
-USB_DESCRIPTOR_ARGS += \
-        --vendor_ep_num_out 0 --vendor_ep_num_in 0 \
-        --webusb_url $(USB_WEBUSB_URL)
-endif
-
-ifeq ($(USB_RENUMBER_ENDPOINTS), 0)
-USB_DESCRIPTOR_ARGS += --no-renumber_endpoints
-endif
-
-ifeq ($(USB_HIGHSPEED), 1)
-USB_DESCRIPTOR_ARGS += --highspeed
-endif
-
 $(BUILD)/supervisor/shared/translate.o: $(HEADER_BUILD)/qstrdefs.generated.h
 
-$(BUILD)/autogen_usb_descriptor.c $(BUILD)/genhdr/autogen_usb_descriptor.h: autogen_usb_descriptor.intermediate
-
-.INTERMEDIATE: autogen_usb_descriptor.intermediate
-
-autogen_usb_descriptor.intermediate: ../../tools/gen_usb_descriptor.py Makefile | $(HEADER_BUILD)
-	$(STEPECHO) "GEN $@"
-	$(Q)install -d $(BUILD)/genhdr
-	$(Q)$(PYTHON3) ../../tools/gen_usb_descriptor.py $(USB_DESCRIPTOR_ARGS)
-
 CIRCUITPY_DISPLAY_FONT ?= "../../tools/fonts/ter-u12n.bdf"
 
 $(BUILD)/autogen_display_resources.c: ../../tools/gen_display_resources.py $(HEADER_BUILD)/qstrdefs.generated.h Makefile | $(HEADER_BUILD)
diff --git a/supervisor/usb.h b/supervisor/usb.h
index f8fd713715..c8a699065d 100644
--- a/supervisor/usb.h
+++ b/supervisor/usb.h
@@ -53,6 +53,11 @@ bool usb_enabled(void);
 void usb_init(void);
 void usb_disconnect(void);
 
+void usb_add_interface_string(uint8_t interface_string_index, const char[] str);
+void usb_desc_init(void);
+void usb_build_device_descriptor(uint16_t vid, uint16_t pid, uint8_t *current_interface_string);
+void usb_build_configuration_descriptor(uint16_t total_length, uint8_t num_interfaces);
+
 // Propagate plug/unplug events to the MSC logic.
 #if CIRCUITPY_USB_MSC
 void usb_msc_mount(void);