Prevent the device from being identified as a CDC device

Sets bDeviceClass, bDeviceSubClass, bDeviceProtocol,
bInterfaceClass, bInterfaceSubClass and bInterfaceProtocol
to 0 and remove all functional descriptors.
This means the ODrive is no longer recognized as
communications device class (CDC) device, thus avoiding
problems where the OS or other applications try to
communicate with or hog the device.

Related resources:
http://www.microchip.com/forums/m789836.aspx
https://www-user.tu-chemnitz.de/~heha/viewchm.php/hs/usb.chm/usb5.htm

Tested on Linux: the device no longer shows up as tty.
To be tested on macOS and Windows.

Firmware/Board/v3/Middlewares/ST/STM32_USB_Device_Library/Class/CDC/Inc/usbd_cdc.h

@@ -58,7 +58,7 @@
 #define CDC_DATA_FS_MAX_PACKET_SIZE                 64  /* Endpoint IN & OUT Packet size */
 #define CDC_CMD_PACKET_SIZE                         8  /* Control Endpoint Packet size */ 
 
-#define USB_CDC_CONFIG_DESC_SIZ                     67
+#define USB_CDC_CONFIG_DESC_SIZ                     (67 - 19)
 #define CDC_DATA_HS_IN_PACKET_SIZE                  CDC_DATA_HS_MAX_PACKET_SIZE
 #define CDC_DATA_HS_OUT_PACKET_SIZE                 CDC_DATA_HS_MAX_PACKET_SIZE
 

Firmware/Board/v3/Middlewares/ST/STM32_USB_Device_Library/Class/CDC/Src/usbd_cdc.c

@@ -198,11 +198,11 @@ __ALIGN_BEGIN uint8_t USBD_CDC_CfgHSDesc[USB_CDC_CONFIG_DESC_SIZ] __ALIGN_END =
   0x00,   /* bInterfaceNumber: Number of Interface */
   0x00,   /* bAlternateSetting: Alternate setting */
   0x01,   /* bNumEndpoints: One endpoints used */
-  0x02,   /* bInterfaceClass: Communication Interface Class */
-  0x02,   /* bInterfaceSubClass: Abstract Control Model */
-  0x01,   /* bInterfaceProtocol: Common AT commands */
+  0x00,   /* bInterfaceClass: Communication Interface Class */
+  0x00,   /* bInterfaceSubClass: Abstract Control Model */
+  0x00,   /* bInterfaceProtocol: Common AT commands */
   0x00,   /* iInterface: */
-  
+#if 0
   /*Header Functional Descriptor*/
   0x05,   /* bLength: Endpoint Descriptor size */
   0x24,   /* bDescriptorType: CS_INTERFACE */
@@ -229,7 +229,7 @@ __ALIGN_BEGIN uint8_t USBD_CDC_CfgHSDesc[USB_CDC_CONFIG_DESC_SIZ] __ALIGN_END =
   0x06,   /* bDescriptorSubtype: Union func desc */
   0x00,   /* bMasterInterface: Communication class interface */
   0x01,   /* bSlaveInterface0: Data Class Interface */
-  
+#endif
   /*Endpoint 2 Descriptor*/
   0x07,                           /* bLength: Endpoint Descriptor size */
   USB_DESC_TYPE_ENDPOINT,   /* bDescriptorType: Endpoint */
@@ -294,11 +294,11 @@ __ALIGN_BEGIN uint8_t USBD_CDC_CfgFSDesc[USB_CDC_CONFIG_DESC_SIZ] __ALIGN_END =
   0x00,   /* bInterfaceNumber: Number of Interface */
   0x00,   /* bAlternateSetting: Alternate setting */
   0x01,   /* bNumEndpoints: One endpoints used */
-  0x02,   /* bInterfaceClass: Communication Interface Class */
-  0x02,   /* bInterfaceSubClass: Abstract Control Model */
-  0x01,   /* bInterfaceProtocol: Common AT commands */
+  0x00,   /* bInterfaceClass: Communication Interface Class */
+  0x00,   /* bInterfaceSubClass: Abstract Control Model */
+  0x00,   /* bInterfaceProtocol: Common AT commands */
   0x00,   /* iInterface: */
-  
+#if 0
   /*Header Functional Descriptor*/
   0x05,   /* bLength: Endpoint Descriptor size */
   0x24,   /* bDescriptorType: CS_INTERFACE */
@@ -325,7 +325,7 @@ __ALIGN_BEGIN uint8_t USBD_CDC_CfgFSDesc[USB_CDC_CONFIG_DESC_SIZ] __ALIGN_END =
   0x06,   /* bDescriptorSubtype: Union func desc */
   0x00,   /* bMasterInterface: Communication class interface */
   0x01,   /* bSlaveInterface0: Data Class Interface */
-  
+#endif
   /*Endpoint 2 Descriptor*/
   0x07,                           /* bLength: Endpoint Descriptor size */
   USB_DESC_TYPE_ENDPOINT,   /* bDescriptorType: Endpoint */
@@ -385,11 +385,11 @@ __ALIGN_BEGIN uint8_t USBD_CDC_OtherSpeedCfgDesc[USB_CDC_CONFIG_DESC_SIZ] __ALIG
   0x00,   /* bInterfaceNumber: Number of Interface */
   0x00,   /* bAlternateSetting: Alternate setting */
   0x01,   /* bNumEndpoints: One endpoints used */
-  0x02,   /* bInterfaceClass: Communication Interface Class */
-  0x02,   /* bInterfaceSubClass: Abstract Control Model */
-  0x01,   /* bInterfaceProtocol: Common AT commands */
+  0x00,   /* bInterfaceClass: Communication Interface Class */
+  0x00,   /* bInterfaceSubClass: Abstract Control Model */
+  0x00,   /* bInterfaceProtocol: Common AT commands */
   0x00,   /* iInterface: */
-  
+#if 0
   /*Header Functional Descriptor*/
   0x05,   /* bLength: Endpoint Descriptor size */
   0x24,   /* bDescriptorType: CS_INTERFACE */
@@ -416,7 +416,7 @@ __ALIGN_BEGIN uint8_t USBD_CDC_OtherSpeedCfgDesc[USB_CDC_CONFIG_DESC_SIZ] __ALIG
   0x06,   /* bDescriptorSubtype: Union func desc */
   0x00,   /* bMasterInterface: Communication class interface */
   0x01,   /* bSlaveInterface0: Data Class Interface */
-  
+#endif
   /*Endpoint 2 Descriptor*/
   0x07,                           /* bLength: Endpoint Descriptor size */
   USB_DESC_TYPE_ENDPOINT      ,   /* bDescriptorType: Endpoint */

Firmware/Board/v3/Src/usbd_desc.c

@@ -189,8 +189,8 @@ __ALIGN_BEGIN uint8_t USBD_FS_DeviceDesc[USB_LEN_DEV_DESC] __ALIGN_END =
   0x00,                       /*bcdUSB */
 #endif /* (USBD_LPM_ENABLED == 1) */
   0x02,
-  0x02,                       /*bDeviceClass*/
-  0x02,                       /*bDeviceSubClass*/
+  0x00,                       /*bDeviceClass*/
+  0x00,                       /*bDeviceSubClass*/
   0x00,                       /*bDeviceProtocol*/
   USB_MAX_EP0_SIZE,           /*bMaxPacketSize*/
   LOBYTE(USBD_VID),           /*idVendor*/