// MSC Interface static const struct usb_interface_descriptor msc_iface = { .bLength = USB_DT_INTERFACE_SIZE, // Length of this descriptor. .bDescriptorType = USB_DT_INTERFACE, // This is an Interface Descriptor. .bInterfaceNumber = 1, // This is the second interface (number starts at 0) .bAlternateSetting = 0, .bNumEndpoints = 2, // 2 endpoints for this interface .bInterfaceClass = USB_CLASS_MSC, // This is an MSC (Mass Storage Class) interface .bInterfaceSubClass = USB_MSC_SUBCLASS_SCSI, // That implements the ancient SCSI command set .bInterfaceProtocol = USB_MSC_PROTOCOL_BBB, // Using the bulk-only transport protocol, over the 2 endpoints .iInterface = 5, // Name of interface. Index of string descriptor. .endpoint = msc_endp, // MSC Endpoints .extra = NULL, .extralen = 0 };