USB Descriptor

static const U8 abReportDesc[] = {
    0x05, 0x01,                    // USAGE_PAGE (Generic Desktop)
    0x09, 0x06,                    // USAGE (Keyboard)
    0xa1, 0x01,                    // COLLECTION (Application)

    0x05, 0x07,                    //   USAGE_PAGE (Keyboard)
    0x19, 0xe0,                    //   USAGE_MINIMUM (Keyboard LeftControl)
    0x29, 0xe7,                    //   USAGE_MAXIMUM (Keyboard Right GUI)
    0x15, 0x00,                    //   LOGICAL_MINIMUM (0)
    0x25, 0x01,                    //   LOGICAL_MAXIMUM (1)
    0x75, 0x01,                    //   REPORT_SIZE (1)
    0x95, 0x08,                    //   REPORT_COUNT (8)
    0x81, 0x02,                    //   INPUT (Data,Var,Abs)
    0x95, 0x01,                    //   REPORT_COUNT (1)
    0x75, 0x08,                    //   REPORT_SIZE (8)
    0x81, 0x01,                    //   INPUT (Cnst,Var,Abs)

    0x95, 0x03,                    //   REPORT_COUNT (5)
    0x75, 0x01,                    //   REPORT_SIZE (1)
    0x05, 0x08,                    //   USAGE_PAGE (LEDs)
    0x19, 0x01,                    //   USAGE_MINIMUM (Num Lock)
    0x29, 0x03,                    //   USAGE_MAXIMUM (Kana) Scroll Lock
    0x91, 0x02,                    //   OUTPUT (Data,Var,Abs)
    0x95, 0x05,                    //   REPORT_COUNT (1)
    0x75, 0x01,                    //   REPORT_SIZE (3)
    0x91, 0x01,                    //   OUTPUT (Cnst,Var,Abs)

    0x95, 0x06,                    //   REPORT_COUNT (6)
    0x75, 0x08,                    //   REPORT_SIZE (8)
    0x15, 0x00,                    //   LOGICAL_MINIMUM (0)
    0x26, 0xff, 0x00,                    //   LOGICAL_MAXIMUM (101)
    0x05, 0x07,                    //   USAGE_PAGE (Keyboard)
    0x19, 0x00,                    //   USAGE_MINIMUM (Reserved (no event indicated))
    0x29, 0x91,                    //   USAGE_MAXIMUM (Keyboard Application)
    0x81, 0x00,                    //   INPUT (Data,Ary,Abs)
    0xc0                           // END_COLLECTION
};

static const U8 abDescriptors [] =
{
        //
        //  Device descriptor
        //
        0x12,
        DESC_DEVICE,
        LE_WORD(0x0200),                // bcdUSB
        0x00,                                   // bDeviceClass
        0x00,                                   // bDeviceSubClass
        0x00,                                   // bDeviceProtocol
        MAX_PACKET_SIZE0,               // bMaxPacketSize
        LE_WORD(0xFFFF),                // idVendor
        LE_WORD(0x0003),                // idProduct
        LE_WORD(0x0100),                // bcdDevice
        0x01,                                   // iManufacturer
        0x02,                                   // iProduct
        0x03,                                   // iSerialNumber
        0x01,                                   // bNumConfigurations

        //
        //  Configuration descriptor (Len=9)
        //
        0x09,                                   // bLength
        DESC_CONFIGURATION,             // bDescriptorType
        LE_WORD(32+9+9+9+7),    // wTotalLength
        0x02,                                   // bNumInterfaces*
        0x01,                                   // bConfigurationValue
        0x00,                                   // iConfiguration
        0xC0,                                   // bmAttributes
        0x32,                                   // bMaxPower

        // --
        // Interface 0, Alternate Setting 0, MSC Class (Len=9)
        //
        0x09,
        DESC_INTERFACE,
        0x00,                                   // bInterfaceNumber
        0x00,                                   // bAlternateSetting
        0x02,                                   // bNumEndPoints
        0x08,                                   // bInterfaceClass = mass storage
        0x06,                                   // bInterfaceSubClass = transparent SCSI
        0x50,                                   // bInterfaceProtocol = BOT
        0x00,                                   // iInterface

        //
        //  EP (Len=7)
        //
        0x07,
        DESC_ENDPOINT,
        MSC_BULK_IN_EP,                         // bEndpointAddress
        0x02,                                           // bmAttributes = bulk
        LE_WORD(MAX_PACKET_SIZE),       // wMaxPacketSize
        0x00,                                           // bInterval

        //
        //  EP (Len=7)
        //
        0x07,
        DESC_ENDPOINT,
        MSC_BULK_OUT_EP,                        // bEndpointAddress
        0x02,                                           // bmAttributes = bulk
        LE_WORD(MAX_PACKET_SIZE),       // wMaxPacketSize
        0x00,                                           // bInterval

        // --
        // Interface 1, Alternate Setting 0, HID Class (Len=9)
        //
        0x09,
        DESC_INTERFACE,
        0x01,                                                   // bInterfaceNumber*
        0x00,                                                   // bAlternateSetting
        0x01,                                                   // bNumEndPoints
        0x03,                                                   // bInterfaceClass = HID
        0x00,                                                   // bInterfaceSubClass
        0x01,                                                   // bInterfaceProtocol (keyboard)
        0x00,                                                   // iInterface

        //
        // HID descriptor (Len=9)
        //
        0x09,
        DESC_HID_HID,                                   // bDescriptorType = HID
        LE_WORD(0x0110),                                // bcdHID
        0x00,                                                   // bCountryCode
        0x01,                                                   // bNumDescriptors
        DESC_HID_REPORT,                                // bDescriptorType
        LE_WORD(sizeof(abReportDesc)),  // wDescriptorLength

        // EP descriptor (Len=7)
        0x07,
        DESC_ENDPOINT,
        INTR_IN_EP,                                             // bEndpointAddress
        0x03,                                                   // bmAttributes = INT
        LE_WORD(8),                                             // wMaxPacketSize [LE_WORD(MAX_PACKET_SIZE)]
        0x20,                                                   // bInterval

        //
        //  String descriptors
        //
        0x04,
        DESC_STRING,
        LE_WORD(0x0409),

        16+2,
        DESC_STRING,
        'M', 0, 'o', 0, 'b', 0, 'i', 0, 'l', 0, 'i', 0, 't', 0, 'y', 0,

        18+2,
        DESC_STRING,
        'T', 0, 'e', 0, 'l', 0, 'e', 0, 'b', 0, 'o', 0, 'a', 0, 'r', 0, 'd', 0,

        14+2,
        DESC_STRING,
        'A', 0, 'D', 0, 'R', 0, '2', 0, '0', 0, '1', 0, '2', 0,

        // terminating zero
        0
};