USB keyboard "boot interface"

; implicit HID Report descriptor for Keyboard Boot Interface
;
; Keyboards aren't required to supply this descriptor since BIOS
; isn't expected to query for report format anyway.
;
; A proper USB HID class driver will query the report format and
; issue a Change Protocol to allow the device to switch from the
; boot report format to its true report format.

Usage Page (Generic Desktop),
Usage (Keyboard),
Collection (Application),

   ; Input report (device->host) structure:

   ; byte 0:  keys 224-231 (modifiers)
   Report Count (8),
   Report Size (1),
   Logical Minimum (0),
   Logical Maximum (1),
   Usage Page (Key Codes),
   Usage Minimum (224),
   Usage Maximum (231),
   Input (Data, Variable, Absolute),

   ; byte 1:  reserved
   Report Count (1),
   Report Size (8),
   Input (Constant),

   ; bytes 2-7:  up to 6 of keys 1-255
   Report Count (6),
   Report Size (8),
   Logical Minimum (0),
   Logical Maximum(255),
   Usage Page (Key Codes),
   Usage Minimum (0),
   Usage Maximum (255),
   Input (Data, Array),


   ; Output report (host->device) structure:

   ; byte 0, bits 0-4:  LEDs 1-5
   Report Count (5),
   Report Size (1),
   Usage Page (LEDs),
   Usage Minimum (1),
   Usage Maximum (5),
   Output (Data, Variable, Absolute),

   ; byte 0, bits 5-7:  padding
   Report Count (1),
   Report Size (3),
   Output (Constant),

End Collection