git.rot13.org Git - goodfet/blob - client/USBConfiguration.py

   1 # USBConfiguration.py
   2 #
   3 # Contains class definition for USBConfiguration.
   4
   5 class USBConfiguration:
   6     def __init__(self, configuration_index, configuration_string, interfaces):
   7         self.configuration_index        = configuration_index
   8         self.configuration_string       = configuration_string
   9         self.configuration_string_index = 0
  10         self.interfaces                 = interfaces
  11
  12         self.attributes = 0xe0
  13         self.max_power = 0x01
  14
  15     def set_configuration_string_index(self, i):
  16         self.configuration_string_index = i
  17
  18     def get_descriptor(self):
  19         interface_descriptors = bytearray()
  20         for i in self.interfaces:
  21             interface_descriptors += i.get_descriptor()
  22
  23         total_len = len(interface_descriptors) + 9
  24
  25         d = bytes([
  26                 9,          # length of descriptor in bytes
  27                 2,          # descriptor type 2 == configuration
  28                 total_len & 0xff,
  29                 (total_len >> 8) & 0xff,
  30                 len(self.interfaces),
  31                 self.configuration_index,
  32                 self.configuration_string_index,
  33                 self.attributes,
  34                 self.max_power
  35         ])
  36
  37         return d + interface_descriptors
  38