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     def set_configuration_string_index(self, i):
  13         self.configuration_string_index = i
  14
  15     def get_descriptor(self):
  16         interface_descriptors = bytearray()
  17         for i in self.interfaces:
  18             interface_descriptors += i.get_descriptor()
  19
  20         total_len = len(interface_descriptors) + 7
  21
  22         d = bytes([
  23                 7,          # length of descriptor in bytes
  24                 2,          # descriptor type 2 == configuration
  25                 total_len & 0xff,
  26                 (total_len >> 8) & 0xff,
  27                 len(self.interfaces),
  28                 self.configuration_index,
  29                 self.configuration_string_index
  30         ])
  31
  32         return d + interface_descriptors
  33