tools/usb_gadget/msos20_descriptors.py

   1 # Copyright 2015 The Chromium Authors. All rights reserved.
   2 # Use of this source code is governed by a BSD-style license that can be
   3 # found in the LICENSE file.
   4
   5 """Microsoft OS 2.0 Descriptor generation utilities.
   6
   7 Classes to help generate Microsoft OS 2.0 descriptors.
   8
   9 Based on documentation here:
  10 https://msdn.microsoft.com/en-us/library/windows/hardware/dn385747.aspx
  11 """
  12
  13 import uuid
  14
  15 import usb_constants
  16 import usb_descriptors
  17
  18
  19 class PlatformCapabilityDescriptor(usb_descriptors.Descriptor):
  20   """Microsoft OS 2.0 platform capability descriptor.
  21   """
  22
  23   def __init__(self, **kwargs):
  24     super(PlatformCapabilityDescriptor, self).__init__(**kwargs)
  25     self._descriptor_set = None
  26
  27   @property
  28   def descriptor_set_size(self):
  29     if self._descriptor_set is None:
  30       return 0
  31     return len(self._descriptor_set.Encode())
  32
  33   def SetDescriptorSet(self, descriptor_set):
  34     self._descriptor_set = descriptor_set
  35
  36 PlatformCapabilityDescriptor.AddComputedField('bLength', 'B', 'struct_size')
  37 PlatformCapabilityDescriptor.AddFixedField(
  38     'bDescriptorType', 'B', usb_constants.DescriptorType.DEVICE_CAPABILITY)
  39 PlatformCapabilityDescriptor.AddFixedField(
  40     'bDevCapabilityType', 'B', usb_constants.CapabilityType.PLATFORM)
  41 PlatformCapabilityDescriptor.AddFixedField('bReserved', 'B', 0)
  42 PlatformCapabilityDescriptor.AddFixedField(
  43     'MS_OS_20_Platform_Capability_ID', '16s',
  44     uuid.UUID('{D8DD60DF-4589-4CC7-9CD2-659D9E648A9F}').bytes_le)
  45 PlatformCapabilityDescriptor.AddField('dwWindowsVersion', 'I')
  46 PlatformCapabilityDescriptor.AddComputedField(
  47     'wMSOSDescriptorSetTotalLength', 'H', 'descriptor_set_size')
  48 PlatformCapabilityDescriptor.AddField('bMS_VendorCode', 'B')
  49 PlatformCapabilityDescriptor.AddField('bAltEnumCode', 'B', default=0)
  50
  51
  52 class DescriptorSetHeader(usb_descriptors.DescriptorContainer):
  53   """Microsoft OS 2.0 descriptor set header.
  54   """
  55   pass
  56
  57 DescriptorSetHeader.AddComputedField('wLength', 'H', 'struct_size')
  58 DescriptorSetHeader.AddFixedField('wDescriptorType', 'H', 0x00)
  59 DescriptorSetHeader.AddField('dwWindowsVersion', 'I')
  60 DescriptorSetHeader.AddComputedField('wTotalLength', 'H', 'total_size')
  61
  62
  63 class ConfigurationSubsetHeader(usb_descriptors.DescriptorContainer):
  64   """Microsoft OS 2.0 configuration subset header.
  65   """
  66   pass
  67
  68 ConfigurationSubsetHeader.AddComputedField('wLength', 'H', 'struct_size')
  69 ConfigurationSubsetHeader.AddFixedField('wDescriptorType', 'H', 0x01)
  70 ConfigurationSubsetHeader.AddField('bConfigurationValue', 'B')
  71 ConfigurationSubsetHeader.AddFixedField('bReserved', 'B', 0)
  72 ConfigurationSubsetHeader.AddComputedField('wTotalLength', 'H', 'total_size')
  73
  74
  75 class FunctionSubsetHeader(usb_descriptors.DescriptorContainer):
  76   """Microsoft OS 2.0 function subset header.
  77   """
  78   pass
  79
  80 FunctionSubsetHeader.AddComputedField('wLength', 'H', 'struct_size')
  81 FunctionSubsetHeader.AddFixedField('wDescriptorType', 'H', 0x02)
  82 FunctionSubsetHeader.AddField('bFirstInterface', 'B')
  83 FunctionSubsetHeader.AddFixedField('bReserved', 'B', 0)
  84 FunctionSubsetHeader.AddComputedField('wSubsetLength', 'H', 'total_size')
  85
  86
  87 class CompatibleId(usb_descriptors.Descriptor):
  88   """Microsoft OS 2.0 compatible ID descriptor.
  89   """
  90   pass
  91
  92 CompatibleId.AddComputedField('wLength', 'H', 'struct_size')
  93 CompatibleId.AddFixedField('wDescriptorType', 'H', 0x03)
  94 CompatibleId.AddField('CompatibleID', '8s')
  95 CompatibleId.AddField('SubCompatibleID', '8s', default='')