CopyConfigurationDescriptor
Returns the configuration descriptor with the specified index.
Declaration
virtual const IOUSBConfigurationDescriptor * CopyConfigurationDescriptor(uint8_t index);Parameters
- index:
The index number of the configuration.
Return Value
A pointer to the configuration descriptor, or NULL if the descriptor wasn’t found. It’s your responsibility to free the returned descriptor.
Discussion
This method searches the descriptor cache for the specified descriptor. If the descriptor isn’t in the cache, the method retrieves it from the device using a GET_DESCRIPTOR control request (USB 2.0, section 9.4.3) and adds it to the cache. When making a GET_DESCRIPTOR control request, this method acquires the service’s workloop lock and may call commandSleep.