LinkManager.cc

            // Start the channel on Mav 1 protocol
            mavlink_status_t* mavlinkStatus = mavlink_get_channel_status(mavlinkChannel);
            mavlinkStatus->flags |= MAVLINK_STATUS_FLAG_OUT_MAVLINK1;
            _mavlinkChannelsUsedBitMask |= 1 << mavlinkChannel;
            return mavlinkChannel;
        }
    }

    return 0;   // All channels reserved
}

void LinkManager::_freeMavlinkChannel(int channel)
{
    _mavlinkChannelsUsedBitMask &= ~(1 << channel);
}

void LinkManager::_mavlinkMessageReceived(LinkInterface* link, mavlink_message_t message) {
    link->startMavlinkMessagesTimer(message.sysid);
}