BWN_SHARED_CHAN
savedcookie = bwn_shm_read_2(mac, BWN_SHARED, BWN_SHARED_CHAN);
bwn_shm_write_2(mac, BWN_SHARED, BWN_SHARED_CHAN, channelcookie);
bwn_shm_write_2(mac, BWN_SHARED, BWN_SHARED_CHAN, savedcookie);