RX_HEADER_LEN
bw32(bp, B44_RXMAXLEN, bp->dev->mtu + ETH_HLEN + 8 + RX_HEADER_LEN);
bw32(bp, B44_TXMAXLEN, bp->dev->mtu + ETH_HLEN + 8 + RX_HEADER_LEN);
#define RX_PKT_OFFSET (RX_HEADER_LEN + 2)