GRETH_BD_LEN
status = GRETH_BD_EN | GRETH_BD_IE | (skb->len & GRETH_BD_LEN);
greth->tx_bufs_length[greth->tx_next] = skb->len & GRETH_BD_LEN;
status |= skb_headlen(skb) & GRETH_BD_LEN;
status |= skb_frag_size(frag) & GRETH_BD_LEN;
greth_read_bd(&bdp->stat) & GRETH_BD_LEN,
pkt_len = status & GRETH_BD_LEN;
pkt_len = status & GRETH_BD_LEN;