eth_tx_start_bd
struct eth_tx_start_bd *tx_start_bd;
struct eth_tx_start_bd **tx_bd, u16 hlen,
struct eth_tx_start_bd *h_tx_bd = *tx_bd;
*tx_bd = (struct eth_tx_start_bd *)d_tx_bd;
struct eth_tx_start_bd *tx_start_bd,
struct eth_tx_start_bd *tx_start_bd, *first_bd;
struct eth_tx_start_bd *tx_start_bd;
struct eth_tx_start_bd start_bd;
struct eth_tx_start_bd *start_bd = &txbd->start_bd;