e1000_adv_tx_desc
sizeof(union e1000_adv_tx_desc), EM_DBA_ALIGN);
scctx->isc_txd_size[0] = sizeof(union e1000_adv_tx_desc);
union e1000_adv_tx_desc *txd = NULL;
txd = (union e1000_adv_tx_desc *)&txr->tx_base[i];
status = ((union e1000_adv_tx_desc *)&txr->tx_base[cur])->wb.status;
status = ((union e1000_adv_tx_desc *)