e1000_adv_rx_desc
sizeof(union e1000_adv_rx_desc), EM_DBA_ALIGN);
scctx->isc_rxd_size[0] = sizeof(union e1000_adv_rx_desc);
union e1000_adv_rx_desc *rxd;
rxd = (union e1000_adv_rx_desc *)&rxr->rx_base[next_pidx];
union e1000_adv_rx_desc *rxd;
rxd = (union e1000_adv_rx_desc *)&rxr->rx_base[i];
union e1000_adv_rx_desc *rxd;
rxd = (union e1000_adv_rx_desc *)&rxr->rx_base[cidx];