rx_desc_type
memsize = dmfep->rx.n_desc * sizeof (struct rx_desc_type);
pnext = pstart + sizeof (struct rx_desc_type);
pnext += sizeof (struct rx_desc_type);
struct rx_desc_type *desc = dnetp->rx_desc;
struct rx_desc_type *descp = &(dnetp->rx_desc[index]);
sizeof (struct rx_desc_type) * dnetp->max_rx_desc,
sizeof (struct rx_desc_type) * dnetp->max_rx_desc,
struct rx_desc_type *rx_desc; /* virtual addr of recv desc */