NDESC_BUFMODE
#define NRXPAGES ((NRXDESCS/NDESC_BUFMODE)+1)
#define NRXREAL (NRXPAGES*NDESC_BUFMODE)
page = id/NDESC_BUFMODE;
desc = id%NDESC_BUFMODE;
(desc/NDESC_BUFMODE) * XGE_PAGE + sizeof(struct rxdesc) * \
(desc%NDESC_BUFMODE), sizeof(struct rxdesc), what)
#define XGE_RXD(desc) &sc->sc_rxd_4k[desc/NDESC_BUFMODE]-> \
r4_rxd[desc%NDESC_BUFMODE]