ie_xmit_buf
struct ie_xmit_buf xb;
xb.ie_xmit_buf = (void *)sc->xmit_cbuffs[sc->xctail];
WRITE_MEMBER(sc,struct ie_xmit_buf, ie_xmit_flags,
iezero(sc, ptr, sizeof(struct ie_xmit_buf));
ptr += sizeof(struct ie_xmit_buf);
void *ie_xmit_buf; /* 24-pointer to the actual buffer */
volatile struct ie_xmit_buf im_xd[NTXBUF];
u_int ie_xmit_buf; /* 24-pointer to the actual buffer */
sc->xmit_buffs[i]->ie_xmit_buf =
sc->xmit_buffs[sc->xctail]->ie_xmit_buf =
volatile struct ie_xmit_buf *xmit_buffs[NTXBUF];