EN0_BOUNDARY
ether_outb(data, EN0_BOUNDARY, data->EC_RXBUF_END_PAGE);
ether_outb(data, EN0_BOUNDARY, data->EC_RXBUF_END_PAGE);
ether_outb(data, EN0_BOUNDARY, nextboundary - 1);
ether_outb(data, EN0_BOUNDARY, data->EC_RXBUF_END_PAGE - 1);