root/sys/arch/newsmips/stand/boot/promdev.h
struct romdev {
        int fd;
        int devtype;
        char devname[32];
};

#define DT_BLOCK        1
#define DT_NET          2

int net_open(struct romdev *);
int net_close(struct romdev *);
int net_mountroot(void);
int prom_getether(struct romdev *, u_char *);