ref: 3c7eaa9d6bbdd448675a7e9d4fe46bc0a48a4ade dir: /sys/src/cmd/nusb/usbd/fns.h/
int attachdev(Port*); void detachdev(Port*); void work(void); Hub* newhub(char *, Dev*); void hname(char *); void checkidle(void);