ref: 1c0e91bc1b5dc31f51a1eb5acf5f99378e2c14af 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);