ref: 5f7a6b7ea3c4ae1b51beffe3309e9b6b0491e71f 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);