ref: 21622cb6b9d0d169f1b87c20d5efe129e6e4e85d 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);