ref: 2dea7c2f8e55b4de0c79448c3ce03351a8f75e3b dir: /sys/src/cmd/nusb/usbd/fns.h/
int attachdev(Port*); void detachdev(Port*); void work(void); Hub* newhub(char *, Dev*); int hname(char *); void checkidle(void);