ref: c28f07b5840216c4e83e1d3b21d8a9ed7c41f8f9
dir: /sys/src/cmd/nusb/usbd/fns.h/
void attachdev(Dev*); void detachdev(Dev*); void work(void); Hub* newhub(char *, Dev*); int hname(char *); void assignhname(Dev *dev); void checkidle(void); int portfeature(Hub*, int, int, int);