ref: f5bbb69877c377e1ff5e4a8cf1bfb3fc8e39b85a 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);