ref: 6187b862b7d9ffc7baf3ed2fb2a203f1815a2e25 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);