ref: 4d4107b38547c7f9f135cc22d3a29fcbad4a8c34 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);