ref: b6e966d03ba5e331dae9fae1b05a9f97f9a1e272 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);