ref: 5fc5c18208546c77f2c279f7f6acf6b01a2d2645 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);