ref: f31e1f4e4272beae2bc8a40ee2d5fb5a3061a3d3 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);