clone_create
DEF_CLONE_CMD("create", 0, clone_create),
DEF_CLONE_CMD("plumb", 0, clone_create),
if (clone_create(&vkbd_dev_clones, &vkbd_dev_cdevsw, &unit, dev, 0))
i = clone_create(&drv->clones, &drv->cdevsw, &unit, &dev, 0);
i = clone_create(&drv->clones, &drv->cdevsw, &u, dev, 0);
int clone_create(struct clonedevs **, struct cdevsw *, int *unit, struct cdev **dev, int extra);