utop
uintptr_t ubase, utop;
utop = ubase + stksz;
if (sp >= ubase && sp <= utop) {
win + sizeof (struct rwindow) <= utop;
win + sizeof (struct rwindow) <= utop;
if (utop(diskname, new_cc.cf_dev_prom))
} else if (utop(new_cc.cf_devfs, new_cc.cf_dev_prom)) {