config_rootsearch
cf = config_rootsearch(NULL, "mainbus", NULL);
cf = config_rootsearch(NULL, "mainbus", NULL);
cf = config_rootsearch(NULL, "mainbus", __UNCONST("mainbus"));
if ((cf = config_rootsearch(NULL, rootname, aux)) != NULL)
cfdata_t config_rootsearch(cfsubmatch_t, const char *, void *);