bi_biosgeom_entry
struct bi_biosgeom_entry bbe;
bi->num * sizeof(struct bi_biosgeom_entry));
bibg_len = sizeof(*bibg) + nefidisks * sizeof(struct bi_biosgeom_entry);
bibg_len -= (nhd - nvalid) * sizeof(struct bi_biosgeom_entry);
bibg_len += nhd * sizeof(struct bi_biosgeom_entry);
struct bi_biosgeom_entry disk[1]; /* var len */
struct bi_biosgeom_entry *be;