Techniques that determine a strict subset of multiple processor cores from a set of multiple functional processor cores integrated within a single integrated circuit package. The determined strict subset of multiple processor cores differs from a previously determined strict subset of multiple processor cores from the set of multiple functional processor cores used to initiate an immediately previous core booting. In response to a processor reset, booting of the strict subset of multiple processor cores is initiated. Also, support for selecting multiple modes of operations, either supporting fault tolerance or extended life.