Heterogeneous multicore platforms have become an attractive choice to deploy mixed criticality systems demanding diverse computational requirements. One of the major challenges is to efficiently harness the computational power of these mul-ticore platforms while deploying mixed criticality applications. The problem is acerbated with an additional demand of energy efficiency. It is particularly relevant for the battery powered embedded systems. We propose a partitioning algorithm for unrelated heterogeneous multicore platforms to map mixed criticality applications that ensures the timeliness property and reduces the energy consumption.