In this paper, we introduce an integrated power methodology for multi-core SoC designs. It features not only a bottom-up IP-based power modeling for all kinds of IP components ranging from hardware accelerators, processors, and memory blocks, but also a top-down system-wide ESL power estimation formulation. By linking these two methods of different levels of abstraction, one can thereby easily profile the power consumption of a multi-core SoC running a complete application while retaining high accuracy of estimation. We have realized the proposed methodology into two software tools: (1) PowerMixerIP, an IP-based power model builder that uses different strategies to build versatile power models for general IPs and processor IPs, and (2) PowerDepot, an ESL power estimation tool that can interact with the users in a simple way and then generate the needed power monitors to be embedded into the ESL design in SystemC for super-fast power estimation so as to facilitate early-stage system-wide power profiling. The application of these tools on a dual-core real-life designs executing an H. 264 shows that the average error of the ESL power estimation is less than 2%, while the speedup can be up to 2400X when comparing to gate-level simulation.