You will require the specification of the hypothetical multi-core architecture. This will include the instruction set, cache relationship(s), potentially memory bus configuration(s) and timing information. Instruction pipeline information and other internal features.
With this information at hand, you write what is called an emulator. You would choose a good language for the emulation, C++ (or C) would be a good choice.
You would define a class object that maintains the state of the virtual processor and instantiate as many such processor class objects as you wish to emulate in your simulation. The processor class objects would be initialized according to the level of detail you wish to emulate: e.g. does a processor have multiple cores, do cores within the same processor share the same cache (and how), how memory is shared between processors, etc...
Emulated instructions will likely be performedusing multiple time states with different instructions requiring different numbers of time states, and instructions within a core may be pipelined so more than one instruction in each processor core will be at various states of completion. You would likely have a synchronized time state between all processors but your simulation could permit skewing of the time states if you want to go to that extent in your simulation. Most multi-processors systems have something that is used as a master timing reference such as one timing source for the shared memory Front Side Bus. But this is dependent on your design of the hypothetical archetecture.
Writing such a simulator is a major project.
The next phase would be to adapt a compiler (Open Source C++ like GNU would be a likely candidate) such that it produces object code for this hypothetical processor. Then you would need to write (adapt) a Linker to construct a file containing an execuitable image.
You would also need to implement a rudimentary operating system within your virtual environment. Something like a BIOS. The simulation begins bypopulating some virtual memory with boot code and starts emulation. One of the first things in the emulated boot code is a BIOS call to load the test application. The test application makes BIOS calls to instantiate the additional processors and to start the interpretation.
This is a major undertaking.
Jim Dempsey
