A few months ago, I wrote an article longing for the need of a multicore processor simulator - preferably one that is free. One of the reader of my blog have left a message about COTSon (I wonder why (s)he wanted to be anonymous). So I started reading more about it, starting with the white paper that was in SIGOPS. And I liked what I read.
COTSon is the result of a collaborative effort by HP and AMD. The best part about COTSon is that it is not just a multicore processor simulator, but can also act as a full blown system simulator. That means it can simulate a range of hardware models and software stack. It is based on AMD SimNow, which performs high speed instruction set translation for x86 and AMD Athelon type processors. The software stack that it can simulate includes everything that runs on x86 and AMD Athelon including proprietary software like MATLAB for instance.
What COTSon does is not a cycle-accurate or bit-accurate simulation, which runs over the entire weekend to tell what is wrong. Rather it's a fully functional simulation. So may be COTSon can act as a first cut simulation at one level higher than the Transaction Level Modeling. Or on the other hand, COTSon can be used as a tool to visualize the paradigms of TLM. Maybe COTSon is what we need in the design cycle in this world where time-to-market is of prime importance.
I am now interacting with a friend doing his doctorate in Vrije University about COTSon, how we can learn how to use it and use it. We would know the reality only when the rubber hits the road. Lets see how good it is and I will post at the end of my analysis with some greater detail.