Sunflower is a suite of tools, comprising the Sunflower full-system (embedded microarchitecture, networking, power, battery, and analog signal) simulator, a miniature energy-scavenging hardware sensor platform, and a handheld interface device.
 
The suite is intended to provide a complementary and comprehensive platform for research in micro- and system-architectures for embedded systems, with attention to energy-efficiency, reliability, and ecological impact.

You can grab the source on github here it and can find the project's more extensive web pages at http://www.sflr.org