There is a new document out from Intel that describes their Excite project. No URL to source code, AFAICT.
Finding BIOS Vulnerabilities with Symbolic Execution and Virtual Platforms
By Engblom, Jakob (Intel), Added June 6, 2017
Finding BIOS Vulnerabilities With Excite
Finding vulnerabilities in code is part of the constant security game between attackers and defenders. An attacker only needs to find one opening to be successful, while a defender needs to search for and plug all or at least most of the holes in a system. Thus, a defender needs more effective tools than the attacker to come out ahead.[…]