"...The AMD Generic Encapsulated Software Architecture (AGESA) is a library of validated processor procedures designed to aid customers with quick adoption of AMD technology into their products. AMI?s drop-in support of AGESA allows minimal time-to-market for APTIO® customers to integrate AMD Processor Solutions into their products. AMI?s integration in APTIO® indicates that AGESA? code is versatile enough that it can be dropped in totally new architecture (UEFI) with minimal build changes...."
I think it has to do more with boot-up code and the P-state of the CPU.