This is a prototype loosely based on the PSA FF-A v1.0 specification. Any interface / platform API introduced for this is subject to change as it evolves. Cactus is meant to be the main test Secure Partition run at S-EL1. It is the one meant to have most of the tests that a Secure Partition has to do. Ivy is meant to be more minimalistic and run at S-EL0.