The interactive tests do not seem to function. They can be enabled in the non-secure part by building with -DTFM_INTERACTIVE_TEST=on but this doesn't enable the secure code which I find quite baffling. The documentation claims there is another define for that, -DTFM_PERIPH_ACCESS_TEST=ON but this does not work, with both of these set inside one of the CORE_TEST_INTERACTIVE ifdefs in tfm_ss_core_test.c you can add a load of load of garble, compile the code and it compiles fine therefore proving that it isn't building with this feature enabled.