This task is to move the SST secure PSA API implementation in a common location inside the services folder to store all secure PSA API implementations.
In my view we should investigate other options for having the API definitions stand out from the service internal files.
There is an ongoing effort to limit the number of steps that need to be taken in order to integrate a new partition into the system, or to disable/enable one that is already present.
I would therefore suggest to keep service API files in the service folder and not create a new location for them.
My suggestion on resolving the original problem is to associate service API functions with e.g. a dedicated section, which would help sort them in the appropriate location in memory in the scatter files/linker scripts. However I suggest to open this up to a wider discussion here.
This task has been resolved by adding the attribute "section SFN" in all the PSA SST secure function implementations which allows to place the code in the unprivileged section
which is callable from any secure partition.