Hi Igor,
First of all thank you for your answer.
I've actually already consulted all these guides, my board is up and running with Trusty (RPMB key programmed, AVB key generated...) and I have a Trusted Application of my own runnning in Trusty that is waiting on a custom port.
I'd like to communicate with it through an Android application (running in the rich os) but both the android guides and the trusty aosp homepage are pretty vague on how this could be achieved.
Regarding Gatekeeper/Keymaster, they're communicating by means of services/HALs and a kernel module interacting with the trusty driver.
What would be the best way to achieve this from scratch, having a shared library talking to the kernel and JNI wrappers in the app to talk to this particular library ?
I understand this question may be Android-related but I'm giving it a shot here.
Thanks again for your help in this Igor.