https://en.wikipedia.org/wiki/Trusted_execution_environment
OP-TEE  
       Code Organization
       OP-TEE Secure Storage Architecture 
       Use case Demonstration 
Trusty TEE
        Code Organization 
        https://projectacrn.github.io/latest/developer-guides/trusty.html#trusty-tee
        Trusty Secure Storage  Architecture  
        1.       https://events19.linuxfoundation.org/wp-content/uploads/2017/12/Implement-Android-Tamper-Resistant-Secure-Storage-Bing-Zhu_and-Secure-it-in-Virtualization-Bing-Zhu-Intel-Corporation.pdf
       2. https://projectacrn.github.io/latest/tutorials/trustyACRN.html
       Use case Demonstration