[mbed-tls] On the future of on-target testing

Hello,

Mbed TLS supports building and running unit tests in one of two modes: “hosted” or “on target”. The on-target mode relies on Greentea, the Mbed OS test framework. The on-target mode is unmaintained (there's no CI for it and the Mbed TLS maintainers hardly ever even try to build it these days) and we're considering retiring it in Mbed TLS 2.28.

If you do use Mbed TLS's on-target unit testing, either by building target_test.function or by plugging your own file instead of target_test.function or host_test.function, please let us know and weigh in on https://github.com/ARMmbed/mbedtls/issues/4912 https://github.com/ARMmbed/mbedtls/issues/4912 .

Best regards,