Building for another OS

[OscarVsp]

Hello,

I am currently investigating the possibility of using a TEE such as Keystone for an RTOS (such as Zephyr or RIOT).
I would like to use the Keystone SM and adapt the RTOS to run tasks in enclaves.

As I understand it, since the current build process uses buildroot, which is designed for Linux, it wouldn't be possible to simply “change the operating system” here (but maybe I'm wrong?). What would be the right way to build the SM but for a different operating system?

My idea was to use the sm subdirectory and the build process with OpenSBI that is mentioned in the README but when I try I run into some problems, so I want to make sure this is the right way to do it before I share them.

Thanks!