Secure + Non-Secure integration example

[ainaracatgirl]

The RP2350 supports ARM TrustZone and Secure + Non-Secure binaries when running on the Cortex-M33 cores.
Currently, there is no example that shows how to create a project that has a Secure side (using the set_rom_callback() bootrom API) and a Non-Secure side (using the secure_call() bootrom API) that gets loaded and executed by the Secure side.

It seems this goes further than just building two binaries and putting them in flash with different partitions, but also requires the use of linker scripts to reserve memory for the Non-Secure side, then marking it as NS using SAU registers.

I'm struggling with setting up such a project and would greatly appreciate an example to guide me in the right direction.