I am working on mbed-os/tf-m port on M2351. From M2351 NS, it needs to call platform-specific secure function at pre-rtos stage. Currently, tfm_ns_lock_dispatch doesn't dispatch until NS lock is ready. I would like to support it by exporting tfm_ns_lock_get_init_state. NS world can call secure function straight when it is now at pre-rtos stage (tfm_ns_lock_get_init_state returns false).
A related change is submitted in 1123.