I have an STM32 application with two levels of secure code. A bootloader at “LEVEL2” and an application at “LEVEL3”. I am unclear if I should run FreeRTOS in NTZ mode, or in TZ-Secure. I will not have a non-secure element, nor will I have NSC obviously.
To head off the “why use TZ on chip at all then?” questions, some of the features we need only work when the chip is running TrustZone.
I think this post by @aggarg on the FreeRTOS blog is excellent. Unfortunately it looks like that particular blog post has aged out of the main blog page. However it is still the first hit when you google “freertos armv8-m”, and it is the second hit when you google “freertos m33 secure”, with the first hit now being this forum thread