TF-M vs TF-A — When Do You Reach For Which?
TF-M lives on Cortex-M with SAU and NSC veneers. TF-A lives on Cortex-A with EL3 and BL1/BL2/BL31. Pick by the silicon, not by preference.
ARM
What TrustZone-M Adds to Your Build
A walk through what TrustZone-M adds to a build: two projects, two memory maps, SAU configuration, the veneer region, and signed images. None of it is gratuitous.
What Actually Happens Before main() Runs?
The six things that happen between reset and main() on a typical Cortex-M, in order, and what goes wrong at each stage.