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.
Quick Take
Do I Need a Secure Element If My MCU Has a Crypto Accelerator?
Why a hardware accelerator and a secure element aren’t substitutes for each other, when one is enough, and when you actually want both.
Is SysTick Accurate Enough for Microsecond Timing?
What SysTick gets right at microsecond resolution, what bites you, and when to reach for a hardware timer instead.
Why Does My Code Work in Debug But Break in Release?
The four usual suspects when code works at -O0 and breaks at -O2, in the order to check them.
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.