• Calling non-secure Reset Handler from Secure main
    Hi, I am trying to run the example for ARMCM33_DSP_FP_TZ code provided in Keil MDK on a new Cortex-M33 MCU by our company. I have made necessary edits to the linker script to assign the correct values...
  • Reading non-secure world code memory from the secure world
    Hi! I am currently using an ARM Cortex-M23 based Nuvoton M2351 with the Keil MDK IDE. I am trying to read non-secure domain code memory (stored at 0x10040XXX) from privileged secure world code. I...
  • A few intricacies of writing Armv8-M Secure code
    Arm TrustZone brings lightweight compartmentalisation to the M-Profile with Armv8-M security extensions. Compartmentalisation is a technique that separates code from important data or permissions, improving...
  • Programming FPU for Secure and Non Secure Use
    I was getting a NOCP Usage Fault when my non-secure thread entered WIC sleep and a Secure Handler woke up the processor from WIC sleep. I wasn't using any FPU code and I could not understand why the...
  • Interrupts from the secure world to the non-secure world.
    Hello experts, I am using SAM L11 (Core is Cortex-M23). I did a simple test of the interrupt. In the case of the handler was the secure world, it worked as I expected. The instruction sequences are...