Periodic SPI reads in TF-M secure partition

RE: Periodic SPI reads in TF-M secure partition

afok-esmart — Fri, 27 Sep 2024 07:53:01 GMT

(OP replying) For approach #2, I was able to get it working by making sure the main thread i.e., main() never returned/exited by using an infinite while loop with a short delay inside.

My guess is that, without the main thread, the work item handler gets executed in the idle thread or some other low-priority thread (which may not be running frequent enough). Could be related to how, "depending on the priority of the thread handling the offload (computation from an ISR), the ... other higher-priority threads may execute before (it) ... is scheduled"?

RE: Periodic SPI reads in TF-M secure partition

afok-esmart — Fri, 27 Sep 2024 07:42:44 GMT

Thank you for the suggestions. I'll give them a try a little later. So far I've had more progress when having it in non-secure partition (will post separate reply regarding this), but may need to revisit having it in secure partition.

RE: Periodic SPI reads in TF-M secure partition

Amanda Hsieh — Thu, 26 Sep 2024 20:15:15 GMT

What exactly are you doing in the interrupt when you have it in secure mode? It is not very clear from the message.

Can you maybe try to delay the SPI reading after cold boot to rule out the possibility that you try to use uninitialized services?

Can you try to use Debugging to step through the secure partition code? I can't promise that this will show what goes wrong, but it is worth a try.

RE: Periodic SPI reads in TF-M secure partition

afok-esmart — Tue, 24 Sep 2024 22:26:45 GMT

Sounds good, thank you. Please also note my update to the original post (edit #1) when you get the chance.

RE: Periodic SPI reads in TF-M secure partition

Amanda Hsieh — Tue, 24 Sep 2024 19:03:58 GMT

Hi,

I am working on your case and will update it later when I collect enough information.

Regards,
Amanda H.