LPC55S69 Loading big array of data

greys_mayf — Sat, 23 Apr 2022 14:36:45 GMT

Dear NXP Community,
I am currently working with LPC55S69 board on a program with 2 projects (secure and non-secure) to extract details from images (the images have a size of around 300x300). I am trying to load an image using different methods, but none have actually worked up until now (mostly due to my little knowledge of the platform and embedded systems). What I have tried until now.

Store the image data in an array in the non-secure project and let it be part of the FLASH. I was able to get this working and could actually debug and see the data. I am not sure if access the whole array would cause any exceptions. From here, I wanted to call the secure project and transfer the data to another array during execution. I thought this would have the data stored in RAM of the secure project. When I declared the structure that would hold the data and tried to write to it through assignment, the program would just hang, but not crash. Maybe I didn't give enough space to the RAM in the project settings or I am unaware of what could be happening.
Store the image data immediately to the secure project as an array. I enlarged the FLASH seciton and moved the section of the veneer_table to start after the enlarged. I tried to replicate what I did in the non-secure project, but I still get a SIGTRAP during debugging.
I also tried having the data stored in a SD card and work with the libraries offered to access the SD card. Unfortunately, I couldn't get it to work with the already existing Secure project. Nevertheless, even if I could get this to work, I would still need to load the data onto memory during execution.

Therefore, my overall goal is to get the data loaded into the secure project and be able to read it. I would really appreciate it if you could give me some directions. Please let me know if you need any details about the project, because I am aware this is not enough.

Re: LPC55S69 Loading big array of data

Alice_Yang — Wed, 27 Apr 2022 03:41:27 GMT

Hello greys_mayf,

If you want to Trustzone function, recommend first refer to the "Chapter 47: LPC55S6x/LPC55S2x/LPC552x Trusted Execution Environment" of um11126.

You can see cpu in NS state can't access the data in Secure part:

Alice

LPC MicrocontrollersのトピックLPC55S69 Loading big array of data

LPC55S69 Loading big array of data

Re: LPC55S69 Loading big array of data