I am trying to integrate a very simple TouchGFX Application into the SBSFU (I only really need SB right now) application, on STM32U5A9J-DK
I've switched out the Nonsecure application for mine, I've modified flash_layout to do primary only, no external loader, 1 image. I modified the template loader script to have a Framebuffer section that spans SRAM3 (minus the secure section) and SRAM5. I'm using the startup_stm32...c that the original nonsecure application uses.
Right now. It builds and boots, and shows "Jumping to first Image Slot" and just sits. I think it's getting into the Appli_Secure, because the Users LEDs on my board are lighting up.
I found some verbiage elsewhere that indicates that I likely need to unsecure the IOs and SRAMs that the new NonSecure application uses, but when I start doing that, things go haywire.
For example, I've got my project setup so that I can switch back to using the original demo Appli_NonSecure with my modifed flash_layout.h and linker script, and so I switch back to that, and the demo appears functional. I get the menu with the ability to toggle the secure LED. Great. But then I go into secure/src/main.c and execute code that unsecures my NS_DATA_XXXX that is now in SRAM3 and SRAM5, and the demo app stops functioning, and I get similar behavior to what I indicate above. I separately tried to go into partition_stm32u5a9xx.h and set SAU_REGION4 to be my new NS_DATA_START3 section, and I see the identical behavior as above.
And so, I'm at a place where the stuff I think I may need to be doing for my new Appli_NonSecure is breaking the original Appli_NonSecure. I don't yet understand why unsecuring memory that AFAICT is unused in either the Appli_Secure or the original Appli_NonSecure is breaking things.
Are there any resources that anyone could point me to that might clearly be corelated to the issues or challenges I'm seeing? I feel like I've read all the usual suspects (UM2851, AN4992, et cetera), and these all have alot of words about what can and can't be done, but it feels like very little about how to actually do these things.
