Execute application or certain files from SDRAM in stm32H750b-dk

[MaazSk]

Hello Everyone,

I am using stm32h750b-dk. I want my application to run from from SDRAM or to start with certain .c files to run from SDRAM. I am using zephyr_code_relocate but this does not help. When I use zephyr_code_relocate then when the function is called the code halts and does not proceed further. Also, if I include another file which is a .cpp which has some instances then I get a fault error as below any help how to do this would be greatful.

Also, if I use SRAM to relocate the code everything works fine without any issue. The problem is when I use SDRAM

Thank you

[FRASTM]

Hello @MaazSk

I am not sure the sdram (SDRAM1) through FMC controller can execute code, like the octoSPI does with memory Mapped mode

[MaazSk]

Won't zephyr relocate create a linker script? I read it creates a linker script. Also for the FMC I set it st,mem-swap = sdram-sram Which will help us to swap

[MaazSk]

Hi @FRASTM,
I was able to run the application from SDRAM and it was relatively slow. No issues with that one. I wanted to know what shall I do if I want the zephyr kernel to run from sram0. I want to relocate complete zephyr kernel to sram0

[FRASTM]

Ok, try with CONFIG_XIP=n
it will not use the flash for building and linking, then "flashing" will place the code in the sram0 @ 0x24000000
And you also have to change the Option Byte BOOT_CM7_ADD0 to address 0x24000000 with the stm32CubeProgrammer
Then Downloading the code is done with stm32Cubeprogrammer : zephyr.hex is placed at 0x24000000

*** Booting Zephyr OS build v4.0.0-39-g88b75599dc40 ***
Hello World! from RAM stm32h750b_dk/stm32h750xx

[MaazSk]

Hi @FRASTM,
Is there a way to keep XIP and relocate zephyr kernel files in SRAM or SDRAM. My thought is too keep initialization files like init.c static_init.c in Flash so it will be executed through XIP and other files will be placed in SDRAM. I think I need to keep other files also in external flash so that my device works properly. Could you please suggest a better approach to achieve this?

[FRASTM]

I would recommend to see what the samples/application_development/code_relocation_nocopy/ does.
Some functions are placed in RAM or flash with the corresponding linker script. The CMakeLists.txt makes source files built in a specific mem area