i.MX RT Crossover MCUsのトピックRe: Reallocation FlexRAM

Reallocation FlexRAM

KhaledG — Thu, 30 Oct 2025 16:13:31 GMT

Hi
I'm trying to reallocate the FlexRam to be DTC = 128KB, ITC = 64KB, OC = 64KB on i.mxrt 1024
I did these changes

I also modified the linker file to fit with these changes.
Now it works, but my question is about these two lines

"LDR R0, =0x20001fff\n" // load initial value of stack pointer into R0

"MSR MSP, R0\n" // Reinitialize stack pointer by new value

Why without these lines it doesn’t work even if I modified the linker so _vStackTop must be up to date!

Re: Reallocation FlexRAM

Omar_Anguiano — Mon, 03 Nov 2025 22:45:13 GMT

Please refer to this post for more details on why SP is reset: RT1176 ROM code does not set stack pointer correctly - NXP Community

BR,
Omar

Re: Reallocation FlexRAM

KhaledG — Thu, 12 Feb 2026 20:56:23 GMT

Thank you for your response,
It worked but when i try to set DTCram = 192KB, OCram = 64KB and ITCram = 0KB, i cant find the define ARM_MPU_REGION_SIZE_192KB !
Thank you.