topic Heap and Dynamic Memory Allocation on K64F in Kinetis Design Studio

Heap and Dynamic Memory Allocation on K64F

torquatocecchin — Mon, 08 Jun 2015 08:02:58 GMT

Hi, I'm using FRDM-K64F dev board and I would like to use the the Heap for large array data allocation.

I tried suggested settings for heap and stack in PE (like changing heap and stack in the PEx CPU Build panel) with no compiling errors but failing debugging at run time.

I would like to configure the heap for using .data sections areas and allow malloc() to dynamically allocate arrays in this area.

I don't use any ROTS since I prefer bare metal configurations and programming with KDS and PEx without KSDK.

A user heap section specification like possible with FreeRTOS would be perfect but I don't know how to do it without.

Thank you for your help guys.

Re: Heap and Dynamic Memory Allocation on K64F

Alice_Yang — Tue, 09 Jun 2015 02:05:12 GMT

Hello Torquato,

Could you please show your configuration and code , and i will test on my side .

Alice

Re: Heap and Dynamic Memory Allocation on K64F

torquatocecchin — Thu, 11 Jun 2015 08:15:59 GMT

Hi Alice.

Thanks for your the interest.

I kept the standard memory sections config.

I tried changing the in the Build Options settings panel:

the Heap amount from 0x0400 to upper values (0x0C00 or 0x1000) with no compiling and linking errors, but I have run time exceptions on isatty() call.

Following suggestions like described in Memory Areas and Using malloc() , I tried to configure linker with -WI switch but I think that symbol definition is different from the one I used. I found other suggestions like reported in compiler construction - use no heap in gnu gcc - Stack Overflow and others without achieving more heap.

I'm testing the available memory amount with this simple function

uint32_t GetAvailableMemory(void)

{

char *p;

uint32_t siz = 1;

p = calloc(1,siz);

while (p)

{

siz++;

p = realloc(p,siz);

}

free(p);

return siz;

}

At least I could follow tweaks like Allocation of Variables at Absolute Address in RAM - Cypress using static or global pre-allocation

but I would like not to change malloc()-like calls because I'm generating C-code from a Matlab algorithm.

The .ld Linker file obviously reflects the PE config for I ask to generate linker code.

Re: Heap and Dynamic Memory Allocation on K64F

Alice_Yang — Mon, 15 Jun 2015 12:10:32 GMT

Hello Torquato,

I test your code on my side , the realloc() function can work well, while i don/t know why you use while(p) , does here the "P"can repeated by some other

cycle conditons?

And i'm sorry that i don't know where you think is wrong , could your tell me ? and tell me the right situation you think ! thank !

Alice