I have a `STM32F103VCT6`

microcontroller with 48kb of SRAM, and recently i've got a memory collision:

I have some static variable (lets call it `A`

) located in heap with size of `0x7000`

and I wrote some simple function to get info about stack and heap:

```
void check(int depth) {
char c;
char *ptr = malloc(1);
printf("stack at %p, heap at %p\n", &c, ptr);
if (depth <= 0) return;
check(depth-1);
}
```

So I got something like this:

```
stack at 2000939b, heap at 20008fd0
stack at 20009383, heap at 20008fe0
stack at 2000936b, heap at 20008ff0
stack at 20009353, heap at 20009000
stack at 2000933b, heap at 20009010
stack at 20009323, heap at 20009020
stack at 2000930b, heap at 20009030
stack at 200092f3, heap at 20009040
stack at 200092db, heap at 20009050
stack at 200092c3, heap at 20009060
stack at 200092ab, heap at 20009070
```

All static variables (incliding `A`

) already got their heap, so heap is located at `0x8fd0`

. And seems like, originally, stack pointer is located at `0x939b`

, that is far away from 48kb (`0xc000`

)

And when I changed the `A`

variable size to `0x4000`

I've got this picture:

```
stack at 2000639b, heap at 20005fd0
stack at 20006383, heap at 20005fe0
stack at 2000636b, heap at 20005ff0
stack at 20006353, heap at 20006000
stack at 2000633b, heap at 20006010
stack at 20006323, heap at 20006020
stack at 2000630b, heap at 20006030
stack at 200062f3, heap at 20006040
stack at 200062db, heap at 20006050
stack at 200062c3, heap at 20006060
stack at 200062ab, heap at 20006070
```

So, seems like stack location is not located at the end of SRAM but, some how, rely on user defined variables.

How can I align the stack to be at the very end of SRAM (at the 48kb)?

I am using the CooCox IDE with `GNU Tools ARM Embedded`

toolchain.

Thank you!

**EDIT:**

Sorry for some misunderstanding here, `A`

isn't const, i've called it static only because of keyword:

```
static uint8_t A[A_SIZE];
printf("A is at %p\n", &A);
```

This shows that `A`

is located at the begginning of the memory:

```
A is at 20000c08
```