SW4STM32 and SW4Linux fully supports the STM32MP1 asymmetric multicore Cortex/A7+M4 MPUs

   With System Workbench for Linux, Embedded Linux on the STM32MP1 family of MPUs from ST was never as simple to build and maintain, even for newcomers in the Linux world.
And, if you install System Workbench for Linux in System Workbench for STM32 you can seamlessly develop and debug asymmetric applications running partly on Linux, partly on the Cortex-M4.
You can get more information from the ac6-tools website and download two short videos (registration required) highlighting:

System Workbench for STM32

You are viewing a reply to Issue snprintf floats  

Issue snprintf floats

The answer to this is, no it does not always work. I will continue this monologue.

I have used the solution from: http://www.openstm32.org/forumthread353#threadId354Question
It appears to be an incorrect _sbrk implementation

I have update the example project on bitbucket

_sbrk implementation

caddr_t _sbrk(int incr) {

extern char end asm(“end”);
extern char _min_heap_end asm(“_min_heap_end”);
static char *heap_end;
char *prev_heap_end;

if (heap_end == 0) {
heap_end = &end;

prev_heap_end = heap_end;
if (prev_heap_end + incr > &_min_heap_end) {
if (heap_end + incr > stack_ptr) {
errno = ENOMEM;
return (caddr_t) -1;
heap_end += incr;
return (caddr_t) prev_heap_end;


Update to linker file:

/* User_heap_stack section, used to check that there is enough RAM left */
._user_heap_stack :
. = ALIGN(4);
PROVIDE ( end = . );
PROVIDE ( _end = . );
. = . + _Min_Heap_Size;
PROVIDE ( _min_heap_end = . );
. = . + _Min_Stack_Size;
. = ALIGN(4);
} >RAM