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

itoa() and utoa() have bad results

9.2.1 is the eclipse version, the gcc version is :
arm-none-eabi-gcc (GNU Tools for Arm Embedded Processors 7-2018-q2-update) 7.3.1 20180622 (release) ARM/embedded-7-branch revision 261907

you can find the compiler in this directory :
then usind cmd : arm-none-eabi-gcc.exe --version

char is unsigned by default on gcc- arm architecture, unless -fsigned-char is used.
you can test it :
char c = -1;
if(c < 0)
printf(“char is signed”);
printf(“char is unsigned”);
for other types (short, int, long ... ) they are signed by default

Best reagrds,