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 Redirect Printf through UART2  

Redirect Printf through UART2

I have syscall.c in my SW4STM32 project.
I do this below:
“In main.c , #include “stdio.h” , also create the new implementation for this method ;
void __io_putchar(uint8_t ch) {
HAL_UART_Transmit(&huart1, &ch, 1, 1);

However I get no printf output . Calling HAL_UART_Transmit(&huart3, &ch, 1, 1); directly works.

I get a warning message that probably explains the problem:
’__io_putchar’ defined but not used -Wunused-function main.c /myproject/Core/Src line 150 C/C++ Problem

Why is __io_putchar not being used ?