Manual CubeMX C to C++ project conversion fails when including FreeRTOS

1
votes

Toolchain is the SW4STM32, gcc, processor is STM32F303K8 (Nucleo 303K8), minimal test project with no actual user code at all. The process how to convert a project generated by ST CubeMX is well documented and apparently works. However, when i specify FreeRTOS in Cube, linker fails to find the init function MX_FREERTOS_Init(). The function prototype is included in main.cpp and the definition exists in another source file (freertos.c). This works in C but when converting the project to C++ the linker fails to link the function.

The C2C++ conversion i did as follows:

  • add ccnature to the .project file
  • copy main.c to main.cpp (& remove main.c from the build)
  • duplicate gcc compiler settings over to g++ in project properties
  • point linker script to the one in the project directory

The above enable Eclipse to compile main using g++ and to link using G++ linker. However linking consistently fails in ...\Debug/../Src/main.cpp:97: undefined reference to `MX_FREERTOS_Init()'

What is remarkable is that even when i delete all references to MX_FREERTOS_Init() from main.cpp so that the text simply does not exist anywhere, linker STILL fails exactly the same. It even reports the same line number even though the text is completely different. This behavior does not change never mind if i clean the project, rebuild and refresh all indexes etc etc.

Any suggestions anyone? Or do i have to skip specifying FreeRTOS in Cube and do it all manually?

3
c++eclipselinkerfreertos

3 Answers

0
votes

I have faced with the same issue. So, I would like to suggest renaming freertos.c file to freertos.cpp.

0
votes

I have the same question using atollic for stm32， solved by adding extern "C" to main.cpp

/* USER CODE BEGIN PV */
/* Private variables ---------------------------------------------------------*/
#ifdef __cplusplus
 extern "C" {
#endif
/* USER CODE END PV */

/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config();
void MX_FREERTOS_Init(void); /* (MISRA C 2004 rule 8.1) */

/* USER CODE BEGIN PFP */
/* Private function prototypes -----------------------------------------------*/
#ifdef __GNUC__
/* With GCC, small printf (option LD Linker->Libraries->Small printf
   set to 'Yes') calls __io_putchar() */
#define PUTCHAR_PROTOTYPE int __io_putchar(int ch)
#else
#define PUTCHAR_PROTOTYPE int fputc(int ch, FILE *f)
#endif /* __GNUC__ */
#ifdef __cplusplus
}
#endif
/* USER CODE END PFP */
0
votes

I would suggest a C++ RTOS for example the free disortos. (Google it)