sw4stm32 printf not working
Dear All
I would like to redirect printf output to UART.
It seem very simple in this field and many example in internet.
I try that with “System Workbench”(SW4STM32).
The IDE doesn’t show anything wrong.
adding below to “uart.c”
.#ifdef GNUC
/* With GCC/RAISONANCE, 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 */
/**
* @brief Retargets the C library printf function to the USART.
* @param None
* @retval None
*/
PUTCHAR_PROTOTYPE
{
/* Place your implementation of fputc here */
/* e.g. write a character to the EVAL_COM1 and Loop until the end of transmission */
HAL_UART_Transmit(&huart1, (uint8_t *)&ch, 1, 0xFFFF);
return ch;
}
calling printf() in “main.c”
printf(“\n\r UART Printf Example: retarget the C library printf function to the UART\n\r”);
The “printf()” seem don’t work in my chip.
But “HAL_UART_Transmit” is function in main.c. That imply the UART port work fine.
Then try adding something GPIO action(output toggle) inside the “PUTCHAR_PROTOTYPE” routine. If printf() running, “PUTCHAR_PROTOTYPE”(fputc() or __io_putchar()) should be call. The GPIO action hasn’t execute, mean “PUTCHAR_PROTOTYPE” hasn’t be call.
Is there any where necessary to modify for such redirection except “uart.c”?
My code is generated by STM32CubeMX and hasn’t “syscall.c”
Is it a root cause of my problem?
Or System Workbench is not support printf() redirection?
Please share your comment.
BR
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