topic Re: RT1170-EVK how enable PRINTF for use on secondary M4 core ? in i.MX RT Crossover MCUs

RT1170-EVK how enable PRINTF for use on secondary M4 core ?

EdOfTheMountain — Fri, 18 Mar 2022 20:14:13 GMT

On bare-metal and / or FreeRTOS SDK examples for cm4/cm7 running on a evkmimxrt1170, the PRINTF output from M7 displays on serial terminal. However, M4 calls to PRINTF are not sent to serial port.

Must I ensure BOARD_InitDebugConsole is called only from the M4 ?

1) How can make M4 access the serial port using PRINTF and NOT the M7 ?

2) Can both M4 and M7 access the same serial port using PRINTF if both call BOARD_InitDebugConsole ?
I understand this may be problem with un-synchronized combined output.

3) Are there any examples for RT1170-EVK, that both M4 and M7, can have their own dedicated serial port for printing debug statements?

Thanks in advance for any debug console tips,

-Ed

Re: RT1170-EVK how enable PRINTF for use on secondary M4 core ?

jingpan — Mon, 21 Mar 2022 09:19:45 GMT

Hi @EdOfTheMountain

Yes, you can use M4 to print via UART only. The LPUART1 is used to print information. M4 can also access LPUART4.

Regards,

Jing

Re: RT1170-EVK how enable PRINTF for use on secondary M4 core ?

EdOfTheMountain — Mon, 21 Mar 2022 17:09:04 GMT

This seems to work

Comment-out C7 call to BOARD_InitDebugConsole in evkmimxrt1170_hello_world_cm4
On C4, add #include "fsl_debug_console.h" and call to BOARD_InitDebugConsole

PRINTF using float "%f" does not printing anything?

Removing "CR_INTEGER_PRINTF" from the preprocessor did not fix?

Re: RT1170-EVK how enable PRINTF for use on secondary M4 core ?

jingpan — Tue, 22 Mar 2022 02:29:44 GMT

Hi,

It seems you've solved this problem.

https://community.nxp.com/t5/i-MX-RT/RT1170-EVK-how-enable-PRINTF-float-Removing-CR-INTEGER-PRINTF/m-p/1431426

Thanks for sharing.

Regards,

Jing