STM32L053-DISCO can't use putc,printf in Keil, EWARM

[COMOkr]

#include "mbed.h"

DigitalOut green_led(LED1);
DigitalOut red_led(LED2);

Serial a(PA_9, PA_10);

int main() 
{
    green_led = 1;
    
    a.baud(9600);
    red_led = 1;
    
    a.printf("c");
    
    green_led = 0;	
}

On web compiler, It worked normaly
but in exported projects, didn't work

in "a.printf("c");" , program was stopped
can i have solution?

Platform is STM32L053-DISCO

[0xc0170]

cc @bcostm @adustm @LMESTM @dbestm

[0xc0170]

@COMOkr It might help to provide the version numbers (what version of mbed-os you use), plus what expoters - is it uvision or makefile arm gcc , or any other. As much details as you can provide

[bridadan]

If you change a.printf("c"); to a.printf("c\n");, does it work? Its possible that the buffers just didn't flush

[COMOkr]

this solution was't working..

I always update library before making projects
I don't know that version

exporter - uvision 5 , IAR SYSTEMS
Compiler - uvision 5.21.1.0, IAR Embedded Workbench for ARM 7.50.2.10505

another function was woriking.
only putc, printf doesn't working

#include "mbed.h"

DigitalOut green_led(LED1);
DigitalOut red_led(LED2);

Serial a(PA_9, PA_10);

int main() 
{
    green_led = 1;


a.baud(9600);
red_led = 1;

a.printf("c");

green_led = 0;


}

when printf, program was stopped.
green_led was not changed to 0

[bcostm]

Issue confirmed.

I have checked this:

• pc.printf + NUCLEO_L053R8 + mbed IDE + mbed lib rev129 --> OK
• pc.printf + NUCLEO_L053R8 + uVision5 project from mbed IDE + mbed lib rev129 --> HardFault !
• printf + NUCLEO_L053R8 + uVision5 project from mbed IDE + mbed lib rev129 --> OK
• pc.printf + NUCLEO_F401RE + uVision5 project from mbed IDE + mbed lib rev129 --> OK
• pc.printf + NUCLEO_L073RZ + uVision5 project from "mbed export" --> OK

The L073RZ is mbedOS5 compliant and the L053R8 not. The serial file is common for these 2 devices. So there is something broken in mbedOS2 serial core that causes this issue.

I also recall that as of today it is impossible to generate a project using mbed source files for NUCLEO_L053R8:

• mbed IDE export + mbed-dev --> Error
• python project.py --> generated uvsion project is not correct (missing many files)
• mbed export --> project generated but linking error due to not enough memory space. Apparently we should not be able to generate a project for this platform as it is not mbedOS5 compliant

[LMESTM]

@COMOkr is this issue still valid ? Also in case you still have the problem, may you try out wiht RawSerial class instead of Serial one ?

[LMESTM]

@bcostm this sounds like an issue with exporters rather than a bug in ST HAL ... how should we proceed ?

[bcostm]

I really don't know what is the issue. First I need to check again this config pc.printf + NUCLEO_L053R8 + uVision5 project from mbed IDE to see if the issue is still present.

[theotherjimmy]

@bcostm @LMESTM If you think that we should turn of export for targets that don't support mbed OS 5, let me know. I can make that patch, and then we can verify that the export shows "not-supported" and close this issue.

[bcostm]

If you think that we should turn of export for targets that don't support mbed OS 5, let me know.

I don't know if the "mbed export" command has to be used only for mbed OS 5 compliant platforms ? If it is the case, then yes we should turn off this exporter on mbed OS 2 only platforms.

[theotherjimmy]

@bcostm mbed export may be used for mbed OS 2 programs as well as mbed OS 5 programs. The difference here is that exporting a mbed OS 5 project to an mbed OS 2 only board might be causing an issue here. I can disable that, as it's not guaranteed supported.

[LMESTM]

@theotherjimmy @bcostm - the above proposal sounds good to me. This seems indeed a bad idea to allow mbed5 projects on mbed2 only boards.

[LMESTM]

I can disable that, as it's not guaranteed supported.

@bcostm Ok with that ?
@theotherjimmy Could you go ahead with this proposal?