I-CUBE-wolfMQTT example code uses LwIP's sockets despite not using FreeRTOS.

[_AdamNtrx]

I added I-CUBE-wolfMQTT and I-CUBE-wolfSSL software packs to my STM32CubeIDE project in CubeMX built into CubeIDE. In CubeMX I set parameters:

• for wolfSSL:
  • RTOS - Single THreaded (no RTOS / Baremetal)
  • IO interface - LWIP (native API)

• for wolfMQTT:
  • FREERTOS Support - False
  • IO - LWIP

Despite that, trying to compile project ends up with errors like "'SOL_SOCKET' undeclared (first use in this function)" or "'AF_INET' undeclared (first use in this function)". It is because example code uses sockets from LwIP library which can't be used if FreeRTOS is disabled. Even in lwipopts.h LWIP_SOCKET is defined to 0 and you can't enable it in CubeMX if NO_SYS (OS Awarness) is set to OS Not Used. 

Am I missing something? Did I misconfigure settings in CubeMX or are provided examples just wrong?

[ASEHST · Accepted solution]

Hello @_AdamNtrx,

Thank you for your report.

The issue arises because the I-CUBE-wolfMQTT examples use BSD sockets via LWIP, which requires FreeRTOS to be enabled (NO_SYS=0) to provide this socket interface.

In your current configuration (NO_SYS=1, FreeRTOS disabled), LWIP does not provide the socket definitions and functions, hence the errors 'SOL_SOCKET' undeclared and 'AF_INET' undeclared.

To resolve this issue, please try to:

• Enable FreeRTOS in CubeMX (NO_SYS=0) to use the BSD socket interface with LWIP, which matches the configuration expected by the examples.
• Or adapt the code to use LWIP’s raw API, but this requires specific development since the current examples do not support this mode.

With Regards,

[_AdamNtrx]

Thank you for the answer. Do you know by any chance which parts of the code need to be changed to use LwIP's raw API?