topic MCXE31B: ethernetif.c is not compiled in MCX Microcontrollers

MCXE31B: ethernetif.c is not compiled

jonasa — Thu, 26 Mar 2026 07:49:00 GMT

Hi,

I 'm trying to port this example project:
\mcuxsdk\examples\lwip_examples\lwip_ping_enet_qos\bm
board:
\mcuxsdk\examples\_boards\frdmmcxe31b

To my own project for a custom board.

In the prj.conf file I have these lines:

CONFIG_MCUX_COMPONENT_component.silicon_id=y
CONFIG_MCUX_COMPONENT_driver.enet_qos=y
CONFIG_MCUX_COMPONENT_middleware.lwip=y
CONFIG_MCUX_COMPONENT_middleware.lwip.contrib.ping=y
CONFIG_MCUX_COMPONENT_middleware.lwip.enet_ethernetif=y
CONFIG_MCUX_PRJSEG_middleware.lwip.generated_config=y

But it seems like the file

\mcuxsdk\middleware\lwip\port\ethernetif.c

is not compiled.

It's not in the generated compile_commands.json file.

and when I build I get this error:

C:/work/mcx/mcuxpresso-sdk/voltra_mcx/apps/voltra_hello_world/voltra_hello_world.c:123:(.text.main+0xbe): undefined reference to `ethernetif_wait_linkup'

What do I need to change so that ethernetif.c is built.

In the example project it builds and everything works.