Hello Bardia,
I would recommend checking the priority of your layer. You can see the priority of all layers that Bitbake can see by using the command:
$ bitbake-layers show-layers
Your layer is priority 6, which may be the same or lower than some other layers. I would test increasing the layer priority.
I would also review the included u-boot recipes and the fsl-u-boot-localversion settings. It is possible that some other configuration is taking precedence. Once you rule out the layer priority the next step would be looking at these inheritances and override them if necessary so your u-boot gets build.
Just as a side note, Yocto is meant to work as a means of distribution of customizable Linux images. It is not meant as a development tool, which means that it does not follow very closely whether files have been changed. I would recommend doing a clean before building to make sure it’s looking for the source code again, otherwise it won’t fetch any code that was already fetched and it won’t build anything already built.
I hope this helps!
Regards,
