Hi
For the core recipe files need to create a Yocto image, you can refer to our core-image-minimal.
danielchen_1-1733363494723.png
You can show the bb file
cat poky/meta/recipes-core/images/core-image-minimal.bb
danielchen_0-1733364501642.png
Next, you can check
poky/meta/recipes-core/packagegroups/packagegroup-core-boot.bb
Regards
Daniel