I have a development board based on i.mx6ull. I can't find the official uboot and kernel on the NXP official website. I hope to get the official uboot and kernel source code based on the i.mx6ull evk development board.
You will need to refer to the below doc, follow the steps to download and build your first project.
It can take time if you are new to YOCTO project.
Well I answered your question. could you please help have a look at my question?