How to customize ST32MPU Distribution Package using result from the Developer Package ?

[DNA01]

I am going to build linux system on a board based on STM32MP257F and have read many kinds of related technical documents.

In the process, a question bothers me. I want to modify only several components such as uboot and kernel in existing STM32MPU Distribution Package. To do that, the STM32MPU Developer Package is needed because their source cdoes and build tools are required. This is where the major problem lies. Those are as follows:

1. To build the source files, what is used between Developer Package’s SDK and Distribution Package’s BitBake ?
2. After the modified components are built anyway, how and where are their binary images added into the Distribution Package including their configurations ?

I have read in the documents that interoperation between the Developer Package and the Distribution one is available.

But, I have not found out its actual usage example.