What is needed before porting the board to the LmP
It is out of the scope of this guide to detail the steps of creating a BSP including the bootloader or the operating system support and other critical packages - the recommendation is to search for the SoC vendor porting guide which usually details how to port the default BSP to another board.
LmP provides a set of bootloaders and operating systems updated with the latest known vulnerability fixes. The recommendation is to have those packages as a base for creating the new needed BSP which leads to the creation of append files for the recipes of those packages.
LmP supports a wide variety of SoC families from different vendors with different boot flows. The following image shows three examples of boot flow currently supported by LmP: