FYI. The BSP documentation could be downloaded from here
https://www.nxp.com/design/software/embedded-software/i-mx-software/embedded-linux-for-i-mx-applicat...
Yocto User's Guide is about how to setup the build env. and how to build the Yocto BSP for your board.
Linux Usr's Guide is about how to program the images to the board and how to use the images.
Linux Reference manual is about the driver details supported in this BSP.
Hope the information useful for you.
