Hello,
If you are willing to use the i.MX8MN. I suggest you use our Linux BSP. You could find more information on the following web-page.
One can find most of the information under the supporting information part.
Furthermore, you can start using our SDK to implement the M4 cortex in all the real-time processing applications that your product needs. You can find them in the following web-page:
You just need to select the desired board and the packages that you want to add.
Hope this information can be useful to you.
Best regards,
Diego.