Hi @svab,
Thanks for reaching to us. If you are trying to use L4T, the Jetson nano doesn’t support A/B partitioning. But if you go with the Yocto-way, did you already checked this tutorial? NVIDIA Tegra Jetson Nano. Please notice the 2GB version is not supported/tested (yet).
The configuration files from that tutorial will take care of the partitioning. If you need to customize the sizes of the partitions, or any other detail, you can check Partition configuration | Mender documentation.
These links cover everything I think you have to know at this point, but please feel free to ask any extra detail you need to configure after following them.
Have a nice day!
Luis