1. Program the Greengrass-enabled firmware

Digi provides pre-built images with pre-installed Greengrass core software:

If your device is already running from Linux, use the update package (*.swu) to program the firmware. Follow the steps at Program the firmware from Linux. Download the update package dey-image-aws-swu-ccimx6ulsbc-<timestamp>.swu from ftp://ftp1.digi.com/support/digiembeddedyocto/2.2/r3/images/ccimx6ulsbc/fb.

Or you can use U-boot to program your device, following the steps at Program the firmware from U-Boot. Download the partition images from ftp://ftp1.digi.com/support/digiembeddedyocto/2.2/r3/images/ccimx6ulsbc/fb.