You can use Wic in two different modes, depending on how much control you need for specifying the Openembedded build artifacts that are used for creating the image: Raw and Cooked:
Raw Mode:
You explicitly specify build artifacts through
wic
command-line arguments.
Cooked Mode:
The current
MACHINE
setting and image name are used to automatically
locate and provide the build artifacts.
You just supply a kickstart file and the name
of the image from which to use artifacts.
Regardless of the mode you use, you need to have the build artifacts ready and available.