It seems that the below pages for that purpose. But they are broken now. )-:

https://source.tizen.org/documentation/developer-guide/getting-started-guide/creating-tizen-images-mic?langredirect=1

https://source.tizen.org/documentation/developer-guide/all-one-instructions/creating-tizen-images-scratch-one-page?langredirect=1

Is there any page for making Tizen image from the scratch?