Yup. Stop the logs rolling around on the floor and having to put yer foot on it to stop it moving.
I made one out of 4 lengths of 3×2. 2 x About 18 inches long, parallel about 10 inches apart, wide enough for the log to sit on and not move, but not so wide that the logs sit on the floor between them and rolls around.
Then screw the other two bits of 3×2 screw on as cross members. Flip it over and get cracking. Or chainsawing.
Just saw them in half half way through, turn it over and finish off.
As the jig is made of scrap don’t worry about the odd little chain Nick.