I split everything by axe and wedges. You end up with some firewood and some good half logs. Than I take the angle grinder with a very rough disc to get the worst spots off. The last step was going to a person with a planer..
You can also use big table saw or go nuts with a handsaw :)
If your log is a bit too thick you can also ripsaw with the chainsaw. It's easier than it looks. Make a undeep cut of 1cm deep over the length and keep repeating this. You will end up with two halves that you can plane. :)