Can i have a specific kernel saved on grub?

I’m not exactly sure I understand your question entirely. But if you mean by using the last used kernel there is a simple way to do that. So, if you want to enable the grub so that on boot it selects by default whichever kernel you last used, then please follow these commands from this post here:

If I somehow misunderstood your question, then please free free to ignore this of course :wink: