When I open Firebug console it is always empty and only new logs will appear. I would like to open Firebug and see say logs from the last 5 minutes -- is there a way to configure Firebug to do this?
This is not possible in Firebug. I remember this was previously requested in Firebug's issue tracker, though I can't find the issue right now.
Anyway, Firebug is officially discontinued in favor of the Firefox DevTools. And their console shows also messages that were logged before the tools are opened.