If you're looking for strictly boot logo (not the loading screen logo when you respring or the later ~5-10 seconds of booting up), you'd need a tweak like Animate. There was an older method of using Winterboard to implement it back with Evasi0n7, but that's no longer the case since it won't show until the later few seconds prior to your boot up of your firmware.
If you're looking for a loading screen logo change, you can implement that using Winterboard. I don't reboot/turn off my device often unless the battery's died out, so I don't dwell with boot logos. If it's the latter though, I can provide directories for you to implement loading screen changes yourself.