So, I've not been able to actually dig up an answer to this: Were cannons protected by the 2nd amendment? Or merely not prohibited in a legal environment in w

So, I've not been able to actually dig up an answer to this: Were cannons protected by the 2nd amendment? Or merely not prohibited in a legal environment in which the government claimed the authority to prohibit them? I can't find any reference to discussion of cannons as "bearing arms."