In general we have a burned media with signed content (let's say Super Mario Wii U). And then the dev team figures out a severe bug. So they provide a patch as update. Let's say (very high level) this is the original game. [header] [signed binary content 0 -- 1000] [signed binary content 1001 -- 2000] ... [signed binary content x -- y] And then the patch needs to "replace" or "response" part of code in section 3. Now we have the situation where my original is loaded at memory and then "somehow" it applies the update patch. Do you know how "the patch" is applied? Do you think it's an OS (internal OS from consoles) thing?