What I'm saying is that no practical amount of testing and verification can eliminate the need for updates. Let me give some practical examples I've seen: a bug in the silicon vendor BSP that prevented programs from accessing half of the physical memory. In another case the vendor provided optimistic battery curves that caused safety issues in certain conditions, so changes were needed after units were already in the field. In another case, a factory was taking the stuff we were giving them and using it to build weird Frankenstein images from various binary blobs, so nothing that had been produced for those weeks corresponded to anything that had been tested.