Current Android system upgrade procedures usually fall into the following two categories, with inconvenience respectively:
- complete upgrades, which override the existing system entirely
- require downloading large binary blobs altogether for small system upgrades
- delta upgrades, which apply block-level or filesystem-level patches to the existing system
- require the system to be untampered so that the patch can be applied
With Portage managing the different components of Android, it’s possible to perform small updates painlessly, while retaining the ability to shape the system as we’re pleased, such as to make it a full-blown GNU/Linux system.