Google has published Android 'Jelly Bean' 4.1 factory images for its Nexus devices, which are the first Android smartphones and tablets to get the new version of the operating system.
Binary image files for the Nexus S, Galaxy Nexus and Nexus 7 were uploaded to the Google Developers site on Friday. The files will be useful for those who have put custom Android builds on their devices and want to return them to a fresh-out-of-the-box state.
The new factory images "may not be disassembled, decompiled, reverse engineered, modified or redistributed", Google said on its developer page.
However, Google made Jelly Bean open source earlier this month, giving third-party developers a chance to modify the code for their own iterations.
Google's Nexus devices are partly aimed at developers, and they always get upgrades before other Android devices do. This is partly because they use a stock version of Android, without the skins that manufacturers often use to augment the OS.
Skinned devices take longer to upgrade as the manufacturers need to make the operating system play nicely with their proprietary features.
The Nexus S is the oldest of the devices that got a factory image on Friday. The last time it got a major upgrade, to Ice Cream Sandwich, the update took months for Google to roll out. This time it came less than a month after Jelly Bean's launch at the end of June, with the rollout beginning around 10 days ago.