OTA Updates | iFirmware

Contents

1. Issues with Jailbreaking
2. Contents
- 1. Version 1
- 2. Version 2
- 3. Version 3
3. List of OTA Updates
- 1. AirPods
- 2. Apple TV
  - 1. Accessories
- 3. Apple Watch
- 4. HomePod
- 5. iPad
  - 1. iPad
  - 2. iPad Air
  - 3. iPad mini
  - 4. iPad Pro
  - 5. Accessories
- 6. iPhone
- 7. iPod touch

OTA (over the air) updates were introduced with iOS 5. They allow a user to update the firmware on their device without the desktop iTunes program.

There are three known versions of the update file containers.

Version 1

Version 1 updates came first, and were replaced with version 2 with iOS ???. They contain four main files:

archive.cpio.gz

The actual encrypted patch archive.

It is a collection of BSDIFF40 and the requisite flashing tools (bbupdater, imeisv, etc.).

Info.plist and Info.plist.signature

Information about the update and an accompanying signature.

libupdate_brain.dylib

A code library for stage 2 of the update process.

Version 2

Version 2 updates were introduced with iOS ???. Instead of an archive.cpio.gz file, they contain two folders: added and patches. As their names imply, added contains unencrypted files to be added to the filesystem while patches contains BSDIFF40 files of files that need to be patched.

Version 3

Version 3 updates were introduced with iOS ???. Quite a number of changes were made to the structure. The most major changes are listed below:

The added folder no longer exists.
links.txt was added. It contains a list of symbolic links (symlinks) to be created.
The patches folder contents no longer use the BSDIFF40 file format, but a modified version known as BXDIFF41.
payload and prepare_payload were added. They hold the filesystem contents in a proprietary format.
removed.txt was added. It contains a list of files to be deleted prior to updating.

List of OTA Updates

This is a comprehensive list of every OTA update that has been released to the public.

AirPods

...

Apple TV

Note: Apple TV updates are organized by their marketing version (the one displayed in the Settings app), not the version of iOS it is based on. Also of note: Apple TVs never received versions marketed as 8.x.

4.x