Apple released its 6th generation mobile operating system iOS 6.0 firmware and many users may have updated their iDevice firmware to iOS 6.0 without knowing that this new firmware also brings new basebands and their jailbreak and unlock status would have lost. iPhone Dev team published a blog post giving the details for downgrading iOS 6.0 firmware to iOS 5.x frmware on iPhone, iPad and iPod touch.
In blog post iPhone Dev team has warned that iPhone 4S, iPad 3 (and some iPad 2) users won’t be able to downgrade from iOS 6 to iOS 5.1.1 once Apple stops signing iOS 5.1.1 firmware and they will be stuck until a jailbreak for iOS 6 is released. iPhone Dev Team will also release a new version of Redsn0w that allows users to jailbreak tethered on iOS 6 once the issues with Cydia and modules like PreferenceLoader are fixed.
The Dev team has listed down the scenarios for different iOS devices.
1) A4 devices and 3GS will always be downgradable (and jailbreakable) due to limera1n. The tethered iOS6 jailbreak for those devices (and untethered for old-bootrom 3GS) will be out when Cydia and other important pieces are all working properly
2) iPad2 owners who have both 4.x blobs and 5.x blobs will always be able to downgrade to those versions, even once you come up to 6.0 and the 5.1.1 window closes (don’t do that yet though!). You need both 4.x and 5.x blobs to qualify for the downgrade even if you only wish to downgrade to 5.x
3) iPad3, i4S (and iPad2 owners who don’t satisfy #2) will always be able to RE-restore the current 5.x OS that’s already on their device. So if you’re at 5.1.1 when the window closes (and you’ve saved your blobs), you’ll always be able to RE-restore to 5.1.1 again. This makes the 5.1.1 jailbreak a lot less fragile — you don’t have to worry about messing up your install with funky extensions or getting into a boot loop, because you can always RE-restore from 5.1.1 to 5.1.1 again (or from 5.0.1 to 5.0.1 again, etc). But once you fall off the 5.x train by restoring to 6.x, you’ll be stuck there until the next jailbreak.
How To Downgrade From iOS 6.0 To iOS 5.1.1 On iPhone, iPad, iPod touch:
These are the supported iDevices models:
- iPhone 4S, 4, 3GS
- New iPad 3, iPad 2
- iPod Touch 4-Gen.
1) Turn the device off, connect it to the computer via USB, and launch iTunes
2) Place the iOS device into DFU mode: with the device off, hold down the Power and Home buttons together for 10 seconds then release the power button, continue holding Home button until iTunes notifies you of a device in recovery mode being detected. The device’s screen should stay black as if turned off.
3) Restore within iTunes through either method a or b:
a) Restore from the iOS 5.1.1 backup you made before installing iOS 6 beta
b) Restore to iOS 5.1.1 IPSW by Option-Clicking the “Restore” button, and then restore fromiCloud backup when finished
4) Let iTunes restore back to iOS 5.1.1, the device will reboot when finished
According to iPhone Dev team iPhone 4 and iPhone 3GS users will able to downgrade if they have the SHSH blobs using Redsn0w. So, if you are planning to upgrade your iOS firmware then you must save SHSH Blobs by using latest version of TinyUmbrella v6.00.00 before Apple stop siging iOS 5.1.1 firmware.