It’s merry time again! iPhone Dev Team’s lead hacker Eric McDonald (aka @musclenerd) has just released the updated redsn0w 0.9.11b1 that allows you to downgrade your iPad 3, iPhone 4S and iPad 2 firmware without using iTunes. Till now downgrading firmware between iOS 5.x was only possible only for non-A5 devices such as iPod touch 4G/3G and iPhone 4/3GS including the first generation iPad
With redsn0w 0.9.11b1, the support for downgrading the mobile operating system has been extended to A5/A5X devices – iPad2, iPad3, and iPhone4S. Interestingly, this has been achieved by the team without a bootrom-level exploit.
If you have inadvertently upgraded your device firmware and want to revert to older one to retain untethered jailbreak, the upcoming Redsn0w 0.9.11b1 utility will allow jailbreakers to downgrade between versions of iOS 5.x (for instance, iOS 5.1 to iOS 5.0.1) and restore to the older firmware without iTunes. But yes, it will only work if you have already saved SHSH blob files for the firmware you want to restore to.
A new set of options (under Extras -> Even More-> Restore) will be made available – Local Restore and Remote Restore. Local blobs will use those SHSH blobs that are saved into your machine and Remote option will allow you to use SHSH blobs that are saved in Cydia. In order to enable Remote option, you have to connect your device in DFU mode.
Some important points:
- You cannot downgrade without the personalized SHSH blobs for your device at that lower firmware. You need to have fetched those blobs while the signing window was open, using either Cydia’s built-in TSS@Home feature, or with TinyUmbrella. The new Restore screen of redsn0w lets you choose either the remote blobs or local ones (for the earlier firmware). If you don’t know where TinyUmbrella put your blobs, TinyUmbrella has a button that will show you (copy them out of that folder and feed them to redsn0w).
- The A5 downgrade method actually updates to the latest firmware before downgrading to the earlier one. This process updates your baseband to whatever is newest. DO NOT USE THIS METHOD IF YOU RELY ON UNOFFICIAL UNLOCKS of your iPhone 4S. Those who used the temporary SAM technique to unlock their iPhones to specific SIMs shouldn’t be affected by this baseband update.
- This method can be fixed by Apple with a firmware update. It’s a (pleasant) mystery why they haven’t fixed it yet, because reverse-engineering of the restore ramdisk indicates they do know about it. It’s possibly too niche to bother to fix right now.
- The least-tested devices with this method are the iPad2,3 and iPad3,2 (because we don’t have those models). If you do and you feel like experimenting, please let us know how it turns out in the comment section below!
- This update involves a bunch of new redsn0w code. We recommend sticking to the previous version 0.9.10b8b unless you’re specifically using this new feature, until all the bugs are worked out! (Note: If redsn0w gets stuck at the “Waiting for device” stage for more than 30 seconds, you’ve hit a pesky GUI bug…that will be fixed in an upcoming version!)
Lots of work is going within the hacking community. Pod2g is almost ready with his 5.1 untethered jailbreak. Till then if you inadvertently updated your A5 device to iOS 5.1.1 or 5.1, you can download redsn0w 0.9.11b1 to downgrade from iOS 5.1.1/5.1 to iOS 5.0.1 and jailbreak iPhone 4S or iPad 2 using Absinthe.
You can download Redsn0w 0.9.11b1 from our dedicated downloads page.
Update #2: iPhone Dev Team inadvertently left out support for build 9A406 of 5.0.1 for iPhone 4S. It’ll be supported in the next redsn0w update, but in the meantime check if Cydia or TinyUmbrella saved your blobs for the other 5.0.1 for iPhone4S (“9A405″).