With only tethered jailbreak available for iOS 5, there are a lot of users who regret upgrading to the latest version of iOS and want to downgrade their iPhone, iPad or iPod touch to any previous version. This can only be accomplished if you have the SHSH blobs saved for your the version of iOS you want to downgrade to, and even then, due to latest measures taken by Apple, you will not be able to to do so through conventional means. However, if you do have blobs for your iPhone 4 or iPad 2 saved, there is now a new tool available, named TinyCFW, that you can use to downgrade either to older versions of the OS.
First of all, please note that this tool was never meant for public release (according to the developer himself), and that’s why you might find the whole thing a little unpolished. Also, TinyCFW is pretty demanding in terms of system requirements (at least 2.5GB of RAM). You’ll find using the tool extremely simple, especially if you have used TinyUmbrella before. To use TinyCFW, you need to have the IPSW file for the version of iOS that you want to downgrade to. This tool will basically modify the IPSW file you have, and update its baseband accordingly. The modified IPSW can then be used to downgrade your iDevice with the help of TinyUmbrella, or via the usual Ctrl + Restore iTunes method.
If your PC or Mac is good enough to handle the tool, all you need to do is to run it, and point the software to the location of your saved IPSW file. After a few minutes, TinyCFW will be done weaving its magic, and you can downgrade to the desired previous version of iOS. If you encounter any problems on the Windows version of the application, do the following.
- Launch the Control Panel and open System (or right-click on Computer and select Properties from its context menu).
- From within the Advanced tab, select Environment Variables.
- In the User variables section of this tab, add a New variable, and set its values to
Variable name = _JAVA_OPTIONS
Variable value = –Xmx1g
- Click OK.
If the problem persists, it is likely that your computer’s specs do not match the tool’s requirements. For details and support regarding the tool, you can visit the developer’s official page via the source link provided at the bottom.