Tutorial : Reverting to iOS 6 from iOS 7 (iPhone 4)

 

Good news for all the iPhone 4 users who are completely dissatisfied with iOS 7, downgrading to iOS 6 is now possible! Although Apple’s latest variant of the operating system for mobiles – iOS 8 –  was not made available to iPhone 4, it did get the previous update. And unfortunately, iOS 7 threw up quite a bit of issues. In this article, we give a complete tutorial on how to revert to iOS 6 without any shsh blobs.

Why The iPhone 4 and iOS 7 Didn’t Click

Like any new operating system for its time, iOS 7 features required more hardware specs in order to run without any lag. Coming to the device itself, the iPhone 4 was launched way back in 2010 and its A4 processor does not have the power needed to satisfactorily run iOS 7.

NEED A RECAP ON ALL iPHONES LAUNCHED TILL DATE? CHECK THEM OUT HERE!

 

In fact, Apple had designed iOS 7 by considering the next generation iPhones: such as iPhone 5 and 5c, but the Cupertino based tech giant offers its users a 3 year guaranteed operating system update. Now, the iPhone 4 was running iOS 4 when it was launched, so after iOS 4, as per Apple’s update system, it received three consecutive iOS updates. And thus, iOS 7 made its appearance in iPhone4.

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Observed Faults

During the development phase of  iOS 7, Apple conducted benchmark tests with the iPhone 4, and the results clearly showed that the A4 chipset on the device could run IOS 7, but with some lag due to high CPU usage. This was in turn caused due to the renewed user interface in iOS 7.

Needless to say, many iPhone 4 users were frustrated with the performance of their devices running on iOS 7. Another matter of infuriation for the users was the increased battery consumption rate: The iPhone 4 running iOS 6 has almost a full day of battery backup, but the new iOS 7 reduced it to half. All in all, iOS 7 brought in a lot of bugs for iPhone 4 users out there, and a downgrade was the need of the hour.

iOS 7 HAD LOTS OF BATTERY ISSUES, AND HERE’S OUR ARTICLE ON TIPS TO PROLONG BATTERY LIFE!

Problems in reverting to iOS6

Although downgrading iOS 7 to 6 does sound tempting, it does come with its fair share of cons in the equation. If you tried the downgrading process, you will discover different kinds of errors in iTunes. I encountered a similar problem, and after searching the internet for solutions, I came up with an interesting thing about the downgrading process.

It is an open secret that Apple users face many restrictions than other mobile users – and these restrictions apply to the downgrading process too. Apple delivers a scheme called “Signing Servers” which examines the downgrading and upgrading process. Now the errors in iTunes arose due to the need for the application to access the Internet, in order to process the downgrade or upgrade.

Why the need to access the Internet, you might wonder. This was because during the verification process, iTunes transfers the metadata information of IPSW used in the operation. If the IPSW is old, the signing server will not sign the iPSW. Hence there arose a wide range of errors in iTunes.

MISSED SOME HIDDEN iOS 7 FEATURES? WE GOT YOU COVERED. READ UP HERE!

 

The SHSH Blob Conundrum

When Apple releases a new operating system, it closes the old operating system’s signing server. This usually happens within 2 to 3 days. Hence the remedy point is only confined to a couple of days, and that is the reason why we can’t go back to the old operating system.

Ideally, it is quite an impossible task, unless we have saved the SHSH blobs of that operating system. Another problem is that many users don’t even really know what this SHSH blob is, or does for that matter. Let me explain it in simple terms.

SHSH blobs are the signature files which are sent to iTunes by Apple’s signing server. Whenever Apple releases a new operating system, many users rush to download it and forget about saving the SHSH bulbs. This is one of the major mistakes every iPhone users does every time while upgrading. Hence, it is practically impossible to revert to the previous OS version.

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Limera1n Exploit:

Thankfully, every software problem has a solution, and the solution to the SHSH problem is none other than the man who discovered the LImer1n exploit in A4 based devices- George Francis Hotz. Limera1n exploit is a bootrom exploit and comex’s Packet Filter Kernel Exploit to achieve an untethered jailbreak on many devices especially A4 devices from Apple. It is a hardware exploit and is considered as a permanent working jailbreak method. 

Unfortunately (or fortunately, in regard to this article!), this procedure works only on iPhone 4, as it is an A4 device.

Process:

So finally, we boil down to the actual procedure. Thanks to our heroes Geekgrade and George Francis Hotz. I’ve tested it on my device and it runs ok. Before trying to downgrade, you need these things.

  • A computer (Windows or MAC)
  • iReb (download)
  • iTunes patched (download)
  • The IPSW_geekgrade custom firmware to which you want to return to. (download)
  • Redsn0w (download)
  • The original firmware that you want to go back (people who choose to get iOS 4 won’t need this)

After these steps, all you need to do is:

  • Install iTunes on your computer.
  • Open iREB and follow the instructions to set your phone to PWNED DFU Mode.
  • After coming in to PWNED DFU Mode, Connect the phone to iTunes. It will show the restore options.
  • Hold shift and select Geekgrade IPSW. The process continues. At the end your phone will shows the iTunes connect symbol. Don’t need to panic!
  • Run Redsnow as administrator and go to more options and proceed to select IPSW option.
  • Now, tip out the original IPSW file.
  • At once, select Just Boot option and stick with the instructions.

And voila! Your phone will now boot into iOS 6!

Note:

This is a serious note to all the people who want to downgrade, this procedure is called tethered downgrade. Tethered downgrade refers to a process where you will need redsnow and the original IPSW in order restart your device. I mean if you want to restart you phone, you have to follow the steps 4 to 8 again in order to boot up your device. Here’s a video demonstration of this procedure.