How To: Manually Enable SAFE Mode on an iPhone

The other day I was trying out something on my iPhone and incidentally found a way to change the way my iPhone goes into and comes out of the Standby mode. Unfortunately, while trying out this new discovery, disaster struck and I was no longer able to get out of the Standby mode as the “Slide to Unlock” slider stopped responding. I wasn’t able to receive calls and hard rebooting the iPhone didn’t help either. After about 4½ hours of painstaking hardship, I finally called it quits and decided to restore my iPhone using iTunes. But, restoring meant losing the pictures, contacts, notes and messages which I had updated since I last synced my iPhone with my Computer, which incidentally was a long time back (2 months to be precise) and therefore it meant losing a lot of precious data. Then, suddenly out of nowhere, the idea of booting my iPhone in Safe Mode struck my mind. I rebooted my iPhone in Safe Mode, reverted the changes I did which had inadvertently caused the trouble and restarted the phone in normal mode. And Voila! I was back to business within a few minutes.

Safe Mode Screen on an iPhone

But, before I actually go on explaining how to manually enable Safe Mode on an iPhone, here are some jargon busters for people who might be unfamiliar with some of the terms used further in this post.

First off, let’s start with – JailBreak. JailBreaking is the process which allows a user to run any code on iPod Touch, iPhone and iPad as opposed to only the Authorized code meant to be run by Apple. It is estimated that about 10% of all these devices around the world have been Jailbroken.  Once a device is Jailbroken, a user can download and install unofficial 3rd Party applications which can extend the functionality of these devices and in some cases help circumvent the security measures enforced by Apple including “Unlocking” of the iPhone to enable using of the iPhone with any GSM network in the world and not just be restricted to AT&T (US) or the local service provider with which Apple has tied up with in a particular country to provide iPhone with a time bound service contract.

MobileSubstrate is a set of system shared dynamic libraries “.dylib” files (similar to “.DLL” files in Windows) utilized on Jailbroken devices which allow developers to write programs that extend already written programs for the iPhone. Using MobileSubstrate, a coder can modify the behavior of other applications including Apple’s built in apps, without having their source code. MobileSubstrate loads 3rd party .dylib files (“MS extensions” / “MS libraries” / “MS plugins”) and hooks them to the targeted programs. This behaviour, though also possible without MobileSubstrate, is way too easy to do so utilizing MS.

MobileSubstrate is a pre-requisite for many JailBroken programs like – Backgrounder, Clippy, SummerBoard etc. However, as with any code, a faulty MS extension can wreak havoc and make the SpringBoard (iPhone Shell which manages the iPhone OS home screen and icons – similar to the “Explorer” shell in Windows) crash which may disable the normal functionality of the iPhone. To counter this kind of a scenario, MobileSubstrate provides a “Safe Mode” (similar to the “Safe Mode” in Windows) for SpringBoard that basically disables any 3rd Party Application or extensions to run. Once in Safe Mode, you can disable and/or remove the application or extension which is causing problems to restore normal functionality of the iPhone.

Usually, MobileSubstrate’s Safe Mode is auto triggered as and when a fault occurs. But, it can also be triggered manually in case it is not auto triggered automatically and you’re unable to access the application or extension causing the problem.

Here’s how you can enable “Safe Mode” manually on the iPhone:

1. Open MobileTerminal on the iPhone (If you’re unable to do so proceed with Step#2, else skip to Step#3)
2. SSH to the iPhone using WinSCP/PuTTy (Windows) or Terminal (Linux or Mac)
3. Login using the following default values (provided you haven’t changed them yourself):
    UserName: root
    PassWord: alpine
4. Once logged in, enter the following command
    touch /var/mobile/Library/Preferences/com.saurik.mobilesubstrate.dat
5. Respring the SpringBoard

If you followed the above steps correctly, you will see a screen similar to the one below:

Unlock Screen of an iPhone in Safe Mode