« Back To Blog | 12th June 2011 (8 months, 2 weeks ago)
I was recently lucky enough to get my hands on a free iPhone 3gs to succeed my battered HTC Hero. I figured that unlocking it would be childs-play and started looking around for articles on how to go about it. I quickly noticed that the majority of blog posts and tutorials out there describe the steps involved along with a tedious list of version numbers & buzzwords, without really explaining what you are doing. Coupled with my impatience, I managed to accidently update the iPhone to a firmware that won't allow unlocking.
To help others avoid this, and get their head around what's involved, this is a quick guide to what's involed with as little version numbers and buzzwords as possible.
Jailbreaking your iPhone allows you to run 3rd party apps (i.e. apps that have not been purchased in the AppStore) and gain access to other internals that Apple do their best to hide from you. The process involves downloading a tool onto your PC/Mac (there are two tools: redsn0w or pwnagetool), connecting your iPhone and allowing the tool to modify the iPhones firmware
Unlocking is a secondary process that allows you to use your iPhone on networks other than the one with which the iPhone was initially purchased to operate on. To unlock your iPhone, you must first jailbreak it. Once you have done that you can download and run an application (called ultrasnow) on the iPhone that will carry out the unlocking.
There are a few things you should know before you go about jailbreaking and unlocking:
The first thing to know about is the version of iPhone you have. There are 4 different generations:
A wikipedia comparison of the different iPhone versions
The firmware is the operating system that is running on your iPhone. It's more popularly known as iOS. iOS is also used in iPod Touches, iPads and Apple TVs.
Depending on what device you are using (iPhone,iPad etc.), different versions of the firmware are available to you. Furthermore, depending on which model of iPhone (original/3g/3gs/4) you are using, a subset of firmwares are available to you.
The operating system/firmware/iOS is updated via iTunes. You are usually prompted to update your firmware when a new one becomes avaiable. The firmware is downloaded automatically from apple and come in the form of a IPSW file. They are usually around 400mb in size.
To find out what version of your firmware is running on your iPhone, go to Settings, click "General", then click "About" and scroll down until you see "Version". As an example, you can see in the following image from iClarified that their firmware is 2.2
The firmware mentioned above looks after all aspects of your iPhone, i.e. the visuals, the camera and so on. One important part of the firmware is responsible for looking after the communications (i.e. phone/voice etc) and is known as the Baseband. The baseband is generally automatically upgraded when you perform a system update via iTunes and has it's own stream of version numbers. You need to know which one you have. To find out, look at the same screen as above (Settings>General>About) and scroll down to the bottom. You will see Modem Version:
IP(hone/ad/touch)SoftWare has been mentioned alreayd, but I'll say it again incase it was skimmed over. It's the firmware file bundle that iTunes downloads and installs on your iPhone/iPad/iTouch when you undergo an update.
When you reboot your iPhone, before it loads iOS you can boot into a
These are the various jailbreaking tools available for download. Which one you want depends on:
Depending on the approach you take, you can have a tethered or untethered jailbreak.
Whether or not your jailbreak will be tethered or untethered depends on your particular situation and what mix of firmwares you have etc.