Let's start with defining "jailbreak." Well, in my own words, Apple has put stupid limitations on this wonderful piece of phonery, and jailbreaking is removing those limitations. A factory iPhone is like having a Lamborghini Murcielago with a governor at 15 mph. For example, Apple says that the iPhone 3g doesn't do video. The correct statement is, "Apple doesn't ENABLE the iPhone 3g to do video." Jailbreaking does. . . . among with a host of other things.
***Theoretically, jailbreaking DOES void your warranty, but if you have a problem, just restore your original software before taking it to the Apple store. It's the equivalent to GM saying your warranty is void because your car is dirty - just wash it before you take it in. Problem solved. Amen.
Anyway, enough blabber. Let's get to the biz.
This guide will go through jailbreaking NOT UNLOCKING the iPhone 3G for use with AT&T service. Unlocking allows you to use the iPhone with any GSM service provider (in the US, there are only 2: T-Mobile and AT&T). There are similar, but different, procedures for the first-generation iPhone, iPhone 3GS, and iPod Touch.
Things you'll need:
- An iPhone 3G (duh)
- The proper .ipsw (iPhone software file (which you can find relatively easily by Googling). . . . or better yet, here) This tutorial is stricly for 3.0 **(or 3.01. . . .so I guess that's not strictly. I suppose the more accurate way of saying it is, it's not for 3.1. Although I haven't tried jailbreaking 3.1 yet, I've just read bad things about it.)
- A jailbreak application. redsn0w is cute, but I like PwnageTool better. It's easy, and has more configuration options.
- If you have your iPhone set up already, you may wanna back it up before proceeding. It'll preserve your texts, contacts, calendars, settings, etc. I recommend even doing a full back-up as opposed to just syncing. In iTunes, right-click (Ctrl+Click on Mac) your iPhone and select "Back Up." Let it do its thing
- Open PwnageTool and select iPhone 3G. Click Next arrow
- Browse to the correct .ipsw file "iphone1,2_3.0_7a341_restore.ipsw" and continue
- Select "General," then press Next arrow. (At this screen, you can customize your applications. I'm skipping that, because I've had trouble when I pre-install certain jailbroken apps. I haven't narrowed it down to which one(s) yet though. So just to be safe, don't mess with any more of these options unless you know what you're looking for).
- Deselect the Options "Activate the phone" and "Enable baseband update" and make the Root partition size 700 Mb. This is a safe number, maybe too big, but so what.
- Click the Back arrow to return to the options menu
- Click "Build" and then the Next arrow
- Choose a location for your jailbreak file. It will be named something like "iphone1,2_3.0_7a341_custom_restore.ipsw"
- At some point in the building process, it will prompt you for your system password. Enter it.
- After the file builds, PwnageTool will guide you into putting the iPhone into DFU mode.
- Entering Device Firmware Update mode
- Although the application will guide you through this, I'll still cover it here.
- Turn off the iPhone 3G
- Hold Home and Power button for 10 seconds
- Release Power button, but continue holding Home button for additional 10 seconds
- If this procedure completes correctly, PwnageTool will tell you.
Screenshots from PwnageTool by iPhone Dev Team