These are instructions on how to jailbreak and unlock your iPhone 3G on iOS 4.2.1 using PwnageTool 4.1.3 for Mac OS X. This tutorial will explain how to upgrade your baseband if needed for an unlock.
Step One
Make a folder called “Pwnage” on the desktop. Download a couple of things:
If you are on the 05.14 or 05.15 baseband you will also need the iPad 3.2.2 firmware. You can find out your baseband version in Settings -> General -> About -> Modem Firmware.
Finally got ultrasn0w working fully on 4.2.1. Apple inadvertently(!) broke ultrasn0w via aggressive compiler optimization
MuscleNerd previously announced that the ultrasn0w unlock should be available by Sunday for the iPhone 3G and iPhone 3GS. The unlock for the iPhone 4 will take much more time.
UPDATE: this is not a reason for update to iOS 4.2.1, wait for utilities.
DevTeam hacker MuscleNerd tweeted that they after releasing redsn0w jailbreak for 4.2 the team can start working on iPhone unlock. Users can expect the unlock for the iPhone 3G and iPhone 3GS this week. The iPhone 4 unlock will take more time and no concrete info is available about that yet.
The ultrasn0w unlock will be released for iOS 4.1 firmware. So is you need unlock, do not update to iOS 4.2.1.
DevTeam recently released new version of redsn0w to jailbreak iOS 4.1. New RedSn0w 0.9.6 b1 supports iOS 4.0 and iOS 4.1 running on iPhone 3G or iPod touch 2G.
There is only Mac OS X x86 version, that you can download here.
Select your stock 4.1 or 4.0 ipsw (you’ve already used this to update your device to 4.1 or 4.0)
Select “Install Cydia” and any of the other options shown above, then click “Next”. Use DFU mode to install the jailbreak.
As usual DevTeam reminds us:
IF YOU USE THE ULTRASN0W UNLOCK, PLEASE WAIT FOR PWNAGETOOL TO SUPPORT 4.1. DO NOT USE REDSN0W
That’s because to use redsn0w at 4.1, you need to already have updated to official 4.1 from Apple. If you do that, you lose the ultrasn0w unlock (possibly forever).