As always, we don’t recommend you to use unofficial bundles. You should wait on the iPhone DevTeam to drop an official tool. Here’s the story: this is not just a random bundle found on the internet. We made this bundle with our own two hands – and we used them to pull out all of our hair.
It’s still a tethered jailbreak, and you will need a way to boot into the jailbreaking kernel – redsn0w will not help you in this case.
NOTE: if you don’t like to mess with your iPhone – and even if you do – we don’t recommend you to use this bundle. We are not aware all ALL its bugs, so anything could go wrong at any time. We are not responsible for your mess-up. Wait on the iPhone DevTeam to drop an official release.
HOW TO Create A Custom Firmware:
1. Download everything on your desktop and extract archives
2. Right click on PwnageTool.app and ‘Show Package Contents’
3. Browse to Contents>Resources>Firmware Bundles> and copy the iOS 4.2.1 bundle you downloaded
4. Now close the window, load PwnageTool and create your custom firmware ( MAKE SURE you install OpenSSH in the process )
5. Once you have the custom firmware , load iTunes and click alt+restore ( hold the alt/option key and click on restore )
6. Browse for the custom firmware, select it, and wait for your iPhone to be restored
7. That’s it. Now you have a jailbroken iPhone 4 running on iOS 4.2.1 – except your iPhone won’t boot in the jailbreaking kernel and now the fun begins…
HOW TO Boot Into The Jailbreaking Kernel:
2. Install libUSB. Open terminal
sudo port install libusb
3. Duplicate your custom firmware and create a folder on your desktop called ‘ Tethereboot’ ( or whatever you want to call it – doesn’t matter )
5. Take the duplicate custom firmware, change the extension from .ipsw to .zip and unarchive
6. Inside there’s two files that you need:
Take them out and put them in the Tetherboot folder along side the tethereboot utility you just downloaded
7. Open Terminal , put your iPhone in DFU mode and type:
./tetheredboot iBSS.n90ap.RELEASE.dfu kernelcache.release.n90
8. Ok, that’s it. Your iPhone will boot into the jailbreaking kernel.
9. Now you will have to SSH in and add Cydia.
NOTE: again, if you don’t know what you’re doing DON’T DO THIS. Wait for the iPhone DevTeam to drop an official release