Guide: iOS 4.2.1 GM on iPad and iPod touch 4G Jailbroken Using PwnageTool with Working Cydia !

I have just jailbroken my iPad using PwnageTool bundles released by Johnny Franks. These bundles can be used to jailbreak the newly released iOS 4.2.1 GM on both iPad and iPod touch 4 with working Cydia !

The process involves patching of the existing version of PwnageTool with these new bundles, and then using it to build a custom firmware file for the mentioned iOS devices. To make Cydia working, you will have to use the included patched Cydia binary and use bspatch command to apply this patch, more on this in the detailed step by step guide posted below:

Cydia on iOS 4.2.1

Patching PwnageTool for iOS 4.2.1 Jailbreak:

Step 1: Download PwnageTool 4.1.2 from the download link given below.

Step 2: Download the latest version of PwnageTool Bundle for iPad and iPod touch 4 on iOS 4.2.1 from here, and then copy them to your desktop.

Step 3: Now download iOS 4.2.1 GM for iPad or iPod touch 4G. You can get the official bits if you are a registered developer, or from different content sharing sites around the web. Please do not ask for the download links as they are illegal to share; a simple Google will do it all !

Step 4: Copy PwnageTool that you downloaded in Step 1 to a folder on your desktop. Right click, and then click on “Show Package Contents” as shown in the screenshot below.

iOS 4.2.1 Jailbreak

Step 5: Navigate to Contents/Resources/FirmwareBundles/ and paste iPad1,1_4.2.1_8C148.bundle file in this location and then simply close this folder.

iOS 4.2.1 Jailbreak

Step 6: Once you are done, close all the open windows and start this patched version of PwnageTool, Select “iPad, Apple TV 2G” option and click next.

PwnageTool 4.1

Step 7: PwnageTool will now identify iOS 4.2.1 GM firmware file as shown in the screenshot below.

iOS 4.2.1 Jailbreak

Step 8: PwnageTool will now create the custom .ipsw file for your iOS device which will be jailbroken.

Jailbreak iOS 4.2.1

Step 9: Now follow the following steps to enter DFU mode:

  • Hold Power and Home buttons for 10 seconds
  • Now release the Power button but continue holding the Home button for 10 more seconds
  • You device should now be in DFU mode

PwnageTool 4.1 (3)

Step 10: You will now have to restore your iPad or iPod touch 4 to this custom firmware 4.2.1 file. Start iTunes, click on your device icon from the sidebar in iTunes. Now press and hold left “alt” button (“Shift” button on Windows) on the keyboard and then click on “Restore” (Not “Update” or “Check for Update”) button in the iTunes and then release the “Shift” button.


This will make iTunes prompt you to select the location for your custom firmware 4.2.1 file. Select the required custom .ipsw file and click on “Open”.

Step 11: Now sit back and enjoy as iTunes does the rest for you. This will involve a series of automated steps. Be patient at this stage and don’t do anything silly. Just wait while iTunes installs the new firmware 4.2.1 on your iPad or iPod touch 4. Your iOS device screen at this point will be showing a progress bar indicating installation progress. After the installation is done, your device will restart automatically and you should now have a fully jailbroken iPad or iPod touch 4 on iOS 4.2.1.

Patching Cydia for iOS 4.2.1 Jailbreak:

New version of Cydia isn’t out yet. But using MSFT_Guy’s method, you can patch the existing version of Cydia to make it work on 4.2.1 by patching it using bspatch command in Terminal on OS X.

Step 12: Download Cydia.patch file for iOS 4.2.1 from here and copy it to /Applications/ by SSH’ing into your iOS device. [NOTE: You must have SSH enabled on your device]

Step 13: Now by using the original Cydia binary from here, type the following commands in Terminal app on Mac OS X:

mv Cydia_ Cydia.bak
bspatch Cydia.bak Cydia_ Cydia.patch

chmod +x+s /Applications/

That’s it! Enjoy Cydia on your jailbroken iOS 4.2.1 device !

Cydia on iOS 4.2.1Cydia on Jailbroken iPod touch 4, running iOS 4.2.1

Download PwnageTool 4.1.2 for Mac
Download iTunes 10.1 for Windows or Mac
Download iOS 4.2.1 GM for iPad or iPod touch 4G [iOS Dev Center]

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