Upgrade Your Jailbroken iPhone OS to 3.1.2 Using PwnageTool 3.1.4

Written by JM December 24, 2009

Apple released the new iPhone OS 3.1.2 firmware, the iPhone Dev-Team likewise released an updated jailbreaking and unlocking tool – PwnageTool 3.1.4.

It supports the ff:

╔ iPhone 3GS OTB

╔ iPhone 3G and 2G,

╔ iPod Touch 1st ; 2nd Gen

Reminder: PwnageTool is for Mac OS X only.

Read First:

This tutorial is for those who already have a jailbroken iPhone and upgrading to iPhone OS 3.1.2
If you have the first generation iPhone (2G), you can use this tutorial to jailbreak and unlock your phone.
If you have an iPhone 3G/3GS, you can use this guide to jailbreak only. Then use Ultrasn0w to unlock.
For best results, use the latest iTunes (9.0.1).

- Download The PwnageTool

Steps

1. Open iTunes and when prompted, select Download Only (do not install) to download the iPhone OS 3.1.2 firmware to your hard drive.

2. Use the default Simple mode and select iPhone 2G or iPhone 3G depending on your phone. Click the arrow button below to continue.

3. The PwnageTool will browse for the IPSW file you downloaded. Select it and click on the next arrow.

4. Select Yes to create an .ipsw file.

5. Select No if you would need to unlock your iPhone.

6. PwnageTool will now build your custom .ipsw file.

7. Enter your Mac OS X user account password.

8. Select Yes since you already have a jailbroken iPhone 3.0.

9. Click OK.

10. You have now created a Custom Restore IPSW file (iPhone1,1_3.1.2_7D11_Custom_Restore.ipsw).

11. Close PwnageTool.

12. Place your iPhone in Recovery Mode:

Disconnect your iPhone from your Mac and switch your iPhone off.

Hold the Home button (do not release) and connect back your iPhone to your Mac. Keep holding the Home button until you see a dock cable pointing to the iTunes icon or a caricature of Steve Jobs.

13. iTunes will now open and detect your iPhone in Restore mode.

14. Press and hold the Alt/Option key on your Mac and click on the Restore button in iTunes. Browse for the Custom IPSW Firmware and select it.

15. iTunes will now load the custom firmware to your iPhone. Let the process continue until it’s done.

16. When it’s done, sync back all your data from iTunes.

Note: If you have apps from Installous, you need to install the AppSync for OS 3.1 from Cydia (source: http://cydia.hackulo.us) in order to sync back those apps from iTunes to your iPhone.

- credits to Menoob.