[How To] Jailbreak iPhone 3GS (New Bootrom) With iOS 4 (Windows Users With SHSH Blobs)

Developer of popular jailbreaking tools such as Sn0wbreeze, iH8Snow has just published a detailed guide on how to jailbreak iOS 4 for iPhone 3GS with the new bootrom for Windows users. Mac users can checkout this guide to jailbreak iOS 4 for iPhone 3GS (new bootrom) with SHSH blobs (ECID files).

Some important points before we proceed:

• This guide is for advanced users who own a Windows PC. Mac users can checkout this guide.
• Jailbreaking your iPhone may void your warranty so if you don’t want to mess around with that, proceed with caution.
• Do NOT forget to make a backup of your iPhone before proceeding. You can follow the instructions to do so here.
• This guide is meant for iPhone 3GS users with the new bootrom only. You can use the F0recast utility to find out what bootrom your iPhone 3GS has.
• This will be a tethered jailbreak, which means that the jailbreak needs to be reapplied every time your phone turns on. For example, if you let the battery run out or restart your iPhone 3GS then you will need to reapply the jailbreak by connecting it to your computer (tethering).
• It will only work if you had saved your iPhone 3GS’s SHSH blobs (or ECID files) for iPhone OS 3.1.2. iH8sn0w has clarified that it won’t work with iPhone OS 3.1.3 SHSH blobs.
• iPhone 3GS with older bootrom can use PwnageTool for Mac or Sn0wbreeze for Windows users.
• If you are using an iPhone 3G, you can use Redsn0w to jailbreak iOS 4. You can checkout our detailed step-by-step guide for Mac and Windows users by clicking here.
• Currently the iPhone 4 cannot be jailbroken.
• After the jailbreaking process is complete remember to change the password of your jailbroken iPhone.
• This guide will NOT unlock your iPhone 3GS. You can use Ultrasn0w to unlock it after you have successfully jailbroken iOS 4.

If you gone through all the points mentioned above and meet the requirements then you can follow the step-by-step instructions given below:

How To Jailbreak iPhone 3GS (New Bootrom) With iOS 4 (Mac):

WHAT YOU WILL NEED:
* An iPhone 3G[S] -- new bootrom
* 3.1.2 SHSH blobs.
* difrnt's iBSS grabber
* Payload Pwner-r2 for the 3GS.
* sn0wbreeze V1.6.2
* iBooty
* LibUSB (64-Bit users read carefully!!!)
* 3.1.2/4.0 3GS firmware downloaded.
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STEP A : Grabbing your 3.1.2 iBSS file.
Pointing your hosts :
I : If you have your shsh blobs saved on Cydia/Saurik's server then follow this tutorial. -- http://saurik.com/id/12
II : If you have it saved with TinyUmbrella, then download the GUI here. -- http://thefirmwareumbrella.blogspot.com/
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Restoring to grab the iBSS file.
I : Place your device in DFU.
II : Start up the iBSS/iBEC grabber.
III : Put the save folder on a new folder on your desktop.
IV : Hit "Start Monitoring".
V : Now go back to iTunes and do SHIFT + Restore. Then browse for your 3.1.2 IPSW. You will need to restore
to 3.1.2 in order to pwn 4.0.
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Saving your iBSS
I : After Restoring, Go to the folder that you have specified to save your iBSS file.
II : You will see folders like (Per**.tmp). Go into one of them, and you'll see a folder called "Firmware". Go there. Then go to the folder "dfu".
III : Copy the iBSS file to a safe place, then you can remove the folder created by the iBSS Grabber.
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STEP B : Creating custom 4.0 firmware.
I : Download sn0wbreeze from http://ih8sn0w.com and create your custom 4.0 ipsw.
*Ignore the warnings after browsing for the ipsw.*
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STEP C : Installing LibUSB for iRecovery
Run this mini tool to detect your O/S + Arch. -- Windows + Arch. Detector
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WARNING : IF LIBUSB IS NOT INSTALLED PROPERLY, YOUR USB MIGHT NO LONGER WORK!
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Windows XP Users download this installer -- LibUSB Installer
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Windows Vista/7 users RUNNING 32-Bit:
* Download the installer and run it in compatibility mode for Windows XP.
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If you are a 64-Bit user, follow this tutorial -- LibUSB 64-Bit Tut
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Once LibUSB is installed iRecovery should be able to function now.
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STEP D : Pwning iBSS + iBoot
I : Download this easy tool here -- Payload Pwner-r2 for 3GS // It will help you create the payloads.
**SAVE THE PAYLOADS WHERE iBooty is.**
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STEP E: iBooty Prep.
Most of you know of the utility "iBooty" that I made for Aki_nG.
It will work as long as you place all of the correct files there.
I : Download iBooty GUI here -- iBooty for 3GS and Extract it.
II : Extract your Custom IPSW created by sn0wbreeze with 7-Zip or another un-archiver.
III : Grab the kernelcache and bring it into the same folder as ibooty.
Also grab the iBEC from the folder "Firmware\dfu\iBEC.n88ap.RELEASE.dfu"
IV :
* Rename your iBSS 3.1.2 signed to "ibss312.dfu"
* Rename your Kernel 4.0-Custom to "kernel.40"
* Rename your iBEC 4.0-Custom to "ibec40.dfu"
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Your folder should look like this :
- iboot.payload <-- Created with Payload Pwner.
- exploitibss312 <-- Created with Payload Pwner.
- ibec40.dfu <-- Grabbed from Custom IPSW made by sn0wbreeze.
- irecovery.exe <-- Comes with iBooty.
- readline5.dll <-- Comes with iBooty.
- iBooty.exe <-- Comes with iBooty.
- ibss312.dfu <-- THIS NEEDS TO BE YOUR iBSS from the restore!
- kernel.40 <-- Grab from Custom IPSW made by sn0wbreeze.
- sn0w.img3 <-- Comes with iBooty.
======
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STEP F: Restoring to 4.0 + Booting
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*MAKE SURE YOU ARE ON 3.1.2 WHEN DOING THIS*
I : Run iBooty and Select "Prepare Device for Custom Firmware". Run the Process and if you see a snow flake, you can proceed!
II : Now open iTunes and restore to the custom ipsw.
***WHEN DONE, YOUR DEVICE WILL HAVE A BLACK SCREEN AND NOT BOOT! ITS IN A DFU LOOP [THIS IS NORMAL!]***
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STEP G : Booting
I : Just Re-Run iBooty and select "Boot It". If all goes well it will boot!
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Enjoy!
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