Source: http://www.bingner.com/pwnstrap.html
Developed By sbingner & posixninja


PwnStrap


This procedure should work to bootstrap the restore
of any 3GS or Apple TV2 with PwnageTool 4.1+ image


THIS WILL NOT WORK FOR ANYTHING LESS THAN A 3GS.
THIS WILL NOT WORK FOR A CFW NOT PREPARED WITH PWNAGETOOL.
THIS WILL NOT WORK FOR ANY OTHER FIRMWARE BELOW iOS 4.1
YOU HAVE BEEN WARNED.

For iPhone 4 you can use umbrella


Linux
Required files:
Your PwnageTool cooked 4.1 firmware:-
Firmware 4.1 Pre-Jailbroken Custom IPSW Files – SiNfuL iPhone

unofficial Linux iRecovery for new Devices
Linux iRecovery that will bootstrap loading up ATV2 pwnagetool image

With this image, you can run “ ./irecovery -p Path/To/Firmware.ipsw ” with an iDevice in Recovery Mode

******************
Windows
Required files:
Your PwnageTool cooked 4.1 firmware:-
Firmware 4.1 Pre-Jailbroken Custom IPSW Files – SiNfuL iPhone

unofficial Windows iRecovery for new Devices
Windows iRecovery that will bootstrap loading up ATV2 pwnagetool image by following the procedure below

iTunes 10 for greenpois0n to run correctly
Apple – iTunes – Everything you need to be entertained

greenpois0n
greenpois0n – Mmmm…pois0n
We have reliable information that this process works better with greenpois0n RC3
Download:-
megaupload: greenpois0n RC3 

iphoneworld.ca: greenpois0n RC3

Windows XP appears to be the most reliable.. if you have access to an XP box, use it !!!
Please give feedback if you got this working on Vista 
We have had reports that this is NOT working on Windows 7.. let us know if you have a fix 
Windows 7 update.. the software was developed on Windows 7 so it should work !!!
try putting both irecovery and greenpois0n into Win XP/sp2 compatibility if you encounter problems on Win7 

Automatic Procedure:1) Place your device into Recovery Mode.
While the phone is off, hold down the Home button and immediatly plug it into your computer.
(connect to iTunes logo should appear on the device)

2) In a command prompt, run irecovery.exe -p Path\To\Firmware.ipsw
Follow all the instructions.

3) once greenpois0n tells you jailbreak success…
your device should appear to reboot… (the screen can be white or connect to iTunes logo)

4) now you can send your CFW from iTunes

If you don’t read the actual output from greenpois0n may the fleas of a thousand camels infest your private parts.
*****************

if you have problems with the single command above you can use the manual method below..
Manual Procedure:
1) Put phone into Recovery mode (NOT DFU)
While the phone is off, hold down the Home button and immediatly plug it into your computer.

2) From a command prompt (Start>Run>”cmd”), change to the directory where you extracted irecovery, and enter irecovery -s

in the irecovery console enter the following commands :-

setenv boot-args 2
setenv auto-boot false
saveenv
/exit

3) Run greenpois0n – it will guide you to DFU mode, then it will stop on a white screen after you click “Jailbreak”.
It should say “Jailbreak Complete!” and NOT “Jailbreak Failed!” next to the progressbar at the bottom.

4) Extract the iBSS from your custom PwnageTool image (firmware.ispw/Firmware/dfu/iBSS.BoardID.RELEASE.dfu) into your irecovery folder.
You can use WinRAR or another ZIP extractor to do this. IPSW files are really just ZIP files!

5) irecovery -f iBSS
iBSS should be replaced with the name of the iBSS that you just extracted from the pwnagetool image – ie iBSS.n88ap.RELEASE.dfu

6) At a command prompt: irecovery -s

in the irecovery console enter the following commands :-

setenv boot-args 0
saveenv
go image decrypt 0×41000000
go jump 0×41000040
/exit

At the “go jump” point your device should appear to reboot. Whether it goes back to a white screen or shows the Connect to iTunes screen depends on the firmware image used.

7) Restore your PwnageTool cooked firmware from iTunes.

Related posts:

  1. HOW TO: Create A Custom iOS 4 Firmware Using PwnageTool 4.0 [video]
  2. HOW TO: Create Custom Jailbreak Firmware 3.1.3 Using PwnageTool 3.1.5 [Mac]
  3. Fix 1604 Error During iPhone 3.1.3 IPSW Custom Restore

Related posts brought to you by Yet Another Related Posts Plugin.