The iPhone Dev Team are still working on exclusive untethered jailbreak for iOS 4.2.1.They have released a new version of Redsn0w to support single click tethered jailbreak for iOS 4.2.1 on iPhone, iPod Touch, and iPad.This new version allows you to bypass some of the screens, when you choose “Just boot tethered for now”.
Redsn0w 0.9.6rc7 is available for Mac and Windows now! Here’s what the iPhone Dev Team posted on their blog:
We’ve updated redsn0w to include “one-click” support for those of you running the tethered 4.2.1 jailbreak. Using command-line arguments, you can now bypass the screens you’d normally see as you use redsn0w to “Just boot tethered for now”.
The available command line arguments are:
-j to ask redsn0w to “Just boot now”
-o for old-bootrom iPod touch 2G and iPhone 3GS
For example, to get redsn0w for Mac to do a tethered boot of an iPod touch 4G jailbroken at 4.2.1: open ~/Desktop/redsn0w.app –args -j -i ~/Desktop/iPod4,1_4.2.1_8C148_Restore.ipsw
This assumes both redsn0w and the IPSW are on your OS X desktop, so modify as necessary! Included in the zip is an example script file that you can double click on to launch redsn0w like this (the Windows example assumes everything is in C:\). (Mac users: please remember to change the permissions of your custom *.command files to allow execution.)
This should help ease the pain of the tethered jailbreak until @comex comes up with a 4.2.1 untether (or for those of you with legit access to the 4.2b3 IPSW, until the “Jailbreak Monte” untether is out of beta)!
– PLEASE UPGRADE TO iTunes 10.1 FOR BEST RESULTS
– WINDOWS 7 USERS SHOULD RUN redsn0w IN “XP COMPATIBILITY” MODE
– Make sure you’re using a USB 2.0 port
Jailbreak iOS 4.2.1 Using Redsn0w 0.9.6rc7 for Mac users:
Extract Redsn0w 0.9.6rc7 zip file contents and place ‘Redsn0w.exe’ and the shell command ‘boot-ipt4g.command’ on your desktop. Also place your iOS IPSW firmware for your iDevice on desktop.
Next double click on ‘boot-ipt4g-command’ to run it. This will automatically run the following command in your Mac OS X terminal:
open ~/Desktop/redsn0w.app —args -j \ ~/Desktop/iPod4,1_4.2.1_8C148_Restore.ipsw
The above command works for iPod Touch 4G on iOS 4.2.1. In order to make it work for your iPhone or iPad, right click on the command, select ‘Open With –> TextEdit’, and edit the command to reflect your current IPSW firmware.
Replace ‘iPod4,1_4.2.1_8C418_Restore.ipsw’ to the exact name of your device’s firmware.
When you double click the command, your Redsn0w 0.9.6rc7 will automatically skip all the steps, including selection of iOS firmware and the ‘Just booth tethered now’ option to directly take you to the screen where you are asked to put your iPhone in DFU Mode.
Jailbreak iOS 4.2.1 Using Redsn0w 0.9.6rc7 for windows users:
Extract the Redsn0w 0.9.6rc7 zip file and copy Redsn0w.exe, the shortcut ‘boot-ipt4g’ and your iOS IPSW firmware to C drive.
The shortcut ‘boot-ipt4g’ points to the following command:
C:\redsn0w.exe -j -i “C:\iPod4,1_4.2.1_8C148_Restore.ipsw”
As you can see, you are expected to place both Redsn0w.exe and your iOS IPSW firmware in your C: for this command to work.
Right click on the shortcut, select ‘Properties’ and go to the ‘Shortcut’ tab. Edit the command to reflect your current IPSW firmware. Replace ‘iPod4,1_4.2.1_8C418_Restore.ipsw’ to the exact name of your device’s firmware.
Make sure you put quotes around the file path.
When you double click the shortcut, Redsn0w will automatically process the IPSW so that you don’t have to select it manually and select the ‘Just booth tethered now’ option (the –j argument in the command). So you are directly taken to the screen where you put your device in DFU mode.
Make sure you have the latest version of iTunes and also you are using a USB 2.0 port.