There is a way to jailbreak your iPhone 3GS and the iPhone 4 running on iOS 5.0.1 without updating baseband using Redsn0w for Mac. You have to preserve an unlock from lower baseband version.
Here are full instructions on how you can the jailbreak possible without updating baseband. Redsn0w 0.9.9b9d for Windows and Mac released by the iPhone Dev Team as an update for Ultrasn0w 1.2.5.
Please note this jailbreak is tethered for every device but the old bootrom iPhone 3GS which means you will need to connect your device to the computer each time you reboot. Also, it may be prudent to save your SHSH Blobs by following this tutorial before continuing if you haven’t already.
Before we get into it, you have to:
* First of all get the Redsn0w 0.9.9b9d from below.
* Download iOS 5.0.1 Firmware
* Best to create a Pwnage Folder and place all into it.
Lets start the guide:
Step 1 : Download the latest released Redsn0w 0.9.9b9d for Windows and Mac from here.
Step 2 : Launch Redsn0w right now!
Step 3 : Click to select Custom IPSW from the Extra menu.
Step 4 : Navigate to the Pwnage folder on your desktop and select the IPSW we downloaded then click Open.
If you are using the iPhone 3GS you may be asked to identify whether you are on a newer or older model.
Step 5 : RedSn0w will now begin building a custom IPSW for you.
Step 6 : You’ll be notified once RedSn0w has completed building your IPSW. Click the OK button.
Step 7 : Now Click the Pwned DFU button from the Extras menu.
Step 8: Plug your iPhone into the computer and make sure its OFF then click the Next button
Step 9 : RedSn0w will now guide you through the steps to get into DFU mode. You can find more help with DFU mode here.
Step 10 : RedSn0w will now run the LimeRa1n exploit.
Step 11: You’ll then be notified that your iPhone is in Pwned DFU mode.
From now : Launch iTunes by just clicking its icon in your dock. then Select your device from the list on the left then under the Summary tab hold down the Option key and click the Restore button.
You will then be asked to select your IPSW for restore. Navigate to the Pwnage folder on your desktop and select the IPSW that begins with NO_BB then click the Open button.
This time, iTunes will now restore, after that jailbreak your device using the custom IPSW.
JAILBREAK AND INSTALL CYDIA
Follow these instructions to jailbreak your device on the new iOS 5.0.1 firmware posted here.
– iPhone 4
– iPhone 3GS
Once you have jailbroken you will need to rerun redsn0w to boot tethered.
Follow these steps:
Step 1 : From the main RedSn0w menu click the Extras button.
Step 2: Select Just boot from the Extras menu to just boot tethered.
If you have a supported baseband you can now install UltraSn0w to unlock your device. Instructions are here.