If you have an iPhone 4 Unlocked with Gevey Sim running iOS 4.x.x and you want to update to iOS 5.0.1 firmware with Gevey Unlock. In order to update you must first preserve your unlockabe iPhone 4 baseband that can be unlocked with Gevey SIM.
Note: In order to do this you will need to restore your iPhone 4 with custom iOS 5.0.1 ipsw with Redsn0w 0.9.10b5 to preserve the unlockable baseband.
What is Gevey Sim:
Gevey Sim is hardware that unlocks iPhone 4 running on baseband 01.59.00, 02.10.04, 03.10.01, and 04.10.01 on the iOS 4.x.x, and iOS 5.x.x.
Required Downloads:
- Download Redsn0w 0.9.10b5 for Windows. (be sure to run in Administrator mode)
Download Redsn0w 0.9.10b5 for Mac. - Download iOS 5.0.1 ipsw for iPhone 4
- Download iTunes 10.5.3 for Windows and Mac
How To Unlock iPhone 4 on iOS 5 with Gevey SIM
Step 1: Connect your device with your PC via USB and open Redsn0w.
Step 2: Now select Extras and then select “Custom IPSW” option so that you can create your pre-jailbroken custom firmware.
It will start cooking your custom iOS 5 ispw firmware
Step 3: Next click on “Pwned DFU” on the screen.
Step 4: In this step make sure your device is Turned Off and Plugged In to your PC
Next you will have to enter the DFU Mode. To do that, follow the onscreen instructions to get your device in the DFU Mode.
Step 5: Once you’re in the DFU Mode Open iTunes and restore your iPhone 4 to the Custom iOS 5 ipsw (the file name begins with NO_BB.)



