How To Upgrade To iOS 5.1.1: Create Custom Firmware 5.1.1 To Preserve Baseband


by cM Boy on May 24, 2012

Everyone is waiting anxiously for the upcoming untethered iOS 5.1.1 jailbreak by Pod2g. Absinthe 2.0 download will be available anytime soon. We recommend everyone to upgrade their devices to the latest firmware that is iOS 5.1.1 for which jailbreak will be released.

Earlier we told you that jailbreak will be compatible with both iOS 5.1 and iOS 5.1.1 but for A5/A5X devices that includes iPhone 4S / iPad 2 / the new iPad (ipad 3), it will only be available for iOS 5.1.1. Anyways its better to also have latest firmware in your device so we recommend everyone to upgrade to iOS 5.1.1.

Most of you have already migrated to 5.1.1 but there are many users who are on the earlier firmware versions. This guide is specially for the users who rely on some unlock solution for their devices. More precisely, its for those who are using Gevey Sim or Ultrasn0w to unlock their devices. Remember these users need to preserve their baseband while upgrading to iOS 5.1.1. If they try to install iOS 5.1.1 directly from iTunes, their baseband will be updated to 4.12.01 and they will loose the unlock of their iPhone. You can check your baseband on iPhone by going to Settings > General > About > Modem Firmware.

So what we will do is that we will create a custom firmware using Redsn0w and then restore to this customized IPSW. Follow the guide.

How To Upgrade to iOS 5.1.1 By Creating Custom Firmware And Preserving Baseband:

STEP 1: First you need to have necessary downloads.

jailbreak download

STEP 2: Now Launch the Redsn0w application and click on “Extras”

Redsn0w features

STEP 3: Click on “CUSTOM IPSW” button.

custom IPSW

STEP 4: Now browse the iOS 5.1.1 firmware that you have downloaded and placed inside the folder on your desktop.

browse firmware ios 5.1.1

STEP 5: Redsn0w will now start creating the custom firmware.

custom firmware ios 5.1.1

STEP 6 Once it completes the process, it will show you the following screen. It shows the location of new firmware file it has created which is the same folder. The name of the new firmware file it has created starts with NO_BB. Press OK on this Windows.

5.1.1 cfw

STEP 7: Click on the PWNED DFU option on Redsn0w. Put OFF your iOS device and connect it with your computer. Make sure its OFF and connected to your computer and then press the NEXT button.

pwned dfu

STEP 8: Redsn0w will now assist your to enter your device in DFU mode.

  • Hold down both the HOME button and POWER button for almost 10 seconds on your iOS device.
  • Let go the POWER button and keep holding the HOME button until your device is detected in the DFU mode.
  • It will show you a DONE message once its completed.

STEP 9: Open iTunes software on your computer. Hold down OPTION button on keyboard and press RESTORE button on iTunes and select the custom firmware from the folder you created on desktop.

iTunes restore

MAKE SURE you select the custom firmware that starts with NO_BB. iTunes will now start restoring to the custom firmware. Thats it.

NO BB firmware

CONGRATULATION! You have successfully upgraded to iOS 5.1.1 while preserving your baseband. NOTE that the above process has nothing to do with the jailbreak. The above guide is just to upgrade to iOS 5.1.1 while preserving baseband.

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  • Victor Cruz

    this info is very IMPORTANT…thanks

  • zak

    Right now I’m on 5.1.1 can i use this method to do my custom upgrade to 6.0?

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