Apple just released iOS 4.0.1 for iPhone 4, 3GS and 3G. The jailbreak for iOS 4.0.1 is right now only available for iPhone 3G that can be done using Redsn0w 0.9.5b5-3.

Before you go for the guide you must know:

- This jailbreak is for iPhone 3G only.

- I will not be responsible for any loss of your device while attempting this jailbreak, do it on your own risk

How to jailbreak

  1. Download iOS 4.0.1, download according to your device:
    - iOS 4.0.1 for iPhone 3G
    - iOS 4.0.1 for iPhone 3GS
  2. Download and install iTunes 9.2 if you haven’t.
  3. Connect your device to iTunes 9.2 and update your device to the downloaded iOS file. To do this, in iTunes under devices, select your device and in ‘summary’ tab under the ‘version’ click ‘update’ while pressing Shift key. File browser will open and select the downloaded iOS file follow the instructions.
  4. Download and run Redsn0w 0.9.5b5-3 (click here for Mac version)

    image

  5. Browse for the iOS 4.0 IPSW (not the iOS 4.0.1 IPSW) file and click Next. You can download iOS 4.0 for iPhone 3G from here and iOS 4.0 for iPhone 3GS from here.
  6. Check ‘Install Cydia’ and click Next.
  7. Turn off your device and plug it in to the computer and click Next.
  8. Connect your device in recovery mode. To enter recovery mode, Press and hold the “Home” button and the “Sleep/Wake” button at the same time. When As the screen goes black release the “Sleep/Wake” button.
  9. There will be a screen where you have to quickly hold the “Sleep/Wake” button and just after that also hold the “home” button. After few seconds release the “Sleep/Wake” button but keep holding “Home” button until redsn0w starts the installation.
  10. After installation, your device will restart to iOS 4.0.1. Done.

If you see black Cydia icon with no sources then add this repo http://apt.saurik.com/cydia-3.7 and restart your device.

How to Unlock iPhone 3G on iOS 4.0.1

iPhone 3G on baseband 05.13.04, 05.12.01 and 04.26.08 running iOS 4.0.1 can be unlocked using Ultrasn0w. Follow this guide

[RedmondPie helped to make me write this tutorial]