Review - How to upgrade and Jailbreak a Blackra1n Jailbroken 3GS 3.1.2 to iOS 4.0

Finally, I have Jailbreak my iPhone 3.1.2 which was Jailbroken via Blackra1n to the latest Apple iOS 4.0 and Jailbreak with Pwnage Tool 4.0.1. You may click any of the articles below:

I followed closely this below articles:-

1 - How to Jailbreak Your iPhone 3GS Using PwnageTool (Mac) [4.0]

2 - Jailbreak and Unlock iPhone 3gS to iOS4 (also downgrade to lower firmwares) on Mac

3 - iTunes: Backing up, updating, and restoring your iPhone, iPad, or iPod touch software

4 - iOS4 jailbreak pwnagetool - cydia crash

I have to create the custom ipsw twice to get the Cydia working. The first one crashed because I have enabled and downloaded some sources during the Pwnage process.

(Note: Ensure to "uncheck" the "Activate iPhone" because mine is officially unlocked)