iPhone 4.0 Beta Downgrade to 3.1.3

For $7, I was able to have my iPhone’s UUID added to a developers account to enable me to download and install beta 4 of OS4 for the iPhone.  It seems pretty neat, but rather uninspiring- especially since there are no available jailbreaks for OS4 beta on a 3GS (only on a 3G).

Luckily I came upon an article at MacLife that provides a solution for this…

Note: this can only be done on OS X.  The article has links for 10.6, but I was albe to find the 10.5 LibUSB package.

Step 1: Download the following:

• iRecovery v. 1.3 for Mac
• LibUSB Library (10.6) or
  LibUSB Library (10.5)

Install the LibUSB and extract iRecovery to a place where you can access it (such as the desktop).

Step 2: Restore

• Power off your iPhone
• Hold down the ‘Home’ button and plug in the USB cable to your Mac; this will put the iPhone into recovery mode
• iTunes will inform you that your iPhone is in recovery mode and must be Restored. 
• Run an iPhone restore in iTunes as you normally would.
• The recovery will run for a few minutes and then fail with ‘An Unknown Error has Occurred: 1015’

Step 3: iRecovery

• With the iPhone still plugged in, open a terminal (Applications, Utilities, Terminal) and navigate to the location where you extracted iRecovery (cd Desktop).
• Enter the following commands, pressing return between each:

./iRecovery –s

setenv auto-boot true

saveenv

fsboot

exit

The command prompt will return after a few seconds; you can now reboot your iPhone (hold Home + Power for a few seconds). 

After you power back on, you should be able to connect to iTunes and re-activate (and run Spirit to Jailbreak).