Jailbreak iPhone OS 3.0.1, You Already Have The Tools
August 1, 2009
Those of you who have declined to indulge in iPhone OS 3.0.1 for fear of losing your jailbreak, you will be pleased to know that you have no need to worry. The Dev-Team has gone ahead and given you the green light to update and jailbreak using the tools already available at your disposal.
The iPhone Dev-Team has confirmed that you can re-use the same version of redsn0w that you used to jailbreak 3.0 to jailbreak 3.0.1., you just have to do a little extra work. To jailbreak, all you need to do is install iPhone OS 3.0.1, launch redsn0w, and then when asked to select an IPSW file, select your 3.0 IPSW instead of 3.0.1 (assuming you still have it on your computer). That's it! And, since 3.0.1 doesn't touch the baseband, you can take it one step further if you wish and use the current version of ultrasn0w to do a soft unlock.
All of this is capable thanks to OS 3.0.1 essentially being a carbon copy of 3.0, just with a little extra code to patch that icky SMS bug. More detailed information about jailbreaking and unlocking OS 3.0.1 can be found on the Dev-Team's blog.