Whenever Apple seeds a newer iOS update, the only two things that users are concerned about are whether the newer iOS can be jailbroken & whether an unlock is available for iPhone on that update.
Apple recently released iOS 5.1 to the public. And the good news is that, it still can be jailbroken. But the bad news is that the jailbreak is currently tethered & is available only for non A5 devices including iPhone 4, iPhone 3GS, iPod Touch 3G/4 and iPad 1. iPhone 4S and iPad 2 owners still have to wait.
Also, if you’re an iPhone 4 user relying on Gevey unlock, then here’s another good news for you. Gevey sim works on iOS 5.1 while preserving the baseband. If you want to use Gevey, your baseband must be 04.10.01, 03.10.01 or 02.10.01. Currently, there’s no Gevey unlock for 04.11.08. ApplenBerry is still working on it.
Follow one of these 2 tutorials to preserve baseband and create custom iOS 5.1:
- [How To] Preserve Baseband & Update to iOS 5.1 using sn0wbreeze 2.9.2
- [How To] Preserve Baseband & Update your iPhone 4/3GS to iOS 5.1 using redsn0w 0.9.10b6
Here are two screenshots of iPhone 4 running on Gevey sim:
If you’re using Gevey Ultra, you can install FuriousMod 2.0 from Cydia to automate the 112 procedure and get untethered unlock. But note that the jailbreak for iOS 5.1 is tethered and you’ll need to boot your iPhone in tethered mode if it turns off.
Note for iPhone 4S users:
There’s currently no low level bootrom exploit for iPhone 4S. And iOS 5.1 on iPhone 4S cannot be jailbroken currently. Hence you cannot preserve the baseband on iPhone 4S. So if you’re using a locked iPhone 4S and using R Sim or Gevey Ultra S to unlock it, better stay where you are.
Thanks to @w2no for the screenshots.