In a special event yesterday, Apple released iOS 5.1 for download all over the world. Until now, there was no JailBreak available for non-A5 devices if you update either using OTA or iTunes. Fortunately, Geohot’s limera1n exploit has worked again that lets you tethered JailBreak iPhone 4, iPad 1 and iPhone 3GS (old or new bootrom) on the latest firmware, iOS 5.1.
Just update your non-A5 device manually using iTunes if you had a JailBroken device earlier. Otherwise, you might face error while trying to update using the OTA. All those users who rely on ultrasn0w to unlock and preserving their baseband from quite sometime should use the custom firmware to restore. However, ultrasn0w is not updated for iOS 5.1 yet and you need to wait for few more days for the support. Tethered JailBreak signifies that you would require to ‘boot tethered’ from the redsn0w every time the device reboots.If you don’t use the built in ‘boot tethered’ option in Redsn0w once the device is rebooted, all those tweaks/apps which you had installed through Cydia will not work. This also includes the mobile safari from Apple. For the old bootrom iPhone 3GS, the JailBreak remains untethered. So if you are lucky enough to own an iPhone 3GS (old bootrom), Redsn0w will automatically recognize it in the software itself. In addition to it, @pod2g’s steaks4uce exploit works for the MC models of iPod touch 2G.
PS: The tethered JailBreak is not meant for A5 devices such as iPhone 4S and iPad 2. So don’t update accidentally.