If you've updated your iDevice to iOS4.2.1 and want to jailbreak, you'll have gathered that's still a problem for newer devices. You can use Redsn0w, but your device will be tethered, which means you may have to reconnect it to your PC/Mac and run Redsn0w again every time you reboot ie switch your device off and on again.The iPhone Dev-Team has added an update to its blog explaining what "tethered" means:
If you’re on an iPhone3G, old-bootrom iPhone3GS, or non-MC ipt2g, life is easy. redsn0w installed an untethered jailbreak and so nothing below applies.
“Tethered” does not mean you cannot boot at all without PC/Mac assistance. If you have not installed any tweaks that hook into important programs like SpringBoard or CommCenter, your device will actually boot.
However, jailbreak programs like Cydia won’t work (and Cydia may still have a white icon). Also, certain built-in apps that had to be moved by Cydia will fail (Safari being the most noticeable example).
If you’ve installed MobileSubstrate tweaks that hook into SpringBoard or other important programs, your boot will actually fail (you’ll get stuck at the Apple logo). You need to use redsn0w to “Just boot tethered right now”.
Remember, @comex and others are working on a way to untether the 4.2.1 jailbreak. Meanwhile, the above points hopefully will make it all seem less confusing :)
Comments