Dev-Team: tethered jailbreak for iOS 5.1 with redsn0w ready

Of course, just like the rest of us, the Dev Team was waiting-by during yesterday’s event to give us an update on the jailbreaking situation following any announcements. Very briefly during the event, Apple told us iOS 5.1 would begin rolling out. The major takeaway of the announcement was Siri support for Japanese users. Over on the Dev-Team Blog, the team outlined everything you need to know about jailbreaking and updating to iOS 5.1. They also confirmed redsn0w is capable of a tethered jailbreak for non-A5 devices. Here is what you need to know:

Non-A5 devices are supported. That means anything before iPad 2. To be specific, you will have to use the “Just Boot” method with redsn0w 0.9.10b6 (OS X and Windows); however, if you have an old-bootrom 3GS Dev Team said the jailbreak is automatically untethered. There is also now support for MC models of iPod touch 2G via @pod2g’s steaks4uce exploit, allowing redsn0w to automatically jailbreak MC and MB versions of the device. There are a few things you need to remember—as with all new jailbreaks. For instance, iBooks will not work until redsn0w gets an update. For ultrasn0w users, the Dev-Team warned:

If you use ultrasn0w for your carrier unlock, be sure to use a custom IPSW to get to 5.1 first! Don’t ever restore to a stock Apple IPSW! Use redsn0w’s “Custom IPSW” button to create a NO_BB_* version of the 5.1 IPSW and restore to that instead of the stock one. (That option is available only to 3GS and iPhone4-GSM owners.) ultrasn0w itself will be updated for 5.1 in the next few days (same baseband support, not 5.1’s baseband).

[youtube=http://www.youtube.com/watch?v=cP_uof1YGrA]

For current jailbreakers who are considering updating to 5.1, the post explained the ins and outs for various devices:

• Soon after 5.1 appears on Apple’s public servers (i.e. iTunes starts to offer it), Apple will stop signing 5.0.1 SHSH blobs.
• If you have an iPhone4S, the basic rule above is really the only rule: you cannot restore back to 5.0.1 once the 5.0.1 signing window is closed, no matter what (even if you saved your SHSH blobs).
• If you have an iPad2 with saved 4.x hashes, you can in fact downgrade to that 4.x but you won’t be able to get to 5.0.1 once the 5.0.1 signing window is closed (even if you saved your 5.0.1 SHSH blobs).
• If you have a device earlier than the iPad2, you can downgrade to whatever version you want, as long as you have saved SHSH blobs for that version. You’ll need the assistance of geohot’s limera1n exploit with tools like redsn0w to get into “pwned DFU mode” and bypass the downgrade restriction.