First you should make sure you are upgraded to firmware iOS 5.0.1. Just go to your Settings app, then General, then Software Update.

Next, sync & back up your device with your computer or iCloud. Now you can download the program redsn0w to your computer. The download links can be found here: blog.iphone-dev.org Once downloaded you’ll need to unzip the file and move the app to your applications folder. Run redsn0w to begin the jailbreak!

You’ll need to turn off your device and be ready to put it into DFU mode. Follow the instructions in the app on how to do that.

On the next screen you will need to make sure “Install Cydia” is checked and click next. Don’t worry about “Enable Multitasking Gestures” because that is part of the new iOS firmware 5.0.1. Now just click next and wait for the software to do the rest. You will see a few crazy screen shown below but soon your device will reboot and you will have a new application called Cydia where you can install all kinda of hacks and mods no available in the Apple App Store.

Note: A few parts of the process may seem like you device freezes up but things like “Moving Applications” and other steps just take a while. Be patient!

With Turkey Day a few days off, today Apple publicly released FW version 4.2.1. As always, ultrasn0w unlockers please stay far far away from this official firmware (and all official firmware). Wait for the ability to create custom 4.2.1. IPSWs that don’t update your baseband! If you’re not an unlocker, read on!

The best news of all is for owners of iPhone3G, older iPhone3GS, and non-MC iPod touch 2G. Due to a combination of our original pwnage2 exploit, the arm7_go exploit, 24kpwn, and limera1n, your device is “just as jailbreakable as ever.” You reap the full benefit of an untethered 4.2.1 jailbreak.

Next are the owners of all the more recent devices. The good news there is that due to geohot’s limera1n exploit, all recent devices can be jailbroken (this will be true until Apple released new hardware that fixes geohot’s limerain exploit in the bootrom). The bad news is that right now, the 4.2.1 jailbreak is *tethered* on all of these recent devices. A tethered jailbreak means that each time your device loses battery power or needs to be rebooted, you must attach it to a PC or Mac to boot into the jailbroken state. @comex is working hard on a method that may untether the 4.2.1 jailbreak, but it will require you to have your 4.1 SHSH blobs in order to use it. No word on how much more effort it will take though (please don’t bug @comex about it!). (We also have an alternative method that may work, but @comex’s method is much more elegant.)

So when does all this 4.2.1 jailbreak action happen? Well if you’re a JB developer or tinkerer, you’ve already probably used the redsn0w mentioned in our last post to jailbreak 4.2.1 and at least get SSH working. But beyond that, there are still some last minute issues with MobileSubstrate and comex’s kernel patches that are being fixed. We’ll tweet and post a blog update when it’s all available (we hate to give ETAs, but barring any unforeseen problems, probably later today). It happens “now’…see Update #1.

In the meantime, please make sure you have your 4.1 SHSH blobs for all your devices. These will be important even for firmware beyond 4.1 (using both comex’s method and our alternative, depending on how each of them turn out.)

ultrasn0w unlock: After redsn0w is officially released with the new Cydia and kernel patches, we’ll be able to assess the unlock situation. It’s already looking very promising though, so expect the unlock for the 3G and 3GS to be coming this week. The i4 unlock is taking more effort though, and no further concrete info is available about that yet.

Feel free to ask questions in our comments section below, where we’ve got some awesome new additional moderators — sherif_hashim, dhlizard, and Frank55!

Update #1: redsn0w version 0.9.6b4 is now available for your 4.2.1 jailbreaking pleasure. Please read all the above to understand what this jailbreak currently entails.

Check out the Dev-Team’s blog post for the download links for both Mac and PC.

Update #3: (Warning: if you use the ultrasn0w unlock, please read no further…this doesn’t apply to you yet!) We’ve made some updates to redsn0w to make it easier for jailbreak developers (and tinkerers) to get their programs ready for 4.2.1. As noted above, the public version of Cydia (and MobileSubstrate too!) is not 4.2.1-compatible. redsn0w will now let you install your own custom bundles independent of Cydia (the bundle can actually be Cydia if you’ve compiled it on your own). These bundles can be up to 15MB in size, and should be in the form of a gzip-compressed tar file.

The new redsn0w 0.9.6b3 is available at:

* OS X
* Windows

It’s very important that you get the file permissions and ownerships right in your custom redsn0w bundles. To give you a practical example of such a bundle, here’s one that includes OpenSSH, OpenSSL, and the basic apt installer programs:

* SSH bundle v2 (update: v2 has fixed permissions..you can just drop this one right in even if you installed the first version)

redsn0w has also been updated to recognize the 4.2.1GM IPSWs. *However*, as noted above, the 4.2.x jailbreak is not yet untethered for most devices! That means until someone like @comex comes up with a way to untether it, you must use redsn0w (or a similar utility) to boot your device into a jailbroken 4.2.1 state. (The only exceptions to this are the iPhone3G, non-MC iPod touch 2G, and old-bootrom iPhone3GS. redsn0w will jailbreak those untethered!)

With the above redsn0w and SSH bundle, jailbreak developers and tinkerers can jailbreak and SSH into their 4.2.1 devices, provided they’ve done a tethered boot (using redsn0w’s “Just boot tethered right now” option).

Note: The Cydia that’s included in 0.9.6b3 is the same one as in 0.9.6b2, and so it will *not* work on 4.2.1. Don’t try installing it on 4.2.1! Instead, use the SSH bundle, or compile Cydia on your own. If you’re familiar with the apt utilities, you can use “apt-get” to install many programs from the command line. Be sure to do “apt-get update” first to refresh your sources!

PLEASE CONSIDER THIS AN ADVANCED TOPIC!! It’s not meant for the masses because it involves rather nerdy things like command lines and tar files. But for those who know how to use this new redsn0w feature, have fun!

What the jailbreak works on:
    • iPhone 3G, 3GS and iPhone 4
    • iPad
    • iPod touch 2G (with qualifying bootroms), 3G and 4G
    • Apple TV 2G

New features of redsn0w 0.9.6b2:
    • custom bootlogos for iPhone3G/iPhone3GS/iPod2G users (with qualifying bootroms)
    • an option that implements the “DFU” button in PwnageTool. This button (which you can use from Windows) lets you prepare your device for a custom DFU. Even if you’re purely a Windows user, you can get a trusted friend to run PwnageTool over your IPSW to create a custom IPSW. You can now install that custom IPSW on your own Windows box, after you run this redsn0w version.

For all the details and links to download the redsn0w files… check out the Dev-Team’s website.

This version of redsn0w does not provide an untethered jailbreak for those of you with brand new iPhone 3GS, iPod touch 2G, or any iPod touch 3G. redsn0w will jailbreak those but it will still be a tethered jailbreak until some new exploit is found and released.

iphone_dev tweet – “Early adopters have found that redsn0w JB *already* works on 3.0.1 (just point it at 3.0 IPSW!) Even for 3GS & ultrasn0w.”

Last night we released updated versions of our redsn0w jailbreak and ultrasn0w carrier unlock. These versions are now compatible with the iPhone 3GS running at 3.0. Welcome aboard, 3GS owners! (The tools of course remain compatible with all of the other platforms too.) Also last night, saurik released 3GS-compatible versions of MobileSubstrate and WinterBoard, components that enable many different add-ons and themes.

We realize we upset some folks (e.g. existing 3GS owners) with our earlier announcement that we wanted to hold onto the 3GS iBoot-family hole until 3.1 was out. Our aim there was to get as many people as possible onboard (within reason of course) before revealing the hole, since Apple will fix it immediately. But all of that became moot when the purplera1n release was made, since it uses the same hole.

For those of you who already own 3GS phones, the outlook is bright. As long as you have your personalized (signed) dfu/img3 files, you’ll always be able to jailbreak (even if you slip up and install stock Apple firmware in the future). For those of you without 3GS phones, it’s a race against the clock to use this particular hole. There’s nothing we can do about that, but we will always be looking for new holes.

Continue reading HERE.

Dev-Team Quotes:
“Released: redsn0w 0.8 (incl. 3GS, hactivate, linux) http://is.gd/1pRlV”

“yep, redsn0w 0.8 also jailbreaks all the other devices at 3.0 too”

There isn’t an official post on the Dev-Team’s website about this one. To get the jailbreak just go HERE and download the jailbreak that you need.

“redsn0w is an easy to use, multi-platform, multi-device jailbreaking and unlocking (iPhone 2G only) tool for the iPhone 2G (original iPhone), the iPhone 3G (but not the 3GS) and also the iPod touch (first and second generation). Currently it is available for Windows and Mac OS X (there are some issues using redsn0w with OS X PPC, please use an Intel Mac until we have this problem resolved).

REDSN0W PROVIDES SIMILAR FUNCTIONALITY TO QUICKPWN.

If you want to build custom firmware files with more flexibility it is suggested that you use ‘PwnageTool’ on Mac OS X.

1.GOLDEN RULE: If you are using a 3G iPhone with yellowsn0w and rely on yellowsn0w to obtain cellular service, then you should NOT use redsn0w right now. Ultrasn0w (the 3G carrier unlock) is not included with this release and therefore your baseband will be locked and unable to use an operator other than the official one it was bought for. UltraSn0w will be released via APT (cydia and icy) soon. If you have an original iPhone (1st generation) then 3.0 carrier unlock works with this redsn0w release.

2.Yellowsn0w in its current form will NOT work with the baseband version that is present in the 3.0 update, you will need Ultrasn0w, which will be released sometime soon, Ultrasn0w will work with all iPhone 3G models (but not 3GS), even ones that were previously unlockable, Ultrasn0w (when available) will be released via APT (this means you will be able to get it via Cydia or Icy).

3.Please read all parts of this post before downloading and using these tools.
4.Read items 1, 2 and 3 again and again.
5.At the bottom of this post are the bittorrent files for the latest version of redsn0w.
6.This app is suitable for the recent 3.0 release
7.redsn0w will NOT work for the iPhone 3GS.
8.redsn0w WILL work for Original iPhone (1st Generation), Original iPod touch, iPod touch 2G and the iPhone 3G (not the iPhone 3GS).

To use redsn0w simply upgrade the device in iTunes to firmware version 3.0 and run redsn0w to activate and jailbreak the device (and if you are using an original iPhone 2G, it will unlock it too!)”