Dev-Team Blog
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0615 fun 

The iPhone Dev Team is happy to announce a baseband downgrade option in redsn0w for those who are using the iPad’s 06.15 baseband on the iPhone3G or iPhone3GS.

Typically you’d have the 06.15 baseband if you unlock with ultrasn0w but updated your iPhone baseband past 05.13.04.  With this new capability, you can now downgrade specifically from 06.15 to 05.13.04 (even if you never had 05.13.04 on that device before).  This gives you the best of both worlds: ultrasn0w compatibility and a normal iPhone baseband with full GPS and the ability to use stock IPSWs again.

Here are the steps:

  1. Use the “Extras->Select IPSW” button in redsn0w to tell it which firmware version you have installed (new-bootrom 3GS users can usually skip this step but it doesn’t hurt for them to do it too).
  2. Do a controlled shutdown of your iPhone (“slide to power off”).  This step is very important to avoid mount problems when the ramdisk is running!
  3. Go back to the first screen and click “Jailbreak”.  Enable the “Downgrade from iPad baseband” checkbox, disable Cydia if you already have it installed, and click Next to proceed through the normal DFU ramdisk steps.

After the ramdisk gets launched and you see the Pwnapple running on your iPhone, you’ll eventually get to the “Flashing Baseband” step.  THIS STEP TAKES A VERY LONG TIME to complete and there won’t be any feedback while its running.  Please just let it be for the next 3-8 minutes!  When the ramdisk has done its job it will reboot the phone on its own.

For those who are wondering if you can update your 3G or 3GS to 06.15 solely for the purposes of downgrading to 05.13.04, the answer is “yes” for 3G owners, and “maybe” for 3GS owners.  The iPad baseband is not compatible with 3GS units manufactured week 34 of 2011 or later.  If you have an iPhone3GS and if digits 3-5 of its Serial Number are 134 or later (xx134…), then you should NOT try to install the 06.15 baseband on your 3GS!  It will brick your radio, preventing both the downgrade from working and normal iPhone software from using it as a phone!  Be warned!

Thanks very much to @dilbert4life for graciously loaning us his 3GS at 06.15 (we had no such devices because we always prevent BB updates!)

If you have any questions or comments, please use our comments section below!

Here are the download links.  Enjoy!

Update #1: If you’re still using ultrasn0w after going down to 05.13.04, many people have reported that re-installing Mobile Substrate and/or ultrasn0w fixes crashes and “No Signal”.

Update #2: There’s a subset of 3GS iPhones that won’t take the downgrade.  We now understand why (they use a slightly different NOR chip), and should be receiving a loaner of such a phone on Thursday the 28th.  After we have one in hand we’ll tweak the redsn0w payload to handle that variation too! The improved downgrader is now available here.
Pre-DC 

With only a week to go before WWDC 2012 and the surprises Apple will announce there, today seems like a good time to release updates to our suite of free software to include the rocky-racoon jailbreak and untether developed by @pod2g and @planetbeing!  Today’s updates are:

  • PwnageTool 5.1.1
  • redsn0w 0.9.12b1
  • cinject 0.5.4 (version 0.5.3 also had rocky-racoon but this includes some updates)
  • ultrasn0w 1.2.7 (5.1.1 compatibility only - no new baseband support)

If you’ve already installed rocky-racoon, don’t bother reinstalling it unless you’ve had problems and would like to try a different tool.  The underlying untethered jailbreak (rocky-racoon) is identical to what is already installed by last week’s tools like Absinthe, cinject-0.5.3, and the rocky-racoon Cydia package — only the injection method offered by the above tools differs.

redsn0w allows owners of A4+earlier devices to install rocky-racoon two different ways:

  • backup/restore method similar to Absinthe and cinject
  • its traditional limera1n-based ramdisk install.  If you have a lot of media on your A4 device (music, movies, TV shows, etc), then the ramdisk method is preferrred because it avoids any possibility of later problems related to syncing to iCloud (including Photo Stream and Music Match).  The ramdisk method is not available for A5 devices or later because limera1n can’t be used.  If you’d like to use redsn0w’s ramdisk method, just be sure to put the A4 device in DFU or Recovery mode before starting redsn0w (otherwise it will immediately start to use the backup/restore method).

We’ve also added a new redsn0w feature specifically for those who got in on the SAM unlock: you can now include your SAM tickets as part of your initial ramdisk jailbreak of iPhone4 or earlier, or alternatively you can upload your SAM tickets to any device after its been jailbroken.  redsn0w accepts either the individual SAM activation ticket plist file, or the entire zip file created by redsn0w’s “Backup” button.  As usual, redsn0w continues to cover all of its previous jailbreaks and untethers (so redsn0w-0.9.12b1 covers everything from 5.1.1 all the way back to 4.1). 

PwnageTool also avoids any possible sync issues, but again it applies only to A4+earlier devices.  If you unlock your iPhone with ultrasn0w or a commercial method, you must use PwnageTool to avoid updating your baseband otherwise you’ll lose the unlock.  PwnageTool will also jailbreak+untether the AppleTV2,1 5.0_2B206f (unless you customize the IPSW further, you’ll have just basic SSH access to the device).

If you’d like to contribute to those that actually developed rocky-racoon, please visit here (any other links you may see are not going to the actual rocky-racoon developers, they’re being diverted to other “related” or fraudulent accounts).

This particular jailbreak brought an unusual amount of fanfare and hoopla to the table, including “press releases” and other haughty silliness.  We’d just like to take this opportunity to remind everyone that jailbreaking is about freedom, not fame and donations!

Here are the download links.  Please use our comment section below to give feedback.  Enjoy!

Update #1: Starting with version 0.9.12b2, redsn0w will now explicitly ask users with limera1n-able devices whether they want to inject rocky-racoon using the DFU ramdisk method or the backup/restore method (the ramdisk method is better for those with lots of media on their device that would create very large backups, and it’s required for those with unactivated iPhones).  If you’ll always want to use limera1n, you can select that in the Preferences pane.  It also fixes an iBooks issue on old-bootrom 3GS iPhones, and provides more useful error messages when things go wrong.

5x redux 

What’s old is new again!

Jailbreakers with devices that pre-date the iPad2 will always be able to downgrade (with SHSH blobs) to previous firmware versions due to geohot’s limera1n exploit, which allows us to bypass the restrictions that Apple places on restores.  But until now, that ability has been limited to those older devices (if you have an older device and don’t know how to do that, check the popular tutorial sites or ask in the comments below).

Starting with redsn0w version 0.9.11b1, those with newer devices (iPad2, iPad3, and iPhone4S) can join the downgrade fun too!  In a radical departure from previous versions of redsn0w, it now directly supports restoring IPSWs to your device.  The first use of this new feature implements a hack that allows A5 downgrades without a bootrom-level exploit.

Some important points:

  • The new feature is at Extras->Even More->Restore
  • You cannot downgrade without the personalized SHSH blobs for your device at that lower firmware.  You need to have fetched those blobs while the signing window was open, using either Cydia’s built-in TSS@Home feature, or with TinyUmbrella.  The new Restore screen of redsn0w lets you choose either the remote blobs or local ones (for the earlier firmware).  If you don’t know where TinyUmbrella put your blobs, TinyUmbrella has a button that will show you (copy them out of that folder and feed them to redsn0w).
  • The A5 downgrade method actually updates to the latest firmware before downgrading to the earlier one. This process updates your baseband to whatever is newest.  DO NOT USE THIS METHOD IF YOU RELY ON UNOFFICIAL UNLOCKS of your iPhone4S.  Those who used the temporary SAM technique to unlock their iPhones to specific SIMs shouldn’t be affected by this baseband update.
  • This method can be fixed by Apple with a firmware update.  It’s a (pleasant) mystery why they haven’t fixed it yet, because reverse-engineering of the restore ramdisk indicates they do know about it.  It’s possibly too niche to bother to fix right now.
  • The least-tested devices with this method are the iPad2,3 and iPad3,2 (because we don’t have those models).  If you do and you feel like experimenting, please let us know how it turns out in the comment section below!
  • This update involves a bunch of new redsn0w code.  We recommend sticking to the previous version 0.9.10b8b unless you’re specifically using this new feature, until all the bugs are worked out!  (Note: If redsn0w gets stuck at the “Waiting for device” stage for more than 30 seconds, you’ve hit a pesky GUI bug…that will be fixed in an upcoming version!)

Of course all eyes are on @pod2g for his upcoming 5.1 untethered jailbreak.  Watch his blog or twitter feed for the latest updates about that, but in the meantime if you accidentally updated your jailbroken A5 device to something later than 5.0.1, feel free to try this new A5 firmware downgrade feature of redsn0w!

Update #1: We accidentally left out one of the two flavors (“9A406”) of 5.0.1 for iPhone4S.  It’ll be in the next update, but in the meantime check if Cydia or TU saved your blobs for the other 5.0.1 for iPhone4S (“9A405”). Version 0.9.11b2 adds support for that second “9A406” flavor of 5.0.1 for the iPhone4S.

Update #2: Version 0.9.11b3 should fix the spurious “Restore failed” messages people were sometimes getting, and it behaves better with nearby devices that have wifi syncing enabled!

Update #3: Version 0.9.11b4 completes the tethered JB support for 5.1.1 on A4 devices and earlier, including proper “Stitching” and “Custom” creation of NO_BB IPSWs.

Here are the redns0w download links: