The iPhone Dev-Team released RedSn0w 0.9.14b2 with improved algorithm for baseband downgrade from the iPad’s 06.15 baseband to 05.13 on the iPhone 3GS and iPhone 3G. The 06.15 baseband was used by many users to unlock their device. Now it is possible to to get back true GPS and an ultrasn0w unlock.
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.
The revised steps are:
Connect your iPhone in normal mode, then click “Jailbreak” after redsn0w identifies its model and BB version (you needn’t pre-select the IPSW anymore).
Choose the “Downgrade from iPad baseband” option (you needn’t worry about de-selecting Cydia anymore).
Do a controlled “slide to power off” shutdown of your phone and 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!
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”.
The iPhone Dev-Team released RedSn0w 0.9.14b1 that can perform a baseband downgrade from the iPad’s 06.15 baseband to 05.13 on the iPhone 3GS and iPhone 3G. The 06.15 baseband was used by many users to unlock their device. Now it is possible to to get back true GPS and an ultrasn0w unlock.
iPhone Dev-Team released RedSn0w 0.9.9b9 with full iOS 5.0.1 support (no need to point to iOS 5.0 any more). New version also features support for SHSH and APTickets:
native support for 5.0.1 (no need to point redsn0w at 5.0 IPSW or use command-line args). Support automatically extends to all of redsn0w’s various functions: “Jailbreak”, “Just boot”, “Fetch blobs”, “Stitch blobs”, “Recovery Fix”
iBooks fixed in 5.0 and 5.0.1. This is a targeted fix that doesn’t remove entire sandbox mechanism. 5.x users already using redsn0w “Just Boot” can just use the new version without redoing entire jailbreak again
3GS old-bootrom owners can now create custom IPSWs without blobs
ultrasn0w compatability update (i.e. same baseband requirements) for 5.0.1 will be available on Cydia Monday
support for newer 8GB iPhone4 (which until now had problems with “Fetch blobs”). Thanks to @JKjeepnJeff for loaning us one of these newer i4 units for testing!
allows Windows users (not just OS X users) to use the “Custom” button to create IPSWs without baseband updates. (Update: please wait for 0.9.9b9b for this!)
accommodates APTickets in 5.x (until next Apple countermove). APTickets are crypto-verified before submitting to Cydia, just like the main blobs. Cydia server support for sending back the APTickets is upcoming. For now, use stitched IPSWs for 5.x. Due to APTickets, stitched 5.x IPSWs now require user to start in “Pwned DFU” mode
Support added for stitching 4.x blobs to iPad2-GSM IPSWs. Similar to @notcom’s TinyCFW but doesn’t require lots of RAM or a TSS-assisted restore. Won’t work for iPad2 5.x blobs (or iPhone4S at all) until a bootrom-level exploit is out
top line now shows whether (and where) a redsn0w update is available, or if the version being run is the latest. Uses DNS TXT record to alleviate any concerns about snooping
no 5.1 beta support at this time (major apps like Cydia are not yet compatible)
@pod2g has been doing a great job porting his 5.x untether…check his blog for updates!
Owners of newer 3GS iPhones must not flash the iPad baseband. The iPad baseband will not work on 3GS iPhones built later than 2011 week 35. You have a week 35 or later device if your serial # starts with xx135.
Update #17b: Version 0.9.9b9b enables the “Custom” button for Windows users, and make the 3GS week 35 warning a more explicit part of the process.