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saurik's downgrade 3.1 to 3.0
- Thread starter Knique
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This is from his blog.
To this end, I have constructed a server that duplicates the functionality exposed by Apple's signature server, except using "on file" results rather than live requsests.
All we need, then, is to make iTunes use it. Luckily, most operating systems also have the ability to locally define bypasses on specific hostnames through a file called hosts. Using this, we can redirect requests to Apple's signature server to Cydia.
So, open the file C:\Windows\System32\drivers\etc\hosts (Windows) or /etc/hosts (Mac OS X) and add the following entry to the bottom of the file.
74.208.105.171 gs.apple.com
Now, when iTunes thinks it is talking to Apple, it is talking to Cydia instead. Doing this will allow iTunes to access signatures already stored by Cydia's "on file" feature.
This server will also act as a cache for any SHSH blobs it hasn't seen, acting as an intermediary to Apple's server. This effectively registers your device with the "on file" mechanism, which means you can now enjoy the protections of being able to downgrade your firmware in the future even if you aren't jailbroken.
This point should be stressed: even if you don't jailbreak, and even if you never intend to jailbreak, you should consider using the new "on file" service.
Let's say that Apple releases an OS upgrade in the future, you take it, and they break something important. Maybe they break your e-mail account, or your todo list. Your business is now crippled.
If only you could downgrade, right? Alas, Apple won't let you anymore. That's where the new signature cache server comes in: by doing your restores through this server you secure your ability to not accept upgrades from Apple if the need is dire.
Performing the Restore
Now, one would have hoped that the process would be as easy as "restore using the 3.0 IPSW". If only we were that lucky. The first problem is that a downgrade from 3.1 to 3.0 must be initiated in DFU mode.
So, we begin: hold down the lock and menu buttons (some call these the power and home buttons) for 10 seconds, letting go of the lock button but continuing to hold menu until iTunes recognizes the device with the message: "iTunes has detected an iPhone in recovery mode. You must restore this iPhone before it can be used with iTunes.".
Note that, at this point, your iPhone's screen should be entirely black. Many people confuse "DFU" with "recovery" (and in fact, iTunes itself glosses over this), but they are quite different. If you see anything on your screen, such as the iTunes logo and a sync cable, or a cartoon of Steve Jobs swearing in Cyrillic, you are in recovery mode and need to try again. One can find videos online that may help.
At this point, you should do a "normal" restore to the 3.0 software. When doing this, remember to hold down the option key (on Mac OS X) or the shift key (Windows) while clicking the Restore button in iTunes. Select the firmware (which is probably named iPhone2,1_3.0_7A341_Restore.ipsw), and things should be on their way.
To this end, I have constructed a server that duplicates the functionality exposed by Apple's signature server, except using "on file" results rather than live requsests.
All we need, then, is to make iTunes use it. Luckily, most operating systems also have the ability to locally define bypasses on specific hostnames through a file called hosts. Using this, we can redirect requests to Apple's signature server to Cydia.
So, open the file C:\Windows\System32\drivers\etc\hosts (Windows) or /etc/hosts (Mac OS X) and add the following entry to the bottom of the file.
74.208.105.171 gs.apple.com
Now, when iTunes thinks it is talking to Apple, it is talking to Cydia instead. Doing this will allow iTunes to access signatures already stored by Cydia's "on file" feature.
This server will also act as a cache for any SHSH blobs it hasn't seen, acting as an intermediary to Apple's server. This effectively registers your device with the "on file" mechanism, which means you can now enjoy the protections of being able to downgrade your firmware in the future even if you aren't jailbroken.
This point should be stressed: even if you don't jailbreak, and even if you never intend to jailbreak, you should consider using the new "on file" service.
Let's say that Apple releases an OS upgrade in the future, you take it, and they break something important. Maybe they break your e-mail account, or your todo list. Your business is now crippled.
If only you could downgrade, right? Alas, Apple won't let you anymore. That's where the new signature cache server comes in: by doing your restores through this server you secure your ability to not accept upgrades from Apple if the need is dire.
Performing the Restore
Now, one would have hoped that the process would be as easy as "restore using the 3.0 IPSW". If only we were that lucky. The first problem is that a downgrade from 3.1 to 3.0 must be initiated in DFU mode.
So, we begin: hold down the lock and menu buttons (some call these the power and home buttons) for 10 seconds, letting go of the lock button but continuing to hold menu until iTunes recognizes the device with the message: "iTunes has detected an iPhone in recovery mode. You must restore this iPhone before it can be used with iTunes.".
Note that, at this point, your iPhone's screen should be entirely black. Many people confuse "DFU" with "recovery" (and in fact, iTunes itself glosses over this), but they are quite different. If you see anything on your screen, such as the iTunes logo and a sync cable, or a cartoon of Steve Jobs swearing in Cyrillic, you are in recovery mode and need to try again. One can find videos online that may help.
At this point, you should do a "normal" restore to the 3.0 software. When doing this, remember to hold down the option key (on Mac OS X) or the shift key (Windows) while clicking the Restore button in iTunes. Select the firmware (which is probably named iPhone2,1_3.0_7A341_Restore.ipsw), and things should be on their way.
Has anyone tried this to confirm if it works or not?! I'm really excited about this as I've been needing to do a restore but don't want 3.1 as I still want to jailbreak.
ALSO, do you know if it works to do a plain restore from 3.0 jailbroken to 3.0 vanilla?
ALSO, do you know if it works to do a plain restore from 3.0 jailbroken to 3.0 vanilla?
missed that one
thanks if saurik posted this which it's his blog so no doubt he did saurik is very careful about what he blogs. I have no doubt if done correctly it will work!
thanks if saurik posted this which it's his blog so no doubt he did saurik is very careful about what he blogs. I have no doubt if done correctly it will work!
I've read through Saurik's blog, and I want to clarify one thing. I have a 3gs with 3.0.1 jb'd right now. To start this process, I'm going to have itunes running and therefore it is going to try an upgrade me to 3.1, but I am pointing to my 3.0 ipsw file, signing through Saurik's server. At the end of this will I have 3.1 firmware on my phone, but jailbroken??
Sorry for the stupid question. Just want to be sure before I dive in.
Sorry for the stupid question. Just want to be sure before I dive in.
No No No. Its only for people that were foolish enough( like me) to upgrade to 3.1 and want to go back so they can jailbreak 3.0.
It will only work if you registered your ECID with Cydia (clicked make it easy)
I will not jailbreak 3.1 it will only downgrade the 3GS
You are sitting right where you need to be. Be patient the 3.1 jailbreak will come soon enough.
It seems to be working.. 3GS user who clicked "make my life easier" on cydia on 3.0.1.. Keep in mind, you can only downgrade to 3.0, not 3.0.1. I'm not sure if you can upgrade to 3.0.1 after the downgrade, but all it is is a small SMS fix anyways 
No go for me!!!!
I did not store my backup files with Cydia. I'm stock until the 3.1 jailbreak is released. The pain of it all.
I did not store my backup files with Cydia. I'm stock until the 3.1 jailbreak is released. The pain of it all.
No! For that you must wait for PwnageTool from the Dev-Team. This is for people who accidentally upgraded to 3.1 or who have problems and need to restore 3.0.
Let me make this as clear as possible: many very smart people who are very knowledgeable and whom I trust when it comes to the iPhone have written that is is impossible to downgrade the baseband. You will need to accept this fact.
It seems to be working.. 3GS user who clicked "make my life easier" on cydia on 3.0.1.. Keep in mind, you can only downgrade to 3.0, not 3.0.1. I'm not sure if you can upgrade to 3.0.1 after the downgrade, but all it is is a small SMS fix anyways
This is true in most cases, but apparently some people who clicked "make my life easier" toward the end of the window will have both the 3.0 and 3.0.1 SHSH on file. Unfortunately, the only way to find out if you have 3.0.1 on file or not is to try to restore to 3.0.1.
i have no need to downgrade, but after reading saurik's blog, i am amazed at how he, the dev team, and other iphone hackers stay ahead of apple.
i mean, dude put up a server right before 3.1 came out if i remember to collect info needed. its like he knew apple finally figured out a way to really put a stop to unlocking and jailbreaking. like he has someone on the inside who sneaks little bits of info to him.
i may be wrong about that, but i love my jailbroken phone. and saurik, the dev team and others are extremely intelligent men/women
i mean, dude put up a server right before 3.1 came out if i remember to collect info needed. its like he knew apple finally figured out a way to really put a stop to unlocking and jailbreaking. like he has someone on the inside who sneaks little bits of info to him.
i may be wrong about that, but i love my jailbroken phone. and saurik, the dev team and others are extremely intelligent men/women
I don't find it annoying, I have learned way more about this OS, Terminal, etc. than had JBing not been available. I also don't upgrade each time Apple dangles a shiny update in front of me.
