Downgrade from 4.1 beta 3 to 4.0.1; saving my backup

[funrush]

Hi I updated to 4.1 beta 3 last week. All worked great, but I really miss the jailbreak features so I would like to downgrade to 4.0.1 to be able to jailbreak my phone again. When I do and I restore to a backup I made using firmware 4.1 beta3 iTunes says the backup is not compatible with this old firmware version.

Is there a way to make the 4.1 backup work with 4.0.1?

Thanks

 

[impulse462]

Unless you have your 4.0.1 SHSH blobs saved, you're out of luck.

And no i don't think older firmwares work with newer firmwares back ups, but i'm not sure however.

 

[funrush]

Unless you have your 4.0.1 SHSH blobs saved, you're out of luck.

And no i don't think older firmwares work with newer firmwares back ups, but i'm not sure however.

The downgrade was successful. Do I need these 'blobs' to make the backup work? Or to make the downgrade work?

Is there a way to make iTunes believe that it is a 4.0.1 backup (by editing some .plist file)

 

[impulse462]

The downgrade was successful. Do I need these 'blobs' to make the backup work? Or to make the downgrade work?

Is there a way to make iTunes believe that it is a 4.0.1 backup (by editing some .plist file)

Not really sure how the downgrade was successful considering the different basebands, but if what you say is true, just set up as a new phone and then sync.

I'm pretty sure New firmware backups will not work with older firmware, however anyone is free to correct me here. SHSH blobs are purely for downgrading and they have no effect on whether you can trick back-ups or not.

 

[Applejuiced]

No, you cant make that backup compatible with older firmware.
If you dont have any previous backups saved up then only thing you can do is wait for 4.1 to be out officially and then restore to that backup.

Not really sure how the downgrade was successful considering the different basebands, but if what you say is true, just set up as a new phone and then sync.

It works.
You can downgrade to older firmware with a newer baseband.
People do it all the time to JB and unlock their iphones.

 

[funrush]

Not really sure how the downgrade was successful considering the different basebands, but if what you say is true, just set up as a new phone and then sync.

I'm pretty sure New firmware backups will not work with older firmware, however anyone is free to correct me here. SHSH blobs are purely for downgrading and they have no effect on whether you can trick back-ups or not.

Hi. I downgraded to 3.1.2 first, I got a 1604 or 1004 warning or something. I used iRecovery to get it out of this 'restore mode loop'. That worked and got the clean 3.1.2 to work. Then iTunes failed to put the newer back-up on the 3.1.2 firmware so I upgraded to 4.0.1. That firmware was also incompatible with the 4.1 backup. Now I'm back to 4.1 and it works good but I can't jailbreak this firmware version...

I never even heard of these 'blobs', what's that?

 

[impulse462]

No, you cant make that backup compatible with older firmware.
If you dont have any previous backups saved up then only thing you can do is wait for 4.1 to be out officially and then restore to that backup.



It works.
You can downgrade to older firmware with a newer baseband.
People do it all the time to JB and unlock their iphones.

I mean I know that's possible, I've done that. But I always had to run blackrain or redsnow.

Example would be I upgraded my 3gs to 4.0 GM, but I downgraded to 3.1.2 to use pwnage tool. I was running 5.13.04 with 3.1.2, but to access my springboard i had to run blackrain again. Unless I can just use something to kick it out of recovery mode?

Just an observation though.

 

[Applejuiced]

I mean I know that's possible, I've done that. But I always had to run blackrain or redsnow.

Example would be I upgraded my 3gs to 4.0 GM, but I downgraded to 3.1.2 to use pwnage tool. I was running 5.13.04 with 3.1.2, but to access my springboard i had to run blackrain again. Unless I can just use something to kick it out of recovery mode?

Just an observation though.

Yep, you will need a program to kick it out of recovery mode.
Recboot or tinyumbrella would work also.

 

[Mikey B]

I mean I know that's possible, I've done that. But I always had to run blackrain or redsnow.

Example would be I upgraded my 3gs to 4.0 GM, but I downgraded to 3.1.2 to use pwnage tool. I was running 5.13.04 with 3.1.2, but to access my springboard i had to run blackrain again. Unless I can just use something to kick it out of recovery mode?

Just an observation though.

I'm confused. Here you say you knew it was possible to downgrade without your SHSH's on file, but earlier you said the OP was out of luck. But yes, you need another program to kick it out of recovery mode.

OP: The "blobs" or SHSH blob, or ECID BLOB are different names for the same thing. Basically it's a unique identifier specific to each firmware release that is used to authenticate the firmware by Apple's servers when restoring an iPhone.

You save the blobs and upload them to Saurik's severs to bypass this signing process and get an older version of iOS on your device. iTunes, instead of looking to Apple's servers for the signature, looks at Saurik's.

Here's a good step by step I found:
1. Download iOS 4.0 firmware file.

2. Connect your iPhone/iPod touch to computer

3. Start iTunes 9.2 and Windows (Alt Key+ Click Restore) Mac (Hold Option + Click Restore), Now manually select iOS 4.0 firmware.

4. During the restore process you will get an 1015 error. Don’t worry, that’s normal. Just click on Ok and close iTunes.

5. Download iRecovery [Mac | Windows]

6. open terminal on Mac (or Command Prompt on Windows) and type following commands
cd Desktop
. / iRecovery -s
setenv auto-boot true
saveenv
fsboot
exit





7. Now unplug your iPhone and turn it off by pressing the home+power button.

8. Turn it on now by pressing the power button. Plug-in your iDevice and load iTunes to continue with activation.

Your iPhone 3G should now be downgraded to iOS 4.0. iPhone 3GS users can downgrade to iOS 4.0 only if you had saved your ECID files of earlier version.

Disclaimer: This guide is for educative purposes only. Do it at your own risk. We are not responsible for any damage that may arise.

[via]Blogsdna

 

[impulse462]

@Mikey

I know you have to have your SHSH's on file. When I downgraded my 3GS I had my SHSH's on file.

Sorry if I didn't mention that.




I was referring to the fact that I knew you could run older firmware with a newer baseband as I've done that before