Updating from 4.1 to 4.2.1: Preserve baseband with TinyUmbrella?

[AdamA9]

Guys,

Been reading around on here and the internet and getting conflicting views from people so thought I would ask the question directly here.

I have 4.1 on an iPhone 4. Using my iMac I want to update to 4.2.1 jailbreak and preserve my baseband, which is currently 01.59.00

I have TinyUmbrella and Greenpois0n waiting (but no 4.2.1 file). I have read that TinyUmbrella will let me keep my baseband, but I've also read that I cannot do this for 4.2.1 - what is correct?

Do I just need to follow these steps?

1. Save SHSH via TinyUmbrella
2. Download a 4.2.1 file from somewhere (anyone have a link?)

... then what? I'm not sure after this?

Thanks for your patience guys

 

[himni]

Download the correct ipsw from here

open TU save your SHSHs and click start TSS server

open iTunes with your iP4 connected and click restore while holding the cmd key (whatever it is called on an Apple keyboard it's shift for windows)

Select the file you downloaded and it will install it and you should save your BB.

TU has a walk through here


I have down this multiple times and it has worked for me every time. I updated from 4.0 to 4.1 and now 4.2.1 and still have my 4.0 BB. You have to Jail break after you do this I think because 4.2.1 has a minimum BB version requirement.

 

[studmule]

Himni is right. After you do the upgrade, your iphone will be in recovery mode, and tinyumbrella won't be able to kick it out. You have to use greenpois0n, put it in DFU mode and jailbreak it. This will also kick it out of recovery mode.

 

[hackthatphone]

Or just forget tinyumbrella and use pwnagetool to do this.

 

[Applejuiced]

Yep, since you're using a mac I'd just create a custom 4.2.1 with pwnage tool and restore to that.
Pefect tool.

 

[AdamA9]

Thanks guys.

Cannot find solid instructions online on the best way to JB with pwnage tool, and preserving my baseband. Is there a reliable place on the intertubes to look?

Thanks.

 

[dhlizard]

Himni is right. After you do the upgrade, your iphone will be in recovery mode, and tinyumbrella won't be able to kick it out. You have to use greenpois0n, put it in DFU mode and jailbreak it. This will also kick it out of recovery mode.

The TU Mac version has been updated to kick out of recovery on 4.2.1
Windoze version not available yet.

 

[Applejuiced]

Thanks guys.

Cannot find solid instructions online on the best way to JB with pwnage tool, and preserving my baseband. Is there a reliable place on the intertubes to look?

Thanks.

http://www.iclarified.com/entry/index.php?enid=13925