Confusion on Updating/UL/JB 3GS (OS 3.1 / FW 05.11.07)

[djverbal]

First off, I realize this is probably a rediculously obvious question...so thank you for understanding!

Today, I picked up a 3gs iPhone from a friend. It is not jailbroken or unlocked, and I would like to do both. My confusion is how do I upgrade and unlock/jailbreak in since it is still running OS 3.1 (7C144) and firmware 05.11.07 ?

Obviously, I want to avoid updating the firmware, but am looking for the best way to upgrade to 4.2.1, unlock and jailbreak.

Thanks in advance for your help!!

[iYeow]

Itunes 9.2 to 10
Download tiny umbrella > plug it in > click save shsh. ( you only have 4.2.1 shsh blobs, if you have anything lower, you are very lucky )
Download redsn0w 0.9.4 and download 3.1.2 ipsw for 3gs
Jailbreak your 3.1 with Redsn0w.
Now you are jailbroken at 3.1
Download Snowbreeze 2.1 and download 3gs 4.1 ipsw
Build your custom firmware of 4.1 , use expert mode and uncheck activate my iphone.
Once created , it will be placed on your desktop.
Put your iphone into recovery mode.
Open up itunes : Shift + restore to the custom fw of 4.1
Now you are jailbroken at 4.1
Unlock with Ultrasn0w from Cydia.

DO IT VERY CAREFULLY AND FOLLOW STEP BY STEP

[djverbal]

It worked great up until I tried to restore to the custom fw of 4.1
At that point, it prepares it in iTunes, then tries to verify it with apple and errors out to: "The iPhone could not be restored. An unknown error occurred (3194)"

Any thoughts?

[iYeow]

Is your iphone back to Home screen.

Are you restoring to custom firmware ?

When you run tiny umbrella, what shsh blobs can you download from Cydia.

[Mes]

iTunes Errors - The iPhone Wiki

Do you have SHSH blobs for 4.1?

[iYeow]

iTunes Errors - The iPhone Wiki

Do you have SHSH blobs for 4.1?

I am quite sure he doesn't have 4.1 shsh blob but what i am trying to do is to use the iboot exploit to see if it can bypass shsh verification.

He has the old bootrom too.

Try putting your jailbroken iphone into dfu mode and restore to custom fw of 4.1.
You can always get out of DFU mode by holding both buttons until it reboots.
You can kick out your recovery mode by using Exit recovery from the feature of tiny umbrella.

[djverbal]

Is your iphone back to Home screen. No, it's still in recovery mode

Are you restoring to custom firmware ? Yes, the one I made from sn0breeze

When you run tiny umbrella, what shsh blobs can you download from Cydia.
3GS 4.2.1(8C148A)-3275618418165 That's the one listed in tiny umbrella

[iYeow]

Use Exit recovery to kick it out, you will be back to home screen.
Put your iphone into dfu mode and try and restore again.

DFU mode : Plug your iphone in > Hold both buttons for 10 secs, then release the Power button but keep holding the Home button until you hear a beep on your pc,the screen is Black.

[Mes]

...

Yes sir

Q: Does this only work for old-bootrom?

[iYeow]

If this doesn't work, then you cannot go to IOS 4.xx for the moment. But you can build a custom firmware of 3.1.3 from Snowbreeze 1.5.2.
Put your iphone into recovery/dfu mode and shift + restore to cfw of 3.1.3.
If this still doesn't work, then stay at 3.1 for now and install only minimum stuffs from Cydia to avoid your iphone from crashing. If your iphone crashes, you have no way of restoring but to go to 4.2.1 which locks up your iphone.

[djverbal]

No luck restoring when in either DFU or Recovery mode.

Is there a chance that you cannot upgrade to 4.1 while preserving baseband?

Thanks for all of the help everyone!