Upgrade from 3.1.3 to 4.1?

[acer34e]

I have an iPhone 3GS that is Jailbroken and Unlocked running firmware 3.1.3. I want to upgrade to firmware 4.1 because it is the latest firmware that can be Jailbroken untethered (I have the new bootrom) and Unlocked (definitely need this for t-mobile).

My question is can I upgrade directly to the 4.1 firmware or do i have to upgrade to 4.2.1 and then downgrade? I haven't used TinyUmbrella to download my SHSH blob yet, but at the top of Cydia it says

SHSH: iOS 4.0, 4.0.1, 4.0.2, 4.1

What would be the best way to do this? Thank you for your help!

[NinjaBaby]

Download the new firmware you want (ill post a link in a sec)
put it in DFU mode
it'll restore with the new firmware on it
do the jailbreak/unlocking proccess again with the program you use!

Thats what I did with my friends iPhone )



HOW TO PUT YOUR IPHONE IN DFU MODE
Step One
Open iTunes and connect the iPhone to your Mac.


Step Two
Press and hold the Home button and the Sleep/Wake button at the same time.


Step Three
After exactly 10 seconds release the Sleep/Wake button. Continue holding the home button until you iTunes pops up a message telling you that it has detected an iPhone in recovery mode.


The iPhone screen will remain black like this:


NOTE***: It may take a few attempts to get your iPhone into DFU mode. Generally, I hold down both buttons then release the Home button just before I think the Apple logo would appear. If you are still holding both buttons down and you see the Apple logo you are holding them down for too long!


FROM: iClarified - iPhone - How to Put an iPhone Into DFU Mode

[acer34e]

Thanks NinjaBaby! Can't wait to finally run a firmware above 4. I'll be really happy when 4.2.1 becomes an untethered jailbreak!

[Simon]

If you want to keep the ability to unlock then you need to use a custom firmware to preserve your baseband. You can make one with either pwnage tool or snowbreeze then restore to that in itunes. before restoring get the latest tiny umbrella, open it once then close it (this sets your hosts to cydia so that the restore will go through since you arent going to 4.2.1).

[mike_smith]

Sorry misinformed

[Simon]

1. Download official ios 4.1 and latest Tiny Umbrella.
2. Close itunes if it's open.
3. Then open Tiny Umbrella and click "Save SHSH".
4. Then click "Start TSS Server" in Tiny Umbrella.
4. Then Open itunes and hold shift and click restore.
5. Browse to official ios 4.1 and click open. Accept confirmation message.
6. Once its done you will get the expected error of 1004 in itunes (means baseband upgrade failed).

Now in Tiny Umbrella click exit recovery. Thats it. Now jailbreak with GreenPois0n and unlock with Ultrasn0w 1.2

This method only works on iPhone 4 not 3GS. A custom firmware is needed for a 3GS to preserve baseband.

[mike_smith]

Thanks for the correction x98car

[Simon]

It can be used to restore but not preserve baseband. If he were to follow that his baseband would still be updated.

[acer34e]

Thanks mike_smith and x98car. So tonight I'll download the latest TU and run it. Then I'll download the custom firmware ad use that to upgrade so I preserve the firmware. I think I saw some the firmware on JailbreakMatrix. Would I just use one of theirs or are there extra steps I need to take? I've been backing up all of my data today. Can't wait!

[Simon]

You should probably just make your own custom firmware with pwnage tool or sn0wbreeze.

Here are tutorials: Mac: iClarified - iPhone - How to Jailbreak Your iPhone 3GS Using PwnageTool (Mac) [4.1]
Windows: HOW TO: Jailbreak iOS 4.1 with Sn0wbreeze 2.1

[acer34e]

One quick question to add: I bought my phone from an Apple Store unattached to any phone plans and then jailbroke and unlocked it to use a T-Mobile card. Do i need to use the hacktivate option when using sn0wbreeze?

[Simon]

If you have a ATT sim (even a non active one) then you should use that to activate.

[acer34e]

I took out the non-active ATT sim card and there is now a T-Mobile Sim card in there. Do i still use the hactivate or just the normal activate?

[Simon]

If you say you have a ATT sim then choose not to activate when making the custom firmware. Put the ATT sim in during the restore process and let itunes activate it after the restore. Doing this will help with battery life and your push notifications should work properly. Hactivating can break them.