Hi -

Noob here. I am looking to upgrade my unlocked/jailbroken iPhone 3GS (running 3.1.2 and 5.11.07), currently jailbroken using Blackra1n, to version 4.1 and then jailbreak/unlock it.

I've gone through the forums and done my searches, and as far as I can tell, I should:
- download Pwnage Tool 4.1.2 -- done
- download iPhone3,1_4.1_8B117_Restore.ipsw -- done
- run the Pwnage tool and follow the instructions to jailbreak the phone, and then install ultrasn0w via Cydia to unlock.

Is that all?

I have a few questions:

1/ Do I need to do anything with Tinyumbrella in order to prevent my baseband from being upgraded, or does the Pwnage tool 4.1.2 upgrade the firmware without touching the BB? I believe this to be the case, but just wanted to doublecheck.

2/ I dont have a SHSH certificate for 3.1.2 stored on my computer. Does that mean I am screwed in case I mess things up? Anything else I can do in order to back my iPhone up and try to restore to that state, or do I risk turning it into a brick if I screw up?

3/ I've read that Pwnage only works with old bootrom. I dont know if I have the older or newer one. I tried going into DFU mode but am unable to do so - every time I try to power on or connect the iPhone to my Mac, I get the "Connect to iTunes in order to verify the phone" screen and have to run Blackra1n. I tried using f0recast, and for the Untethered field, it says "Depends if it is refurbished". The phone was a present from a friend who bought it at a mall in Singapore, and I dont think even she knows if it is refurbished or not. So - any ideas? Olethros's post indicates that Pwnage will work with both old and new bootrooms.

4/ I dont have the original SIM that the phone came with. Is that needed? As far as I can tell, no, but want to confirm this nonetheless.

5/ Is 4.1 the best option or should I consider going with 4.2 or even 4.3? I'd like to avoid the battery-drain option, if possible.

6/ Anything else I am missing? Is this the best way for me to proceed or is there another, better/less-prone-to-mistakes/easier-to-reverse option out there?

Thanks for your help and I apologize for the noobiness of the questions.

Vandit

Originally Posted by vkalia

looking to upgrade my unlocked/jailbroken iPhone 3GS (running 3.1.2 and 5.11.07), currently jailbroken using Blackra1n, to version 4.1 and then jailbreak/unlock it.

I've gone through the forums and done my searches, and as far as I can tell, I should:
- download Pwnage Tool 4.1.2 -- done
- download iPhone3,1_4.1_8B117_Restore.ipsw -- done
- run the Pwnage tool and follow the instructions to jailbreak the phone, and then install ultrasn0w via Cydia to unlock.

Is that all?

Pretty much, you should answer NO when it asks you if you want to load the iPad baseband. If Pwnagetool asks you for the iPad IPSW - you have answered incorrectly and you should quit pwnagetool and start again.
I strongly recommend you install SAM to get legitimate activation and reduce the chance you will have poor battery life.

Originally Posted by vkalia

Do I need to do anything with Tinyumbrella in order to prevent my baseband from being upgraded, or does the Pwnage tool 4.1.2 upgrade the firmware without touching the BB? I believe this to be the case, but just wanted to doublecheck.

You are correct about the baseband - pwnagetool disables the command to upgrade baseband when it makes the custom IPSW.
However you need either TinyUmbrella or your hosts file set to point at Cydia/Saurik's server - this is because you require a SHSH to load iOS 4.1 and Apple has long since stopped allowing restores of iOS 4.1.

Originally Posted by vkalia

dont have a SHSH certificate for 3.1.2 stored on my computer. Does that mean I am screwed in case I mess things up? Anything else I can do in order to back my iPhone up and try to restore to that state, or do I risk turning it into a brick if I screw up?

Yes, you are operating without a safety net. You can never restore back to iOS 3.1.2 after you upgrade to iOS 4.x (because you lack a saved 3.1.2 SHSH)

Originally Posted by vkalia

I've read that Pwnage only works with old bootrom. I dont know if I have the older or newer one. I tried going into DFU mode but am unable to do so - every time I try to power on or connect the iPhone to my Mac, I get the "Connect to iTunes in order to verify the phone" screen and have to run Blackra1n. I tried using f0recast, and for the Untethered field, it says "Depends if it is refurbished". The phone was a present from a friend who bought it at a mall in Singapore, and I dont think even she knows if it is refurbished or not. So - any ideas? Olethros's post indicates that Pwnage will work with both old and new bootrooms.

Pwnagetool was limited to old bootrom only for iOS 3.1.2 through to iOS 4.0.2, then gehot released limera1n. The limera1n exploit has allowed Pwnagetool to support the new bootrom 3GS (but unless a compatible kernel exploit is available for the specific iOS version, you are limited to a tethered jailbreak).
Thanks to comex, there is a kernel exploit available for iOS 4.1, so pwnagetool can jailbreak iOS 4.1 on new bootrom 3GS untethered. From your description - it's 99.99% likely you have new bootrom 3GS. If you are restoring iOS 4.1 or 4.2.1 it doesn't matter (as they can both be jailbroken untethered with the correct Pwnagetool version)

Originally Posted by vkalia

I dont have the original SIM that the phone came with. Is that needed? As far as I can tell, no, but want to confirm this nonetheless.

No, but it can help with SAM activation (which I strongly recommend you use)

Originally Posted by vkalia

Is 4.1 the best option or should I consider going with 4.2 or even 4.3? I'd like to avoid the battery-drain option, if possible.

4.2.1 is equally fine, if you use SAM you should not get a battery drain.
Stay away from 4.3 it is not safe for unlockers yet. Plus it is a "tethered jailbreak" only for new bootrom devices.

Originally Posted by vkalia

Anything else I am missing? Is this the best way for me to proceed or is there another, better/less-prone-to-mistakes/easier-to-reverse option out there?

Pwnagetool custom IPSW are normally reversible, but as you lack a SHSH for your current iOS version, that can't be reversed.

Thanks, Olethros.

I have to admit I am in 2 minds as to whether or not to do this, or no. I dont want to brick up the phone for no reason (I have no real need to upgrade to 4.x). As soon as I summon up the courage, I'll give it a go, I suppose

Vandit