Am I about to do this right? 3GS 3.1.2 -4.1 and then jailbreak/unlock
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.