Upgrade unlocked jailbroken 3gs from 3.1.3 to 4.x?
I would like to upgrade my jailbroken and unlocked 3gs from 3.1.3 to 4.3.3 and again have it jailbroken and unlocked. I have my 4.x SHSH files, but not the 3.1.3 SHSH file, so I understand this will be irreversable, so I want to do it correctly.
I had received the phone with 3.1.3 after Apple stopped signing that version and did Spirit jailbreak followed by UltraSnow unlock. Modem firmware (baseband) is 05.12.01 and I suspect its new boot rom, but I am not sure and from what I am reading don't think it matters.
I am thinking I will do the following - would this be the right way to proceed?
1) Start my tiny umbrella TSS server so my 4.3.3 SHSH is available for use.
2) Run Pwnage Tool and create a custom firmware for 4.3.3. Make sure I do NOT check Enable baseband update in order to preserve my modem firmware. Load my custom firmware into the 3gs via iTunes using DFU mode. These steps are described at
I plan to use iTunes 10.2.2 and pwnage tool 4.3.3 on a Mac.
This will get me the jailbreak and my modem firmware will remain 05.12.01.
3) For the unlock, I should use UltraSnow, per these instructions, right?
iClarified - iPhone - How to Unlock the iPhone 4, 3GS, 3G Using UltraSn0w
One article suggested my existing unlock would survive step 2 and that I may not need to do this step.