Friday, June 25, 2010

How to find bootrom version of iphone 3GS (new bootrom or old bootrom)

When the hackers released the pwnage(v4.0/4.0.1) jailbreak tool for iOS4, it is mentioned that the 3GS phones with the latest bootrom (iBoot-359.3.2) cannot be jailbroken. Only the old bootroom (iBoot-359.3) can be unlocked for now. So, now the big question is how to find which bootrom does your 3GS phone have.

The iphone week number will help as a thumb rule to find if your 3GS iphone is having old or new bootrom. The 4th and 5th digits of the serial number will tell the week number of the phone. If your iphone week number is <40, then you will definitely have old bootrom. If the week number is >45 then you will definitely have new bootrom. In between, we cannot say for sure.

The sure shot method to determine the bootrom is to use some tool like 'usbview' after putting the iphone in DFU mode (Connect your iPhone to iTunes, turn off, click power+home button for 10 seconds, leave POWER button after 10 seconds, holding HOME button). After putting the phone in DFU you can follow one of the following methods.

method-1
- put the phone in DFU mode
- run the application usbview
- check "config descriptors" and refresh
- in the left panel, click Apple USB device
- in the right panel, find an entry which reads iBoot 359.x.x

method-2
- put the phone in DFU mode
- In windows, got to Start > Control Panel > System > Hardware > Device Manager
- Find "Universal Serial Bus (USB) Controller" and go to Apple Mobile Device USB Driver.
- Right click and choose properties and go to details
- Select device instance path
- The end of the info string will tell the bootrom version

method-3
See this link to find one more method using forecast(f0recast) tool. This tool will give the final summary if your 3GS phone can be jailbreakable, unlockable. Note that this tool is not yet updated to give suggestions for iOS4. It can accurately tell if your 3GS phone is jailbreakable, unlockable only till 3.1.3 firmware.

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