Although we didn’t get our hands on a new iPhone 3G yet, things are as expected: the iPhone 3G uses a new bootloader for its baseband modem as confirmed by Geohot.

Bootloader versions from the “old” iPhones

As far as we are aware the there are those 3 different bootloader versions known on old iPhones:

• 3.8 (very rare)
• 3.9 (iPhones before november 2007) and
• 4.6 (iPhones after november 2007).

It is widely known, that exploits for these old bootloaders have been found, that allow to SIM unlock any of these old iPhones. No matter which software revision is running.

No Unlock for iPhone 3G, but for old iPhones

For the new iPhone 3G bootloader, there is no (public) exploit known yet. Although the iPhone Dev Team states they can unlock firmware 2.0 – the unlock is most likely meant to work on “old” iPhones only. The only exploit yet known (in both old and new iPhones) is an iBoot bug. The iPhone Dev Team provided a video showing Pwnage Tool neutering the baseband for firmware 2.0:

Video: Pwnage Tool Bootneuter on firmware 2.0 (on an old iPhone)

Bootneuter 2.0 from iphonedev on Vimeo.

A new jailbreak for iPhone 3G and old iPhones

The Pwnage Tool 2.0 (and Geohot’s yiPhone) will most likely feature an iBoot bug to jailbreak old and new iPhones. iBoot is needed by iTunes to talk to when restoring firmware. About a year ago, Geohot found out that iBoot provides a full interactive shell. The only problem was, iBoot only allowed signed code to run. The iPhone Dev Team now managed to break the chain of trust from the earliest boot stage. Thus allowing to run unsigned code and in the end jailbreaking old and new iPhones (see video):

Video: Talking to iBoot unsigned

Talking to iBoot? from iphonedev on Vimeo.

Both videos are provided by iPhone Dev Team. Kudos to you guys.