http://www.iphoneatlas.com/2008/03/1...ng-the-iphone/

solution has been released for the iPhone, allowing users to boot multiple iPhone OS versions (e.g. 1.1.1 and 1.1.4) from the same device. This capability may come in handy when a future, SDK-compliant iPhone OS release (2.0) is released and users with to maintain compatibility with old “jailbreak” applications while taking advantage of enhancements in the new release.

humm this is very nice. or would be very nice.
but what about more infos?

yes...there's a guide...

http://www.zdziarski.com/papers/dualboot.txt

iPhone 1.1.x Dual Boot / Jailbreak
Brought to you by NerveGas, planetbeing, ghost_000, dinopio, bgm, MuscleNerd
and the iPhone-Elite and iPhone/iTouch Dev teams.

good info but in wrong section of forum. I'll move it to general section

WoW


So this sound like the way the Dev have gained access to 1.2fw so fast.

Nice work

We've also put the doc up on the Dev Team wiki with a link back to this thread to discuss the technique.

Initially this was solely a jailbreak method but it's actually pretty useful to just be able to dual-boot anyway

DevTeam..... now u r talking! Thats great! Great news!

Originally Posted by MuscleNerd

One very very nice thing about the s5l CPU boot sequence in the iPhone/iPod Touch (as opposed to the S-Gold CPU boot sequence in the iPhone) is that it is always recoverable, even when it doesn't look like it DFU restore is very powerful, even when playing around with filesystem partitions.

A true DFU restore will unjam you and you'll be left with fresh system. If you want instead to debug your current situation and not simply get your device working again, you can try setting your boot-partition to 0 and your boot-args to simply -v (and then the obligatory auto-boot true and cmd saveenv)

That being said, IRC is probably a more suitable/interactive place to debug your particular situation.

MuscleNerd, thanks a bunch for this info - I'll look into this tomorrow.

Sunny, I really don't want to argue about this here. But you know that is exaggerated and inaccurate. I didn't say I hated the dev team, I said I didn't like certain members. And... Well... I said I wouldn't get into this...

Law, I hope you and others can trust me and others who supported zibri early on...

On a purely technical level if there's a problem or ambiguity with the steps on the wiki, it should be cleared up I'll walk through the steps on a freshly restored 16GB iPod Touch again and try to find such an issue.

so someone told me i can find out about dual booting an iphone in this thread