I need something clearing up...

I've always been under the impression that the 3GS cannot be untethered on 3.1.3 without pwnage - however, I've since read and been told that the bootrom is hard-coded and cannot be upgraded with a firmware update...so...

I'm currently on 3.1.2 JB, with SHSH's stored on Cydia... Can I..

Update to standard 3.1.3 (Officially unlocked so no worries about baseband) and then get an untethered JB using redsn0w 0.9.4?

If not, can I using a custom 3.1.3 with Pwnage...?

Thanks!

Originally Posted by philstone

I've always been under the impression that the 3GS cannot be untethered on 3.1.3 without pwnage - however, I've since read and been told that the bootrom is hard-coded and cannot be upgraded with a firmware update...so...

You misunderstand this. The tethered/untethered thing is not currently an issue with 3.1.3

This is because people who were tethered jailbreak on 3.1.2 can't upgrade or restore to 3.1.3 and manage to jailbreak at all with the tools available today.

Originally Posted by philstone

I'm currently on 3.1.2 JB, with SHSH's stored on Cydia... Can I..

Update to standard 3.1.3 (Officially unlocked so no worries about baseband) and then get an untethered JB using redsn0w 0.9.4?

No there is no currently released tool that can directly jailbreak a 3.1.3 3GS

You need to start from 3.1.2 (preferably jailbroken) and restore pwnagetool custom IPSW

Originally Posted by philstone

If not, can I using a custom 3.1.3 with Pwnage...?

Yes restore pwnagetool 3.1.3 (from jailbroken 3.1.2) - this will not upgrade your baseband but you will have an untethered jailbreak for 3.1.3

or

upgrade to official 3.1.3, then downgrade to 3.1.2 (with your saved SHSH) and then restore to pwnagetool 3.1.3 (this will upgrade your baseband and give you an untethered jailbreak)

Excellent, thanks! Going to go with the latter option - 3.1.3 upgrade on its way...

Cheers!

Originally Posted by Olethros

You misunderstand this. The tethered/untethered thing is not currently an issue with 3.1.3

So this is tied to the new bootrom, which naturally is only available on the 3.1.3, right?

Originally Posted by philstone

So this is tied to the new bootrom, which naturally is only available on the 3.1.3, right?

The tethered/untethered factor is tied to the bootrom version and what exploits are available for that bootrom version.

The bootrom version is determined at the factory when the iPhone is made and cannot be changed.

Today because the new bootrom blocked the 24kpwn bootrom exploit, no-one with new bootrom can jailbreak 3.1.3 (at all) so as a result there is no "tethered jailbreak" for 3.1.3. Only old bootrom iPhones can jailbreak 3.1.3 (via custom IPSW) and they use 24kpwn exploit to make this an untethered jailbreak.

Soon Spirit will be released, it will support 3.1.3 (it won't work if you are stuck at the connect to iTunes to activate screen) and it somehow allows untethered jailbreak on all devices currently on sale (including the iPad and new bootrom 3GS)