for people stuck on emergency screen (despite GreenPois0n jailbreak attempt!)
3GS locked and not jailbroken.
Baseband 05.15.04
firmware 4.2.1
bootloader 6.4
Model MC131
I understand that i can't activate it at this time (RIGHT?) but i'm at least trying to jailbreak it.
I've tried 3 times now and it seems to work fine, but when the iphone reboots back up (after showing the file download, GreenPois0n logo etc) it's still stuck on the emergency screen.
In itunes the only option available is to eject.
You don't have to stay away from 4.2.1, using redsn0w only to put your iphone into DFU mode and then restore your iphone to custom firmware of 4.2.1 will get you to IOS 4.2.1 while preserving your baseband to be unlockable.