Ich verstehe nicht, wieso hier alle sagen, es ginge weder der Downgrade vom iPad 2 von 6.x auf 5.x noch ein Restore von 5.x.x auf eine andere 5.x.x!?
Mit redsn0w 0.9.15b3 geht BEIDES.
Voraussetzungen sind allerdings:
Für den iPad 2 Downgrade von iOS 6 auf iOS 5:
1. Das iPad 2 darf NICHT via OTA geupdated worden sein (Stichwort APTicket)
2. Es müssen sowohl 4.x als auch 5.x Blobs vorhanden sein (nur 5.x Blobs reichen NICHT; wer nur 4.x Blobs hat kann aber immernoch auf iOS 4 zurück)
Für den Re-restore von iOS 5.x.x auf iOS 5.x.x:
1. Das iPad 2 darf NICHT via OTA geupdated worden sein (Stichwort APTicket)
2. Es müssen die entsprechenden 5.x.x Blobs vorhanden sein, auf welche man Wiederherstellen will.
Und damit niemand nach der Quelle für meine Aussagen fragen muss hier die entsprechenden Stellen des Blogs vom iPhone Dev Team, die das besagen:
iPhone Dev Team schrieb:1. redsn0w now lets you restore an A5+ device from any iOS5 to any other iOS5 as long as you have correct 5.x blobs for the starting (current) and ending points of the restore
APtickets eliminated “higher-version only” comparison of firmware restores (just like BBtickets did for the baseband)
example restores supported by redsn0w if you have the correct blobs: 5.1.1-to-5.0.1, 5.0.1-to-5.1.1, 5.1.1-to-5.1.1, 5.0.1-to-5.0.1
if you don’t have the blobs locally, let redsn0w try to fetch them remotely (redsn0w always tries both Apple and Cydia). Any succesful remote fetch also saves a local copy too.
2. You DO NOT QUALIFY for iOS5-to-iOS5 restores if you got to your current 5.x via an OTA update
the tickets saved by Cydia, redsn0w, and TinyUmbrella do not cover OTA update ramdisk images
even if they did, it’s the “wrong kind” of ramdisk (you’d need to start at that earlier pre-OTA FW)
devices fresh from factory or refurb may fall in the “does not qualify” category (your results will vary)
it’s okay if you previously got to 5.x via an OTA update, as long as your current 5.x was installed via a normal iTunes restore. All that matters is how you got to your current 5.x most recently
redsn0w detects an OTA/normal-restore APticket mismatch very early, so if you don’t know your status there should be no harm in trying. Any device in recovery mode after such a mismatch can boot normally again just by going back to “Even More” screen from the “Restore” screen (or use “Recovery Fix” if you quit redsn0w before doing that).
[...]
4. iPad2 owners (all three models) with saved 4.x blobs can use those instead, even from 6.x
if you have both 4.x and 5.x iPad2 blobs, you can always get to 5.x via the 4.x blobs, even if you’re currently on 6.x
you cannot get to 5.x from 6.x without the 4.x blobs (but you may still qualify for the iOS5-to-iOS5 restore described above)
if somehow you have 4.x blobs but no 5.x blobs, you can still go down to 4.x from 6.x
this only applies to iPad2 owners (they’re the only A5+ devices that ever had a public 4.x FW)
redsn0w still supports (but doesn’t require) jailbreaking A5+ devices at 5.0.1 and 5.1.1. Just head back to the first page after re-restoring to 5.x. It’s always much faster to jailbreak those FW versions with a freshly-restored device, before letting iTunes restore from a saved userland backup.
Quelle:
http://blog.iphone-dev.org
Sprich ne saubere Wiederherstellung auf/innerhalt der gleichen Firmware!
