Recently, lot of my friends rely on me regarding iPhone stuffs. Therefore, please let me confirm my understanding below and please correct me if any is wrong.
3G OFFICIAL UNLOCK
JB:
4.0 (05.13.04)--> newest redsn0w
3.1.3 (05.12.01)--> redsn0w 0.9.4/spirit
3.1.2 (05.11.07)--> redsn0w 0.9.4/blackra1n/spirit
Downgrade:
current 4.0 --> to whichever firmware using fixed hosts file and iReb or iRecovery in order to kick out from Apple logo or recovery mode OR downgrade to whichever firmware that you kept SHSH on cydia (option+restore) in iTunes.
3G LOCK
JB+Unlock:
4.0 (05.13.04) --> newest redsn0w+ultrasn0w
3.1.3 (05.12.01) --> redsn0w 0.9.4/spirit+ultrasn0w
3.1.2 (05.11.07) --> blackra1n/spirit/redsn0w 0.9.4+ultrasn0w
Downgrade:
same as 3G OFFICIAL UNLOCK
3GS OFFICIAL UNLOCK NEW iBOOT
JB:
4.0 (05.13.04)--> NO DIRECT TOOLS YET (if you have SHSH on file, you can restore back to such SHSH firmware, jailbreak, BUT CANNOT restore by CFW 4.0 created by PwngeTool)
3.1.3 (05.12.01)--> SPIRIT
3.1.2 (05.11.07)--> SPIRIT/BLACKRA1N
Downgrade:
current 4.0 (05.13.04)--> able only if you have SHSH on cydia, fixing hosts file and GO!
3GS OFFICIAL UNLOCK OLD iBOOT
JB:
4.0 (05.13.04)--> NO DIRECT TOOLS YET (if you have SHSH on file, you can restore back to such SHSH firmware, jailbreak, AND CAN be restored by CFW 4.0 created by PwngeTool)
3.1.3+3.1.2--> same as New iBoot
Downgrade: same as New iBoot
3GS LOCK NEW iBOOT
JB+UNLOCK:
4.0 (05.13.04)--> NO DIRECT TOOLS YET (if you have SHSH on file, you can restore back to such SHSH firmware and jailbreak, BUT CANNOT restore by CFW 4.0 created by PwngeTool.
3.1.3--> Spirit+ultrasn0w
3.1.2--> Spirit/blackra1n (need to run it for every reboot) + ultrasn0w
Downgrade:
current 4.0 (05.13.04)--> able to downgrade if you kept SHSH on cydia, fixing hosts file and GO!
3GS LOCK OLD iBOOT
JB+UNLOCK:
4.0 (05.13.04)-->NO DIRECT TOOLS YET (if you have SHSH on file, you can restore back to such SHSH firmware and jailbreak, then CAN BE restored by CFW 4.0 created by PwngeTool.
3.1.3 Spirit+ultrasn0w
3.1.2 Spirit/blackra1n+ultrasn0w
Downgrade:
current 4.0 (05.13.04)--> able to downgrade if you kept SHSH on cydia, fixing hosts file and GO!
3G OFFICIAL UNLOCK
JB:
4.0 (05.13.04)--> newest redsn0w
3.1.3 (05.12.01)--> redsn0w 0.9.4/spirit
3.1.2 (05.11.07)--> redsn0w 0.9.4/blackra1n/spirit
Downgrade:
current 4.0 --> to whichever firmware using fixed hosts file and iReb or iRecovery in order to kick out from Apple logo or recovery mode OR downgrade to whichever firmware that you kept SHSH on cydia (option+restore) in iTunes.
3G LOCK
JB+Unlock:
4.0 (05.13.04) --> newest redsn0w+ultrasn0w
3.1.3 (05.12.01) --> redsn0w 0.9.4/spirit+ultrasn0w
3.1.2 (05.11.07) --> blackra1n/spirit/redsn0w 0.9.4+ultrasn0w
Downgrade:
same as 3G OFFICIAL UNLOCK
3GS OFFICIAL UNLOCK NEW iBOOT
JB:
4.0 (05.13.04)--> NO DIRECT TOOLS YET (if you have SHSH on file, you can restore back to such SHSH firmware, jailbreak, BUT CANNOT restore by CFW 4.0 created by PwngeTool)
3.1.3 (05.12.01)--> SPIRIT
3.1.2 (05.11.07)--> SPIRIT/BLACKRA1N
Downgrade:
current 4.0 (05.13.04)--> able only if you have SHSH on cydia, fixing hosts file and GO!
3GS OFFICIAL UNLOCK OLD iBOOT
JB:
4.0 (05.13.04)--> NO DIRECT TOOLS YET (if you have SHSH on file, you can restore back to such SHSH firmware, jailbreak, AND CAN be restored by CFW 4.0 created by PwngeTool)
3.1.3+3.1.2--> same as New iBoot
Downgrade: same as New iBoot
3GS LOCK NEW iBOOT
JB+UNLOCK:
4.0 (05.13.04)--> NO DIRECT TOOLS YET (if you have SHSH on file, you can restore back to such SHSH firmware and jailbreak, BUT CANNOT restore by CFW 4.0 created by PwngeTool.
3.1.3--> Spirit+ultrasn0w
3.1.2--> Spirit/blackra1n (need to run it for every reboot) + ultrasn0w
Downgrade:
current 4.0 (05.13.04)--> able to downgrade if you kept SHSH on cydia, fixing hosts file and GO!
3GS LOCK OLD iBOOT
JB+UNLOCK:
4.0 (05.13.04)-->NO DIRECT TOOLS YET (if you have SHSH on file, you can restore back to such SHSH firmware and jailbreak, then CAN BE restored by CFW 4.0 created by PwngeTool.
3.1.3 Spirit+ultrasn0w
3.1.2 Spirit/blackra1n+ultrasn0w
Downgrade:
current 4.0 (05.13.04)--> able to downgrade if you kept SHSH on cydia, fixing hosts file and GO!