The Dev Team have released an updated version of Redsn0w in order to support the recently released iOS 5 GM (Gold Master build). iOS 5 final version is going to be out next week on October 12, and this would be the last developer build from Apple.
Developers registered with either Standard or Enterprise program can right away update their firmware via OTA to iOS 5 GM. Or they could download iOS 5 from Apple’s servers.
Redsn0w 0.0.9b4, the latest version of the jailbreak tool for Mac and Windows, can automatically detect iOS 5 GM IPSW. It also adds the –r command line option for those who like to play with their own custom ram disks.
Note that the jailbreak is still tethered for all devices except the iPhone 3GS with an old bootrom.
So each time you reboot your device, you will have to boot your iDevice into tethered mode by using the ‘Just Boot tethered’ option of Redsn0w. Otherwise many jailbreak apps and even native ones like Mobile Safari will crash upon launching.
The iPhone hacker community is yet to come up with an untethered jailbreak for iOS 5. Recently, there have been confirmed reports of Chronic Dev Team’s involvement in a possible untethered exploit for iOS 5.
If you have already jailbroken iOS 5 GM by pointing an older version of Redsn0w (redsn0w 0.9.9b2 or redsn0w 0.9.9b3) to iOS 5 Beta 7 IPSW, there is no need go through the full jailbreak process. You can simply use the latest version of Redsn0w to make the tethered boot easier.
Windows users have a special goodie that comes packed with Redsn0w. If you make a copy of Redsn0w and name it as “justboot.exe” (or for that matter any name with a ‘boot’ in it), you can launch Redsn0w directly in the tethered boot mode skipping all those initial screens.