i have a CDMA 4.0 iphone running 4.2.8(8E401). I JB using jailbreakme.com and has been working fine.

i want to upg to JB 5.0.1 untethered but i'm not sure the steps to get to 'square 1'.

instructions say "if you haven't upgraded to 5.0.1, do it". but, i'm not sure what that means. do i just go to itunes and upgrade to 5.0.1? i'm used to the old days of JB/unlock where if you upgraded your firmware/OS you bricked your phone.

in brief, someone please tell me what i need to do to get to 5.0.1 to start the JB process from a previously JB 4.2.8 phone. if it really is just 'go to itunes and upgrade', i'd appreciate the confirmation. if i need to restore/upgrade, or some other secret handshake, please let me know.

thanks.

If you're not unlocking:

1) Use iTunes to restore to iOS 5.0.1 directly.
2) Use redsn0w to jailbreak iOS 5.0.1 on the device.

If you're unlocking or want to block the baseband update even if you're not unlocking:

1) Use PwnageTool/redsn0w to create a No_BB iOS 5.0.1 firmware (baseband stripped firmware).
2) Use redsn0w/iReb to put the phone into 'Pwned DFU' mode.
3) Shift-Restore the No_BB firmware to your device in iTunes.

You're correct, this is a departure from previous iOS revisions where restoring a stock firmware took you off the jailbreak train. Since the latest iOS is susceptible to multiple userland exploits and the iPhone 4 has a hardware level bootrom exploit, it's not necessary (at present) to restore only to a jailbroken firmware. It's still possible though, so if you prefer this route, use redsn0w to create the custom firmware as opposed to upgrading first.

Make sure you're aware that redsn0w will NOT actually flash the iOS revision on to the phone, you MUST do that in iTunes after creating the .IPSW.

thanks. sounds much easier now

finally got around to trying it. upgraded to 5.0.1. launched redsn0w, entered DFU, waiting for reboot :-(

the phone is not locked in DFU or anything, the phone just reboots back to normal (non-JB). redsn0w is just stuck at 'waiting'. any idea what's going on?

nm...had to go in to extras and hand-pick the IPSW. no problemo after that.