How far can I go with 2g iphone and keep the unlock?

[s8lam2000]

Hi, I'm a new member but have been reading these forums for a while.

I have been searching for a long time now for a definitive answer, so far I have only found sketchy info.

So, the big question is, what version firmware can my 2g iphone be upgraded to keeping the unlock, and how (exactly, I'm no expert) do I go about it?

2g 8gig iphone
Firmware: 3.1.2 (7D11)
Model: MB213B
Modem firmware: 04.05.04_G
PC: Windows 7

I have downloaded the latest version of ipsw I can find which is iPhone1,1_3.1.3_7E18_Restore.ipsw (googled jailbroken ipsw) but would prefer a link to a known firmware if required.

The phone was unlocked years ago using Ziphone, and has since had upgraded firmware which has kept the unlock. But since the 3g, most support discussion for 2g's has faded leaving me unsure of a way forward.

Not sure if relevant but it will have a virgin mobile sim installed.

All help and advice appreciated.

[Orby]

You can go all the way to the highest firmware (3.1.3--"7E18") on the 2G and you will remain permanently unlocked. If your iPhone is unlocked via BootNeuter (the last, if not only, major tool released for the 04.05.04_G baseband), then you have what is essentially a carrier unlock. I suspect you have this unlock, so upgrade with impunity (if you don't, redsn0w or PwnageTool will handle the permanent unlock for you on first boot).

The official 3.1.3 IPSW can be downloaded from Apple here.

I wouldn't move up to 3.1.3 (from .2) unless you have a very specific need for it (such as an app you use requiring 3.1.3), but if you have to, the easiest routes would be either restore to a custom PwnageTool firmware (PwnageTool... 3.1.5 I think) or restore to a stock IPSW and then run redsn0w (0.9.4) to jailbreak.

Please note: the activation server for the 2G phones work much differently than the server for the current phones. The server checks not only for a correct carrier's SIM, but also if it is valid (at least for AT&T in the US). You may have to "hacktivate" and then run SAM to get a legitimate activation and getting your push notifications/Youtube working correctly.

[s8lam2000]

I think it was BootNeuter I used to unlock.

I dont specifically need to upgrade for any reason, except that lots of the apps on Itunes require a higher version of firmware.

I have just downloaded redsn0w 0.9.6rc16 and the official 3.1.3 IPSW you linked to.
When I choose that file in redsn0w it gives the message "unable to recognise specified IPSW".
Reading up on this I believe I need to use a 3.1.2 IPSW, but am unsure which is the correct one to download.
Or, is there an already a custom IPSW file available to just download and restore to?

QUOTE
"Please note: the activation server for the 2G phones work much differently than the server for the current phones. The server checks not only for a correct carrier's SIM, but also if it is valid (at least for AT&T in the US). You may have to "hacktivate" and then run SAM to get a legitimate activation and getting your push notifications/Youtube working correctly."

I am slightly confused about this. I thought that once the iphone was initially activated, it did not need to be done again?
I am in the UK, which should be on O2, but I have a virgin mobile sim installed. I have a random 02 sim I could install temporarily though.

If anything goes wrong or is undesireable, would I be able to downgrade using everything I have to get it to 3.1.2? And, will the baseband be affected by the update?

Thanks for the help.

[Simon]

If you activate it with the O2 sim you will get an invalid sim detected screen if you try and put another carrier sim in, even if it is unlocked. iPhone 2G is different this way then the newer iPhones as orby explained.

You should use redsnow 0.9.4 (point redsnow to a 3.1.2 firmware) to jailbreak and hactivate the iPhone instead of activating with a official sim. Then you can install SAM to fix push notifications.

[Mes]

If anything goes wrong or is undesireable, would I be able to downgrade using everything I have to get it to 3.1.2? And, will the baseband be affected by the update?

A 2G can always be unlocked on any iOS version that will load. BootNeuter unlocks it automatically.