This tutorial will show you how to check your boot rom on a 3GS and show you how to update to iOS5 untethered.
* * PLEASE REMEMBER THIS IS FOR OLD BOOT ROM 3GS IPHONES * *
1st we need to check if your iPhone has the old boot rom as this only works untethered for them.
PC METHOD
Step 1: Put your iPhone into DFU Mode (not recovery mode)
Connect your iPhone to your computer.
Turn iPhone off.
Start iTunes.
Hold Power and Home buttons together for 10 seconds or so.
Release Power button but keep holding the Home button until your computer recognizes a new USB device.
iTunes will now recognize your iPhone.
Note: Your iPhone screen at this time should be blank (black in colour),
if not, then you are most likely in Recovery Mode, not DFU mode.
Step 2: Right Click on My Computer and click on: Properties -> Hardware (tab) -> Device Manager
Step 3: Select the “+” to open sub-menus tree items for "Universal Serial Bus (USB) Controller".
Step 4: Now look for "Apple Mobile Device USB Driver", right click and select Properties.
Step 5: Go to "Details" and find "Device Instance ID".
Step 6: Simply scroll through the string and you’ll find the boot ROM version (iBoot)
Step 7: If it’s 359.3, you have old boot ROM. If it’s 359.3.2 or anything above that, its a new boot ROM.
TO EXIT DFU MODE. PRESS AND HOLD THE POWER AND HOME BUTTON UNTIL THE
BOOT LOGO APPEARS AND RELEASE BOTH BUTTONS. The phone will then boot
normally.
Now if you have the
old boot ROM then we can go ahead with an untethered iOS 5 Jailbreak. If you are on the
new boot rom then there is only a tethered jailbreak at the moment.
BUT one more thing to check, is your baseband, if you require
your phone to be unlocked to a different service provider (network)
other than the one the phone is locked to.
* * NOTE: Ultrasn0w (available from Cydia after
jailbreaking) will only unlock 04.26.08, 05.11.07, 05.12.01, 05.13.04,
and 06.15.00 on the 3GS * *
Things you need for this:
iOS 5 Restore firmware (we need this to make a custom firmware from) -
Download Here (This is my 3GS restore pack downloaded from apple)
Tiny Umbrella (to save your SHSH Blobs (apples firmware signatures) -
Download Here
Sn0wbreeze-v2.8b8 for iOS 5 (to create the custom firmware) -
Download Here
iTunes 10.5 (to install your custom firmware) -
Download Here
* * IMPORTANT ** MAKE SURE YOU DO A
BACK UP & SYNC OF ALL YOUR DATA WITH ITUNES BEFORE ANY FURTHER
STEPS SO IT CAN BE RESTORED AFTER THE FIRMWARE IS UPDATED * *
1st we use TinyUmbrella to grab your shsh blobs and save them on your computer.
Start TinyUmbrella with your iPhone connected and on.
Highlight your phone on the left.
Click the 'Advanced' Tab in the box at the bottom.
Make sure all the boxes are ticked,
EXCEPT the iphone4 base band
Click 'Save SHSH' and let it run.
Once complete you will see your saved SHSH that are now on your PC. Keep the program open we need that later, so just minimize.
Now to make the custom firmware:
1) Run Sn0wbreeze-v2.8b8 for iOS 5.
2) Click OK, then click the blue arrow at the bottom
3) Select the iOS 5 Restore file you downloaded
4) Select Old Boot Rom
5) Click the blue arrow at the bottom
6) Select 'Expert Mode' and press the blue arrow at the bottom
7) Select 'General' and press the blue arrow at the bottom
8) Tick 'Activate the iPhone - (Hacktivate)' and don't touch anything else and press the blue arrow at the bottom
9) It's up to you if you want to change any of the custom boot logo's or
not have them on at all. Then press the blue arrow at the bottom
10) Skip this next section and press the blue arrow at the bottom
11) Select 'Build IPSW' and press the blue arrow at the bottom
12) Just choose the spinner, unless you want to play Pac-Man lol. Sit back and wait.
13) Finished and now the file your going to update you old boot 3GS with
is on your desktop. Click ok and follow the instructions to put the
phone into DFU Mode (also as described above)
14) Now re-open TinyUnbrella and click 'Start TSS Server'
15) Run iTunes and it will detect your phone and ask if you want to restore it
16)
Hold down 'SHIFT' and click 'RESTORE'
17) Select the custom firmware from your desktop
18) Go make a brew and sit back for it to finish
19) Once the phone is set up then you can go to Cydia and search Ultrasn0w to unlock your phone to any network.
You can now reboot your phone at any time without it having to be
tethered to your computer when the phone needs to reset after adding
modifications\
From source : http://forum.iphone-developers.com/iphone-hacking-jailbreaking-modding/2415-tutorial-check-3gs-old-boot-rom-update-ios-5-untethered-old-boot-rom-only.html