[JustCause]

I've got an iPhone 5S laying around that's still on iOS 8.4 and is Jailbroken with TaiG. I would like to jump up to iOS 10.3.3. I've successfully used futurerestore before but only with an iPad so I didn't have to deal with the baseband and sep.

Can I upgrade from iOS 8.4 to iOS 10.3.3 using futurerestore + SHSH Blobs, and what do I need to do as far as baseband and sep are concerned?

[Jesse78]

If you have a Mac, Try using This:
https://github.com/MatthewPierson/1033-OTA-Downgrader

It's supposed to Downgrade your A7 Devices to iOS 10.3.3 using already signed OTA Blobs. 

If you're on Windows or Linux, I'd say wait until this method supports Linux/Windows.

[JustCause]

I gave it a try but for some reason it just keeps giving me an Error saying there is No Apple device in DFU mode, even though my device is in fact connected in DFU mode. You can see in the terminal output that it shows "Found:...." and it sits on that line for about 30 seconds, then gives the Error on the line after.

I even tried it with my device in Normal Mode just to see what it would do, but this time it gave me an "ERROR: Unsupported model..." which is silly because it's an iPhone 5S which obviously is a supported device.

I see that the tool is still brand new so hopefully they will make some changes. Perhaps I will get in touch with the dev and let him know.

Terminal Output

Code:

JustCauses-Mac:Vieux justcause$ ./vieux -i 10.3.3.ipsw
Given IPSW Path is 10.3.3.ipsw
Vieux - A tool for 32/64 Bit OTA downgrades
Still in BETA so expect issues/broken things
If you are using a 64 Bit device then connect it in DFU Mode
If you are using a 32 Bit device then just have it connected in normal mode
Starting IPSW unzipping
Continuing...
IPSW found at given path...
Cleaning up old files...
Files cleaned.
Unzipping..
Found: CPID:8960 CPRV:11 CPFM:03 SCEP:01 BDID:00 ECID:00000176ADB12AC4 IBFL:1C SRTG:[iBoot-1704.10]
ERROR: No Apple device in DFU Mode 0x1227 detected after 30.00 second timeout. Exiting.
JustCauses-Mac:Vieux justcause$

[GeoSn0w]

It appears that the tool's Github page has an issue open by someone with a similar DFU-related error. It's likely a bug in the way the program works/detects the device, or the USB passthrough isn't working well.
https://github.com/MatthewPierson/1033-O.../issues/68

You can try to run: "python -m easy_install pyusb" without speech marks in the Terminal and then try again.