Supporting the unsupported
This project brings iOS 7.x to the Apple iPod Touch 4th generation. This device's latest official firmware is 6.1.6 , released by Apple in 2014.
The iPod Touch 4g is similar to the iPhone 4, except for some components and ram.
While the iPod Touch 4g got 256MB ram, the iPhone 4 got 512MB RAM.
That is most likely the reason why Apple decided to not give this device the iOS 7 update.
This decision made people, back in the days, a lot angry, because they couldn't run the "biggest iOS update" on their beloved device.
But we all know that Apple sometimes (often) decides to not give updates to devices considered "old" just for marketing strategies, and to make people choose to buy the newer generation product.
Said that, the iPod Touch 4g uses the same A4 processor that's found in the iPhone 4, and that's what makes porting iOS 7 possible. Let's get in depht and find out how!
Before getting into details, let's talk a bit about how all this become a thing:
In 2013, an iPhone hacker called "winocm", released a set of tools called "ios-kexec-utils".
To avoid super-technical informations, let's just say a tool included in this project, kloader, is really useful to achieve multi-booting on iOS.
For a lot of time, back in the days, almost no one got interest in it (mainly because people didn't know how to use it), but recently, thanks to Coolbooter and @nyan_satan, finally it become "popular" and manually dual-booting become something easier for people to do.
Dual-booting offers not only the possibility to get a fully working 2nd os in your device, but also debugging boot-args, booting diags, switchboards and, in our case: booting firmwares from other devices.
Now, in the case of the iPod Touch 4g, where there is a public bootrom exploit available, we could've already done it without dualbooting, but it would've been a lot harder to do.
So, since the iPhone 4 got iOS 7 and its hardware is really similar to the iPod Touch 4g one, why not trying something?
The first guy who tried experimenting with this is the twitter user @Ralph0045
He successfully booted the iPhone3,1 (iPhone 4) iOS 7.0 firmware on an iPod4,1 (iPod Touch 4g) by using dual-boot.
People (including me) got excited by this and wanted to try it, so later he released 2 ipsws to get iOS 7 without having to dualboot.
But obviously the firmware wasn't perfect, because of the small hardware differences between the devices, so there were some...
This is a list of issues that have been fixed:
Device panicked after about 5 minutes of use - Fixed by @Ralph0045
Wifi didn't work - Fixed by me (@albyvar25)
Some units produced after 2011 didn't work - Fix concept by me (@albyvar25), but thanks goes to @Nalu_Tech who tested it!
And these are issues that are still present:
Multitouch doesn't work (touch does work)
Both front and rear cameras won't work
No audio output
No bluetooth
Some sensors (like rotation and light) are broken
Battery indicator is stuck at 100%
If you decide to give it a try, keep in mind that:
-this is a dirty hack so no guarantees it will be 100% stable
-even if it's not that bad, remember that the iPod Touch 4g still has only 256MB ram so don't stress it much
-device can't be activated so you can't use iCloud or App Store (but you will still be able to jailbreak it and use appsync + on-device ipa installer to get apps)
-if you use the ipsw, it won't be untethered
-you accept the risk of "bricking" your device
NOTE: you will still always be able to restore and fix it
@nyan_satan for the dualboot guide
@Ralph0045, without him all this probably wouldn't have existed
Me (@albyvar25) for the wifi fix
@JonathanSeals for jailbreak stuff
Everyone else who contributed.