iBoot is responsible for downloading source code of the iOS component – the program starts when the device is turned on, immediately after the Boot ROM. This iOS component is used to download and verify the kernel, checks it for the signature of Apple. It is difficult to imagine that the company would allow a leak of such code into the network, therefore, most likely, it is a leak.
The appeared archive on GitHub is related to iOS 9. Developers can not claim that this code is used in the current iOS 11, but it can not be excluded. It is not possible to compile the code due to the lack of some components. What does not prevent researchers from starting to look for vulnerabilities in iBoot.
According to experts, the leak can allow to write a full-fledged iOS emulator for other platforms, but it is unlikely that someone will succeed without a part of the components. In addition, this code appeared on GitHub before, just attention was paid to it just now.
The current generation of the iPhone is additionally protected from hacking thanks to a special Secure Enclave Processor chip. It not only enhances the protection of the device, but also eliminates the vulnerabilities used to create a jailbreak.