Jan 13, 2021 07:00:00

Reported successful booting of Ubuntu via NFS using iPhone 7 with storage failure

There was a report on

Reddit on the overseas bulletin board that 'Ubuntu was successfully started using the iPhone 7 with the NAND storage failure'. The root file system built on another PC with debootstrap is shared by NFS and mounted on the iPhone 7 side.

SUCCESS: iPhone 7 with dead NAND netbooting unmodified Ubuntu 20.04 arm64 over usb gadget ethernet: linux
https://www.reddit.com/r/linux/comments/kux9xx/success_iphone_7_with_dead_nand_netbooting/

The movie that actually boots Ubuntu on iPhone 7 is as follows.

iPhone 7 booting Ubuntu 20.04 --YouTube


This hack consists of a jailbreak tool for iOS ' checkra1n ', ' Sandcastle ' that can run Android on iPhone, and a group of network-related tools developed by reporter newhacker1746 . Both checkra1n and Sandcastle exploit an unfixable boot ROM vulnerability ' Checkm8 ' found in the iPhone, which has expanded the use of the iPhone 7 with NAND failure due to Checkm8.

New method to jailbreak iPhone 8 and iPhone X discovered, patch cannot be fixed-GIGAZINE

As a method, first build a root file system by debootstrap in an environment where arm64 architecture such as Raspberry Pi 4 can be used, and publish it in the LAN by NFS. debootstrap is software that can build a new root file system on the host, and by using it together with the chroot command that can change the root directory, you can build an environment isolated from the host.

The Linux kernel deployed on the iPhone uses ' linux-sandcastle ', which was modified by Corellium , the developer of Sandcastle, to work on A9X / A10. It is explained that the IP address of the host that is the NFS sharing source is set so that the root file system on NFS is mounted when the kernel is built.

After establishing a network connection between the iPhone and the host PC with newhacker1746's tools, start pongoOS on the iPhone using checkra1n . The flow of hacks is that you can start Ubuntu by loading the built custom kernel and device tree on the iPhone with Sandcastle's tool. The kernel is expanded in RAM and the root file system is mounted with NFS so that Ubuntu can be booted even if the NAND of iPhone 7 is broken.

In addition, X11 and Wayland seem to work in this hack, and a movie that actually starts the GUI of Ubuntu has also been released.

iPhone 7 booting Ubuntu 20.04 (to GUI) --YouTube