One of the reasons Google’s Nexus devices were so popular with enthusiasts was their development-friendly nature, which made installing and flashing custom recoveries like TWRP, custom ROMs, and kernels relatively easy. With the debut of the Google Pixel and the Pixel XL, things changed for the worse — a patch of the most popular root methods and a difficult-to-manipulate A/B partition caused a real headache for developers. The situation improved over time, but some in the community saw the Pixel as “hacker-friendly” as its predecessors.
Luckily, the Pixel 2 and Pixel XL haven’t suffered the same fate. Two weeks after releasing the alpha version of TWRP, XDA Senior Recognized Developer Dees_troy released TWRP Beta 2 for the Pixel 2 XL and Beta 1 for the Pixel 2. The biggest change is that both phones can now be decrypted in TWRP, though Dees_troy notes that a future Android security patch might break the functionality.
Dees_troy notes that the developers of the beta release of TWRP are trying to grab the files they need from the Pixel 2’s system and vendor partitions, but that if they aren’t successful, they’ll fall back to the ones they’ve built.
It’s a huge step forward for Pixel 2 development. It took two weeks for the Pixel 2 and the Pixel 2 XL, which were released in mid-October, to get an alpha release of TWRP, and it had serious limitations. Users couldn’t decrypt, backup, or restore data; MTP did not work; factory reset using the custom recovery was unreliable; and the recovery menu could only be used in a “temp-boot” state. (Separately, root was achieved on the Pixel 2 / Pixel 2 XL using Magisk).
The reason? Dees_troy says that the Pixel 2’s decryption is different than the Pixel 1’s and most other File Based Encrypted (FBE) devices on the market. In a technical explanation on Google+, he stated that the Pixel 2’s hardware security module is supplied by NXP, and that there’s both (1) a new interface between the Android’s user space and the module — “Weaver” — and (2) anti-rollback protection features introduced with Android 8.0 Marshmallow.
If you’re interested in reading the Dees_troy’s excellent writeup, head to the source link.
Source: Dees_troy on Google+