[JiaYu S3 Questions & Answers] AlexZap:
Systemless works!!! sort of...

so over the weekend, i got around to installing AICP build 2 on my phone. first, let me say to the devs: kudos on an excellent job. rom is smooth, and everything works great! some minor annoyances aside (i don't even consider them bugs), i have to say, keep up the great work!

so, i thought i would play with some of the systemless root and systemless xposed stuff going around. if i killed the rom, i could always recover, just reflash the boot image and/or system image and everything should be fine, right? well, it took some work, as there aren't too many tutorials out there, but i managed to get everything installed, and i have a fully systemless root and systemless xposed installation going on my phone. it DOES NOT let android pay work. although it comes close, the phone still doesn't pass the safety net check. it verifies the system partition as safe, and verifies the algorithm as good, but it fails on not having a device fingerprint. as discussed before, this is because it is a custom rom. oh well. if you DO have apps that complain about you having a rooted ROM, this should fix it, as long as they aren't verifying through safetynet (i think only android pay does that at the moment).

anyway, here are my steps. i did them on aicp, they should work on cm13 and on PA as they all use similar boot images :

Requirements :

100% stock system + boot (this system partition should be fresh like you just installed the ROM, plus gapps, and boot should be unmodified.

Downloads : (Things you're going to need)

update-unsu.zip: osm0sis' script for removing whatever superuser utility that is currently installed in system

magisk: the heart of the systemless setup. currently this points to v3, check here if there is an updated version

phh su for magisk: flashable zhip for phh su. there is a supersu version you could try if you want to also. phh su is UGLY, but it is recomended by the author of magisk. again, v2. check here for an updated version. it comes with the magisk manager, which you need to unroot/unxposed on the fly

phh su manager apk: need it to control phh su. if you install it before any of the flashing, be sure not to let it update your su binary. no need for that.

material design xposed installer: i guess the regular xposed installer wont work with systemless installs. gotta use this one. check here for an updated version if needed.

systemless xposed: if you want to run xposed, might as well do it systemless at this point, right? check this thread here for an updated version (currently v86.4)

steps:

place any files you are going to flash in a place accessible by twrp. i.e. not on adoptable storage. i used a usb otg drive, but whatever works for you

if needed, first reflash a stock system and boot image. you could reinstall the rom if you had to. be sure to reinstall whatever gapps package you have too. remove xposed, or any other system mods.

after verifying your phone boots up fine, go back to twrp. flash update-unSU.zip. this will remove the stock system root.

flash Magisk-v3.zip that you downloaded above

flash phh-superuser-magisk-v2.zip. this will install your systemless root.

(optional) flash xposed-v86.4-sdk23-topjohnwu.zip. if you want xposed, this will install it for you.

boot up your phone. if you installed xposed, you have to wait while the art cache is remade, otherwise you will just boot up

install the phh su manager from the play store. now you can control your SU

install the material xposed installer. xposed at your finger tips!

in your app drawer you have a new application: Magisk Manager. when you open it, it will ask for root permissions. then you can use it to toggle root and xposed on and off. what it does basically is set a timer, then unmount the image where the su binary (and xposed) are installed. after the timer is up, these partitions are automatically remounted, giving you xposed and root back. pretty cool, right?

Notes

what amazes me most is that the flashable zips work out of the park on the mediatek boot image. this is really really really cool. hopefully osm0sis will update some of his scripts to support magisk. i'd love to add busybox to the systemless root image, as well as adb. anyway... let me know if you have any issues with this... i'll do what i can to help.

Thanks
[MENTION=4470081]topjohnwu[/MENTION] for magisk and just being awesome

@DVDandroid for the material installer
[MENTION=4419114]rovo89[/MENTION] for creating Xposed
[MENTION=1915408]phhusson[/MENTION] for the original phh root, an opensource alternative to superSU

@DerTeufel1980, [MENTION=5238428]superdragonpt[/MENTION], and [MENTION=4761533]fire855[/MENTION] for a collection of awesome ROMs to work with

probably others...