There are a few threads that deal with upgrading lollipop to marshmallow, but they seem to raise as many questions as they answer – mainly since they were usually written before rooted images were distributed.
Basically, I am on an unlocked, rooted stock XT1575 with TWRP 2.8.7.0. It sounds like it’s less efficient and has lots of potential problems to go back to stock, unroot, install OTA, do new system root, and re-add TWRP.
Instead, it sounds like the simplest method to get to stock rooted MM, with least steps and potential problems, should be this:
- Update TWRP to 2.8.7.1 using IMG file here from within TWRP Recovery (TWRP Manager did not install it when I tried via Android proper – I was still at 2.8.7.0)
- Do a full TWRP backup of my current Lollipop stock rooted installation (I assume this means I can restore without problems if the MM install goes awry)
- In TWRP, Wipe->Swipe to Factory Reset
- Transfer to phone and Flash via TWRP the stock rooted odexed ROM from this thread (not sure if there is a good argument for deodexed? I’ve never gotten a clear answer why one should be better, but would stick with odexed just because I believe it is "stock" so maybe less problems?)
- Reinstall all programs on initial setup
I assume if I do this I will: have marshmallow; have root; have working TWRP.
Does anyone see any obvious problems with this method? Thanks, I really appreciate any comments.