[Galaxy Note 3 Android Development] TheROMFlashinator:
Hello Te3k! Good timing on your post, I recently just unsoft bricked and frp unlocked and bootloader unlocked a phone I had in the drawer because I've been trying to de-google and custom rom upgrade as many devices as I can that I own! :) But the information on how to go further with that particular device is sparse and not so clear (its on stock android10 so far was just happy to revive it at this point).

So I figured while I keep researching that to make sure I lineage and degoogle that correctly, I would practice with my old trusty note 3 which I also remembered having difficulty running custom roms on it. I like you experienced almost the same where literally no matter what basically no custom roms would run on it EXCEPT ONE (well and of course stock roms but that's boring xD). Previously and what was just on there before upgrading successfully the only custom rom I got to work on it was AOKP oreo 8.1 found here on xda a couple years back.

I always wondered why that was but at that time I was just happy to have something newer and nonbloated than stock old lollipop. Seeing your post got me to experiment and try to figure out why our devices won't run custom roms. We both can't have something wrong with our particular devices so it must be something else, and I think I figured out the solution even though I don't know why it works.

The way you described it, it is not a standard bootloop that happens (same as me). A standard bootloop just shows the first manufacturer logo (our case for this device samsung) and then very quickly loops only that logo. For us it gets past that but then when for example seeing the lineage logo appear it will either almost get to the startup screen or crash before it and then loop doing that again and again. Once I did actually get to the startup screen but then when I touched the screen it crashed and looped. It seems that touching it makes it crash sooner but even without touching anything it still does regardless.

So I looked back and tried to see what was different about the AOKP rom which was different from all the others I had tried. And the difference jumped out at me immediately.

With the other roms I was very particular to get the rom for my particular variant (for me it's TMobile SM-N900T / hltetmo) and I don't know if I wasn't looking 100% closely at it at the time or just no roms were working so I was willing to try anything and I flashed that AOKP hlte generic rom just to see if I could get anything to work. (I didn't realize at the time though that that's what it was that let it work).

So hlte instead of hltetmo is basically the non carrier branded generic version of the phone I believe and as strange as it seems that's what got the latest official lineage rom working for me on my hltetmo note 3! :D

html6405's unofficial lineage roms here OR even the official lineage roms don't work for me and I experience the same problem as you with them IF i select my tmobile variant choosing hltetmo... However, noticing the working rom I had on it was just hlte unified AOKP I for the heck of it tried the hlte version of the rom instead and bingobangobongo! The lineage logo progressed past startup sequence and into the setup and welcome screens and its working!

Then I installed magisk had it patch the boot image (thats why lineage has the boot file neatly next to the rom download also with their recovery But I'm using the latest version of TWRP 3.7.0 for hlte since TWRP is better all around and more feature full if you've got it working [that's a question for my other device whether it is or not])

Then rebooted to TWRP recovery and used it to flash the patched boot image and fingers crossed it loads up and I now have root as well. :)

This is great, but there's a slight complication: I'm also trying to help a friend get their location services working properly on their degoogled phone and figuring out the best way to do it while still remaining degoogled. On AOKP I was trying using the UnifiedNLP on it's own with various backends Mozilla, Apple, Local Wifi, etc and it didn't seem to be working correctly so I've been getting this far to test with microg instead but just using the NLP part of it, but now I realize it may have just been the signature spoofing was needed and maybe that would've worked, but I'll still try it with microg as well to find a solution. Also could be the device being old and location not working to well on it either.

So I could either install the hlte version of lineage with signature spoofing patched in already along with including microg bundled (lineageformicrog unofficial fork) or I could use this magisk module I found called 'microG Install Revived' which claims to also include signature spoofing with the module so I decided to try that.

And yeah it seems that does work although the microg settings still claim it doesn't support signature spoofing but its checking system wide rather than just for microg with the magisk module. Basically its a one specific application suite sig spoof rather than allowing it systemwide.

But I wanted to verify my theory that flashing the hlte generic non variant roms is the solution and after making a twrp backup of this setup (lineage official 18.1 + magisk root + module signature spoof + microg) I proceeded to get the lineage for microg version and do the usual factory reset plus system wipe and flash it!

And it also works fine and in this case I only needed to redo patching the boot image with magisk and flashing it and installing some NLP backends and it's equivalent or greater (because now it does allow full system sig spoofing and the boxes are checked in the self check in microg settings, whether you think that's better or worse is up to you). Also made a TWRP backup of this setup as well so now I have restorable AOKP 8.1 rooted, or lineage 18.1 official no sig spoof magisk rooted microg moduled, or lineage 18.1 unofficial sig spoofed magisk rooted! :D

So there you have it! Hopefully it works for you as well to get custom roms going for you again on this classic device! Maybe if it does and I helped you then you could help me get TWRP working on my newer device I'm being more careful with since it's the one I have my service sim card in lol and don't want to wreck it, although I haven't had a device that was totally unrecoverable yet :D But unlike this one TWRP doesn't read the partitions so I feel like it cant flash and it would be unwise to try it and have had to stick with fastboot on it which if people are providing TWRP flashable zips I'm not sure how to translate that to fastboot flashable commands just yet. Lol that device has fastboot and no TWRP these samsungs have no fastboot just odin so TWRP is better in that case especially since I'm on linux and odin never worked that great for me even if I do boot up windows to use it I don't want/need to anyway.

Hope you get yours going with much newer software on this thing! It works better than expected and is really smooth for such an old device. So much so that it might actually be worth it now getting a new battery for this thing to bring back the battery life of it!

The reference links to what I have documented above are below:

TWRP 3.7.0 hlte:

Download TWRP for hlte

Download TWRP Open Recovery for hlte

dl.twrp.me

Lineage 18.1 hlte:

LineageOS Downloads

download.lineageos.org

microG Installer Revived:

GitHub - nift4/microg_installer_revived: Install microG GmsCore, GsfProxy, FakeStore (or Play Store if you want so) and MapsV1 to /system/

Install microG GmsCore, GsfProxy, FakeStore (or Play Store if you want so) and MapsV1 to /system/ - nift4/microg_installer_revived

github.com

Lineage 18.1 for microg hlte:

hlte

A post that I learned you could still sig spoof and use microg even with official lineage and about the revived micro magisk installer module:

I just switched to LineageOS 18 w/ MicroG and oh my lord is this stuff still com... | Hacker News

news.ycombinator.com

The AOKP website where I realized it was a rom for hlte and not my hltetmo variant: (Although for some reason the rom is not available there anymore but it's actual download link can still be found here at xda)

AOKP.co: Devices :: Android Open Kang Project

Android. Infused with magical unicorn bytes.

aokp.co

Where you can still get the rom which was the only custom rom that worked for me previously until now:

https://xdaforums.com/t/beta-rom-ao...-oreo-for-galaxy-note-3-unified-beta.3781639/

:D