Develop Bugs

Questions about the new project Treble on Android

Hi guys.
I have some questions about the new android treble feature.
The way it is advertised, it seems to be the END of the fragmentation problem on android. But i dont know if it is over advertised.
1) "The A/B partition system is only for seamless update."
I've read this on the internet and the only difference between A and A/B is that A will update like older androids while A/B will be with the phone turned on with only a reboot being necessary. This shouldn't be something that will make treble more or less useful for the end-users.
2) Why I dont see people talking about system repartitioning the phone to enable A/B partition? Most phones have 32GB, with most being over 20GB in /data. Why not just repartition 1GB to enable A/B partition?
3) "The treble updates will still be released by the phone's manufaturer."
Really? I dont know if the updates are comming from google or phone manufacturer. Can someone confirm?
It does not make any sense to try to stop the fragmentation issue by still leaving the update task on the manufacturer's side...
After some time they will stop updating anyway.
4) "Android treble will be useless if the phone does not come with native treble support."
I really don't understand this. Ive read this in reddit I believe. But installing a custom treble supported rom wouldn't be easier to perform updates on the custom rom?
My thoughts are that the updates are going to be handled by google. By doing so, we could install any custom rom and forget it because "google will update it from now on". This makes sense to me. If treble is not heading to this, then they are doing it wrong...
IMO, I think that treble would be great if users could perform:
Get your old android phone's manufaturer proprietary files;
Save those files in a vendor folder;
Execute them in android 8 and on;
Leading every android device to the latest android version.
(This in a perfect world. I know this option is a dream.)
BUT, I believe this could be an option at least for the devices that received the oreo update (because they received the "updated proprietary files" that would work for the new android treble and by consequence, on all new android versions.
If so is true, the best that could happen is for custom rom devs, create their roms by packing the vendor files, integrating with AOSP and linking the updates from the google server. Done, phone will be "forever updated".
Any comments on those, please?
Thank you.

facsi2 said:
Hi guys.
I have some questions about the new android treble feature.
The way it is advertised, it seems to be the END of the fragmentation problem on android. But i dont know if it is over advertised.
1) "The A/B partition system is only for seamless update."
I've read this on the internet and the only difference between A and A/B is that A will update like older androids while A/B will be with the phone turned on with only a reboot being necessary. This shouldn't be something that will make treble more or less useful for the end-users.
2) Why I dont see people talking about system repartitioning the phone to enable A/B partition? Most phones have 32GB, with most being over 20GB in /data. Why not just repartition 1GB to enable A/B partition?
3) "The treble updates will still be released by the phone's manufaturer."
Really? I dont know if the updates are comming from google or phone manufacturer. Can someone confirm?
It does not make any sense to try to stop the fragmentation issue by still leaving the update task on the manufacturer's side...
After some time they will stop updating anyway.
4) "Android treble will be useless if the phone does not come with native treble support."
I really don't understand this. Ive read this in reddit I believe. But installing a custom treble supported rom wouldn't be easier to perform updates on the custom rom?
My thoughts are that the updates are going to be handled by google. By doing so, we could install any custom rom and forget it because "google will update it from now on". This makes sense to me. If treble is not heading to this, then they are doing it wrong...
IMO, I think that treble would be great if users could perform:
Get your old android phone's manufaturer proprietary files;
Save those files in a vendor folder;
Execute them in android 8 and on;
Leading every android device to the latest android version.
(This in a perfect world. I know this option is a dream.)
BUT, I believe this could be an option at least for the devices that received the oreo update (because they received the "updated proprietary files" that would work for the new android treble and by consequence, on all new android versions.
If so is true, the best that could happen is for custom rom devs, create their roms by packing the vendor files, integrating with AOSP and linking the updates from the google server. Done, phone will be "forever updated".
Any comments on those, please?
Thank you.
Click to expand...
Click to collapse
1) A/B devices also have a thing called "skip_initfs". In older devices, which is indeed A-only, we have the kernel ramdisk in boot partition. But in A/B devices, the boot ramdisk is only for recovery - when booting the system, the system actually contains the initramfs instead and it gets mounted to / (rootfs) instead of /system.
In short, A/B devices have init and ramdisk all in the system partition. This means Treble ROM's for A/B devices can easily have their own initfs, which makes things a little easier.
2) It also needs bootloader (either SBL or ABOOT, can't remember) support for AB, and these are almost never open source.
3) Treble allows OEM's (the hardware, e.g. Qualcomm) and the ODM (the brand, e.g. Xiaomi) to work independently. Treble provides a contract that the ODM and OEM must each pass verification black-box style, allowing independent development without reliance on the other. Best analogy I can think of is how drivers for Windows work - they don't need to know about what edition of Windows or model of PC it is; they just need to follow standards when making their hardware drivers - and if they do they can be sure that it should work with any other software.
Theoretically, Android P GSI should work straight away on a Treble-enabled Oreo phone. Maybe only with minimal changes - still too early to say. But this is the idea of it.
4) Not entirely true. Unofficial Treble (e.g. like we did for Mi A1) allows us to use GSI's thanks to Phh's work. And unlike many other official Treble devices, we have 100% compatibility with GSI's thanks to the fact that that we can fix GSI stuff on our own end. Many Treble devices are not properly "GSI-ready" vendor implementations, a common theme is that they still put essential Camera stuff in their system ROM instead of vendor (Treble verification I guess doesn't care about Camera support, sadly).
Updates from Google directly is a different program entirely; that's only for devices in Android One program.
Treble support with blobs from before Oreo is practically impossible. They need to be either modified and recompiled with the VNDK standards, or a very smart person needs to shim them. Don't ever expect a pre-Oreo device without source code to be Treble compatible - it's a monumental task that basically requires reverse-engineering the proprietary blobs. If you don't find that useful, then those are the breaks - this stuff was only introduced relatively recently. Treble is not a time machine
But again: Treble does NOT mean "updates directly from Google". That's only for official Android One devices.
Maybe one day Google will have an official thing akin to GSI. But not today. As it is, GSI - generic Treble ROM's - are the love child of Phh, there is no such thing as official updates directly from Google outside of Android One (and Pixel ofc).
As for your other speculation, it's mostly redundant - apparently, all devices that launch with Android P are required to have Treble. If I remember correctly. If the pre-P device is popular and open enough, then yeah you will get unofficial Treble (like we did with Mi A1). But that's all up to the device community. But just to reiterate one more time - this does NOT mean updates will come directly from Google.
In case you're wondering why the updates won't come directly from Google (and I predict that this will never be the case, outside of Android One program devices) - simple fact is because Android != Google. Google will never force Android vendors to use Google servers or update channel because Android itself is a very open platform; Treble is an architectural change regarding HAL abstraction - not an enforcement of Google doctrine. It'd be absurd if they did pull a stunt like that; would be like GNU saying "hey Ubuntu, Debian, and all you other guys - you have to use GNU update servers now, all your own servers are not allowed".

Many thanks, Dan. The smart thing to do is hope a new good phone gets released with latest android. Then we can keep if for a longer time thanks to treble. Planned obsolescence sucks.
Just for the curiosity, I own a moto z play and a galaxy s5 (just because of the IR blaster).

facsi2 said:
Many thanks, Dan. The smart thing to do is hope a new good phone gets released with latest android. Then we can keep if for a longer time thanks to treble. Planned obsolescence sucks.
Just for the curiosity, I own a moto z play and a galaxy s5 (just because of the IR blaster).
Click to expand...
Click to collapse
I have to say I am very glad I got the Mi A1. They did take a while to release the source code, but being an Android One device it was already "Treble-ready" - the HAL and vendor files were already binderized, as per requirements for Treble (that's the most difficult part in getting a Treble device).
My next device may be the A2, or a Pixel, it really depends on how long I keep this device (probably a while yet, since it's definitely getting P officially even).
And yeah, being a Xiaomi, they always have IR

CosmicDan said:
In case you're wondering why the updates won't come directly from Google (and I predict that this will never be the case, outside of Android One program devices) - simple fact is because Android != Google. Google will never force Android vendors to use Google servers or update channel because Android itself is a very open platform; Treble is an architectural change regarding HAL abstraction - not an enforcement of Google doctrine. It'd be absurd if they did pull a stunt like that; would be like GNU saying "hey Ubuntu, Debian, and all you other guys - you have to use GNU update servers now, all your own servers are not allowed".
Click to expand...
Click to collapse
I think in google (Android) updates being sent by google itself as it is the one who releases android security patches.
I took a look on Mi A1. it only misses NFC. I might wait another year to change my phone.
thanks

facsi2 said:
I think in google (Android) updates being sent by google itself as it is the one who releases android security patches.
I took a look on Mi A1. it only misses NFC. I might wait another year to change my phone.
thanks
Click to expand...
Click to collapse
What do you mean? Security updates can't be sent directly from Google, because every device is different and usually heavily modified at the source code level.
The whole point of Android One is that they are relatively pure, bit they still need to compile seperate security updates for different devices.
In short, there's no such thing as generic firmware, every firmware and therefore every update is still device-specific. Excluding GSI of course, which is not an official thing remember.
True about NFC, I never used it so forgot.

CosmicDan said:
What do you mean? Security updates can't be sent directly from Google, because every device is different and usually heavily modified at the source code level.
The whole point of Android One is that they are relatively pure, bit they still need to compile seperate security updates for different devices.
In short, there's no such thing as generic firmware, every firmware and therefore every update is still device-specific. Excluding GSI of course, which is not an official thing remember.
True about NFC, I never used it so forgot.
Click to expand...
Click to collapse
Isnt google responsible for those security updates in a general ROM and then manufacturers have to port that update for their devices?
https://source.android.com/security/bulletin/
What I meant was with treble, we could update our android directly from google, without having to wait for the manufacturer. Pretty much as how windows update work.

facsi2 said:
Isnt google responsible for those security updates in a general ROM and then manufacturers have to port that update for their devices?
https://source.android.com/security/bulletin/
What I meant was with treble, we could update our android directly from google, without having to wait for the manufacturer. Pretty much as how windows update work.
Click to expand...
Click to collapse
Yes, that's how they work.
But no, we cannot. As I said multiple times already - there is no such thing as a generic device to Google. GSI is created by Phh. Generic updates simply do not exist.
If Google ever makes an official GSI of some sort, or Phh works with someone to make an OTA system for his GSI's, then it could happen. But I wouldn't hold my breath for either of those things - the first one I already explained why it isn't feasible yet, and the second one costs too much money.

CosmicDan said:
Yes, that's how they work.
But no, we cannot. As I said multiple times already - there is no such thing as a generic device to Google. GSI is created by Phh. Generic updates simply do not exist.
If Google ever makes an official GSI of some sort, or Phh works with someone to make an OTA system for his GSI's, then it could happen. But I wouldn't hold my breath for either of those things - the first one I already explained why it isn't feasible yet, and the second one costs too much money.
Click to expand...
Click to collapse
I am confused. What is android AOSP rom then?

facsi2 said:
I am confused. What is android AOSP rom then?
Click to expand...
Click to collapse
https://en.m.wikipedia.org/wiki/Android_(operating_system)#AOSP
Read the "Development" paragraph. The following "Update schedule" section goes on the explain the history and situation of how updates work, basically the same as what I've already said.

got it. Many thanks.
Treble will be really useful for the users.
Btw, do you know if the source code released for moto z play the "same code" available for mi a1? I wonder if it is possible to do the same update you did on A1 on the ZP...

facsi2 said:
got it. Many thanks.
Treble will be really useful for the users.
Btw, do you know if the source code released for moto z play the "same code" available for mi a1? I wonder if it is possible to do the same update you did on A1 on the ZP...
Click to expand...
Click to collapse
Useful for users and developers!
I don't know what you mean by that question. By "same update" do you mean repartition for Treble?

CosmicDan said:
Useful for users and developers!
I don't know what you mean by that question. By "same update" do you mean repartition for Treble?
Click to expand...
Click to collapse
I ended up editing the phrase before sending it and I didn't fully checked it:
Do you know if the source code released for moto z play IS the "same code" available for mi a1? I wonder if it is possible to do the same update you did on A1 on the ZP
What I am asking is if the source code available for Moto z play have the contents to be able to port treble as you did on mi a1. I don't know by looking the contents on GitHub, if the code available is complete for that job.
Thanks

facsi2 said:
I ended up editing the phrase before sending it and I didn't fully checked it:
Do you know if the source code released for moto z play IS the "same code" available for mi a1? I wonder if it is possible to do the same update you did on A1 on the ZP
What I am asking is if the source code available for Moto z play have the contents to be able to port treble as you did on mi a1. I don't know by looking the contents on GitHub, if the code available is complete for that job.
Thanks
Click to expand...
Click to collapse
To port Treble to a device, these things are needed:
1) All the source code required to build standard AOSP, e.g. device tree and kernel. If you already have custom ROM's working f well for you device, this will likely be true.
2) Binderized vendor HAL. If you have *official* Oreo update from Motorola, this MAY be true. Manual inspection of compatibility_matrix.xml is required here, if everything in there matches the Treble requirements as listed on Android Developers then chances are it is ready.
3) An unused partition of ~500MB or more for Vendor, or the ability to repartition the device (many Qualcomm devices are standard GPT partitioned eMMC these days, if it is then it's possible).
That's a summary of the requirements. Obviously some technical investigation is required. Forward that info to any device developers who are interested in the project.

I read somewhere that device to be even updated to Pie have to have enabled Treble? Oreo required it only for launched devices and Pie require it from ALL devices.
Is it right or not? Unfortunately I cannot find it again

CosmicDan said:
To port Treble to a device, these things are needed:
1) All the source code required to build standard AOSP, e.g. device tree and kernel. If you already have custom ROM's working f well for you device, this will likely be true.
2) Binderized vendor HAL. If you have *official* Oreo update from Motorola, this MAY be true. Manual inspection of compatibility_matrix.xml is required here, if everything in there matches the Treble requirements as listed on Android Developers then chances are it is ready.
3) An unused partition of ~500MB or more for Vendor, or the ability to repartition the device (many Qualcomm devices are standard GPT partitioned eMMC these days, if it is then it's possible).
That's a summary of the requirements. Obviously some technical investigation is required. Forward that info to any device developers who are interested in the project.
Click to expand...
Click to collapse
About re-partitioning android device, is there a tool, command or anything universal to all the phones, like how in linux you can re-partition what and how you want. For example, I never saw a re-partition "mod" for samsung devices (ex. to give more space on /system). There is only one reason I can think of.
If samsung "download mode" is stored on a read-only pre-programmed chip, then re-partition should be no problem. If anything goes wrong, just flash stock firmware with CSC or flash official .PIT file.
If that is the case then there are no risks in re-partitioning a device.
There is a tool that can edit .PIT files, but what if someone wipes the bootloader partition?
Would "download mode" still be there for a roll-back, or would the device be permenantly bricked?
Is re-partition-ing safe?
If it is, then why doesn't any 3rd party recovery have an option for that, kinda like GPARTED. Is it impossible or what?
And if bootloader gets wiped, is there a way to re-program the device to the working order?
Sry for so many questions. Already tried to search but never got a straight-forward answer.

Shadow7107 said:
About re-partitioning android device, is there a tool, command or anything universal to all the phones, like how in linux you can re-partition what and how you want. For example, I never saw a re-partition "mod" for samsung devices (ex. to give more space on /system). There is only one reason I can think of.
If samsung "download mode" is stored on a read-only pre-programmed chip, then re-partition should be no problem. If anything goes wrong, just flash stock firmware with CSC or flash official .PIT file.
If that is the case then there are no risks in re-partitioning a device.
There is a tool that can edit .PIT files, but what if someone wipes the bootloader partition?
Would "download mode" still be there for a roll-back, or would the device be permenantly bricked?
Is re-partition-ing safe?
If it is, then why doesn't any 3rd party recovery have an option for that, kinda like GPARTED. Is it impossible or what?
And if bootloader gets wiped, is there a way to re-program the device to the working order?
Sry for so many questions. Already tried to search but never got a straight-forward answer.
Click to expand...
Click to collapse
No, nothing is standard when it comes to embedded systems (which our devices are). By "standard on Linux", you must mean "Standard on x86-based Linux" - which is mostly all MBR or GPT (but even then there are other less-common standards)
But as I said - many Qualcomm devices are in fact standard GPT, you can just use gdisk (a fork of fdisk which is better choice for GPT partition maps).
Repartitioning is relatively safe on SOME devices because they have an emergency bootloader/downloader which is on it's own EEPROM and not the eMMC or whatever. You will have to research the device for yourself to see if it has any "unbrick" capability. Again, many qualcomm devices have what is called "EDL mode" - EDL mode is still possible even if you "cat /dev/null > /dev/block/mmcblk0" for example - albeit you may need to disassemble the device to access test point to get it to be kicked into there.

[REFERENCE] Umbrella Kernel

WARNING:
This is not a post targeted to end users. It is a development reference. If you expect any installable download or even added features out of this thread, please close your browser. Thank you.
What is Umbrella?
Umbrella is a project that aims to make the kernel sources that HMD released for Nokia 8 Sirocco (A1N) compatible with the Nokia 8 (NB1). The idea behind this is to replace the outdated 8.0 kernel sources that HMD released for NB1 with more up to date ones that are used in the 9.0 builds for Nokia 8 Sirocco.
Why do this, you might ask. Well, the answer is simple: The devices are so similar that HMD / FIH already have their kernel sources in a shared source tree. You can validate that yourself, by downloading the kernel config from a stock NB1 kernel (under /proc/config.gz), unpacking it, and searching for the commended entry "CONFIG_FIH_A1N". What umbrella does is take the sources that were released for A1N, readd all device specific files for NB1 (they were pruned) from it's original kernel soure, and integrate the stock kernel config (also called defconf) from NB1.
Doing this also lead to some other small quality of life improvements that are not directly relevant to an end user.
Umbrella contains the latest changes from linux-stable (v4.4.179 at the time of writing, compared to the stock v4.4.153), and Qualcomms Codeaurora upstream
The WiFi driver from Qualcomm is compiled directly into the kernel, instead of being loaded as a module. This allows you to flash umbrella based kernels to every build version while keeping everything else working correctly. The stock kernels use signature enforcement, which means that the wifi module that is loaded from the system partition has to be signed against the kernel, which is not the case for every custom kernel or even the kernels that were built for a different security patch.
Unlike the officially released kernel sources, umbrella does not have stupid typos in it's device trees that cause the phone to display white bars on all of your screen etc.
Umbrella disables the block that FIH put in place to prevent users from rebooting into EDL mode from within android (using adb reboot edl).
Umbrella also includes a patch that causes the device to not reset it's entire memory when the kernel crashes, therefore retaining the last kernel output log, which can be used for debugging
You can compile the kernel with compilers newer than GCC 4.9 (not clang though), without having it immideately crash at boot.
It includes a tool that automatically sets up a crosscompiling environment for the kernel.
What Umbrella is not
Umbrella is not a project to add significant new features, or the ability to tweak things beyond what the stock kernel already offers (which is technically not that bad). It aims to be a reference kernel, a base for (potentially) other kernels that are based on it and add those features. I know that that is kind of a broad goal, considering I am the only one who seems to do actual development for this phone, but who knows. Having a lower entry level might help in case someone is curious and wants to get into kernel hacking. And I would certainly be happy if I wasn't the only one developing for this device.
If you want Umbrella to contain features like:
Overclocking
More governors / schedulers / whatever
Color / Sound / whatever control
Wakelock blocking
etc. etc. etc.
then please Alt-F4 your browser right now. Ok, don't do that but at least please don't request it because it will make you get ignored, nothing else.
Why the name Umbrella?
While I developed the initial prototype I watched through 3 Resident Evil movies, and this is kinda a zombie project, so I think the name fits quite well.
Why are you posting this?
I am posting this because I am hoping that it will be useful for anyone that would like to get into kernel development and tweaking without the hassle that comes with setting up the kernel sources that are released by HMD.
But, one disclaimer: I am not a kernel developer. I am a curious CS student suffering from a bad mix of too much time and stupid ideas that solve stupid problems. I am trying my best to produce something useful and be of help, but please don't expect wonders from me, thanks.
Links?
Source: https://github.com/resident-nokia/umbrella
Download: None, this is a development reference.

Looks promising
Sent from my NB1 using XDA Labs

Nice. this will likely be useful in the future

Updated the umbrella source to the latest 4.4.180 kernel, and May 07 CAF tag (LA.UM.7.4.r1-05100-8x98.0). Also readded some NB1 specific code where it was missing (discovered by doing a diff against the 5140 kernel source that Nokia recently released).
Just in case anyone actually cares about it

THMSP said:
Updated the umbrella source to the latest 4.4.180 kernel, and May 07 CAF tag (LA.UM.7.4.r1-05100-8x98.0). Also readded some NB1 specific code where it was missing (discovered by doing a diff against the 5140 kernel source that Nokia recently released).
Just in case anyone actually cares about it
Click to expand...
Click to collapse
I do. Who knows, in a year's time I might have enough knowledge to build a custom Rom for this phone

Kernel sources which is used on pie has been released officially. Finally, we have an "original" kernel and we've got closed one more step to custom roms.
https://www.nokia.com/phones/en_int/opensource/

techno_man000 said:
Kernel sources which is used on pie has been released officially. Finally, we have an "original" kernel and we've got closed one more step to custom roms.
https://www.nokia.com/phones/en_int/opensource/
Click to expand...
Click to collapse
@THMSP it would be interesting to let us know how different is your kernel mod from the newly released official pie kernel for Nokia 8

MDV106 said:
@THMSP it would be interesting to let us know how different is your kernel mod from the newly released official pie kernel for Nokia 8
Click to expand...
Click to collapse
As I described here: https://forum.xda-developers.com/nokia-8/development/official-source-code-releases-nokia-8-t3930324, they are identical. The only difference are the device tree files (which still contain typos that break the display), and of course all modifications I made to the sirocco kernel source that Umbrella is based on (wifi driver, EDL mode reactivation, upstreaming, etc.)

THMSP said:
As I described here: https://forum.xda-developers.com/nokia-8/development/official-source-code-releases-nokia-8-t3930324, they are identical. The only difference are the device tree files (which still contain typos that break the display), and of course all modifications I made to the sirocco kernel source that Umbrella is based on (wifi driver, EDL mode reactivation, upstreaming, etc.)
Click to expand...
Click to collapse
So, are these new codes broken like 4.84?

techno_man000 said:
So, are these new codes broken like 4.84?
Click to expand...
Click to collapse
I wouldn't call Nokia sources broken, but I would call them incomplete, outdated and impractical to work with. And that hasn't changed.

Iam currently building device tree for nokia 8..
Unable to figure out how to edit init folder specifically for nokia8

[email protected] said:
Iam currently building device tree for nokia 8..
Unable to figure out how to edit init folder specifically for nokia8
Click to expand...
Click to collapse
Please do so! We can't let this phone die so early!

which defconfig file should choose?

lk

[email protected] said:
which defconfig file should choose?
Click to expand...
Click to collapse
nb1_defconfig is for Nokia 8

Can somebody help me? I have built Lineage OS 16.0 for the Nokia 8 with the Umbrella Kernel. However I am facing issues with getting it into work. Firstly TWRP fails to flash it with error 7. I am including the recovery.log file in case anyone wants more detail. I then proceeded to extract the payload.bin file, and flashed boot.img and system.img seperately. However that didnt work either as my phone got stuck at the Bootloader unlocked warning screen. If anyone is interesteed I can upload the .zip outputed by the build
Device Tree: https://github.com/GPUCode/android_device_nokia_nb1
Recovery.log: https://hastebin.com/akohutiwed.sql
Thanks in advanced

emufan4568 said:
Can somebody help me? I have built Lineage OS 16.0 for the Nokia 8 with the Umbrella Kernel. However I am facing issues with getting it into work. Firstly TWRP fails to flash it with error 7. I am including the recovery.log file in case anyone wants more detail. I then proceeded to extract the payload.bin file, and flashed boot.img and system.img seperately. However that didnt work either as my phone got stuck at the Bootloader unlocked warning screen. If anyone is interesteed I can upload the .zip outputed by the build
Device Tree: https://github.com/GPUCode/android_device_nokia_nb1
Recovery.log: https://hastebin.com/akohutiwed.sql
Thanks in advanced
Click to expand...
Click to collapse
hey, did you wipe userdata before flashing this? I think you need to do that, like when switching to using GSIs.
also, have you checked this https://github.com/resident-nokia/twrp? Specifically the fstab file for NB1.

oaid said:
hey, did you wipe userdata before flashing this? I think you need to do that, like when switching to using GSIs.
Click to expand...
Click to collapse
Thanks for the suggestion. I have flashed GSIs before but never had any problems. Also I cannot find any userdata partition in TWRP. I asked in the Lineage OS discord and I was told that probably that TWRP image is broken. I am confused

emufan4568 said:
Thanks for the suggestion. I have flashed GSIs before but never had any problems. Also I cannot find any userdata partition in TWRP. I asked in the Lineage OS discord and I was told that probably that TWRP image is broken. I am confused
Click to expand...
Click to collapse
that's the data partition, if I'm not mistaken ?*
which twrp image are you using? Maybe try Dorian's latest?

oaid said:
that's the data partition, if I'm not mistaken ?*
which twrp image are you using? Maybe try Dorian's latest?
Click to expand...
Click to collapse
Yes I am using the latest TWRP. Before flashing I erased the data partition but still the error persisted

Android 7.1.2 to Samsung Galaxy J2LTE

I have that doubt, until today there is no ROM that can be installed on the J2 which includes Android 7 or at least one Android 6 ROM that is based on AOSP?

Right now, there isn't any AOSP or Nougat-based ROM for the j2lte. Tomorrow, who knows?

TBM 13 said:
Right now, there isn't any AOSP or Nougat-based ROM for the j2lte. Tomorrow, who knows?
Click to expand...
Click to collapse
but I wonder why the other model of the J2, the 3G if it has several roms based on Android AOSP or based on Android 7.1.2 if both have the same processor, greatly changes the shape of its code to make it impossible to use with the J2LTE ?

SharkyBeAre said:
but I wonder why the other model of the J2, the 3G if it has several roms based on Android AOSP or based on Android 7.1.2 if both have the same processor, greatly changes the shape of its code to make it impossible to use with the J2LTE ?
Click to expand...
Click to collapse
You mean the J200H? It has a completly different processor.

TBM 13 said:
You mean the J200H? It has a completly different processor.
Click to expand...
Click to collapse
CPU-Z is my phone (J200M) <J2LTE> and the other screenshot is information taken from the internet that says that the J200H has the same processor as the J200M - J2LTE. Who is lying, Cpu-z or the page where I consulted the information

This is another page that says the J200H has the Exynos 3475.
https://www.sammobile.com/samsung/galaxy-j2/specs/SM-J200H/

More Screenshots of my J2LTE

SharkyBeAre said:
This is another page that says the J200H has the Exynos 3475.
https://www.sammobile.com/samsung/galaxy-j2/specs/SM-J200H/
Click to expand...
Click to collapse
Take a look to this, from https://forum.xda-developers.com/galaxy-j2/development/lineageos-samsung-galaxy-j2-t3659657
Will it work on j200g/gu/BT/F??
Naah.. It won't boot as j200h is sprd but others are ****ty Exynos
Click to expand...
Click to collapse

SharkyBeAre said:
More Screenshots of my J2LTE
Click to expand...
Click to collapse
TBM 13 said:
Take a look to this, from https://forum.xda-developers.com/galaxy-j2/development/lineageos-samsung-galaxy-j2-t3659657
Click to expand...
Click to collapse
Its actually only J200H/DD that is based on spreadtrum SC8830. J200H and J200H/DS is Exynos-based.
afaik, J200H/DD is only sold in some countries like India or here at Vietnam. The rest is available worldwide and therefore more recognizable by most people.
e: further info, codename for J200H/DD (Spreadtrum) is j23gdd, whilst J200H(/DS) (Exynos) is j23gxx.
e2: I can always try to build blindly, considering on5 pro (on5prolte / same Exynos chipset) has Lineage fully functional.
But, *also* considering the lack of time and the mess of J2 Prime RIL I'm making, I cannot guarantee a fully functional one here :<

Prove N. said:
e2: I can always try to build blindly, considering on5 pro (on5prolte / same Exynos chipset) has Lineage fully functional.
But, *also* considering the lack of time and the mess of J2 Prime RIL I'm making, I cannot guarantee a fully functional one here :<
Click to expand...
Click to collapse
Exynos3475 developers already tried. They never managed to get to the boot animation and make logcats work. When they tried the same j2 tree on the on5prolte, it booted without problems.
Basically, the o5prolte got LOS 14.1 with the j2lte device tree.
I managed to get working logs and boot animation in los 14.1 by replacing the init binary with marshmallow one, from the J1XLTE and doing some init.rc fixes
The problem is that zygote crashes.
If i don't replace the init binary, adb detects the device but if i try to do adb shell or adb logcat, i get this:
Exec '/system/bin/sh' failed: No such file or directory (2)
J1XLTE (J1 2016) seems to have the exact same problem. I'm currently working with a developer of that device, because if it boots on it, it boots on ours, and visce versa.
Somehow it isn't able to mount the system partition.
Now, i'm trying LOS 13. It already got more far than LOS 14.1 (i still need to replace the init binary and do some modifications to init.rc). Sensors service seems to be crashing, and there is no boot animation, just black screen.

Prove N. said:
Its actually only J200H/DD that is based on spreadtrum SC8830. J200H and J200H/DS is Exynos-based.
afaik, J200H/DD is only sold in some countries like India or here at Vietnam. The rest is available worldwide and therefore more recognizable by most people.
e: further info, codename for J200H/DD (Spreadtrum) is j23gdd, whilst J200H(/DS) (Exynos) is j23gxx.
e2: I can always try to build blindly, considering on5 pro (on5prolte / same Exynos chipset) has Lineage fully functional.
But, *also* considering the lack of time and the mess of J2 Prime RIL I'm making, I cannot guarantee a fully functional one here :<
Click to expand...
Click to collapse
TBM 13 said:
Exynos3475 developers already tried. They never managed to get to the boot animation and make logcats work. When they tried the same j2 tree on the on5prolte, it booted without problems.
Basically, the o5prolte got LOS 14.1 with the j2lte device tree.
I managed to get working logs and boot animation in los 14.1 by replacing the init binary with marshmallow one, from the J1XLTE and doing some init.rc fixes
The problem is that zygote crashes.
If i don't replace the init binary, adb detects the device but if i try to do adb shell or adb logcat, i get this:
Exec '/system/bin/sh' failed: No such file or directory (2)
J1XLTE (J1 2016) seems to have the exact same problem. I'm currently working with a developer of that device, because if it boots on it, it boots on ours, and visce versa.
Somehow it isn't able to mount the system partition.
Now, i'm trying LOS 13. It already got more far than LOS 14.1 (i still need to replace the init binary and do some modifications to init.rc). Sensors service seems to be crashing, and there is no boot animation, just black screen.
Click to expand...
Click to collapse
than? Does that mean they are trying to work on a LOS Custom Rom for the J2LTE? Forgive me that you don't understand your communication language in front of cell phones, but what I understand is that you are working to get AOSP in J2LTE?

SharkyBeAre said:
than? Does that mean they are trying to work on a LOS Custom Rom for the J2LTE?
Click to expand...
Click to collapse
No, they gave up.
SharkyBeAre said:
you are working to get AOSP in J2LTE?
Click to expand...
Click to collapse
I'm trying, but don't expect something, i'm noob at this.

TBM 13 said:
No, they gave up.
I'm trying, but don't expect something, i'm noob at this.
Click to expand...
Click to collapse
I trust that something good will come out of all the tests you can do being a noob, hopefully, because Samsung's system seems to me the worst, and it takes up a lot of space.
Thanks for all

TBM 13 said:
Exynos3475 developers already tried. They never managed to get to the boot animation and make logcats work. When they tried the same j2 tree on the on5prolte, it booted without problems.
Basically, the o5prolte got LOS 14.1 with the j2lte device tree.
I managed to get working logs and boot animation in los 14.1 by replacing the init binary with marshmallow one, from the J1XLTE and doing some init.rc fixes
The problem is that zygote crashes.
If i don't replace the init binary, adb detects the device but if i try to do adb shell or adb logcat, i get this:
Exec '/system/bin/sh' failed: No such file or directory (2)
J1XLTE (J1 2016) seems to have the exact same problem. I'm currently working with a developer of that device, because if it boots on it, it boots on ours, and visce versa.
Somehow it isn't able to mount the system partition.
Now, i'm trying LOS 13. It already got more far than LOS 14.1 (i still need to replace the init binary and do some modifications to init.rc). Sensors service seems to be crashing, and there is no boot animation, just black screen.
Click to expand...
Click to collapse
That is quite weird? are you sure about the partition layout, compatibility of blobs and some stuff and things?
is system defined correctly in fstab? Is its permissions defined correctly in ueventd?
I see that it is common-ized (and stripped down) in exynos3475-common which might be the cause, as j23gxx/j2lte is 1-year older than on5. Have you tried using stock fstab and ueventd for the ROM? (assuming you are building from source)
e:
afaik/if im not wrong: the dev has only On5 T-Mobile, which should explains why only that device tree (on5ltetmo) is well-configured and why the generic on5prolte is empty.
And, I cant seem to find On5 Pro tree (its ROM is on XDA), so I guess its just a port.

Prove N. said:
That is quite weird? are you sure about the partition layout, compatibility of blobs and some stuff and things?
is system defined correctly in fstab? Is its permissions defined correctly in ueventd?
I see that it is common-ized (and stripped down) in exynos3475-common which might be the cause, as j23gxx/j2lte is 1-year older than on5. Have you tried using stock fstab and ueventd for the ROM? (assuming you are building from source)
e:
afaik/if im not wrong: the dev has only On5 T-Mobile, which should explains why only that device tree (on5ltetmo) is well-configured and why the generic on5prolte is empty.
And, I cant seem to find On5 Pro tree (its ROM is on XDA), so I guess its just a port.
Click to expand...
Click to collapse
Actually, the good device tree is the on5prolte one, cm-14.1-20180513 branch (https://github.com/Exynos3475/android_device_samsung_o5prolte/tree/cm-14.1-20180513) (you can even see Device configuration for the Samsung Galaxy J2 (j2lte) WIP for now in the README.md )
The fstab is working fine, i managed to build TWRP from CM-14.1 source, and it uses the same fstab. TWRP works fine, except for MTP but that is probably because i'm using the nougat kernel.
No, i didn't tried the stock ueventd, but i don't see how that will change something, because the problem is on the init binary itself.
Also, the main j2lte developer (Izzy) has the J2.

TBM 13 said:
Actually, the good device tree is the on5prolte one, cm-14.1-20180513 branch (https://github.com/Exynos3475/android_device_samsung_o5prolte/tree/cm-14.1-20180513) (you can even see Device configuration for the Samsung Galaxy J2 (j2lte) WIP for now in the README.md )
The fstab is working fine, i managed to build TWRP from CM-14.1 source, and it uses the same fstab. TWRP works fine, except for MTP but that is probably because i'm using the nougat kernel.
No, i didn't tried the stock ueventd, but i don't see how that will change something, because the problem is on the init binary itself.
Also, the main j2lte developer (Izzy) has the J2.
Click to expand...
Click to collapse
I did not check the branches .
https://github.com/Exynos3475/android_device_samsung_o5prolte/blob/cm-14.1-20180513/BoardConfig.mk
Is it okey with kernel built with this?
Code:
TARGET_KERNEL_CONFIG := lineage-o5lteswa_defconfig

Prove N. said:
I did not check the branches .
https://github.com/Exynos3475/android_device_samsung_o5prolte/blob/cm-14.1-20180513/BoardConfig.mk
Is it okey with kernel built with this?
Click to expand...
Click to collapse
Maybe they share the defconfig

TBM 13 said:
Maybe they share the ramdisk
Click to expand...
Click to collapse
No. I meant, isnt kernel defconfig defines lots of things (including hardware/software and features of that one phone)?
Is it even possible to use defconfig of other device and it still works?

Prove N. said:
Is it even possible to use defconfig of other device and it still works?
Click to expand...
Click to collapse
If the device is very similar, why not?
---------- Post added at 17:53 ---------- Previous post was at 17:51 ----------
Prove N. said:
Is it even possible to use defconfig of other device and it still works?
Click to expand...
Click to collapse
If the device is very similar, why not?
TBM 13 said:
Maybe they share the ramdisk
Click to expand...
Click to collapse
I accidentally typed ramdisk instead of defconfig lol

TBM 13 said:
If the device is very similar, why not?
Click to expand...
Click to collapse
only with the SoC i guess. I thought On5 has 2GB RAM and J2 has 1, for example. Who knows about driver differences too~

Question which time can we have ROMs for xperia 10 III ?

I just can't wait anymore

Deemooo said:
I just can't wait anymore
Click to expand...
Click to collapse
Just compile AOSP :
- here are sources : https://github.com/sonyxperiadev/device-sony-pdx213
- here are instructions : https://developer.sony.com/develop/open-devices/guides/aosp-build-instructions/
And please share some thoughts, I do not have the device yet so I could not do this myself

PrzeStaw said:
Just compile AOSP :
- here are sources : https://github.com/sonyxperiadev/device-sony-pdx213
- here are instructions : https://developer.sony.com/develop/open-devices/guides/aosp-build-instructions/
And please share some thoughts, I do not have the device yet so I could not do this myself
Click to expand...
Click to collapse
sorry, i don't understand the system domain, i just a normal xperia user, just want to use native android likes los,dotos,rr etc. I'm sorry i can't help you, All i can do is wait, that's some sad.

PrzeStaw said:
Just compile AOSP :
- here are sources : https://github.com/sonyxperiadev/device-sony-pdx213
- here are instructions : https://developer.sony.com/develop/open-devices/guides/aosp-build-instructions/
And please share some thoughts, I do not have the device yet so I could not do this myself
Click to expand...
Click to collapse
Yes I see xperia merge fix in sources actually for kernel sources issue compile . I will create custom kernel for start . lineage later

PrzeStaw said:
Just compile AOSP :
- here are sources : https://github.com/sonyxperiadev/device-sony-pdx213
- here are instructions : https://developer.sony.com/develop/open-devices/guides/aosp-build-instructions/
And please share some thoughts, I do not have the device yet so I could not do this myself
Click to expand...
Click to collapse
I managed to compile the sources but it doesn't seem to be enough.
Sony guide has a step to flash a vendor image:
Build AOSP Android 11.0 - Open Devices - Sony Developer World
developer.sony.com
There are no vendor images for 10 mark III yet.
I guess we need to wait till Sony publishes them. Please correct me if I'm wrong, it's a first time I compile Android

vurg_usk said:
I managed to compile the sources but it doesn't seem to be enough.
Sony guide has a step to flash a vendor image:
Build AOSP Android 11.0 - Open Devices - Sony Developer World
developer.sony.com
There are no vendor images for 10 mark III yet.
I guess we need to wait till Sony publishes them. Please correct me if I'm wrong, it's a first time I compile Android
Click to expand...
Click to collapse
I guess we can create repo vendor and extract proprietary blobs from stock vendor...

I tested phh gsi lineage and its fully stable guy - in bonus green tint is fixed -

Nice
And it's good that there is no green screen in custom roms
I can't wait for DotOS or other roms. XperiaUI is boring.
@ada12 Are you also building recovery?

Kyrimeas said:
Nice
And it's good that there is no green screen in custom roms
I can't wait for DotOS or other roms. XperiaUI is boring.
@ada12 Are you also building recovery?
Click to expand...
Click to collapse
for now no . I run actually gsi phh in daily use for stability . for sources I still work on it I have worked for compile kernel xperia https://github.com/Aarqw12/kernel_PDX213/commits/aosp/LA.UM.9.12.r1 but no luck actually its bootlop only for unknow reason.

Kyrimeas said:
Are you also building recovery?
Click to expand...
Click to collapse
You can try doing it yourself
[GUIDE]Porting TWRP without source
Yes, I know XDA is filled with such guides. But you can only port a TWRP if you implement parts of all the guides. This guide is a summation of all those guides. NOTE: I would be using AIK-Linux in this tutorial, since I don't recommend Windows...
forum.xda-developers.com
No actual programming required.

zpk787 said:
You can try doing it yourself
[GUIDE]Porting TWRP without source
Yes, I know XDA is filled with such guides. But you can only port a TWRP if you implement parts of all the guides. This guide is a summation of all those guides. NOTE: I would be using AIK-Linux in this tutorial, since I don't recommend Windows...
forum.xda-developers.com
No actual programming required.
Click to expand...
Click to collapse
for stability build-in is very recommanded

vurg_usk said:
I managed to compile the sources but it doesn't seem to be enough.
Sony guide has a step to flash a vendor image:
Build AOSP Android 11.0 - Open Devices - Sony Developer World
developer.sony.com
There are no vendor images for 10 mark III yet.
I guess we need to wait till Sony publishes them. Please correct me if I'm wrong, it's a first time I compile Android
Click to expand...
Click to collapse
no need vendor image, need only flash oem.img xperia give really everything . lena sodp is no completly done for now , new features need to be implemented team sodp work on it. I guess just wait more

now xperia 10 III is officially added to open-source programm
Xperia 10 III added to Sony's Open Devices program - Sony Developer World
developer.sony.com
software binary released now we can compile rom

Hello. So is a custom ROM, or Lineageos now available for the Xperia 10 III? I know nothing about programming a phone, so this is something I may not do on my own. I really just need a new phone (still using a 2013 iPhone 5S) but refuse to use Google or Apple's ecosystem (anymore). I also refuse to use a phone made in China, nor lacks a headphone jack and the only other phones that meet these criteria are too large for me (even this one is on the large end). So does anyone have steps to degoogle this phone, as of the near future or so, so I may order this phone asap? I have Windows, Mac, and will be downloading a Devuan-based Linux distro on another computer soon. Otherwise, I know LineageOS has come out for the Xperia 10 II, but how does that one compare to this one?

xinniethewuflooh said:
Hello. So is a custom ROM, or Lineageos now available for the Xperia 10 III? I know nothing about programming a phone, so this is something I may not do on my own. I really just need a new phone (still using a 2013 iPhone 5S) but refuse to use Google or Apple's ecosystem (anymore). I also refuse to use a phone made in China, nor lacks a headphone jack and the only other phones that meet these criteria are too large for me (even this one is on the large end). So does anyone have steps to degoogle this phone, as of the near future or so, so I may order this phone asap? I have Windows, Mac, and will be downloading a Devuan-based Linux distro on another computer soon. Otherwise, I know LineageOS has come out for the Xperia 10 II, but how does that one compare to this one?
Click to expand...
Click to collapse
At the moment, we do not have lineageOS and recovery. There are only aosp sources that we can build.
Ada12 is currently building a custom kernel.
We will have roms for sure in the future.

xinniethewuflooh said:
Hello. So is a custom ROM, or Lineageos now available for the Xperia 10 III? I know nothing about programming a phone, so this is something I may not do on my own. I really just need a new phone (still using a 2013 iPhone 5S) but refuse to use Google or Apple's ecosystem (anymore). I also refuse to use a phone made in China, nor lacks a headphone jack and the only other phones that meet these criteria are too large for me (even this one is on the large end). So does anyone have steps to degoogle this phone, as of the near future or so, so I may order this phone asap? I have Windows, Mac, and will be downloading a Devuan-based Linux distro on another computer soon. Otherwise, I know LineageOS has come out for the Xperia 10 II, but how does that one compare to this one?
Click to expand...
Click to collapse
yeah，i also think we can have roms in the furture，im waiting

Kyrimeas said:
At the moment, we do not have lineageOS and recovery. There are only aosp sources that we can build.
Ada12 is currently building a custom kernel.
We will have roms for sure in the future.
Click to expand...
Click to collapse
at the moment aosp sony custom rom boot . I have tried and its no booted Haxk20 have confirmed recently its have booted finally and guide compile sony is updated. actually they are no lineage custom rom in this devices ( need adapt trees ) but lineage GSI is already available for this phone. for recovery sources bringup its no finish.

xinniethewuflooh said:
Hello. So is a custom ROM, or Lineageos now available for the Xperia 10 III? I know nothing about programming a phone, so this is something I may not do on my own. I really just need a new phone (still using a 2013 iPhone 5S) but refuse to use Google or Apple's ecosystem (anymore). I also refuse to use a phone made in China, nor lacks a headphone jack and the only other phones that meet these criteria are too large for me (even this one is on the large end). So does anyone have steps to degoogle this phone, as of the near future or so, so I may order this phone asap? I have Windows, Mac, and will be downloading a Devuan-based Linux distro on another computer soon. Otherwise, I know LineageOS has come out for the Xperia 10 II, but how does that one compare to this one?
Click to expand...
Click to collapse
You can check "e foundation" GSI. It's ungoogled phones

ada12 said:
at the moment aosp sony custom rom boot . I have tried and its no booted Haxk20 have confirmed recently its have booted finally and guide compile sony is updated. actually they are no lineage custom rom in this devices ( need adapt trees ) but lineage GSI is already available for this phone. for recovery sources bringup its no finish.
Click to expand...
Click to collapse
I'm sorry I have no idea what you're saying. There are already available custom AOSP roms, no? What a "lineage gsi" and how do I compile it (on a Windows)? All I need until a custom rom is released is too remove google from the phone entirely. This is possible?

xinniethewuflooh said:
I'm sorry I have no idea what you're saying. There are already available custom AOSP roms, no? What a "lineage gsi" and how do I compile it (on a Windows)? All I need until a custom rom is released is too remove google from the phone entirely. This is possible?
Click to expand...
Click to collapse
GSI is no a custom rom its a Generic System image , its update only /system ( os framework ) and use blobs,drivers from your /vendor , GSI is universal and run in all devices treble .
They are no custom rom available in public actually for this devices , source for custom rom is availlable but unstable in use ( sound only in headset , ril bug ... )
actually if you want run lineage or other custom android os use PHH GSI , or wait for custom rom ( NO ETA ).

Building LineageOS 18.1 for device that only supports 19.1

I desperately need to get my work profile working on my new OnePlus Nord N200 5G (dre), and I've just discovered that it is apparently impossible to create a new work profile on LineageOS 19.1. It seems, however, that a work profile set up on 18.1 will continue to work after a dirty flash to 19.1. Thus, I'm hoping that I can install 18.1 on my device, setup of the work profile, and immediately dirty flash 19.1. I won't really need a fully functional build of 18.1; just something that will boot up and allow me to create the work profile before I dirty-flash 19.1.
In order to do this, I need to build LineageOS 18.1 for this device. Unfortunately, only 19.1 has ever been supported.
I have a build environment that is currently building 19.1, just as a test. I also have the most recent Android 11 vendor firmware, from which I should be able to extract any required proprietary files.
I'm really missing 2 things:
The list of proprietary files that I should extract from the vendor's firmware. (I have the 19.1 list, but I assume that it won't work.)
What other files do I need to create/edit to add the device to the 18.1 build tree.
Is there a guide somewhere that walks through the process?

Ah, @ipilcher I was hoping someone smarter than me would answer your question. It would do so much for all the Android forks, and Android in general. I've asked the same question to several devs on IRC and they all basically say "no, no easy way to explain it...". My kingdom for a guide that doesn't involve the School of Hard Knocks all the way through.
So in full disclosure, as of today, I haven't managed to build a ROM on an unsupported phone- but I have done full builds from source with LOS and Calyx (with bootloader relocking on the latter) using existing projects.
But... I would assume from others that have gotten the AOSP "Generic Stock Images" to run on various random phones that there isn't really that much you /need/ for what you want to do; you don't need a functioning modem, fingerprint sensor, camera, GPS, notification LED, battery management, etc.
From what I understand, if your vendor follows android specs, all that would be in one of the vendor partitions anyway. From the builds I've done (mostly Motorola and OnePlus devices) the proprietary files (in "stock" LOS) are sourced from a few different places, possibly from generic chipset support (the same tree is used for multiple devices by a manufacturer and/or chipset). One LOS 18.1 build had a whole bunch of (proprietary) files in it that weren't even in the stock rom image! If you are sourcing from stock firmware (OTA off OP site or one of the MSM images here) I'd assume that half the partition is spyware or manufacturer test/calibration tools, and the other half are the drivers you want for a fully functional phone- which, luckily, it seems you can fall short of without failure, so you can probably be pretty lax about picking.
The bootloader chain seems to have a lot of drama between Android 11, 12, and 13 (requiring flashing other partitions outside of the normal system ones)- I've never had a N200 to play with to know if it is high drama, too.
Hey, at least you're using a OnePlus with QC chipset, so EDL can bail you out of pretty much anything you do wrong. I hard-bricked a $500 Pixel and learned how absolutely hideous Google support is- never buying one of those again.
Hope that helps.

SomeRandomGuy said:
Ah, @ipilcher I was hoping someone smarter than me would answer your question. It would do so much for all the Android forks, and Android in general. I've asked the same question to several devs on IRC and they all basically say "no, no easy way to explain it...". My kingdom for a guide that doesn't involve the School of Hard Knocks all the way through.
So in full disclosure, as of today, I haven't managed to build a ROM on an unsupported phone- but I have done full builds from source with LOS and Calyx (with bootloader relocking on the latter) using existing projects.
But... I would assume from others that have gotten the AOSP "Generic Stock Images" to run on various random phones that there isn't really that much you /need/ for what you want to do; you don't need a functioning modem, fingerprint sensor, camera, GPS, notification LED, battery management, etc.
From what I understand, if your vendor follows android specs, all that would be in one of the vendor partitions anyway. From the builds I've done (mostly Motorola and OnePlus devices) the proprietary files (in "stock" LOS) are sourced from a few different places, possibly from generic chipset support (the same tree is used for multiple devices by a manufacturer and/or chipset). One LOS 18.1 build had a whole bunch of (proprietary) files in it that weren't even in the stock rom image! If you are sourcing from stock firmware (OTA off OP site or one of the MSM images here) I'd assume that half the partition is spyware or manufacturer test/calibration tools, and the other half are the drivers you want for a fully functional phone- which, luckily, it seems you can fall short of without failure, so you can probably be pretty lax about picking.
The bootloader chain seems to have a lot of drama between Android 11, 12, and 13 (requiring flashing other partitions outside of the normal system ones)- I've never had a N200 to play with to know if it is high drama, too.
Hey, at least you're using a OnePlus with QC chipset, so EDL can bail you out of pretty much anything you do wrong. I hard-bricked a $500 Pixel and learned how absolutely hideous Google support is- never buying one of those again.
Hope that helps.
Click to expand...
Click to collapse
I just wanted to close this out and thank you for your response.
Fortunately, the issue that was driving me to try to build 18.1 for this device (https://gitlab.com/LineageOS/issues/android/-/issues/4983) has been diagnosed, and I was able to work around it.
Of course, I just realized that my wife's new Moto G 5G is an XT2213-3, not an XT2113-3, so maybe I'll revisit this subject some day.

Welllp... at the risk of being accused of insufficent RTFMing, I did stumble across this article the other day that nicely outlined a few things that I didn't know:
[GUIDE] [how to] CREATE OWN ROM [FOR ANY ANDROID DEVICE] [FOR N00B] [EASIEST METHODS]
NOTE: THIS GUIDE WILL WORK ANY ANDROID DEVICE BUT HAS FEW EXTRA PRE-SUGGESTED LINKS FOR GALAXY ACE PLUS USERS. Special Thanks to - dsixda for his awesome kitchen. Please Hit Thanks button for him. inspired by isidromxz's thread. Please kindly...
forum.xda-developers.com
It isn't exactly "build your own device tree on top of AOSP" which I think is what you wanted and I certainly still do... but it might help someone else who finds /this/ thread with the same question. It also ends with the wonderful quote "This thread is 10 yo. Leave it alone. things have changed" - which is pretty solid advice IMHO.
Ah well, if it wasn't a challenge, there would be no reward, eh?