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Enable usage of mobile data while connected to a WiFi without internet connection
It is possible to allow my device to use mobile data while connected to a WiFi hotspot?
The reason being is that the WiFi hotspot I connect to does not have an internet connection. So I want to be able to access the internet while still being connected to this WiFi network.
I can see that after Android 10, there is a feature called dual acceleration which allows this for certain app like Instagram, Chrome and Facebook. I want to be able to do it for any app. Is there a way of accomplishing this?

I've just recently come across this question, as I have been struggling with the same problem.
I have a potential solution which I've found which might help others. These instructions are for a Samsung Phone, but you may be able to find the equivalent options on Android.
I have a device that requires me to connect my phone to it via it's own hotspot. The hotspot the device creates doesn't have internet access, and because my cellphone thinks it is connected to a wifi network, it then refuses to use mobile data. I only want to use mobile data when connected to this ssid.
These are the steps I used which seemed to work:

Activate hotspot on device which does not have internet access.
In the connection settings connect to device.
Android then prompts you saying the current network does not have internet access.

    Connect just this time
    Always Connect
    Disconnect

IGNORE THIS PROMPT! Close the wifi connection app, and you should now have both a mobile connection and the network connection.

Note:
If you have already accepted one of these options, you can either:

forget the network, and try this again,
otherwise go to
Connections -> Wifi -> Advanced -> Switch to mobile data -> Network Exceptions and delete the entry for the SSID in question.

This unfortunately didn't work for me on my Note 20 on android 11

Works for me with a S21 on Android 13. [Edited by Moderator Firelord]

Unfortunately, I can't find an equivalent setting on Pixel 6.

Worked on my samsung galaxy S22 ultra


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Is app size larger in older Android versions?
I currently have Android 6.0 Marshmallow. If I install a newer Android version, will the app take less storage on my phone? In other words, does an app carry excess luggage to get it working on older phones?

That depends. In Google Play Store you developers publish multiple versions of an app for different Android versions. Additionally you can split modern apps based on the CPU type (ABI), language and other factors so that each device needs to download and store only the required parts. This feature is AFAIK available since Android 5.

@Robert If you are able to confirm which version of Android started allowing those splits, please do let us know. Thanks!

source: Stack Exchange

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

sort: votes


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How to make Android always use external SD card instead of internal storage?
I created an AVD using
 bin/avdmanager create avd -d "Nexus 5" -c 2G -n nexus_5 -k "system-images;android-29;google_apis;x86_64"

The -c 2G is supposed to create a 2GB sdcard.
When I boot the emulator, however, /sdcard seems to point to internal storage on /data/media rather on the 2GB disk:
$ adb shell df -h
Filesystem                    Size  Used Avail Use% Mounted on
tmpfs                         996M  604K  996M   1% /dev
tmpfs                         996M     0  996M   0% /mnt
tmpfs                         996M     0  996M   0% /apex
/dev/block/dm-2               2.4G  2.3G   64M  98% /
/dev/block/dm-1               124M  123M  444K 100% /vendor
/dev/block/vdc                775M  302M  473M  39% /data
/data/media                   775M  302M  473M  39% /mnt/runtime/default/emulated
/dev/block/vold/public:253,80 1.9G  532M  1.4G  27% /mnt/media_rw/1400-1801
/mnt/media_rw/1400-1801       1.9G  532M  1.4G  27% /mnt/runtime/default/1400-1801

$ adb shell ls -l /sdcard /storage/self/primary  /mnt/user/0/primary
lrwxrwxrwx 1 root root 19 2020-12-01 13:29 /mnt/user/0/primary -> /storage/emulated/0
lrw-r--r-- 1 root root 21 2020-07-21 03:02 /sdcard -> /storage/self/primary
lrwxrwxrwx 1 root root 19 2020-12-01 13:28 /storage/self/primary -> /mnt/user/0/primary

$ adb shell mount | grep storage/emulated
/data/media on /storage/emulated type sdcardfs (rw,nosuid,nodev,noexec,noatime,fsuid=1023,fsgid=1023,gid=1015,multiuser,mask=6,derive_gid,default_normal)

When I try to adb push data to /sdcard this fails because there’s not sufficient space available (on internal storage).
How can I tell the emulator to use the external sdcard instead?

That's expected. /sdcard isn't physically external SD card. It's a symlink to primary emulated external shared storage. See details in https://android.stackexchange.com/a/218469/218526, https://android.stackexchange.com/a/205494/218526 and https://android.stackexchange.com/a/218338/218526

Right, I guess my question is: how can make Android use the 2GB device instead of the smaller one. How do I configure this?

If you read the answers I linked, you get the answer to your query. Android by-default doesn't use secondary external shared storage. But apps can, if they want.

/sdcard isn't physically external SD card but a symlink to primary external shared storage. See details in my answers to Android's Storage Journey and What is /storage/emulated/0/?
From your comment:

How can make Android use the 2GB device instead of the smaller one. How do I configure this?

Android by-default doesn't use secondary external shared storage. But apps can, if they want. See my answer to How to save files to external SD card on a non-rooted Android?.
If you want to make Android always use physical SD card as primary external shared storage, you need to change your ROM's configuration from Emulated primary only or Emulated primary, physical secondary to Physical primary only. It's possible by editing the fstab file and some init's .rc file. Follow the above official documentation links for details on configuration changes.

all_licenses: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/


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WhatsApp Calling Recording
I have an android phone (Samsung Galaxy S6). Does WhatApp Record Incoming Voice Phone Calls Automatically ?
In my call info log I see incoming, the length of time and a storage amount (40MB or so).
Can I access this incoming voice call recording ?
If WhatsApp doesnt record incoming or outgoing calls, how can I record them myself ?

No whatsapp calls are end to end encrypted and it doesn't record calls.
You can use Whatsapp call recorder to record calls. Remember to disable internet access of the app for more privacy :)

So what is the MB value beside your phone call in the phone call log mean ?  Is that stored somewhere ?

I don't get it. Can you attach a screenshot?

Here is an example screenshot: https://www.quora.com/WhatsApp-How-do-I-check-a-WhatsApp-call-duration.

See the MB value beside the call duration ?

@user4434 it's internet data used during call.

yeah it's the mobile data used.. during the call.. As @IrfanLatif already said :)

It's generally less like 400kb per minute(as i've read)  The 40mb (as you mentioned) is because it was a video call maybe or you talked tooooo long..

Is there a good app that records whatsapp calls that works and doesnt crash for samsung galaxy ?

yeah i suggested that in the answer


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Why does my mobile data work for some things?
I'm not really sure when this started but I've discovered that I have some type of data. My parents haven't included data in my line yet I'm able to receive notifications from discord, youtube, google feeds etc. I can even do google searches or search for apps on the play store. But I cant actually go on a website or install an app. I cant watch youtube videos or read my discord messages. I cant play online games like brawl stars because it wont connect to the server. I can also use google maps and read reviews. My service provider is tmobile btw. Why does my mobile data work for certain things but not others?

Your data seems to work only for Google apps.

@IrfanLatif the Discord seems to be the odd one out though

Did you try using VPN? If it works then the problem is with your ISP

Also, while internet providers can certainly block requests to certain sites/IP addresses, I think it's quicker to call T-Mobile's customer support to get the answer because we can't be sure, unless the phone is under the supervision of other apps (e.g. parental filter, etc.)

It works with bing search and quora motifs too

This issue is same as yours. t mobile.. no brawl stars.. The problem is with your ISP.
I suggest you to try using a trusted local vpn (check if local one works.. not sure). It won't slow down you internet speed and get the job done too.. I too play brawl stars btw :)


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Automatically restart screencasting on phone
I have an app that continually casts the screen so I can capture images that I run through a tensorflow lite model for object detection. On Android 9 I was able to check a box to remember my decision to start the recording of the screen so when I restart my phone I don't have to intervene to start the service . Now an Android 10 and above they've removed that box and you have to tap it to enable it every single time the phone restarts. How can I Ensure that the screencasting automatically restarts whenever the phone is turned off and turned back on in Android 10 and above. Can I use phone administrator to accomplish this?

You know the scrcpy project? It automatically does all the necessary changes for streaming the screen to a PC and it allows recording.  It just requires an adb connection. May be this would be an alternative to the app you used before.

Thanks for the suggestion Robert. I took a look at the GitHub for this project and it looks like the device has to be attached to a PC or Mac and debugging mode. I'm not sure that's going to help me because my app runs standalone on an Android device and needs to record the screen 24/7. Prior to Android 10 this wasn't an issue like I said because when screen came up and asked to enable capture it had a checkbox that said remember my choice so even when I restarted the phone or the app was restarted it was able to bring it back up again without presenting that dialogue.

Can you please elaborate a bit more why you need screen record 24/7 on a phone not connected to a PC? From my perspective the only use case that comes to my mind would be spy-/malware.

Hey Robert, some of the details about what we do is proprietary and I'm not able to disclose it here however I will just say that we monitor the screen and use onboard machine learning and open CV to grab individual images and check them against an ml that we created for specific image classifications. Imagine if you were giving out phones to employees and you wanted to make sure they weren't doing anything other than work on them you could use this app to check for inappropriate texting or inappropriate images in input and output and then it would load them up to a server and report them. I

Up until Android 9 the dialogue that would come up allowed you to check a box that said remember my choice and since the phones would be set up by administrators this could not be changed so even a restore would allow it us to have the app restart screen capture, and that worked fine. Now with Android 10 they don't have that checkbox anymore and anytime an employee turns on the phone they could just ignore it and that defeats the whole purpose of the app. So what I'm looking to do is to have some code that would lock the screen and reset the password or pattern or fingerprint or whatever

The app can detect whether or not the screen capture is running and normally after a minute after restart it usually is now an Android 10 we can notify the administrator that it's not running but without the phone in hand we cannot force the employee to go back into the app and restart screen recording. If we could somehow lock them out of the phone all together that would be ideal. The employee would have to call in and get the new pattern or code and would be written up. And each time the screen lock is reset we generate a new random password


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downloads not started
I have just got a new android 10 tablet and I'm having a really stupid user interface problem.
When I click a link to a PDF document in the web browswer (Chrome) I click download and nothing happens.
After much routing around I eventually found the downloads listed in the new "google go" app.
This lists my downloads as "downloaded not started" once for each time I clicked it.
There is no obvious way to start the downloads from here.
This is very stupid default behaviour. How do I change it?
I read around somewhere that I needed to:

install a pdf viewer app - done
change the file associations  (in settings/apps & notifications/default apps)

There is no file association for PDF and no (obvious) way to add a new one
I just have:

Assist App   - Google Assistant Go
Browser App  - Chrome
Home App     - Quickstep
Phone app    - phone
SMS app      - message
<blank>    - opening links

I select a PDF viewer (e.g. Adobe) and try to enable "open by default". Nothing happens.
I did actually get some PDFs to download and thought I had fixed the problem but the next time I tried it happened again.
What am I doing wrong?
I find it hard to believe Google can have so thoroughly broken something as basic as this. So what am I missing?
What I expect:

I should be able to download arbitrary files to an arbitrary location
(after clicking that I accept the risk if fine)

Something should tell me where the files were downloaded to without having to search the internet for an answer.

PDF files should open either in the browser directly or from a 'downloads tab'

The "go" app should have a button somewhere to let me start the downloads

How do I make this happen?
Are the "google Go" and "google files" apps the problem? Can I/ Should I replace them with something more intuitive.
The tablet is something model is listed as "Q3".

Maybe try a download manager like this, which is well rated and claims to select download location https://play.google.com/store/apps/details?id=com.dv.adm


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Unknown phone number
An app that I need is not recognizing a SIM/Phone number.
...But the problem is not the app:
Before we go: I've visited other forums, but the answers are uneffective, completely unfit, or oriented to old androids.

If I go to Settings > About phone > Status > SIM Status, I get many Unknowns;
If I go to Settings > Connections > SIM management, the phone number shows Unknown;
I've tested on 5 different phones (see below). This problem happens on three of them, and works as supposed on the other two;
The phone receives and sends calls and messages;
I've resetted APN and stuff, as suggested on other sites;
There is no option to change my own number on any setting

The SIM card is more than two years old.
Below:

Does not work on a new Xiaomi, nor on a Galaxy A01 (gotta make work on this one). Calls and SMS work normally.
Used to work on a Galaxy S9. No one can remember when it stopped.
Works on two motorolas, one old, probably G3, and the other is a G6. Calls and SMS work normally.

Update:
it happens with another SIM.
That SIM belongs to the G3 above. Both SIMs works well on the G3 and the G6, none of them has the number identified on the defective ones (Galaxies and Xiaomi).

How old is the SIM card? How old are the phones you have tested the SIM card in? Is the SIM card working in the phones that show the number?

Updated the question to add the information you requested : )

Linking the app would help //Is the app updated to the latest version on all the phones? //If the versions of the app are different, you can  identify the version that works, obtain that version from sites like APK pure, install on other phones (after uninstall of existing app) and check

Thank you for the attention. Unfortunately, its a proprietary app, only available on our company. Regardless, no function would be available without the login/password. What I can say is that there is only one version, and it's the one we're passing between the phones. The ones that work and the ones that don't. But the app seems innocent to me: Where the phone identifies the number, the app works...

Sorry but I can't find the devices you mention. There is neither a Galaxy 9 nor an A1. My suspicion would be partial defect SIM card (e.g. because it is twisted or filthy). Also check the contact pads if they are worn-out because of e.g. deep scratches.

Galaxy S9 and A01. Corrected. The SIM IS over 2 years old, but there are no visible scratches (it stayed inside the phone all the time). Plus, SMS and Calls work on all of the tested phones. Number shows up on two of them. How can one explain this "works on this phone, doesn't work on that phone" ? Android is the variable here, as far as I can see.

Any other guess ?

Ins't there an adb command to "write the number" on the SIM or wherever it should be ?


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Physical Bluetooth Keyboard is not able to access to chats (Whatsapp, Telegram) in Android 10
I have a very strange situation that I have not found yet something in the internet that could lead me to solve this issue.
I paired my physical bluetooth keyboard (Keychron K2) with my phone (Huawei P30 Lite with Android EMUI Version 10.0.0 which I think is Android 10) and I have found the way to control almost everything, but when I access to a chat application like WhatsApp, I am able to select the available chats in the application but when I type Enter to go into selected chat, it does not go to that chat, it highlights the chat like it was selected but not with the intention to go into it...
If I leave the enter pressed, this will show me available options/actions that I could use with that specific chat like delete the conversation, pin message, etc. This behavior occurs also with Telegram.
Is there any body with some hints regarding how I could be able to access to an specific chat selected to start chatting with my keyboard without having to use the native touchscreen control to start using the application?
Thank you!

I don't think that is possible with a physical keyboard yet. I tried every key and many combinations too.. failed..
Then i tried remapping the key(one and only relevant function available is select/enter which does not work for selecting chats).. failed again..
I downloaded a physical keyboard helper(nothing helpful in it).. it failed too..
I think you'll have to tap the chats on the phone everytime you want to open any from the app.. OR you can create chat shortcuts on homescreen but that will be too weary adding every contact and messing up your homescreen.
An efficient solution will be to use a cursor (controlled from keyboard)

a cursor would not be nearly enough, because many things happen on android through gestures. ideal solution would probably be some way to trigger a list of possible actions on current screen, and pick one. including moving the screen around, which could be the most complicated one (to accelerate scrolling, for instance). at least we would have the END button as an advantage. :D but there's currently a couple of good enough solutions i'm using... i'll post an answer.

@cregox I admire your effort. But the keyboard does the rest job done except opening the chats.. So in my opinion a cursor would be enough to just open the chat. This will be the most simple solution to this i guess

you can use key mapper app (free and open source) to map a bunch of functions, including tapping the screen.
or you can get termux and do everything from CLI. (warning: might be a huge learning curve ahead)
both options are very tech-savy, in exponential quantities, but they mostly work for your case (and mine, i use both).
as i said on the other comment, still looking for the ideal solution (that should be possible) of getting a list of every possible action on screen after pressing some trigger button. something a bit like ctrl+alt+m on termux.
sadly, almost every single app are really not made to work well with keyboard, but luckily a lot of them are simple enough that they do work anyway (like delta chat).


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why is my Samsung tablet listed as a modem?
Exactly what the title says.
It happens when I boot to the bootloader, while my T295 is connected to my PC via USB cable.
How do I fix it?


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Notification doesn't show up on Redmi 8 MIUI 11 and 12
Some push notification from some apps (some games actually, I wasn't aware about other apps) suddenly no longer appeared. When I first bought this phone, they all worked fine, but then I updated MIUI to 11 and 12, and since then notification from games wouldn't appear. They would only appear when:

I opened the said games
In battery-saving mode (on low battery, when I activated this mode, notifs will immediately popped up)

I have turned on notification in Settings for those apps, doesn't help.
Anyone encountered the same problem? Any solution?
My device:
Redmi Note 8 Pro, Android 10 (Q), MIUI Global 12.0.2 Stable

This is usually a problem with battery optimization. Go to your settings and identify the list under battery optimization (that is the stock Android name, it could be battery saver etc). Remove those apps from the list
Edit: As confirmed by OP in comment, it is found under Settings → Battery & performance → App battery saver. Selecting those app(s) from the list, and changing from Battery Saver to No restrictions fixed the problem of missing notifications.

Currently in my device (MIUI 12), the setting is in Settings > Battery & performance > App battery saver. Select the troubled app from the list, and change from Battery Saver  to No restrictions, and finally the notifications appear. Again, thank you very much!


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How can I export all of my MMS pictures before changing phones?
I am currently using the stock Google Messenger app which came installed on my LG V20. I'm getting a new phone and backing up my data beforehand. It turns out that Messenger doesn't have any method to export all the attached MMS pictures. I can long-press each picture and save it individually, but then I have to scroll through hundreds of threads and tens of thousands of messages! I'm guessing I have ~1000 pictures buried in there...
Now I'm pursuing other apps. Perhaps I could import my MMS messages into a new app which would then allow me to save them?
There used to be something called "Save MMS", but it's no longer available. SMS Backup and Restore supposedly backs up pictures in XML format, but I haven't found a way to extract them into files. It looks like Textra will auto-save incoming MMS pictures into a directory, but not with old pictures found during an import...
My goal is to save these images as files and move them to a computer. I don't want them on the new phone.
Does anyone have any clever ideas?

try MyPhoneExplorer it claims to handle MMS (not tested by me)

I use SMS backup and restore app but not MMS. However, this link from that app help page (faq) indicates that MMS can be restored. Give it a try by selecting a date range to copy and restore https://synctech.com.au/faqs/pixel-mms-missing/// xml format is for call logs and SMS text not MMS media


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How to recover lost/deleted images
So basically it went like this:
1.) I plugged my phone to my laptop and transferred all my photos.
2.) After having successfully copied the pictures, I deleted them on my phone via the laptop then unplugged it after.
3.) I checked my laptop and there was one album that was empty. I tried checking it on my phone but the album wasn't there.
What happened and is there any possible methods in recovering the album?

The used protocol via USB is MTP and this protocol is very fragile. Also in older Windows versions some bugs are known which can even destroy files on the phone. For reliable file copy it is better to enable debugging options and  Android Debug Bridge (adb)  and use it for file sync , e.g. via adb-sync.

possible methods in recovering the album depends on phone model (for mediatek chipset try this) also some people claim disk digger is working. in general the chance is very low to zero, there is no hope


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Android 9.0 not showing SSID - Chrysler Uconnect
Recently I bought a Chrysler Pacifica 2019 which has Uconnect 8.4 and built in WiFi. I also bought couple android 9.0 headrest monitor. When I am trying to connect the android devices it doesn’t show the Uconnect WiFi SSID. But it shows my home WiFi and can connect. My iPhone can connect to Uconnect car wifi. The Uconnect WiFi had WPA2 security and my hobe had WPA2 PSK. Please assist.

sure you are talking about WiFi (not bluetooth)? 2.4 GHz or 5 GHz channel incompatibility (wrong country)? beacon interval too low?

Yes I am sure and I am in USA

Seems like issue with Android go edition. Not sure where to get an answer


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How can I export contact groups?
When I export my Android phone's contacts via a VCF file, it seems the contact groups are not indicated in the VCF (and are thus lost if I only import that file).
I see a lot of apps for exporting and importing contacts, but none whose name suggests it will export my contact groups as well.
My questions:

Is there a way for me to export my contacts together with the contact groups?
Is there a way for me to export just my contact groups (i.e. which contact belongs to which group)?
Can I import just-contact-groups "onto" a set of contacts without contact groups (the result of a previous import-export without contact groups)?

Notes:

I don't have a Google account (and won't get one).
In case it matters - the phone from which I'm exporting is a Xiaomi RedMi 3S (Android 6.0.1, MIUI 10).
This question is related, but I don't care about exporting to a VCF specifically; and Android has changed over the years; and the answer there regards a Google account.

Download & install the SA Contacts Lite application; it is available on places where you don't need an account, e.g. via APKPure.com.
Start the app.
In Settings:
3.1 enable Export All Fields.
3.2 Disable Export Photos.
3.3 Enable Merge Duplicates.
Click Export, then Start.
A format selection dialog will come up. Enable Backup and disable everything else; press Next.
An account selection dialog will come up (= the account whose contacts you want to export). Typically you'll want to enable just the default account. Press Next.
Select the range of contacts to export - probably all of them, so just press Next.
Wait for the app while it's "Preparing to export contacts". This may take upwards of a minute for over ~1000 contacts.
Wait for the app to merge duplicates. This takes even more than the previous phase (not quite sure why).
Select the destination for the export - typically just a file on the device's storage somewhere.
Patiently wait for the duplicate merge and actual export to occur. I have no idea why it takes so much time, given how there's so little data.
Choose a way to save the output file; "SD Card" is safe, but there are also options to send it to your Dropbox/Box/Google Drive account or to email you the file.
Ensure the output file is actually placed at/sent to your chosen location.

Then, you can import your group associations as described in discussed in this question.


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Make my screen unlock pin longer than 31 digits
My question is pretty self-explaining. Currently I have a PIN number of maximum possible digits (31) that my Android 10 supports (phone is Huawei P20 Pro). Is there a way to make it longer than that? Any third party software, by rooting the phone or something similar?

Related Why, and how to increase 16-character lockscreen password limit?


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TWRP not asking me to enter password to decrypt
I need to restore from a backup. However TWRP stopped asking me for the password to decrypt. In the terminal emulator I tried twrp decrypt 1234 but got the error "Failed to decrypt data". Whenever I try to use any other feature in TWRP, such as restore, it says "Failed to decrypt data".  and "extracTarFork() process ended with ERROR: 255"
How can I restore from a backup?

@beeshyams no it isn't a multi user backup. It's TWRP 3-3-10, is there a new version for Xperia XZ1 Compact?

@beeshyams as far as I could determine, no there isn't a newer version for XZ1 Compact. By trying things out I got it to work (see answer bellow). I'm curious, is this a known bug? Why is it sometimes TWRP just doesn't ask for password?

TWRP needs a working firmware for decryption. if system vendor or modem is wiped, the workaround is to format userdata in order to remove encryption completely, so TWRP can mount it unencrypted

@alecxs all I did was flash Lineage 17 so how could that corrupt the firmware?

just a guess as you stated you wiped everything. encryption also depends on android version - switching between ROMs can also cause this

If switching between ROMs can cause this how does one backup their phone before trying a new one? I thought this was one of the  main use cases of TWRP. @alecxs

backup data + internal storage -> to external storage like MicroSD Card, USB-OTG or adb pull /sdcard

for switching between ROMs i recommend Migrate

Copied from comments:

TWRP needs a working firmware for decryption. If system vendor or
modem is wiped, the workaround is to format userdata in order to
remove encryption completely, so TWRP can mount it unencrypted.

Through experimenting I was able to get it to work by doing the following. First, try reflashing just TWRP in fastboot mode: fastboot flash recovery twrp.img. This may be enough, but if not se bellow . My phone is an Xperia so replace steps 1. and 2. with however you normally would install firmware.
Steps:

download phone's Firmware as ftf
Use flashtool to flash firmware
Use fastboot to flash TWRP
Use TWRP to wipe all data, but make sure not to wipe the backup you're trying to restore!
Use TWRP to install a new ROM.
Setup new ROM e.g. sign into WiFi
Reboot to TWRP again
Now TWRP should ask for password and you will be able to decrypt


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How to disable FLAG_SECURE by modifying an APK file?
I want to mod an APK so that its FLAG_SECURE can be disabled. Can anyone please guide me in doing that?
I have used apktool to decompile the app, but I don't know which specific file to find in smali to disable this.

There is not one specific file you have to edit. Instead, you have to search all smali files for a specific call. Luckily, the smali syntax is very specific so that you can search easily using a full-text search tool. I prefer Agent Ransack (Windows) or  grep -R (on the command line).
In detail, you have to search the smali files for one of the following calls:
Landroid/view/Window;->setFlags(II)V
Landroid/view/Window;->addFlags(I)V

Before each call in the same line, there is noted which registers contain the parameters.
addFlags
const/16 v2, 0x2000
invoke-virtual {v1, v2}, Landroid/view/Window;->addFlags(I)V

The second entry in the curly brackets is the interesting one (v2 in the example).
If this parameter is set to 0x2000. In detail, this is a bitmask and if the 14th bit is set, the screenshot protection is applied to the current screen.
Effectively, only the fourth position matters. If it is 2 or 6 (2+4) or A (8+2) or C(2+4+8) then the bit you are searching is set. But usually (in 99% of all cases), you will find the value 0x2000.
Search the lines before the invoke-virtual if there is a command that sets the register we are looking for such as: const/16 v2, 0x2000.
If there is the call, and the second parameter has a parameter with the hexadecimal 2 at the mentioned position, you can simply comment out the whole invoke-virtual ... line by placing a # in front of the line.
setFlags
const/16 v1, 0x2000
const/16 v2, 0x2000

invoke-virtual {v0, v1, v2}, Landroid/view/Window;->setFlags(II)V

For setFlags, it is very similar, just that the 0x2000 parameter has to be present in the second v1 and the third v2 mentioned register in the curly brackets.
Do that with every occurrence of setFlags/addFlags invocations.
Again, comment out the whole invoke-virtual ... line by placing a # in front of the line.
Rebuild APK
Then rebuild (apktool b ...) the APK file (you can find it in the dist subfolder) and then use apksigner sign the built APK with a custom certificate and you are ready to install the app. apksigner is part of Android SDK, but can also be downloaded manually, see e.g. my post here.
Alternatively for signing you can use a tool like uber-apk-signer which simplifies APK certificate and key generation + signing the APK.


text:
enable usb debugging via ADB from recovery?
Since ADB debugging is not ON, I keep it off unless I need to do something, I now cant use even Vysor to view whats on screen since my screen died with just some color dots and lines seen on screen. I can only see it in ADB in recovery and funfact - I can still view its files when it connects to computer.
Can anyone tell me how to 'see'the device in regular state via ADB? Like on vysor, I need to see it in adb devices first.
Can I enable USB debugging using adb?
how similar
Now problem is: I get
mount: mounting /dev/block/mmcblk0p24 on /data failed: Device or resource busy

when I try to do the idea listed there,
persist.sys.usb.config, yes done, I even tried ptp and put back there
persist.service.adb.enable=1
persist.service.debuggable=1
persist.sys.usb.config=mtp,adb
in /system/build.prop  - I dont have this file in system... I have default.prop (I added such lines there then pushed the edited file back) btw having installed TWRP and Magisk. TWRP is my recovery  I cant see anything on screen.
Then I try to adb reboot but even if it goes on, empty list of adb devices. I tried making a build.prop with these and pushing it but no change
Is it because the phone goes in lock screen and you cant see the device listed if not unlocked?
Starting TWRP 3.2.3-0-840f04f7 on Sun Dec  6 11:47:42 2020
 (pid 151)
BOARD_HAS_NO_REAL_SDCARD := true
TW_NO_REBOOT_BOOTLOADER := true
RECOVERY_SDCARD_ON_DATA := true
I:Lun file '/sys/devices/f9200000.ssusb/f9200000.dwc3/gadget/lun0/file' does not exist, USB storage mode disabled
TW_HAS_DOWNLOAD_MODE := true
TW_INCLUDE_CRYPTO := true
I:TW_BRIGHTNESS_PATH := /sys/class/leds/lcd-backlight/brightness
I:Found brightness file at '/sys/class/leds/lcd-backlight/brightness'
I:TWFunc::Set_Brightness: Setting brightness control to 162
I:LANG: en
Starting the UI...
Skipping adf graphics because TW_TARGET_USES_QCOM_BSP := true
cannot find/open a drm device: No such file or directory
fb0 reports (possibly inaccurate):
  vi.bits_per_pixel = 32
  vi.red.offset   =  24   .length =   8
  vi.green.offset =  16   .length =   8
  vi.blue.offset  =   8   .length =   8
setting GGL_PIXEL_FORMAT_RGBX_8888
double buffered
framebuffer: 3 (540 x 960)
Using fbdev graphics.
I:TWFunc::Set_Brightness: Setting brightness control to 162
I:Loading package: splash (/twres/splash.xml)
I:Load XML directly
I:PageManager::LoadFileToBuffer loading filename: '/twres/splash.xml' directly
I:Checking resolution...
I:Scaling theme width 0.500000x and height 0.500000x, offsets x: 0 y: 0 w: 0 h: 0
I:Loading resources...
I:Loading variables...
I:Loading mouse cursor...
I:Loading pages...
I:Loading page splash
I:Switching packages (splash)
=> Linking mtab
=> Processing /etc/recovery.fstab
I:Reading /etc/recovery.fstab
I:Processing '/cache'
I:Processing '/data'
I:Processing '/system'
I:Processing '/boot'
I:Processing '/recovery'
I:Processing '/firmware'
I:Processing '/efs'
I:Created '/efs' folder.
I:Processing '/persist'
I:Created '/persist' folder.
I:Attempt to load settings from /persist settings file...
I:InfoManager loading from '/persist/.twrps'.
I:TWFunc::Set_Brightness: Setting brightness control to 162
I:TWFunc::Fixup_Time: Pre-fix date and time: 2020-12-06--05-47-43
I:TWFunc::Fixup_Time: Setting time offset from file /sys/class/rtc/rtc0/since_epoch
I:TWFunc::Fixup_Time: Date and time corrected: 2020-12-06--05-47-44
I:Processing '/preload'

you can not change default.prop you must 'mount -w /system' and change build.prop also concatenate your rsa_key to /data/misc/adb/adb_keys

Ok I try but I said that I get the above error when I try to mount
https://stackoverflow.com/questions/26213954/how-to-solve-adb-device-unauthorized-in-android-adb-host-device (another link I may find useful)

Recovery is the only way to use adb but it reboots or exits after 10s so I have that little time to stay on adb before I have renter again for 10s. What's the problem with it?
So I have no time to find build.prop but it's not in system. I said that using the mount command
I deleted gesture key maybe, to not have a pattern screen but it wont enter adb unless recovery for a while. I added a log of the recovery

that recovery.log is far from complete. 10 seconds is very less time for even fully boot recovery. you can use osm0sis' AIK to unpack boot.img, edit default.prop, repack and flash the modified boot.img

is TWRP crashing in loop? if only adb is disconnecting every 10 sec it is maybe related to battery fully charged. if TWRP is working otherwise, drain the battery a while, then try again. note the first disconnecting after 30 sec is normal, that's on every TWRP (because of MTP is started) but adb should be stable after adb kill-server and second re-connect

osm0sis also have method for adb screenshot you may find useful in recovery


text:
Apps killed by android:Redmi S3
Phone model : Redmi s2
Ram : 3 GB
My phone is killing apps when more than one app is running.
Even when messaging apps are running like messenger. I can't use messenger when other apps are in background.
Task manager always shows 1.3-1.5 GB free memory (So, I don't think that this is because of low memory). I tried with "no restriction" options in battery saver but it doesn't help.
Is there any way of getting out of this?

Some phone manufacturer implement a very aggressive battery saving (called "battery optimization") and therefore apps are killed or suspended. May be this is also the source of your problems. Check the battery options in settings.

See: https://dontkillmyapp.com/xiaomi

I tried with "no restriction" options in battery saver... But remains same

In developers option check if "Background process limit" is set to default or standard limit. If it is 1,2 or 3 processes increase it. And uncheck the "Don't keep activities" if checked.

In developer options 'Background process limit' already in standard and i have tried with 1,2 or 3. Don't keep activity is unchecked because i didn't use it.


text:
(Xiaomi Mi 9 Lite) Mobile data turns off automatically when screen is off!
I have an issue with Mi 9 Lite, when I lock my phone, mobile data turns off automatically after a short period of time, it will turn on as soon as the screen turn on, I tried to enable "Mobile Data Always Active" in developers options but still the same!
Does anyone knows how to disable this?

Are you using some apps to put the device into doze faster? Apps like Naptime have this option

@beeshyams Nope!


text:
Init service not starting in user build
I have an init service that is not starting in user build. When running a userdebug build it works fine but not in user build. Can't seem to figure out why it's not running. I don't see any errors about it in logcat either.
on property:myprop=1
    start mysvc

service mysvc /system/bin/mybinary myargs
    user system
    group system
    oneshot

My app sets this property when I want the service to start.
Any help here is appreciated.

Is /data/logs/ accessible to system UID for writing? What's the SELinux context of the service? Can it access /data/logs/? See kernel log for init services.

Yes, system UID has access to the folder, which is why it works in userdebug build. I'm not worried about SELinux just yet; my build is running under permissive mode.

Just had a look at the kernel log and nothing in there either. My property myprop does get set appropriately but the service is not running.

Which Android version you are on? Set seclabel and try again.

I am running Android 8. Looking into trying with seclabel.

@IrfanLatif Using seclabel worked. Why is that, when I have set the service to be user/group system already?

Can't remember exactly why, need to look into code. But this is the behavior in recent Android releases.

Ok, I see it now, the default context doesn't have enough permission. I'll have make sure I give it enough permission then, but not over do it. Thanks!

The problem was the SELinux context that the process was running under. I was able to fix it by marking the seclabel of my init service.
on property:myprop=1
    start mysvc

service mysvc /system/bin/mybinary myargs
    user system
    group system
    oneshot
    seclabel u:r:su:s0


text:
How can I selectively delete hundreds of SMS conversations?
I work in IT and I'm part of an on-call rotation.  Normally we use a dedicated on-call phone, but that's not available since covid, so I'm using my own device right now.  We had a major networking outage tonight which resulted in roughly 600 SMS notifications from our monitoring service to my phone.
The problem is that each one of these notifications comes from a different address (I don't know why/how that works).  So rather than 600 new messages in a single conversation, I now have ~600 new conversations in my Messaging app with a single message each.  I would like to delete them so I don't have to scroll through 600 conversations to find my conversations with friends.
Is there any way to bulk delete conversations based on some kind of search filter?  I did see this question, but the answers only address how to delete all SMS messages.  I would only like to delete the conversations which were generated by this incident.
I'm on a OnePlus 3T with LineageOS 17.1 (based on Android 10).  My phone is rooted so I can run adb commands on it from my Linux desktop.

if you prefer doing it on Windows you can use MyPhoneExplorer (you can filter by keywords, select all + delete like in Thunderbird)

Act fast to get quick results

Use SMS backup and restore and backup all your SMSes to local storage on device immediately.

Go to the app menu and choose restore. It will select the backup you made. Go to advanced options and select only restore backup since and you choose date before you got flooded by all these SMSes.

Assuming you don't have any important messages after the chosen date , you are good. If you have, follow steps in answer here to backup, selected conversations and choose those to be restored. It doesn't restore duplicates and at most you may end up having to manually delete a few messages

Alternatively, you can export the SMS backup file which is in XML format to your laptop, search for the common term in these messages, delete all those, maybe use a script to do that. Transfer the file to your device and restore to device.

You deleted your original comment which suggested using this same app to export the backups to XML, writing a script to prune the XML file, and running a restore from the modified XML backup.  I'm not sure why you deleted that comment because that's exactly what I ended up doing and it worked quite well.

It's good that your problem was solved by the earlier suggestion. I deleted that comment thinking it was probably difficult (which was a mistake). I added that suggestion to the answer, so that you can mark it as accepted. Thank you


text:
The installation of an application in the Google play store is stuck on pending. How can I know what is causing it?
The installation of an application in the Google play store is stuck on pending. How can I know what is causing it?

Many reasons - internet issues, server problems, free space on your device, firewall rules (if you sure using), VPN etc //Cancelling and trying in a little while often solved the problem for me

@beeshyams thanks, I see. I was hoping that Play could be more verbose regarding the issue.

It does have ;clearing cache of download manager, Play Store etc and few more


text:
Chome flag "Overscroll history navigation" by default
I have casually found this feature without having enabled anything in
chrome://flags.
Suddenly the option has disappeared.
Why this behaviour? I don't understand why the feature was enabled, and I can't see why it suddenly has disabled (I've found Default mode checked in flags section).
EDIT
Chrome version 81.0.4044.96

To answer why enabled or disabled - these are experimental features as you can see when you type Chrome://flags. If they want to make it a permanent feature or not is upto then. User has no choice// Coming to the flag you are concerned about, in all the options except disabled, overscroll is there. Related question

@beeshyams So, being the option Default, it was there from installation. I don't understand however why it has stopped working. Perhaps because indeed it is experimental? Some flags have checked Default, others have Disabled; the picture is very heterogeneous

Experimental is the operative factor //Being experimental how can one have any predictability or coherent view?//Besides you are on old version. I am on 86.x updated from Play store


text:
Change 5 GHz Wi-Fi Access Point channel
Is it possible to set or change the channel of the Android Wi-Fi AP?
No matter it is using root or non root methods.
I'm currently on Android 10.

Xiaomi Mi 8. But I have this problem in different ROMs, that's why I just said Android 10, happening both in MIUI and AOSP.

AFAIK, it's not possible because that needs to be done at the router end by configuration. Nothing at device end to change channels //If your device is rooted, you can enable /disable  5Ghz using Magisk modules


text:
How to mirror your android phone to android tablet?
My android phone has got a feature called screen mirroring. But on my tablet it's called smart view. When I turn it ON on both the devices, for some reason they're not able to detect each other. Phone is from Sony and tablet from Samsung. Though both are android devices but still use different terminologies. Any ideas of how I could get them work together?

There is an app on the Google Play Store that does exactly what your looking for.
AirMirror: Remote support & Remote control devices

Remote Control AirMirror fulfills the goal to control one Android
phone with another phone.
*This feature needs AirDroid installed on the other end, and log in with the same email account.
You can apply AirMirror with the following features:
Remote Control Directly control another phone/tablet, do whatever you
like, no matter where this device is.
*If the controlled device is not rooted, it is required to process Non-Root setting through AirDroid PC beforehand.
Remote Camera Access another phone's view from either front camera or
rear camera. You can put this phone as a family security camera,
guarding your family's safety.
Screen Mirroring Check your device's screen anytime in real-time.
*If you want to control Android devices through PC, you can use AirDroid PC client.
Remote Support You can easily assist your friend or family to solve
mobile device issues through Remote Support.
*This function needs AirDroid Remote Support installed on the other end.
Overview:
Quick Connection by 9-digit Connection Code No account is required,
your friend or family can connect to you simply by their 9-digit
Connection Code.
Screen Sharing Send the screen sharing request with one tap, and you
can see the device screen in real-time.
Voice Call AirMirror provides clear voice communication, you can
simply call and talk, saving time for texting.
Tutorial Gesture Swipe or tap on the shared screen, the Tutorial
Gesture will show on your friend or familyˇs device. Follow to easily
solve the problem.
Voice Message and Text If you are under a surrounding not suitable for
making a call, you can still communicate through sending texts,
pictures and voice messages.
AirMirror facilitates your life. If there is any problem during your
experience in AirMirror, feel free to give us feedback anytime. Thank
you very much for your support of AirMirror!

I was hoping for a default App that is already installed. For example, I successfully shared my phone to my TV by using the default apps. Both were from Sony. Something, without asking for email, or any other personal information?


text:
Android "managed device" recognized as mass storage device. adb doesn't see device. How do I do I determine drivers?
I have an android "managed device" that seems to have been some company tablet. No discernible brand. When I boot, it gives a screen with only a settings app. The settings app is very slimmed down, without access to debugging tools.
Debugging should be allowed by default on this device, because from what I understand, apps were installed and uninstalled from a company kiosk. Therefor, debugging would have had to been enabled.
It is a mediatek device with VID_0E8D. It's got pretty nice hardware. I'd like to be able to at least install apps on it, if not root it and re-install android.
It seems to have locked boot loader.
How to I figure out which drivers I need on windows 7 to recognize it as an android device? android studio nor adb can see it, but I can access the file system. Not the .android system files, just a few redundant files and folders that show up.
Any help would be much appreciated.

As long as you have not managed to enable an USB protocol drivers are not relevant for you. I would try to get into bootloader or recovery system by pressing vol up/down and power or other key combinations while booting. May be you encounter a screen that shows hardware details.

enable usb-debugging and set usb connection to MTP in developer options. check windows device manager, pick android device, install android_winusb.inf https://developer.android.com/studio/run/win-usb

@Robert thanks for the response. It has a locked bootloader, and using power/vol up/down doesn't get me into bios. I'm an experienced web developer, so I have a bit of overall experience. However, unlocking bootloader and/or bypassing security on android devices is somewhat new to me. Do you have any guidance or advice as to what  I could study or look into in order to start analyzing what I need to do to unlock the bootloader or any other means to install new apps? I took it apart. It's a MTX chip, I have the details on that at least... Thanks again.

@Robert It appears to be very secure, being that I can't boot into firmware. Nor does settings allow me into the debugging section. Is there a way to possibly "hotwire" the board to get it to boot into the firmware?

May be - this depends on the board. Please not that your base assumption that debugging has to be enabled is totally wrong. App sideloading does not and never had anything to do with adb. The only relation between both is that on old regular devices both options were in the "Development options" menu.

@Robert I can't find any other way to sideload apps. Especially considering that the settings are so slimmed down. Any suggestions?

If the software is locked you have to directly address the hardware. Open the device, check for hardware debugging connections such as JTAG and read out the firmware for further analysis. Note that this is reverse engineering and therefore off-topic here. You may check https://reverseengineering.stackexchange.com

@Robert Thanks for the direction!


text:
Does Android have a built-in FTP client?
Does Android have a built-in FTP client? Even a basic one, like ones that are built into PC browsers and file managers? I know there are good free apps with FTP clients (like Ghost Commander), but I'd like to know if there's a way that doesn't require app installation. I'm excluding chrome's FTP support, since that is being deprecated, and not all android phones have chrome built-in.

https://play.google.com/store/apps/details?id=lysesoft.andftp

@alecxs I'm looking for built-in FTP clients.

No, for better or worse, Android does not have an integrated FTP client.
As you've discovered, many third-party apps are available to fill this gap.  Some of them are dedicated FTP clients, while others are integrated into file manager apps.


text:
unable to copy a certain file
I am unable to copy a certain file. At first I tried using a cloud share app, then USB file transfer, then ADB, then local file browsing apps, finally a terminal emulator. All fail. I can see the file and the app that created it can partially interact with it, but I cannot copy the file, permission denied. Phone is rooted. This is a large file created by TitaniumBackup. It's large because the backed up app has a lot of data, about 4 GB worth. I can copy all the small files that Titanium creates during its backup process, including the apk and properties files. And I can rename the big file, even delete it, just not copy. Even Titanium itself can delete and restore backups but not upload to the cloud using the built-in function to Sync to Google Drive. I am thoroughly confused.
I don't think it matters but this is a rooted Pixel 5 with stock ROM.
-EDIT- responding to alecxs
adb: error: failed to copy '/sdcard/TitaniumBackup/ws.clockthevault-20201202-212154.tar.gz' to 'vaultcopy.gz': remote open failed: Permission denied
ls -lZ
-rw------- 1 media_rw media_rw u:object_r:fuse:s0

Before chmod: -rw------- 1 u0_a256
After chmod: -rwxrwxrwx 1 u0_a256
But pull still fails:
adb pull /data/media/0/TitaniumBackup/ws.clockthevault-20201130-045341.tar.gz vaultcopy.tar.gz
adb: error: failed to stat remote object '/data/media/0/TitaniumBackup/ws.clockthevault-20201130-045341.tar.gz': Permission denied

Where are you trying to copy it to? If it's to a SD card and the card is FAT32  you can't copy a file larger then 4GB.

I attempted multiple targets, including cloud, my PC, as well as just the same folder where the source file is located /storage/emulated/0/TitaniumBackup/

chmod won't work on /sdcard thats expected. but maybe Titanium is writing files to /data/media/0 which is ext4 where any file size is allowed. but you try to create a file bigger than 4 gb on /sdcard which is most likely fuse mounted (even if it's same location). fuse probably doesn't allow files bigger than 4 gb (because fuse is usually used for fat32). but that still doesn't explain why adb pull fails?

@alecxs chmod does indeed change the permissions to the file when accessed within /data/media/0/TitaniumBackup - I can see the change with the ls -lZ
But even then I can't copy the file out, see edit on the post.

https://android.stackexchange.com/q/91900

assuming the issue is caused by file size not respecting fuse-mount 4 gb file size limitation, this workaround should work
either move the file to another ext4 location which has adb permissions
adb shell mv /sdcard/TitaniumBackup/ws.clockthevault-20201130-045341.tar.gz /data/local/tmp
adb pull /data/local/tmp/ws.clockthevault-20201130-045341.tar.gz

or stream the file content over terminal stdout (linux only)
adb shell su -c "cat /data/media/0/TitaniumBackup/ws.clockthevault-20201130-045341.tar.gz 2> /dev/null" > ws.clockthevault-20201130-045341.tar.gz

you are a genius, dude. I was able to copy the file into local/tmp and then adb pull it to my PC. While I was doing that I was questioning in my head how the file was even created in the first place. Creating a file size larger than the file system allows should not be allowed. So while it is in a way a bug within Titanium, as you say, the file system should not allow this to happen and Titanium should be notified of failure to create the file. Otherwise it thinks it succeeded. I will reach out to Titanium, though. Thanks for your help, man. I was going freakin nuts!

the thing is, Titanium doesn't respect rules. it should use only /storage/emulated/0 like other apps (where this could not happen) but it is kinda 'misusing' it's root permissions writing directly to /data/media/0 instead (where it is 'allowed')

very interesting. I messaged Titanium devs, we'll see if I hear back. This might be a unique case they haven't seen before since most apps don't have over 4GB of data.


text:
I uninstalled/deleted a system privileged app (from /system/priv-app) How can I reinstall it?
I uninstalled the DocumentsUI only to know it wasn't "just" a files manager. My /system/priv-app/DocumentsUI is empty. Putting any 3rd party DocumentsUI.apk in it results in bootloop. I have a custom rom (Aosp extended).
Flashing the /system again would fix the problem I think. Just want to make sure if this will make the condition worse or am I going alright?

Extract the file from ROM's zip file and put in proper place with proper permissions.

The way I did it was a little different.. I made a full twrp backup. Wiped everyhing. Flashed the stock rom. Copied the DocumentsUI.apk from twrp. Wiped again. Restored the backup. Placed the copied apk into /system/priv-app/DocumentsUI. Everything worked perfectly!

This answer was before the edit but holds
Flashing /Data would result in:

Losing your user data.

Worse, it's not going to solve your problem.

Solutions

Dirty flash the ROM ( flash /system without wiping /Data)

As suggested by Irfan in comments,
Extract the file from ROM's zip file and put in proper place with proper permissions.

Second option requires a good understanding of Android. For me, dirty flashing would be fastest and simplest.

You have to root for this
Install any root browser (x-plorer , cx file manager etc.
open /system/priv-app/DocumentsUIGoogle
3.copy all apk files to any internel storage folder
Install all these apk files at once using any split apk installer ( Recommended -com.smartpack.packagemanager )
download link - https://play.google.com/store/apps/details?id=com.smartpack.packagemanager
5.Reboot
Note :- if you are unable to find these apk files then use attached files
vvvvv
https://mega.nz/folder/R1UxBbYJ#BD6jRT52rADTGA09x6EBcA
Note 2 => if you don't have any DocumentsUIGoogle folder then create one and put all apk files into it then install all these apks using package manager.


text:
Using a cell phone to make calls without signing into Google account. Possible?
I intend to close my Google account for personal reasons.  No part of it will I leave operable.
But, I use an Android phone.  I am not asking about Google apps here.  I am asking if the phone will still work for making phone calls.  Mind you if I have it my way there will be no Google account for me to login to.
I am dumping Google in it's entirety.

Edited to match the heading with body. Trust that's fine by you

afaik every device is running fine without google account, it isn't requirement. non-google apps are working too, just google play store is not available for install. but "dumping Google in it's entirety" is impossible

@alecxs It depends on your definition of "dumping Google in it's entirety" to state whether or not it's possible.  If one's definition is not connecting to any Google servers, then it is certainly possible (and easy).  If the definition is not using any Google services, then it is trivially simple.

@RockPaperLz-MaskitorCasket google services is core for android os, i don't agree it is trivial (and i doubt it is even possible) but a good start to play with is app cn.wq.disableservice and microG

@alecxs You can block Google servers (and all Google-assigned IP ranges, for that matter) with a firewall - on the device, on the access point, or at the network level.  Additionally, you can block DNS resolution for all Google hosts.

Yes, you can use it only to make and receive calls and text messages. Equivalent of not signing into a new device but inserting SIM.
I have seen people do this (without signing into Google account) , using it like a non-smartphone.
Somewhat related Can I use an Android One device without a Google account? Isn't there a compulsion?

I have personally used Android phones without any Google account, or even connecting them to the internet.
Many key features will still work:

Telephone calls
Voicemail (call to retrieve messages)
SMS messages
Still camera
Video camera
Audio recording (if there is a pre-installed audio recording app)
Creating contacts
Calendar (including creating events)
Alarm clock
Flashlight
Bluetooth connections (speakers, headphones, etc.)

In fact, without Google slowing down Android, it is a much faster and efficient operating system.


text:
Which phones have the purest Android?
I'm looking for phones with stock Android. I was able to find articles on the internet, but they mention mostly new phones, and I'm more interested in older (cheaper) versions.
I have Google Pixel (one) and from what I read, it's the one with "vanilla" Android. But there are some preinstalled apps on it - like Google Play Music, Google Play Movies, which I cannot uninstall (without rooting). I neither need nor use them and consider them bloatware.
Is it possible to find a phone from a manufacturer which does not have even such Google apps?  Or they just must be there?

Android phones cannot be pure more than roughly, say, 70%. A huge codebase working at backend, not very much visible to the user, is hardware-specific (and so vendor-specific) and isn't part of pure/stock/vanilla Android (AOSP).

There are some Android brands (AFAIK, mostly Chinese brands) that don't have Google apps (because Google is blocked in China), or maybe non-certified devices that cannot have Google apps preinstalled. Otherwise, fsfe - Free Your Android, Liberate Your Device!

You should look for devices running "Android One". Even phones from different manufacturer running Android One it is guaranteed that nothing is changed because this is not allowed for Android One devices.

Interesting, my Samsung Galaxy S10+ let me uninstall Google Play Music/Movies. However, there are plenty of things which I cannot uninstall like Bixby, AR Emoji for whatever f'ing reason, Verizon Cloud, etc.

@Robert as far as overall user experience is concerned it's correct to say that Android One devices are nearly identical. But they are far from stock Android. For instance on Mi A2 Lite out of 216 system packages almost half are not from AOSP, including 46 from Google, 47 from Qualcomm and the rest from Xiaomi or hardware vendors. Similarly out of 107 native daemons 74 binaries are from /vendor/bin. Vendor specific bootloader, modem etc. are in addition to this. So I don't think we can call it a pure Android device.

@IrfanLatif absolutely right though I wasn't aware of such technical devices //I owned MiA1- unlocking bootloader won't wipe data (they corrected later), factory reset using key combo will not invoke FRP,  adb backup not possible etc. So broad brushing Android One = Stock Android isn't right

@IrfanLatif Actually, it’s theoretically possible to be higher than that. The only stuff that needs to be proprietary are the drivers for the baseband processor, it’s technically possible to design a phone that has all other required drivers in the upstream Linux kernel, though I don’t know of any companies that actually make such phones.

@AustinHemmelgarn yes you are correct. There are modular phones like FairPhone claiming to use open source hardware, and also open source OSes like PureOS. But I don't think any of those is 100% open-source.

Can you explain what you consider "bloatware"? For example, my grandmother gets very anxious about any icon that she doesn't immediately understand the use of, even though some of those are doing important things like backups. So I installed extra software to put all the icons she doesn't use on a separate tab in the app drawer and now she's happy. OTOH there's really unnecessary stuff like "theme support" right in AOSP and impossible to remove, but she never complained about that because access to it is in the settings menu so she never noticed it.

@user3067860 I gave two examples from Google. I basically mean apps which I don't use, and that's true that they annoy me the most when I see their icons. not sure how it looks in case of your grandmother, but on Xiaomi/Huawei I can put all those icons into one "not needed" folder, it is only one annoying icon then, but I still know they are there and it kind of disturbs me :) what you did is rather workaround, they still take space on the memory. I was interested more in the matter of approach to this.

@Line OK, but things like "themes" don't bother you? Because that still takes system resources. More system resources than an application that is installed but never opened/running. I ask because things like LineageOS, etc., often have even more features built into the OS, even if they also usually let you remove all visible "apps". Or things might be classified as system apps and not show up as apps even if they technically are (fun fact, "com.android.cellbroadcastreceiver" is a system app).

@user3067860 hmm, maybe that's stupid and lazy but there is something in it, if I don't see an icon, I'm not annoyed that much :) maybe it's more about the simplicity of usage. I don't know much about this theme which you mention, but I'm anyway not considering LineageOS, because I was looking for a manufacturer phone, and those won't be easy to find according to fraxinus answer.

tl:dr; Google phones have the purest Android. They come with Google apps
In Android ecosystem, phones launched by Google are stock Android (aka vanilla). It's the purest form of Android because Google developed the OS and tightly integrated with the hardware (earlier Nexus and now Pixel). They come with Google apps, you can't avoid them, unless you root your device and uninstall.
If you are looking for a phone that is running Android LineageOS -XDA launched a phone that ran LineageOS /Ubuntu out of box. Such devices are more of an exception to the rule (running LineageOS out of the box, as you mentioned in the last paragraph of the question, though LineageOS doesn't qualify as pure Android)

A modern smartphone with true Linux and HDMI out? Color me impressed, and now there is one less early model left to snatch :)

thanks. but then how come there is for example Google Clock preinstalled on Pixel while it isn't on Xiaomi?

@Line That exactly proves the point. Stock Google has a framework and apps that are defined. Other OEMs are at liberty to add system apps or remove them, modify the framework, add their own tricks, bells and whistles, etc, etc. All that is permitted as long as they stick to the framework in principle. It's not just OEMs, even carriers add their own apps, sometimes make bootloader unlockable//The list is endless and that's what makes for a chaotic, fragmented Android eco system //That's one reason some prefer stock stuff, it works as it was designed to and yet gives you flexibility //

Flexibility to play around with things, mostly if you root your device. If you don't, stock works and they are happy with it // Aside, after many years of owning devices by multiple OEMs, I own now a stock Pixel device and an liking it :)

@beeshyams I'd say, even not modifying the core AOSP framework, Google devices are far far from pure Android (AOSP) like Android One devices are (see my comment: https://android.stackexchange.com/questions/231628/which-phones-do-have-the-purest-android#comment304588_231628). Google doesn't make changes to core AOSP framework is their plus point (though some good changes aren't always a bad user experience, see Lineage, Omni etc). But I think we should not accept Google's additions to AOSP a standard set of changes. After all Google is an OEM, like others are.

@IrfanLatif It's not my point that Google is ideal or right or a gold standard (it might have come across like that though). Those observations are only to underline what is stock and what isn't//Also see my comment just below yours adding to what you said!//Edit : Aosp vs Google comparison is a different ball game, isn't it?

This answer completely ignores the existence of AOSP. -1

@Ave yes, it completely does that on purpose. OP is looking for "manufacturers" phone (last para of question).  Does any OEM give AOSP out of box? // That's what I also mentioned in the comment above yours

why are you claiming that LineageOS is not Android? I read everywhere (in the comment to the KERR Answer, on LineageOS site, even when I follow the link from the site you mentioned)

@Line I never said Lineage isn't Android . Question asks for two things 1. Pure Android - Lineage isn't 2. Phone from manufacturer- Lineage normally isn't shipped as out of the box OS, one installs it. There is an exception to that, which is mentioned in my answer// Lineage is Android plus a package of useful features which Irfan mentioned above// I was answering to the terms you set out in your question:)

@Line Since you seem to be interested in Lineage , please have a look at my answer here

@Line To support my point that Lineage isn't pure Android, see this comment

thanks, but still I don't get why did you state "if you're looking for a phone that is NOT using Android..." (then take a look at LineageOS) :(

@Line Thanks for correcting me on my mistake. I fixed it and it should be clear now. Apologies for the confusion// I appreciate the seriousness with which you followed this up, sadly I didn't take that care when writing it up

How about looking for models supported by LineageOS? This is a ROM you can flash to your device, and you can even use it without the Google Apps (or flash them later)

Although they are not included in LineageOS as such due to legal
issues,[44] users can flash the normal Google apps, including the
Google Play Store and Play Apps, with a Zip package, usually referred
to as gapps, while installing LineageOS.

You'll need to make sure that you can unlock your phone's bootloader/root the device (double check before you buy it).

thanks, but the question was about Android.

@Line LineageOS is Android, and it sounds exactly like what you want.

I'm going to be an antagonist here. I would say that LineageOS isn't a "pure Android" experience, merely it is stock Android with a bunch of modifications which made it more customisable than stock Android.

The question has quite deep implications.
Android is not an OS, it is an "ecosystem".
There is Android Open Source Project. This is the "base" of the Android OS.
Hardly usable and you will not find pure AOSP on any factory phone.
Vendors get AOSP and build over it to make some phone firmware that fits their business model (it may as well be useful for the user, but this is completely optional).
Then, there is Lineage OS - a community-built Android OS made for selected phone models. In general, it is built just like the vendors' firmwares, except for not having a real business model and driven more or less by the contributors' understanding of usability.
LineageOS comes without any Google apps (not even Google Play, so you cannot directly get apps from it). But you can use OpenGApps to get either the bare minimum of Google stuff (like "pico" package with Google Play only), something more, or a full-blown Google suite.  There are also great sources to obtain open-source apps, such as F-Droid.
Or you may skip this step and use some other means to get apps (a lot of limitations apply).
It's worth mentioning that neither Google nor phone vendors are happy with people installing LineageOS (or other similar packages). This breaks their business model. The process of replacing the phone vendor's software is intentionally made complex and challenging. In most cases, it also voids phone's warranty.
There are also a niche phone vendors that ship phones with LineageOS.

thanks! could you mention such vendors?

Just came over https://www.fxtec.com/ myself. I never tried one, but looks promising and I intend to order any time now.

p.s. looks like Google Pixel 1 is supported by LineageOS.

In addition to the Pixel phones from Google, Android One phones also enjoy a clean interface and receive timely software updates and security patches. Currently, Nokia and Motorola phones are the most prominent Android One phones (see, e.g., Best Android One Phones in 2020.
Some phone brands like OnePlus and Realme keep their Android flavor light but I would not call them vanilla Android.

and would you call Android One vanilla? I saw this article and exactly - those are prominent phones. and I don't want prominent one ;) (like I mentioned in the question)

Since Android has to be adopted to the hardware you will always have some modifications to vanilla Android. I think that Android One is close enough but for me personally a light version with timely updates are the priority.

Sony Xperia Phones have a very close to Stock Android UI eg Sony Xperia 1 II
You can learn more about the latest update to Android 11 for the aforementioned phone in the following Youtube Video:
Sony Xperia 1 II Update Android 11 | 15 New Features.
Hope this helps & Merry Christmas !


text:
Screensavers for 200 tablets - accessed centrally from one computer - Is this possible?
Hi I'm involved in a project to deploy 200 tablets. All devices will be on different networks in various locations around Australia.
I would like all devices to access the one set of screen savers and be able to update them all on demand. Is there an easy way to do this?
Currently I am thinking of logging into all devices from one gmail account and assigning the screensavers to google photos, and changing the photos from this one location.
I understand that google may not allow to 200 devices to sign into from one account.
Does anybody have any better ideas?  Many thanks, Anthony

Look at Android for Work/Enterprise. While for developers, the guide document does cover the supported scenarios.

there are 3rd party MDM solutions example


text:
Android 10 forensics - Root a cellphone without SD Card and without installing any external apps
I would like to root my Samsung J6 mobile phone that is running Android 10 in order to apply forensically sounding techniques on it (basically recovering deleted data etc). So far, as I researched on web, all of the rooting methods require installing of softwares such as magisk to a component such as either SD card or internal memory of mobile phone. The thing is, I don't have an SD Card inserted on the phone, and I don't want to install any external software into my cellphone memory. Is there any way to root this cell phone without installing any app into its memory(rooting via using only connected computer)? Any help will be appreciated.

All you need is the *nix su binary. Magisk and SuperSu are just tools for controlling access to the su binary to prevent its misuse. Every time a process tries to execute su, these tools will prompt you for granting the permission or let you know in some other way.

@ashu Unfortunately it is not that simple. The su binary is just the tip of the iceberg. On modern devices also SELinux has to be considered.

In the process of rooting a device (unless you use an exploit to temporary gain root permissions) erasing all user data is a mandatory step. On an encrypted device (all modern devices should be encrypted by default) this means that afterwards any data recovery is impossible because the encryption key had changed. On some older Samsung devices there is a vulnerability in the MTP protocol which would allow to root the device via USB, but in Android 10 this should be already fixed.

@Robert makes sense!!

@ashu su binary alone hasn't been working since Android 4.3. You need to run a background daemon: https://android.stackexchange.com/a/217949/218526

Does this answer your question? How to recover data when everything is locked (FRP, OEM)


text:
Factory reset without erasing data will cause second user data removed?
I have two users accounts in my phone(multiuser/multiple profile)
One is for normal use and other is work profile.
When I want to factory reset my phone from normal user profile(admin user) without erasing internal storage data (only removes apps and their data),will it remove work profile data also?
Both profiles have different passwords.
Will my work profile apps and file downloads, pdfs, documents will still be there? Or else entire work profile will also be deleted?
I'm using oneplus 5.

Factory reset option without erasing internal storage means all my pics, files, file downloads will be there. But my Google account, downloaded apps from playstore will be deleted. I want to know whether same will happen to my second user profile. Else my work profile will be completely deleted with all data including internal storage associated with it?

Let me rephrase.. In my phone below is the setting backupandreset->erase all data. Here there is a toggle to delete internal storage, I switched it off so my pics, music will not be deleted. So I'm trying to understand what it would do second user profile in this case. I understand that I shouldn't use the term factory here since it is not erasing everything

Alright folks. Anyone who has difficulty understanding OP's problem, know that OxygenOS specifically offers a way to factory reset the device while keeping internal storage intact. The user is given the choice to either go for full wipe (including internal storage) or leave the internal storage intact (see this image). OP is concerned whether keeping internal storage intact would delete or preserve Work profile apps and work profiles storage or not.

Is your device rooted?

No.. My device is not rooted.

I went ahead tried to factory reset my phone without erasing internal storage.
Device - Oneplus 5, Android 8.1.0 , OOS 5.1.4, Not rooted
Before reset
Users

admin
work

Below are the storage details
admin       - /mnt/user/0
/storage/emulated/0
work        - /mnt/user/11,
/storage/emulated/11
guest mode  - /mnt/user/10,
/storage/emulated/10
After reset, names of users are reset and only default user name is seen which is Device Owner
Users

Device Owner

Below are the storage details
Device Owner  - /mnt/user/0 ,
/storage/emulated/0
Files in /storage/emulated/0 are not deleted. All files of second user got deleted. Looks like it completely wipes second user in this case. Guest user got deleted too.

thx for the update.. is admin password also reset? afaik it is used for TWRP, would be interesting

I am using stock recovery and it doesn't ask password after reset. We need to setup new password. I do not know about TWRP recovery.


text:
Notification icons are not being displayed on the status bar
You can see that I have notifications in WhatsApp and Messages app but the notifications icons are not visible on the status bar. I have searched through the settings but couldn't find a way.
Device = Oppo F9
Version = 8.1 Oreo

Notifications can be permitted at the global, but also application level. Have you checked all their individual settings? Also, the order and placement of your status bar icons could be altered in different ways. Are you using a 3rd party launcher that regulates their placement or masks them altogether?

Yes, i checked individual settings. 2. status bar icons cant be altered, because Android does not allow users/developers to customize status bar. i am not using any launcher.


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RCA Galileo Pro Upgrade?
I have the RCA Galileo Pro and it is very slow, is there a way to upgrade?  I have always had a Samsung, so this is a big change.

Welcome to Android Enthusiasts. you gave less information so we don't know if upgrade is possible or you are already on recent version. consider factory reset it will fix most problems (all personal data will be erased)

For starters: have you seen our updates tag wiki? Further, as alecxs already pointed out, some more details would be helpful – like the Android version you're on, the manufacturer, possibly a link to the specs. Apart from that, an upgrade won't necessarily make it faster – a "cleanup" (like the factory reset) on the other hand usually does.

I assume it's RCA Galileo Pro 2-in-1 Android tablet? From the hardware specs, looks like it's inferior compared to even Samsung Galaxy S6. So, I'm not sure if what you're looking for is a hardware upgrade or software upgrade.

Sorry, it is a RCA Galileo Pro 11.5" 32GB 2-in-1 Android 8.1.

I did just reinstall and it also did a system update.  That was the first one since I purchased.


text:
Asus Zenfone cycling in the starting of charging process
I have an ASUS ZenFone Max Pro (X00T/X00TD)
It is/was discharged and powered off. When i plug it in for charging, it is cycling in start of chaging:

vibration
the icon of empty battery
The bootloader is unlocked... text
the icon of empty battery
empty screen
and then starts again from vibration

I tried to clean the phone's connector, even wiped and stracthed the connector a littlebit, and  changed cable, charging source. (One cable is in the 1A charger, another cable is connected to PC.)  It doesn't get better.
I tried to leave it in the cycling, i hoped it gets some power.
Does the phone charge always when connected to power, or it just start the charging process after it shows the charging animation (which i don't reach)?
I tried to step in Fastboot mode. It stays in this mode, no cycling.
Does the phone charge in fastboot mode?
I tried to step in Recovery mode.

vibration
powered by android
The bootloader is unlocked... text
powered by android
empty screen and turns off

In fastboot mode i tried to flash stock recovery, and also TWRP and RedWolf recovery. The flashing process works, but i still cannot get in recovery mode, to see something more, maybe about battery or i dont know.
Of course the phone does not turn on. The same as when i try to get in recovery mode.

vibration
powered by android
The bootloader is unlocked... text
powered by android
empty screen and turns off

I did not do anything special nowadays with the phone. Bootloader unlocking and rooting was years ago, nor i did upgrade, so nothing special. I just used the phone, it discharged, and i'm in this state.
What can i do?
Is it something with charging, or it has enough power after connected in fastboot mode, but the problem is something with the software?
One more thing: maybe i "pressed" the buttons randomly in my pocket.
Is it possible that in an unlucky situation i got into the recovery mode and pressed something away in recovery menu?
Please help.
edit #1:
Is it possible to turn off the charging screen, charging vibration, screen turning on from fastboot mode? Maybe flash something on or similar? Because then it won't use the slowly charging power.
edit #2:
So the sumary now:

My phone is fully charged.
It does not boot into normal.
It does not boot into recovery, nor by hardware keys, nor by command from fastboot. I tried to flash TWRP, RedWolf and the original recovery too.
Fastboot mode works normally.

Parameters:
D:\Mobil>fastboot getvar all
(bootloader) CPU:SDM636
(bootloader) platform:sdm636
(bootloader) secret-key-opt:*censored*
(bootloader) build-type:user
(bootloader) unlocked:yes
(bootloader) off-mode-charge:1
(bootloader) charger-screen-enabled:1
(bootloader) battery-soc-ok:yes
(bootloader) battery-voltage:4286
(bootloader) version-baseband:       *this is empty, i didn't delete it*
(bootloader) version-bootloader:ZB601KL-0x01-20181019151150
(bootloader) variant:SDM EMMC
(bootloader) partition-type:cache:ext4
(bootloader) partition-size:cache: 0x15E00000
(bootloader) partition-type:userdata:ext4
(bootloader) partition-size:userdata: 0xCEB7FBE00
(bootloader) partition-type:system:ext4
(bootloader) partition-size:system: 0x100000000
(bootloader) secure:yes
(bootloader) serialno:*censored*
(bootloader) product:QC_Reference_Phone
(bootloader) max-download-size:536870912
(bootloader) kernel:uefi
all:
finished. total time: 0.031s

D:\Mobil>fastboot oem device-info
...
(bootloader) Verity mode: true
(bootloader) Device unlocked: true
(bootloader) Device critical unlocked: false
(bootloader) Charger screen enabled: true
(bootloader) Bootloader version: ZB601KL-0x01-20181019151150
OKAY [  0.016s]
finished. total time: 0.016s

But:
D:\Mobil>fastboot boot stock_recovery.img
downloading 'boot.img'...
OKAY [  1.859s]
booting...
FAILED (remote: unknown command)
finished. total time: 1.859s

So booting failed. But i don't know why.

Comments are not for extended discussion; this conversation has been moved to chat.

@Firelord, how can we reach chat normally? I mean now i reach chat by your link. But normally how can we start chat?

Go to [chat]. Search for a user and invite them in. Create a chat room for them before that. It is all there in the link.

Believe it or not...
The solution was very stupid.
I cleaned the phone inside, especially the bottom part. Around the connectors, lot of dirt and drying moisture got in. Just enough for - probably - some short circuit.
I don't know why was it okay for fastboot mode, and not okay for recovery and normal boot.

Good news!
This gets the voltage of the battery:
fastboot getvar battery-voltage

It says it's 4,32 V. If i remember right, this is around a fully charged battery. So probably it charged up when i left in Fastboot state for some hours. And the cycle/loop meant not that it cannot charge, but rather it does not need to charge.
Bad news!
Then what the heck is with my phone?

3,85V is the rated voltage, it is written on the battery. (I disassambled the phone.) Charged voltage is higher, discharged voltage is lower.

can you figure pin-out? you can charge with some universal cell phone charger like this http://cgi.ebay.com/152786628220

Why do i need it? Battery is charged, and phone charges it also in Fastboot.

Do you think it writes a wrong number? Is that possible? Hm. I have been trying so long, it should be dead now, if it would not charged. I think.

See the origial post's end. I just edited it. It says "boot" command is unkown. And that is very strange.

idk but we are still talking about previously working device without any software updates which is dying because of low battery, not about boot-looping device with software issues, right? so if it isn't software issue it must be hardware failure

Sadly you are right. There is only one exception. Once when i get it out of my pocket, i saw the stock recovery screen. I said "reboot system", or similar. (To start normally.) But as i see pictures of others recovery menu, there is nothing i could do wrong with. The worst would be the factory reset, but then it should still start, without my datas.


text:
Why I don't need to provide boot-time PIN anymore?
tl;dr: I have my Motorola Moto Z2 Play / A8.0 encrypted and I was forced to provide PIN during very early boot phase of my phone. Since about 1-2 weeks ago -- when my phone had a one-time accident of very long boot -- Android stopped asking for that PIN at boot time. How can my phone be still encrypted and no longer need that PIN to decrypt itself?

About 2-3 years ago I have encrypted my Motorola Moto Z2 Play (now with Android 8.0). I used the same PIN for the encryption process, so starting from that moment, I had to use PIN three times:

boot (encryption)
startup (SIM card PIN) and
startup (fingerprint unlock).

About 1-2 weeks ago my phone hanged badly. After force-restarting, it needed about 20-30 minutes (!) to actually start.
From that moment on, I am no longer needed to enter PIN to decrypt phone and start Android. The first time, I now need to provide it, is when unlocking my SIM card.
My phone was not reset after that one-time very long boot accident. After it finally got up, I had everything in places: all apps, accounts, settings etc., nothing changed, reset or removed.
I have double-checked that my phone is still encrypted:

There was no system update (phone stays at Android 8.0.0 from 1+ year and probably forever), no new application installed and no change in system configuration for long months.
My phone uses fingerprint + PIN screen lock. PIN in numeric, four digit.
From this answer:

If the phone boots up without asking for a password, it is most likely not protected by encryption in the way you would expect. In theory, it might not be encrypted at all (...).

This answer explains that:

The best way to tell if your Android device is encrypted (and the encryption is actually in use) is to reboot it and see if it asks for a password/PIN with a prompt on a black screen that says: "To start Android, enter your PIN" (...) The lack of prompt means the master key is not encrypted".

I don't see such prompt, so I now know that my master key is not encrypted (while the file system itself seems to be encrypted -- above screenshot). But this answer does not explain how / why my master key was encrypted for 2-3 years and stopped being encrypted two weeks ago after a very long boot accident / force-reset.
So, why or when my Android 8.0.0 can decide to decrypt my master key and no longer need me to enter startup PIN to decrypt it?

Comments are not for extended discussion; this conversation has been moved to chat.

In the settings where you choose a new PIN/pattern/passwords it said something like 'Because you enabled an accessibility feature you're PIN won't be used for enhanced encryption protection'.
I had to disable Lastpass auto-fill and my phone asked for my PIN at startup again.


text:
AVD adb push gapps
i try to get gapps working on my avd. I already use a google api image, but anyway the store is missing. Every tutorial tells me to push open gapps via adb:
https://medium.com/@dai_shi/installing-google-play-services-on-an-android-studio-emulator-fffceb2c28a1
But i have the problem, that system is not writable. I already tried various solutions like this one:
adb push not working on /system, read only
Finally i think this can be the solution: https://stackoverflow.com/questions/49426174/cannot-push-to-android-emulator-because-of-read-only-file-system/49427040
But my problem now is, that the emulator only shows a black screen when i use the -writable-system option. Otherwise it starts fine.
Can someone help me to get the store apk installed on my virtual device?

do you have any cmd line access while on black screen? i guess -writable-system is requirement (which is according to your linked researches only available API < 28)

adb says device offline. But it's API 29. So maybe this is the problem

i tried with API 27, it's still the same. Screen remains black
emulator: WARNING: System image is writable
Failed to open /qemu.conf, err: 2
Windows Hypervisor Platform accelerator is operational```

https://stackoverflow.com/questions/50604060/android-emulator-with-hyper-v

https://stackoverflow.com/questions/25241380/it-seems-too-many-emulator-instances-are-running-on-this-machine-aborting

i tried the solutions, but non worked @alecxs
emulator: WARNING: System image is writable
emulator: WARNING: Your AVD has been configured with an in-guest renderer, but the system image does not support guest rendering.Falling back to 'swiftshader_indirect' mode.
emulator: ERROR: VkCommonOperations.cpp:541: Failed to create Vulkan instance.
Failed to open /qemu.conf, err: 2
Windows Hypervisor Platform accelerator is operational


text:
What Android Stock Apps are replaceable through ADB?
What's the list of stock android apps that a user can replace on their phone?
e.g. could I replace com.android.keyguard to change my lock screen? i.e. Write my own version of it.
I am running Android 8.A list of replaceable apps could really help.
Thanks!

Hello. Unless you specify Android phone and Android version you are using, your question is rather too broad and too varied to be answered precisely. Please narrow it down.

Unless you have a rooted phone system applications can't be replaced at all.

I've read somewhere on XDA that it's possible by uninstalling the system app and then adb install newapp.apk and it takes the position of the previously uninstalled app.


text:
Where do the <unknown> items come from?
At the quick settings dropdown are some items that have no icon and just a label . They cannot be re-arranged and are obviously useless.
Please have a look at the Screenshot
.
I would like to know how I can find the apps or files that are responsible for those and/or a way how to get rid of them.
It is an Android Oreo with some EMUI on top.

Those are may be tiles reserved by the Automate app.

Good tip, I have Automate installed and this could be an option. I need to check that.

Dear moderators, I made a mistake and up and downvoted the comment of @ballzak. I should be upvoted. Can you correct that, please? I am sorry for the inconvenience.

@ballzak You were absolutely right, they came from the Automate app. Unfortunately I made a mistake at your comment and clicked the downvote without reading the warning. Could you pleas create a new one so that I can upvote? Thanks

Do you use Automate app? Those are for making a custom quick settings functions. You can customize them from the app by adding a "quick settings" block and defining its action.

How can I find apps responsible for creating these tiles?

Check in the manifest of each app for Tile Service. It will have android:name=".MyQSTileService" & android:permission="android.permission.BIND_QUICK_SETTINGS_TILE"> & service as action android:name="android.service.quicksettings.action.QS_TILE".

Since you don't know which app created this checking the manifest is going to be painfully slow. I used this app apk analyser to check for service and found for example eu.faircode.email.ServiceTileUnseen (it's an email app and the tile corresponds to unseen mails).
How to hide them?
I am not conversant with EMUI but here are things you can try to get them out of sight:

Customize tiles by

swiping down from the Status bar to open the notification panel.

Touch the pencil icon on the top right corner.

Drag Icons from the top part to the bottom part

Or use an app like Quick Settings to delete those  bothersome tiles

You can improve the answer by suggesting edit to reflect the steps on your device

Customize tiles doesn't really help. The icons are already out of the default sight, but I don't really like the idea to have such things on my device without any clue about their origin. I need to check "Quick Settings".
Most promising seems to be the "Apk Analyzer" and the tip of @ballzak in regard to Automate. Is it possible to lookup the manifest via Termux and its tools?

I don't think it is possible via Termux - that could be a separate question


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How to send commands to Android device using Bluetooth module
I want to add extra physical buttons to my old Samsung Galaxy Note 4 for a project that I'm doing. Essentially, I want to be able to press one of the buttons that are connected to a Bluetooth module (GPIO pins of the module), and based on that specific button that is pressed, it will tell the Note 4 to launch a program or do a specific command. Here's the Bluetooth module that I've been looking at.
How can this be achieved?

Android itself can not do what you want. You need an app that connects to your Bluetooth device and performs the action based on the received Bluetooth data. I am not sure if a standard app like Tasker or similar can communicate with generic Bluetooth devices. If not you have to develop an app on your own.

BlueSPP and a Bluetooth relay can do that.

While this link may answer the question, it is better to include the essential parts of the answer here and provide the link for reference.  Link-only answers can become invalid if the linked page changes. - From Review


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How to increase the size of the system partition?
I have an old Google pixel 1 and I was trying to install a GSI but I get this a message on TWRP saying Size of image is larger than target device, so I went to wipe > advanced wipe > selected the system partition > and clicked repair partition and it said that it only has 1.3 GB of space, and the GSI file is 2.3.. Is there a way to increase this partition size ? thanks.

"if you don't know it - don't do it." seriously, messing with partition tables can permanently brick your device

read the introduction first. then search here for keywords repartitioning, gdisk, sgdisk or parted. don't follow any steps, just try to understand. basically read a lot. after few hours go back to the install instructions where you downloaded the ROM and follow the repartitioning tutorial for your device. Be aware don't screw up fastboot - there is no flash tool available for google devices!

You can do partitioning on Android exactly the same way you do on a Linux machine. The same tools and concepts are used. But it's far more complicated due to many more factors involved. As @alecxs suggested, avoid it if it's avoidable. Android devices are highly brickable. Also please note that on recent devices there is super partition. On such devices trying to modify system/vendor partitions is not recommended at all as it gets even more complex, rather impossible.

Check this video: https://www.youtube.com/watch?v=gZgJgqjsfeM


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Timezone is not updating with WiFi and ethernet network in Android
I am working with Android AOSP. When I connect my Android device with cellular network, then the timezone is updating (if I enable the "auto-update time zone" option). But if I connect my device with WiFi or ethernet network, then the timezone is not updating (even if the "auto-update time zone" option is enabled).
I studied some forums, they are saying that the timezone will not update with WiFi and ethernet network.
Is it right? Please give some summary regarding this issue.

Time synchronization via Wifi/Ethernet bases on the NTP protocol. All NTP server are running with UTC time, hence they can not provide a time zone.
If if they would the time-zone would be useless, as an NTP server can be located anywhere in the world. Typically one NTP DNS name consists on multiple NTP servers, and based on a region the closest server is selected, but that still does not mean that the server is located in the same time-zone as you are.
Only the cellular network has the Network Identity and Time Zone (NITZ) service which provides not only time but also the current time-zone. As a mobile network cell is limited to a very small area it is possible to deliver correct time zone data via cellular.