text:
USB tethered device constantly changing public IP address
I recently switched from iPhone to Android (Galaxy S10e), and use the phone hotspot as my primary internet.
I connect the phone to a gli-net mini router (https://www.gl-inet.com/products/gl-ar750s/) through USB Tether, and from that (only have ethernet enabled on the mini router) to a netgear Nighthawk R7000 router which we use for wifi in the house.
The gli-net router has a firewall rule to keep the TTL at 64 (or was it 65??) so we can continue to get unthrottled speeds.
On the netgear router I have also disabled 2g wifi, and only use 5g.
The problem we have is that our IP address on connected devices changes with each web request. So if we go to https://www.whatsmyip.org, we have a new IP address at almost every refresh.
It seems like there are a few addresses the the laptops rotate between ..*.7/9/15.
The DHCP lease time on the routers is 12 hrs.
Do you have any ideas what I should look at next?
When we connect through a vpn on the laptop (protonVPN for example), our IP address doesn't change at every request.
It worked with the iPhone, so I'm wondering if something is going on in the android I'm not aware of? oh, also, the phone service I'm using only allows 1 hotspot connection, which Android respects. The iPhone ignored that. Do you think the issue could be caused by the phone service + android only allowing 1 device? I assumed that if I tethered to the gli-net that it would see that as my one device..

DHCP affects only your private IP address but whatsmyip shows your public IP address. The public IP is "selected" by the used mobile network and you don't have any influence on it. The public IP is often shared among a large number of customers. The only thing you can do is check if you use the correct APN setting and proxy if your mobile network requires to use one.

Thanks for the info! Yeah, its brand new phone, fresh connection to my phone service (visible) so I think all the APN is correct. I just wondering now if it is visible connection limit that trades the IP addresses between the devices connected to my router. On a VPN, everything is ok, just wonder why the IP address changes at every request otherwise!

May be your device always disconnects after a request. If you can, limit the phone to 4G for a test and see if it changes something. 5G is currently only available in "non-standalone mode" which means it is only used additionally to 4G for a certain time. May be your phone immediately goes back to 4G after finishing a request via 5G and thus your IP is changing with every request because of the 5G disconnect. Could also be a bug of the phone or the network. Also check if this happens when browsing using the phone directly.


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How to check Knox Warranty status for Samsung Tab S6 (T865)?
How to check Knox Warranty status for Samsung Tab S6 (T865) if it is tripped or not?
I go to recovery screen by Power + Volume Up and from there selecting "Reboot to Bootloader" to go Download screen. In there, there is no Knox Warranty info; it is only says like hold Power + Volume Down for more than 7 seconds to Cancel.
So where is that Knox Warranty status?

According to SamsungKnox.com : If the Knox bit has tripped:

A new Workspace can no longer be created on such a device.
The data encrypted and stored in an existing Workspace can no longer be retrieved.
Other Samsung services that utilize Knox security stop working (Samsung Pay, Secure Folder.)

but Knox Warranty counter, where is it?

Finally found the answer on the web :
Volume Up and Down and simultaneously connect the device to PC using USB type-C.
https://www.hardreset.info/devices/samsung/samsung-galaxy-tab-s6/download-mode/

from terminal type cmd 'df -ah' if you can see any knox related mounts, warranty is in valid state /data/knox/secure_fs

Hi, looks like you've found the solution by yourself, which is great! Consider post it as a proper answer since self-answering is not only allowed, but even encouraged!. 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 disable Split Screen view
Hello I have a Galaxy S6 and I was wondering if there was any way to disable the split screen/multi-window option which appears above an app when you press the recents button. Are there any ways I can achieve this? Thanks in advance.

Are there apps which achieve this? If not, I thought of disabling the recent button somehow if this is possible. The reason I am trying to disable the split screen/multi-window view is so I can use an app called AppLock, but I can bypass it by using split screen/multi-window view. Any help is much appreciated.

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


text:
Move App Data from SD Card to Internal Storage
TL;DR: Some apps have a little data on the SD and I want to move it to internal in case the apps actually need it. My intent is to use the SD for something else. However, I can't figure out how to move the data to internal.
I have gone into Application Manager and there is a list of apps (it doesn't just list all apps) with data on the SD card. Most say 0.00B but a few say 32.00KB (and it is one or the other, there are no other sizes). I tap on them to access the available options and all I see is "move to SD". I can't find any option to move data in the opposite direction. All of the apps are mostly on internal storage and I am aware from reading other threads that apps can store data in both places at the same time. I have tried searching both on this site and via Google (and Bing). Unless I put quotes around my entire search, the engines find some way to coerce my question into the opposite of what I want. With the quotes, Google gave me two Reddit posts (that is all); neither of which had a solution as far as I can tell.
Main Questions: Is it possible to move the data apps have stored on the SD card to internal storage? If so, how do I do it?
Side Questions: Why are some apps included on the list but with 0.00B? Does that mean the app has an empty folder on the SD card? Or are there files and I am not supposed to see; so it tells me 0.00B? For the apps with 32.00KB, is that just some standard placeholder/empty file or is there a chance the data is actually needed by the apps?

Edit:
In response to Irfan Latif…
I tried to read the whole post but I started getting lost at Android 3.1. You mention that changing protocols now means that the card isn't mounted on PCs. But I don't understand why the way the phone works would impact how a PC interacts with the card. I assume it has to do with the protocol changes but to me the protocols are nothing but names. I simply don't have that depth of knowledge regarding data storage and transmission. Since I can't follow this step, I can't follow anything beyond it either.
As for "Coming to your question:", the main takeaways I got was that you can't prevent apps from writing to SD and that some apps write there just to test availability. Neither directly answers my questions but I can see some potential implications. However, seeing as I am not an expert (else I would not be asking in the first place), I would appreciate it if you could either confirm or deny what I believe your implications are.

0.00B indicates an empty directory likely created to test for external storage
32.00KB could similarly be a dummy test file

Assuming I have correctly deduced what you are trying to imply by redirecting me to the other question, I now have these questions:

Is there a way to check or do I just have to assume the files are dummy files and hope removing them doesn't break anything?
Given that you cannot prevent apps from writing to external storage, does that mean it is impossible to remove an SD card without risking the loss of app data? Given that removable media is meant to be, I don't know, removed, that seems like a rather stupid design decision.

Edit 2:
Thank you all for your patience. Your explanations have helped me learn the key terms to focus on and now I understand things better. Though I still don't fully understand everything in Irfan Latif's reply to the other question.
Based on your replies to the new questions, it looks like the short answer is "No". While I can understand how using a terminal would help clarify the location of the data, I don't see how it would help clarify the content of the data. The exception would be if Android has a dedicated test directory in which data is guaranteed to be non-essential. However, based on what I have read so far from your replies, other questions, and other sites, that is not the case.
You all seem pretty certain these files are just dummy test files. With the apparent lack of any definitive means to make this determination, I guess I'll just have to assume you are right.
I am aware of the implications of using the SD card as adoptable storage. There are millions of articles about that. But even per Irfan Latif's reply to the other question, that was introduced with Android 6; I am talking Android 5. So thanks for the reminder but from what I can tell, the discussion of adopted vs. portable storage is completely irrelevant to my specific situation.
Lastly, just because there is doubt that the GUI would be showing what I claim, I am going to upload a screenshot (or a few) so you can see what I am seeing. I will post them after this edit since I am not typing this on my phone.

can you give example

Please see my answer to How to stop apps writing to "Android" folder on the SD card?. You can skip to "Coming to your question:" part if not willing to read the underlying details, though I strongly recommend to read the details so that you don't have to ask very basic questions.

Are you sure you the apps save data on the physical sd-card? The folder /sdcard and /storag/sdcard is only by name located on sd-card, actually it is the internal flash of your device.

@alecxs I am not clear on what kind of example/details you are asking for.

@Robert I do not know what folders they are actually in. All I know is that the app manager application lists "app", "sd app", "data", and "sd data" and that some of the apps have a non-zero number next to "sd data".

@IrfanLatif Please see edit.

"all I see is move to SD" means app is not on SD, therefore you "can't find any option to move data in the opposite direction". If your question is about Android directory this 0.00B/32.00KB placeholder can safely deleted. you can check content from terminal with find /path/to/dir

For the 0.00B and 32.00KB files and dummy files part, I won't believe what Android's GUI is reporting. Why I won't needs understanding of some underlying details which you aren't interested in. What I do for my storage management is to get a terminal emulator and use commandline tools as alecxs suggested. It leaves no room for misinformation or confusion. Details here: How disk space is used on Android device? (which you may not find very appealing).

"it is impossible to remove an SD card without risking the loss of app data". It depends on if the card is formatted as Portable or Adoptable storage, what data is written to the SD card, and how important it is to you. If a camera app wrote the whole video recording of half an hour to your SD card, this would be a loss. If some app created just the files directory as a routine matter to detect external storage during app startup, this won't be a loss. What is files directory is explained in Where Android apps store data?.

@IrfanLatif Please see edit.

@IrfanLatif based on the screenshots guess the "move to sd card" button is for creating '.android_secure/*.asec' container which is indeed on second external storage while still having sd formatted as portable (vfat) at same time. completely forgot about that


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Installing full YouTube app on Tecno phone (Android Go) failed silently
I have a Tecno phone with Android 8.1.0 Go. YouTube Go is my system app, however, I grew tired of using it because of its limited features and decided to install the YouTube app. But that's when the trouble started. The app downloads until 100% and then shows that it is installing and then nothing, nothing at all back to square one, and no error is shown.
I have enough space, I have cleared data and cache for Play Store, restarted the phone, even tried APKs but still, nothing worked.
What could be the issue? The only advice I have received so far is to root the phone. What should I do? Other apps download and install just fine.

have you tried 'uninstalling' system app via adb package manager (no root) https://android.stackexchange.com/q/179575

Dupe of Cannot install YouTube app on Tecno devices (Android Go) (but also no answers)


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How we can know from Download Mode screen if device (Galaxy Tab S6) is factory-new?
[] download screen for my Tab S61
Picture above is from my Tab S6's download screen. Do you see any clue showing that this device is not brand-new? For example anything that should be locked but not locked now or any warranty that has voided or anything other than normal as brand-new?

Does this answer your question? Samsung S7 - Developer options not showing after build number pressed 7 times

that post is useful but not much relevant to this topic

What does that (L) following OEM LOCK mean ?

Factory-new devices do originally come with KG STATUS : PRENORMAL? What should be the original KG STATUS for factory-new devices?

OEM lock: on (L) means locked. your bootloader is locked. Warranty void: 0 means your warranty is valid, therefore this device never was unlocked before and is still in factory state. state prenormal is not normal, it means you are not allowed to unlock bootloader (as explained in the linked xda thread). this is probably some recent policy change due a samsung security roll-out in Jun 2020

Thanks, this is important for me as I'm trying to find some evidence to prove that this device is not brand-new or not in factory state if it is so. This device production date is July 17, 2020 so it is probable that this KG being PRENORMAL is for the recent policy change. But we need a proof for existing that policy change. Is there any?

nobody knows anything. this is pure speculation (so far) https://forum.xda-developers.com/t/guide-17-06-2019-rmm-kg-bypass-root-install-twrp-on-exynos-samsung-after-2018.3747535/post-84311531
https://forum.xda-developers.com/t/bounty-fix-for-persistent-rmm-state-lock-after-7-days.3886716

This particular device has Android 9 and I believe that has been flashed back to Android 9 by the seller because Android 10 update for this has rolled out in early April 2020 and so this device with production date of July 2020 should originally comes with Android 10. We suppose that this Prenormal condition is a factory state, now is it possible to flash back while KG is already PRENORMAL?

(I don't remember where I read that when device KG becomes PRENORMAL, no longer can flash even stock ROM) Correct me if I'm wrong.

bootloader has anti-rollback protection, flashing lower bootloader level is impossible. prenormal means "only official released binaries are allowed to be flashed"

BTW according to Chimera RMM lock and KG lock is two different locks; and in my case, KG (but not RMM) is showing in Download screen.
https://chimeratool.com/en/docs/samsung-knox-guard-kg-and-remote-monitoring-and-management-rmm-unlock-functions


text:
How may I modify my root filesystem, which is mounted from /dev/block/dm-0, in order to create a mount point or symlink at /usr, on Android 11?
I need a writable /usr directory to run Gentoo Prefix. I suppose that it can be either a symlink to somewhere else or a mount point for further mounting.
Information collected so far:

Since Android 10, remount rw no longer works with root fs.
Device dm-0 is read-only.

Does this answer your question? Can't remove bloatware after rooted

Do not modify system on systemless-root method. use magisk module bind mount overlay instead


text:
Is it possible to run an X Server and a window manager in TermUX
I am running the TermUX application on an Android 10 smartphone, and can type in it with my Logitech K480 keyboard. I want to run a window manager like fvwm (see fvwm.org).
I have found an article on the internet which seems to mention i can run VNC server and client or XSDL although the latter is unstable, but as far as I understand I can only do this if i have a separate computer running the server, and then my Android smartphone can run the client window manager from TermUX after changing the DISPLAY environment variable
Is this correct?
How can I run an X Server in TermUX and then simply run the window manager with the startx command like in Linux?
Thanks.

Termux is a terminal emulator. Original implementation of X Server runs on a Virtual Terminal (kernel console). Is your kernel built with VTs and Framebuffer Console (physical display) support? Most probably no. So you need an Android specific X Server (like the almost abandoned XServer XSDL app) or need to run the original X Server in headless mode which directs its output to a virtual display like VNC. You can then run a VNC client app on localhost (the Android device itself) or some other host on the network (like a PC) to receive the display and interact with the GUI environment.

Btw X Server programs are built for PCs. Most of them aren't very usable even on a 10-inch tablet screen. So X server running on a phone isn't of much practical use. That's what my experience is. I run Linux distros on Android devices but only with CLI controls.

Related links: Is it possible to install Linux on Android device? and How to quickly understand the Android UI? and How to boot Ubuntu on Android? and How to Play Sound from Termux when using Linux?

Termux officially supports the two methods I mentioned above to run X Server: https://github.com/termux/x11-packages#using-x11-on-termux. But if your device is rooted and want to try your luck with the existing framebuffer support, start from here: https://github.com/meefik/linuxdeploy/search?o=asc&q=framebuffer&s=created&type=issues. However FB isn't very likely to work with the standard Linux tools because its functionality is very limited or non-standard in many cases and Android relies on closed-source HALs provided by OEMs for most of its interaction with hardware components.

Afaik what OP is asking for is not possible, however the hacky solution @Irfan Latif mentioned is, and is also given in the termux wiki(https://wiki.termux.com/wiki/Graphical_Environment)

You can run either an x-server or a vnc-client on the same Android device you have installed termux on. You don't have to use another device for that.
Instructions are available here https://wiki.termux.com/wiki/Graphical_Environment
I suggest you use VNC instead of an x-server.


text:
Termux write permissions
pretext:
as gmail no longer allows me to send zip files, i have been looking into other ways to get my java source directories from android to laptop and back again, depending whether I'm at home or not (folder hierarchy must be preserved). I have been trying to set up git on my android phone and have been using termux as the command shell to do this.
the problem:
I am unable to create a directory for which BOTH termux and the java ide have read write access. I have setup storage permissions in termux. If the IDE can write termux can't, and in another location termux can write but the IDE can't.
What I need is a folder location that both apps have full read write permissions. (I am not too bothered if these permissions extent to other folders)
I do not want to root my device.
Nokia 7.2 Android 10

Apps cannot access other apps' private directories: Where Android apps store data?. All apps with Storage permission can access external shared storage (though subject to some restrictions since Android 10 and 11): How do I access $HOME/storage outside of Termux?. But the shared storage is a permission-less emulated filesystem: What is /storage/emulated/0/?. So you cannot retain files' ownership, mode etc. Root gives multiple options.

Have you tried /data/local/tmp that is the only option outside of the sdcard folder? How about running an git server in termux? If your IDE can handle local GIT repos a remote repo on 127.0.0.1 should be possible, too. You even have two options, git via http or ssh. Of course this would require to have the git repo twice on Android.

I have achieved a solution by making the project folder in the main storage (/emulated/0/ProjectName) instead of on the sd card.
In termux i navigated to (...ProjectName/src/com/package/) and ran 'mkdir test'. In the ide i then created 'test.txt' in the newly made test directory. This all worked fine, although i have not linked git to this directory it proves that write access is there for both apps.
Before i was attempting to use a folder in the sd card which would not allow the permissions. I did not change anything else regarding settings and permissions between these two attempts, but some were changed prior to the initial attempt in the sd card, which may have played a role. If you are having the same issue feel free to comment and i will go through all other settings i changed before this. or maybe someone with better knowledge of android can comment as to why this worked.
edit: quote: "Some phones prevent third party apps from accessing the sd card but with the appropriate permissions all apps can access the internal storage."

Now here is a "so simple a caveman could do it" solution to your main problem, not related to any of the git /termux stuff you have mentioned.
If you use Windows, There is a piece of software called Feem (https://feem.io/) which allows you send files over devices on the same network. Afaik, it should work on windows 7 and up. It definitely works on 10.
If you use linux, use KDE Connect. Basically the same thing.
These are manual transfer tools, ie: you have to send the file manually again if you edit it later on.
Also you will have to compress everything and then transfer the compressed file because these tools can't seem to be able to recursively transfer complete folders while they perform well with compressed files.
You could also try syncthing (https://syncthing.net/) if you want a continuous backup kind of system between your android and pc.
If you make any changes, these will be reflected on your device depending on how you setup the sync. Just have both devices on the same network with syncthing running on both devices and the sync will be done.
BTW, syncthing is cross-platform.
SyncThing should be the best solution to your problem as you won't even have to compress the folders and sub-folders to preserve hierarchy. Syncthing recursively includes all folders and sub-folders while syncing.
Of the tools I have mentioned, Feem is not Free software(as in libre, not gratis) while the other tools are, to the best of my knowledge.
This is my first answer here so please give me some constructive feedback on how I can improve my answers.

some file explorers let you see termuxes storage as a drive in someway.
you could just transfer the files to your phone from your pc and then use a file explorer to transfer.
if you want https://wiki.termux.com/wiki/Internal_and_external_storage

Unfortunately i cannot connect the two devices directly. but if i could that would solve the initial problem ( although does not answer the question asked). Furthermore i could even write a small script to compress the parent directory (at known fixed location, copy to destination, and extract), the equivalent converse could also be written (or even signalled with a boolean argument). (or even source and destination arguments). If anyone needs the appropriate .sh or .bat script let me know and i will post it.


text:
How can I always get desktop version of web sites using Firefox for Android?
Some sites offer restricted functionality based on mobile user agent.  Although the current Firefox for Android (67.2.0) offers the ability to select Desktop site from the menu, I'm required to do that every time I open a new tab.
In the past, I thought there was a way to always go to a desktop version of a specific site, but I can't find it now.  Is there some about:config setting that can help?

try user agent apps from google play

about:config is disabled in Firefox for Android, but if you switch to the Firefox Android Nightly version, about:config is currently working.
If a new key is added general.useragent.override and a desktop user agent string is used (for instance Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:85.0) Gecko/20100101 Firefox/85.0), then all web sites will receive that as your user agent.
This may not be desirable, since many web sites are difficult to navigate on the smaller mobile screen, but until there are user agent switcher add-ons that are allowed by the powers at GoogZilla, this is the best you can do.

Unfortunately, this does not seem available any more.

@VladimirFГероямслава I downloaded the latest "Firefox Android NIGHTLY", typed "about:config" in the address bar, typed "general.useragent.override" and my setting is still there, so I'm not sure what you saw that prompted your suggestion of not being available any more.

I only have Firefox Nightly available, no NIGHTLY. In this one, there is no general.useragent.override. The only similar one is general.useragent.compatMode.firefox

@VladimirFГероямслава You need to ADD the entry.  It isn't there to be configured, but if you add it, it will take effect.

I see, thanks, it is working now.

authors: Vladimir F Героям слава


text:
Use scrcpy to connect to multiple smartphones
I just learned how to use scrcpy. I successfully turned on ADB on the Android and am able to scrcpy to it from my PC. Now, I want to connect to multiple smartphones.
I notice it is a portable app, so is it a matter of duplicating multiple folders of scrcpy? Or can I connect to multiple phones from one instance of scrcpy?

If multiple devices are connected you can select the device to connect to by specify it's serial number. This is documented on the scrcpy help page. Therefore you can start one scrcpy instance per device.

Multi-devices
If several devices are listed in adb devices, you must specify the
serial:

scrcpy --serial 0123456789abcdef
scrcpy -s 0123456789abcdef # short

To get a detailed list of devices you can execute the command
adb devices -l

Thank you, this solves it. My issue seems to be outside the scope of this question. I Samsung Active2 that I can ping, but actively refused on port 5555 when I try telnet nor adb connect x.x.x.x:5555. I'm doing this via wireless as well.

@Sun ADB via wireless is disabled by default (and AFAIR reset with every reboot). Therefore you have to connect the device via USB ADB and enable ADB wireless first.


text:
Question about spacing in .ttf fonts for android
I've been having trouble setting up a font to work well on my phone. I'm using an app that allows me to load ttf files into my system, the problem is spacing between lines/titles being too large (see attached screenshots).
I'm trying to figure out how to edit the ttf on font forge to resolve this, but it's been to no avail.


text:
Sync exchange with local calendar WITHOUT granting permissions to gmail or Samsung
It's pretty simple, what I want, I think:

1 local/offline-only calendar on the phone (default Samsung app)
1 on-line exchange calendar (automatically synced)
ability to show one or the other or both at the same time in the same view
notifications coming from both calendars, as if they're both local

I do NOT want:

to associate a google account with the phone
the gmail app to be in any way involved
to accept Samsung's request to hold my personal information for 5 years on their servers
any kind of sync involving e-mail, contacts etc etc.

It amazes me that this seems nearly impossible to do. Is it/how?

I don't see a problem here Exchange is and was never linked in any way to a Google account. The only "relationship" is that modern Android devices no longer have an mail app for Exchange, instead Google wants you to use the GMail app. But which ap you use is your choice. And as far as I know there is no data exchange with Samsung unless you create/use a Samsung account.

I'll try to clarify further. I don't want e-mail in the picture at all: in particular, I don't want GMail to play any role in the process. What I'm interested in is the calendar. I have a (default Samsung) calendar app. I want it to be the interface to the exchange calendar and to the local calendar on the phone. I would expect the app to provide an option "add remote calendar" where I can enter my exchange credentials and from that moment on, events from the remote (exchange) calendar show up next to events stored locally on my phone.

Android does not work this way. You have to add the Exchange account to your Android accounts list and then you can select what to sync (mail, calendar, contacts). Now the calendar will be visible in the calendar app (which seems to some Samsung modified version on your device).

Why is the user required to grant permission to Gmail when adding an Exchange account to the Calendar?

@Robert if you disable Gmail on an android device (via the app settings panel), you are no longer presented with the option to add an exchange account and if you previously added an exchange account its calendars disappear when you disable Gmail -- so there does appear to be a relationship between Gmail/Google when connecting to Exchange and it does not appear to be managed by an external android service

I managed this using the https://framagenda.org/apps/calendar/ calendar and the DAVx5 app, which uses the caldav protocol. DAVx5 syncs nicely between the built-in calendar app on my phone and the web interface at framagenda.org.
I can define as many calendars as I like ("personal", "business"...) and sync them and can have a local phone calendar (which I no longer use).


text:
Would using a VPN, different browser and XprivacyLua prevent a website from remembering me?
Let's say I registered at a website using Google Chrome on my phone, then later on I used a VPN and Firefox restricted through XprivacyLua to access the same website. Would it be able to know that it was me (my) device that accessed it previously? If so, how can I prevent it?
Android 7 | Rooted

Which website you are talking about? What methods it use to track you (e.g. cookies, tracker scripts, HTTP referrers, user agent info and a long list of fingerprinting parameters, see here)? What purpose your VPN serves except hiding your public IP? Is it really hiding your public IP (see this and this)? What information are you hiding using XPrivacyLua (and from whom)?

Afaik clearing cookies on your local machine should make the site "forget" you, however modern spyware is widespread and very intelligent. For instance fingerprinting is unique to your device and browser so perhaps changing browsers could help, but an opensource browser like brave which offers fingerprinting protection by default would be your best choice both for convenience and security. If the site logs your IP though, you will have to use a VPN and ensure that you have different IP's each time you connect to that site.

VPN and XprivacyLua don't have an (or not much) impact on browser fingerprinting. For that the used web browser is more important. See for example this explanation: https://restoreprivacy.com/browser-fingerprinting/ But I am not sure if Firefox for Android is really good in anti-fingerprinting measures. The Windows version of Firefox totally failed in preventing browser fingerprinting (read in the biggest German tech magazine c't).

@IrfanLatif "Which website you are talking about?" Banks for example. "What methods it use to track you?" I don't know since I can't ask every website I visit, and expect a reply. So let's just assume "every way". "What purpose your VPN serves except hiding your public IP?" Can it serve another purpose? "Is it really hiding your public IP (see this and this)?" I checked and it seems to be hiding it. "What information are you hiding using XPrivacyLua (and from whom)?" https://imgur.com/a/FnIneUv. From the browser.

@JJrussel the point of my comment is that there are a number of factors which decide what unique information about your device and OS is exposed to the internet. I don't think anyone can give a simple realistic answer to your question. The best way to is perform some online browser tests after taking any measures you think are important. Tests show what information about you is visible to the internet.

@IrfanLatif Which tests would you recommend?

The one I linked in my first comment is an example. You can find many online.


text:
Formatted SD Card as internal storage
I formatted my SD card in my Lenovo Tab 4 as internal storage in order to free storage etc, but then realised how I can no longer read the card on my computer.
Is there any way to either have the computer read this SD card or to download files onto it?
Or at least can I unformat it?
Thanks so much

Have you formatted it as portable storage or internal storage?

Internal storage

You can connect your phone via USB to a PC an access the storage. Alternatively if you want to reverse the format as internal storage process see here.

Hey thanks for taking time, but just whenever I connect it to the PC the device doesn't even come up (whether in a phone/tablet or even a SD reader) so I assume the computer can't read it.

Make sure you are using an USB cable that can be used for data transfer (some only allow charging). Use a recent OS (Windows 8.1 or 10 or a recent Linux distro on a PC). And when connecting the phone via USB make sure to unlock (enter PIN/password) on lock-screen first. A locked phone can not be accessed. On Windows check device manager if there are devices with yellow exclamation mark (missing driver).

Windows computer can read FAT formatted SD card.
Lenovo tab 4 has nougat operating system. This tab's formatted card should read by computer. You can reformat sd card and connect it to computer. If card is write protected then you can not able to read it.
Look inside devices and drive. Right click on card and format it.

Hi there, Im having a problem that whenever I plug it in, the device won't even come up (if I insert my tablet with the sd card inside it'll say "Windows has picked up a non recognised device" and if in a SD card reader an empty reader will come up), do you have any advice for that?


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Wi-Fi Verbose logging fields
I've been trying to troubleshoot a Wi-Fi issue (with a specific network) and have Wi-Fi verbose logging on, but I can't find any documentation on what any of the fields in the network selection menu are.
The network in question has the full info of:
Connected [ UN UN UN ] f=2462 00:00:b1:6b:00:b5 standard=4 rssi=-75 score=59 tx=23.3,27.9,1.0 rx=20.9 4G STAs:8[(2)

I understand rssi and STAs (although, I have no idea for the second number for STAs) and f fits the channel frequency, but the rest (UN, tx/rx, standard, score, and 4G) have me stumped.
Does anyone have any idea for these or a pointer to the relevant documentation?

The Android source code is available online.
Your log line appears to be from:
WifiStateMachine.java specifically String getLogRecString(Message msg)
Around line 2196, the string output starts looking similar to yours:
sb.append(" rssi=").append(mWifiInfo.getRssi());
sb.append(" f=").append(mWifiInfo.getFrequency());
sb.append(" sc=").append(mWifiInfo.score);
sb.append(" link=").append(mWifiInfo.getLinkSpeed());
sb.append(String.format(" tx=%.1f,", mWifiInfo.txSuccessRate));
sb.append(String.format(" %.1f,", mWifiInfo.txRetriesRate));
sb.append(String.format(" %.1f ", mWifiInfo.txBadRate));
sb.append(String.format(" rx=%.1f", mWifiInfo.rxSuccessRate));

The variables names appear reasonably descriptive for at least further research. The above file is dated 2017, given that there have been a number of WiFi changes made between OS version, I would find the one matching your version of OS, by looking for a "base" OS version branch (left hand side), and then drilling down to the appropriate WiFiStateMachine.java file:
https://android.googlesource.com/platform/frameworks/opt/net/wifi/
or searching for an appropriate string where you can find where logging is occurring.


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How to extract a raw apk out of installed application?(Raw for reverse eng purpose)
So I developed an application but my hard drive failed and I lost access to project resources, but I had it previously installed on my phone through android studio debugging process.
Now I want to extract a raw apk version out of my phone, Is there any way?
NOTE that any regular apk extraction through Google Play applications outputs a ~700kb apk of my project that lacks resources and cant be reversed, while it has to be ~4.4mb.

On Stackoverflow this question has been answered several times: https://stackoverflow.com/q/43342330/150978 Note that `adb shell pm path  may list multiple APK files if the app is a split APK file. Then you need all of them.

@Robert thanks for your answer Robert, my bad. shall i remove this one?

You can just leave the question as it is - in the end it is a valid question and it is on-topic. May be some one other encounters it and gets directed to the answer.


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ANT+ and UPSM (ultra power saving mode)
I have a Samsung device with ANT+ support and i would like to connect to ANT+ devices when in UPS(ultra power saving) mode.
However, in UPS mode with bluetooth enabled, the ANT+ is not working.
Whereas in normal mode ANT+ works when Bluetooth is enabled.
Note that: ANT+ uses the same range of frequencies than WIFI and Bluetooth 4
Some specific details:
ANT HAL service: 3.0.0
ANT Radio service: 4.16.00
ANT+ Plugins 3.6.40
(I can't tag it as 'ant+')

As the developer of an ANT+ app my first advice is to switch this stuff off when stuff is not working which sorts out half of my support issues.  I suspect there is no way to control this unless Samsung have some back-doors into there power saving control.  What is your use case needing this ultra low power mode?

@Ifor I use for the practise of long term outdoor sports, the saving power mode is a superb function. It enables me to do GPS tracking and check maps for much longer time than in normal mode. And through BLE i can be connected to a BLE sensor but i can't with my good ANT+ sensor. From UPSM I can open/use any installed app but as ANT is a service/ driver I can't.

You must be doing some proper long sessions.  A reasonable modern device should be able to do 5-6 hours without anything specials needed.  If you can go screen off most of the time your looking to double this.  Do you know what the runtime difference is your seeing with this mode?  I am well aware of the desire to stick with ANT+ it is far far better stability wise.

From my experience when I am using UPS mode the battery last not less than 3times more.  Also it avoids the battery draining caused by some services and background apps. I assume that comparing with normal mode in a device with few installed apps the difference will be smaller.

It will be easer to use a bigger power bank instead of investigating mutual influence of radio technologies.

IMO a powerbank is a workaround based in brute force and I would prefer to find out to improve performance for the out of the box hardware. And in android devices there is a lot of margin for performance improvement.

ANT+ functions are not loaded during Samsung ultra saving mode (UPSM).
For non-rooted users has not impact has Samsung  doesn't include any system app that uses ANT+ protocol.
For rooted users, they can manage the system apps, so they can enable ANT apps to be used during UPSM.
Workarounds:

Using Normal saving mode and ANT
or
UPSM with BLE apps and BLE sensors


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How do I get full feature list of Wear OS?
I'm developing a custom version of Android system for a 'Android smart glass' device. I'm trying  to customize a new version of Android ROM that suits this type of wearable device.
Needs features such as bluetooth/wifi direct connection, power saving mode, etc.
After researching the Android community, I find Wear OS suits most of my needs. However, I can't get a full feature set of Wear OS.
How do I get a in-depth analysis or something like full featureset of Wear OS?


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is RPMB Fuse Set a factory state?

I bought a Galaxy Tab S6 and I'm going to verify if it is really brand-new.
I personally haven't alter the device and the above picture is from this device's Download mode screen immediately after my purchase. It reads:

RPMB fuse Set
KG STATUS : PRENORMAL

I have no idea whether RPMB fuse Set is a factory state. Is it?
Concerning KG STATUS being PRENORMAL, I don't think this as a factory state (it seems the seller has already tried to flash an unofficial ROM or perhaps tried to flash back the official ROM from Android 10 to 9)
Do you see any clue that could be used to prove that this device is not in factory state and not brand-new?

At this point, many questions into this topic already noted, it might be the only way to satisfy your need for privacy may be your design and building of a device to your personal specs. Marginal paranoia is to be expected, since the consuming of products sold by others makes it necessary. Perhaps the seller doesn't make you comfortable. Avoid buying from him then.

I really couldn't find any post to answer this question.

This is a question that many people have but not answered clearly according to my search

People have this question that which one is factory state: RPMB Fuse Set or RPMB Fuse Blown? (I've asked this in my other question as well)

consider mark the answer as accepted

What i know:
RPMB fuse - should be set, not blown
Current binary - is samsung official which is to be expected (if there was something else it would say something like "Custom (0xE03)" instead)
FRP lock - is off, which should be that way, it's factory reset protection which means that FRP protected device even after factory reset will require you to log into your google account
OEM lock - is on, this means the bootloader is locked (should be locked)
Warranty void - is 0, this is knox counter and if you try to flash anything on a new device it will trip and always show 0x1 in download mode. Right now afaik there's no way to set it back to 0x0
What i don't know:
RPMB provisioned - RPMB is replay protected memory block (or something like that) and provisioned seems to be its normal state, but from what i could find it relates more to memory integrity than to flashing, so it probably will not change after you install something
KG status prenormal - KG is knox guard, and on my new device i think it was prenormal already, checked on other new device - it was "completed". I don't know what exactly does this status mean, only thing i know is that with prenormal status you can't flash custom roms/recovery/etc
Qualcomm secureboot and secure download - were always enabled for me, and i honestly have no idea if you can even change that
SPU[VALID]:5 - don't know what it is, quick googling gave zero results, i guess it's good that it is valid
Conclusion:
I'd say your device is brand new and with stock everything, but i don't know if there are any clues of it being refurbished, so no hints on that


text:
my device got a ROM flash by the seller prior to my purchase?
I bought a Galaxy Tab S6 a few days ago and I am going to verify if it is really brand-new.
Some facts: The production date of this device is in July 2020 and my purchase date is in February 2021.
First of all, the system date and time is not up-to-date and even confusing. The system date (on the day of my purchase: February 19, 2021) was January 3, 2019 (that is, 7 mounths prior to August 2019 when this device model released by the manufacturer for the very first time).
Besides, the system time doesn't match the device region (UAE) local time and there is about 9 hours difference.
Finally, dates of files in Android folder are mostly January 1, 2019 (which indicates two days prior to my purchase and boot up) and other file dates are for two days later (January 3, 2019) corresponding to when I purchased and booted the device.
Therefore I'm going to conclude that the seller might had flashed ROM into this device a couple days before he sold it to me and this device is not brand-new.
What is your opinion?

The dates you mentioned doesn't match. Based on those dates you have bought the device in 2019.

Sorry, I bought it in February 2021 but on the day of my purchase when I booted up the device, the Android system date was January 3, 2019

By the way your question can be answered very easy: All devices come in a sealed package. If the seal is broken the device is not "brand new" independently on the software that is installed, the Knox state or whatever you aske din the last days.

The seal was not broken but it could be a fake seal. I bought from  third-party seller.

I actually wouldn't be concerned about the time "issue"... The time and date would go back to the default of the kernel until network time could sync. In tablets this is sometimes not enabled by default. If the device had been off long enough, it would "lose" it's internal time and revert to the default time and date (00:00 @ 1/1/2019)  at boot until a network sync and time zone had been configured.

To my knowledge, file dates in Android folder are the same as when a device is booted up for the very first time and after that they get last modification date.

By my logic, I believe that this device was flashed and booted up (and perhaps factory reset) by the seller two days prior to my purchase. My reason is that if I were the very first person who booted up the device (and we suppose that your scenario is the case), all file dates in Android folder would have to be 1/1/2019 soon after I booted the device for my very first time.

But this is not the case as I see some file dates (in Android folder) remain 1/1/2019 and the others are 1/3/2019 which reflect last modify date as the results my very first boot up. So there must be an initial boot up two days prior to when I booted up for my very first time.

Can't this convince you?

@acejavelin It seems you have followed my posts in the few last days. I returned my first device to local warranty company and they swapped it with one that has both unbroken Samsung seal and local warranty company seal. In this post I'm referring to my second tablet. The first tablet had Samsung seal but broken and local warranty seal unbroken.

If you are that worried, just return it and buy one from a seller you believe is more reliable.


text:
Lock computer USB connection
I'm looking for a way to lock computer USB connection with anther password then the regular lock screen password... (or ether disable the usb connection completely without broke the usb port)
There is an app on the play store that called:
Smart AppLock (App Protector) https://play.google.com/store/apps/details?id=com.sp.protector.free
It has the so-called option "USB Connection Lock", but it isn't working...
Some one told me that i need an app or a way that detects whether com.android.settings/.Settings$UsbDetailsActivity
activity is in the foreground or not. If in foreground, than create an overlay or a new activity on top of it which would act as a password lock
but how can i do that?

Why is lock screen password not adequate? Dual lock would achieve nothing. If a person besides you knows lock screen password than they defacto have internal storage data access and app installation privileges.

No, it for a person that doesn't know the lock screen password, and he can't do a simple factory rest... because i have a TWRP recovery mode with password also.  and he is trying to hack my phone with Usb Connection... so i'm searching for a way to block and Usb connection, even myself to block him. and i want just the battery to work with the usb cable, but never a file transfer or something like that... I don't use the Usb port for anything but charging (sorry for my lame english...)

You can set the default USB mode to charging only. Check the Developer Options there it should be configurable.


text:
SAMSUNG a10s boot loop after TWRP flash
I have bought a SAMSUNG A10s phone and tried to install TWRP according to this instruction. I was able to unlock the bootloader and enter the 'Downloading' mode.
I disabled time sycro and automatic updaten, set the time to a few weeks ago and connected the wifi in order to overcome this issue.
I used a Debian computer and the Heimdall tool to flash this TWRP image into the recovery partition (which replaced the existing recovery.img, I took no backup - daft, I know).
Caused by the unlocked bootloader I got a warning with every startup. The usual key-combination for the bootloader menu did not work. So, after a few boot procedures, I tried the offered option to lock the bootloader and perform a factory reset.
Unfortunately, this brought me to bootloop. I was only able to enter the 'Downloading'-mode again. Now, the bootloader is locked again but the images are invalid. I get this error message:
<!>
Partition recovery
Reason recovery: Eroor verifying vbmeta image: invalid vbmetaheader
SAMSUNG recovery, A107FXXU7BTL1, 36415554R
SAMSUNG vbmeta, A107FXXU7BTL1, 36415554R

Quitting this 'Downloading' mode brings me back to the loop which reaches the SAMSUNG logo before it boots angain.
Can anyone explain this situation? Has anyone an idea for a solution? Using Heimdall, I can still read the PIT. So, maybe I can also flash any images. I am very glad for help!

I am already downloading the corresponding firmware from sammobile.

Does this answer your question? How to use ODIN with more than a dozen of mbn, bin, img, ext4 files?

after unlocking bootloader (and necessary factory reset) one must connect wifi and oem unlock again to disable vaultkeeper

@alecxs thanks for your comment. Indeed, I had to disable automatic updates, to set the time longer than 7 days ago and to connect the wifi. This was before I was able to flash anything.

be aware bootloader is not downgradable, therefore i recommend to flash U7 as higher bootloader level may lead in non-unlockable bootloader

@alecxs - I can see the U7 in the error message as a part of the checked image, isn't it? But what does it mean that here, it refers to U7?

yes that is your current bootloader level i am refering to. i don't know which stock ROM you have downloaded but there might be a risk after flashing latest available version your bootloader is locked down entirely and the 7 days trick won't work any longer. therefore flash oldest possible stock ROM (which is U7 already in your case) https://android.stackexchange.com/questions/234025/how-we-can-know-from-download-mode-screen-if-device-galaxy-tab-s6-is-factory-n#comment310253_234025

@alecxs Unfortunately, I know the message "only official released binaries are allowed to be flashed" you quoted yesterday. This was shown in the Downloading Mode after failing to access the TWRP menu. So, can you recommend any strategy for solving this issue without causing remaining damage?

but vaultkeeper is a different story - basically just don't forget to unlock bootloader twice before actually flashing custom binary

@alecxs I am not sure. I missed the unlock field in the developer menu, so I followed this recipe.

Let us continue this discussion in chat.

@alecxs - I am still in the same situation. Right now, I installed JOdin. The phone is connected but I cannot access the PIT. Furthermore, I am not sure about the firmware offered here .. it is just 32 MB. Do you have any ideas?

both download links provided work (2.8GB) you probably clicked the wrong link for boot.img only. unzip the download (3.2GB) and flash the four tar.md5 files according to it's prefix


text:
Installing Android on Nokia Lumia 520 Using MacOS Computer
I am trying to install Android on my Nokia Lumia 520 so I can use it as a hardware device to debug my apps for Android app development. I use a Macbook Air (MacOS), and tried to search for tutorials to install Android on my Nokia Phone, but I can't find any tutorials for MacOS. Can anyone give me the steps for installing it on my Nokia mobile phone?

If you watched the videos from https://forum.xda-developers.com/t/android4lumia-android-for-lumia-52x-620-and-720.3985347/ you'll see a Windows program used to flash stock ROM on device, so you'll be better with Apple Boot Camp / Windows install (or get a old PC with Win). 2) You will also note that a number of features on the phone doesn't work with Android ROM including Camera and Accelerometer. For fun sure, for development, avoid any grief/problems and buy a cheap Android phone where everything works and can be used for debugging Android apps.


text:
Recently deleted my AVD and did not get back the 8 GB it took up?
I haven't used Android Studio in a few months so I went ahead and deleted my AVD and system image from the tools menu inside Android Studio. The image deleted fine, however I notice that while the AVD was gone, I did not get back the ~8 GB it took up. I also see that my pagefile.sys has grown to roughly the same size.
Is this due to the AVD using this as virtual memory and not reallocating it back to my hard drive after deletion? I can manually go into settings and change my pagefile.sys size but I want to make sure that this was a result of the AVD initial install before I mess around with my partitions. I vaguely remember Android Studio asking about RAM allocation for optimal AVD performance during the initial install.

pagefile.sys size is automatically determined by the OS. It seems that your system does not have sufficient RAM and therefore starting the Android emulator increased the pagefile.sys size. Android Studio respectively AVD don't have an direct influence on the pagefile size, this was just because your system lacks physical RAM. For working with Android studio + emulator you should have a minimum of 8GB RAM better 16. You can manually set the page file size in Windows system settings to a smaller value and afterwards back to "auto" to shrink it.


text:
Taking photos is slow
I've a few month old Samsung Galaxy A51 (android 10) and it's camera needs couple of seconds (2-4) BEFORE taking any picture, which is just too long when I want to photo children.
My past phones were all from Samsung Galaxy A series and never had this issue.
Is there anything I can do to make taking photos faster?

Before or after the photo is actually taken. Try a different camera app or check the settings of your camera app if you find something that could cause this delay.

Taking high resolution pictures needs to process the image data. Based on GPU, it may take a while, like ~ 2-3 seconds for ~ 14-20 Megapixel camera phone.
Some phones camera software may take several pictures to increase picture quality or prevent blurry photos using software, which also increase processing time.
You can manually reduce the photo resolution from camera app settings, which may reduce overall processing time. Turn off HDR as well if not needed.
Also try some 3rd party camera app and try which suits your needs.

Thanks for the answer. My problem is the time before taking the picture, not after.

Oh, so if it's a Camera app loading problem, that may be caused by running new/updated app on old hardware. Uninstall updates or try some lite Camera app.

It happens sometimes with me. Make sure you have enough internal free space.
Since you are using a Samsung device, there is an option for device care in the settings. Click on 'Optimize now' it will close the unnecessary background apps and optimizes the memory. Still, if you are facing this issue try restarting your device.
Also, keep your device up to date because they keep on fixing various bugs with new updates.

I've 80 GB free from 128 GB


text:
Intermittent failure to receive SMS and MMS messages
I noticed an issue in mid December where a few messages in a row that were sent in a group MMS were never received on my phone. A few days ago, I had the same issue with an SMS message sent to me. There may have been other instances as well that I'm unaware of. In December, my default messaging app was QKSMS. In the instance a few days ago, my default SMS/MMS app was Signal.
I'm using an Asus Zenfone 6 on Wing's AT&T network (for those don't know, this essentially means Wing bought AT&T contracts in bulk and is reselling them individually).
I don't know of any issues with outgoing messages. The intermittent nature of this problem makes it difficult to troubleshoot. What steps can I take to ensure I don't lose any incoming MMS or SMS messages in the future?

Make sure in the mobile network config APN and MMSC are set correctly set as described here: https://help.wingalpha.com/hc/en-us/articles/360042731211-Android-No-service-No-Data-No-MMS-No-calls-No-texts

you registered Signal for SMS so you won't receive SMS to your SIM card any longer. instead the SMS is redirected to Signal server and sent to you as Signal Message via Internet connection. If you don't wanna lose SMS in future you need to unregister Signal for SMS receiving

@Robert I don't see any way to accomplish step 1 or 2. Listed options for Preferred network type are 2G/3G/4G, 2G/3G, 3G, and 2G and I can't choose a Network Operator anywhere that I can see. The default APN settings mostly matches what's on the page with the following exceptions:
Name is ATT Phone
Authentication type is Not set
APN type includes fota
APN protocol is IPv4/IPv6
Bearer is Unspecified
If I set the bearer to LTE and save the APN disappears from the list. A new APN with bearer set to LTE also doesn't show up in the list. Does that shed any light on this?

@alecxs I had the same issue with QKSMS as my messaging app. Anyway, I think SMS and MMS are handled in Signal the same as they are in any other app and never go through Signal's servers. Where are you seeing that that's not the case?

register your phone number on signal. enable sms in signal settings. now remove the sim card and plug into any other cell phone for testing purposes - you won't receive sms on that sim card any longer. i don't know how other apps handle this. after this experience i don't use any messenger at all. for plain sms i use textra

@alecxs see my answer below for a resolution to this

In my case, the issue with the two non-stock messaging apps was the battery settings. Android was throttling the apps when they weren't in active use to save on battery. For whatever reason, incoming text messages would be directed to the apps but the apps would never wake up and the message would fall into a black hole. The stock messaging app was set to never be throttled in the Android battery settings. Changing Signal to also never be throttled seems to have resolved the problem. This is a known issue for Signal: https://support.signal.org/hc/en-us/articles/360027913252-Troubleshoot-receiving-messages


text:
MacroDroid - To only allow certain people to automatically answer calls
I'm trying to set up a macro using MacrdoDroid to automatically answer calls whenever they occur. However, I only want it to happen when certain people call me. I've tried adding the person's name to the left of the trigger "Incoming voice/video call", and setting the search term to exact instead of contains, and it just doesn't pick it up. It works fine if only "Incoming voice/video call" is there, but not when I add someone's name.

Welcome to Android Enthusiasts! You want to add something like "John Doe Incoming voice call"? If yes, I am not sure that Contains  or Exact would work. Better try using regular expressions.


text:
Can an app find out if the Android phone it's running on supports Bluetooth 4.3 privacy extensions?
I need to find out if the phone my app is running on supports the BT 4.2 bluetooth privacy extensions. If so, it will tell a BT connected device to do the same, if not it will not enable it.
Is there a way to find out by means of a script if the underlying Android supports the privacy extensions?
My assumption here is, based on two low cost phones, that for some mobile phones BT4.2 compatibility is claimed, yet enabling it on the slave device voids the communication with the device.

If you want to get this information from within your app this is more a question for https://stackoverflow.com as app-development is off-topic here. Typically an answer here would involve adbor something like that which is not accessible from within an app.

OP has posted the same question on Stack Overflow for app development/programming question, in case anyone is interested.

OP has taken up the excellent advice from @Robert in doing so and feels delighted to receive such heart felt attention for his quest in seeking the Bluetruth.


text:
VoWifi over UMTS/HSPA/LTE on second SIM?
Can VoWifi use the internet connection over the second SIM?
Backstory: a while ago I was traveling abroad. The roaming costs are astronomical. As my ISP provides a VoIP (SIP protocol) service, I installed a SIP client app and configured it to use my ISP account. As it uses internet to communicate, I could use WLAN or the UMTS/LTE network with a local SIM in my phone (I removed my original SIM). So I could make and receive calls on my original phone number without any hassle, for low cost.
Back to today: SIP is phased out and "replaced" with VoWifi.
The question: if I am abroad, and there is no WLAN available, can I use a second (local, read: cheap) SIM (in a dual SIM phone) to connect to the internet over UMTS or LTE and use it to make and receive calls with my original phone number (using VoWifi)?  Or is VoWifi strictly WLAN-only?
In other words: can I have effortless and cheap connectivity for my regular phone number abroad, like I could using SIP?

VoWifi always uses WiFi only - therefore the name. If voice calls are transmitted over 4G it is called VoLTE instead. Or are you referring to just VoIP? The latter is usually available via Internet and is not restricted to certain special networks or a VPN tunnel.

@Robert I am referring to the function that is advertised as "VoWifi" or "WifiCalling". It is available on many phones and supported by many providers. What I am asking is, can this very feature use mobile internet over a second SIM (which is much cheaper when abroad). As far as I know, VoLTE always uses the mobile internet connection over the same SIM that "holds my phone number", which means: very expensive when used abroad.

As "VoWifi" or "WifiCalling" is not standardized it depends on the company providing this service. If WifiCalling is available on any Internet connection it should also work using a mobile connection (some mobile network providers limit WifiCalling to special Wifis/networks).

@Robert The underlying standards Generic Access Network (GAN) and Unlicensed Mobile Access (UMA)  are over 10 years old. Almost all (modern) smartphones support it. It is definitely standardized.

Sorry, my last comment was not accurate enough. I was not talking about the used protocol, I was talking about the limitations that may be applied by your provider. Those are not standardized, hence a mobile network provider advertising "WifiCalling" may mean that it is accessible from every network worldwide or it could mean that it is only available on Wifi hotspots of the same network provider or a VPN is required or completely different limitations apply.


text:
Android du and df very different: File System Corrupted?
On an Android Nougat (7.1.1) set top box, du and df of my /data partition are very different:
$ adb shell du -sh /data
1.0G    /data
$ adb shell df -H /data
Filesystem      Size  Used Avail Use% Mounted on
/dev/block/sda9  10G   10G  469M  96% /data

I don’t think that anything else is mounted under /data:
$ adb shell mount | grep "\/data"
/dev/block/sda9 on /data type ext4 (rw,seclabel,nosuid,nodev,relatime,discard,noauto_da_alloc,data=ordered)
$ adb shell mount | grep "sda9"
/dev/block/sda9 on /data type ext4 (rw,seclabel,nosuid,nodev,relatime,discard,noauto_da_alloc,data=ordered)

lsof indicates to me that there are dozens of processes holding hundreds of small deleted files of the sort
init          1       root    3w      CHR               1,11       0t0      14517 /dev/__kmsg__ (deleted)
ueventd     391       root    3w      CHR               1,11       0t0      14593 /dev/__kmsg__ (deleted)
  . . .
main        756       root  mem   unknown                                         /dev/ashmem/dalvik-large object space allocation (deleted)
main        756       root  mem   unknown                                         /dev/ashmem/dalvik-large object space allocation (deleted)
  . . .
omm.times  3934     system  mem   unknown                                         /dev/ashmem/dalvik-mark sweep sweep array free buffer (deleted)
omm.times  3934     system  mem   unknown                                         /dev/ashmem/dalvik-mark sweep sweep array free buffer (deleted)

Using busybox, results are different (df shows much less usage), but there is still a large discrepancy between du and df:
$ adb shell busybox du -sh /data
389.4M  /data
$ adb shell busybox df -h /data
Filesystem                Size      Used Available Use% Mounted on
/dev/block/bootdevice/by-name/userdata
                          9.7G      8.6G      1.1G  89% /data

And using toybox, the results are similar to busybox:
$ adb shell toybox du -sh /data
389M    /data
$ adb shell toybox df -h /data
Filesystem      Size  Used Avail Use% Mounted on
/dev/block/sda9  10G  8.6G  1.1G  89% /data

It think that it's important to note that these numbers remain similar after a reboot.
Also, I wish to note that I cannot OTA update this device's Android due to running out of disk space, even though the OTA image is only about 1GB in size. This fact leads me to believe that the results of df are accurate in terms of actual available disk space.
All adb commands are run as root i.e., I did adb root before executing them. But at risk of making this question be too verbose, here's everything run at the adb prompt:
$ adb shell
Z:/ # whoami
root
Z:/ # du -sh /data
389M    /data
Z:/ # df -h /data
Filesystem      Size  Used Avail Use% Mounted on
/dev/block/sda9  10G  8.6G  1.1G  89% /data
10.197.12.14:/ # busybox du -sh /data
389.4M  /data
Z:/ # busybox df -h /data
Filesystem                Size      Used Available Use% Mounted on
/dev/block/bootdevice/by-name/userdata
                          9.7G      8.6G      1.1G  89% /data
Z:/ # toybox du -sh /data
389M    /data
Z:/ # toybox df -h /data
Filesystem      Size  Used Avail Use% Mounted on
/dev/block/sda9  10G  8.6G  1.1G  89% /data
Z:/ #

A user in comments has asked for the following:
Z:/ # while read num; do (( sum += num )); done <<< $(find /data -type f -exec stat -c%b {} +); expr $sum / 2048
393

I understand that du reports free space by scanning reachable nodes, and that this could therefore mean that my file system is corrupt. However, unfortunately, this is for devices in the field, and I don’t want to have to (and don’t think I can) run fsck or e2fsck.
What might be causing the huge difference between du and df on this device, and how might this problem be resolved? I’m happy to provide further logs.

df and du mostly differ somewhat (see here why) but not that much. There seems to be some problem with your du binary. Use a different one. See here what you should expect: How disk space is used on Android device?

You've called to both as "normal user". So df can report the "free space" (aka "Disk Free") normally – while du can only sum up what the user has access to. Nothing broken, works as designed. Try both as root, see the screenshot by @alecxs

Thanks, @IrfanLatif. I added busybox results to the original question.

@Izzy Per my original description, I called them as root.

@zippy your original description shows your commands prefixed with a $. Commands called as root carry a #. But I indeed missed your comment on adb root (also as it's quite uncommon; I never had a ROM allowing me that on any of my devices, not even custom ROMs). But yes, you can run fsck (even in read-only mode if you prefer), it is available on-device.

https:/i.stack.imgur.com/n0cBI.png https:/i.stack.imgur.com/qwTbp.png

@alecxs -- I put the results of that command into the description. Our busybox is here: https://links-w.astronics.com/MBSlU8bHA_k/  password "busybox.zip" without the quotes. And what I haven't mentioned yet is that I cannot OTA upgrade this unit due to disk full (!).

393M sum of all files (with read access) is congruent with du. busybox v1.15.3 works fine too. thought about hard-links but that should produce opposite results, so no idea :(

check 'du -sh /proc/*/*/mnt' (not sure this is helpful as i have disabled mount namespace separation in SuperSU completely and don't know how to check)

The reason for a delay in responding is that a customer was visiting this week. @alexcs, I tried the remount, but it doesn't seem to have an effect. I'm also trying to build an fsck for Nougat on aarch64 on toybox (there is none built in) but that's not working. Can anyone point me to an aarch64 fsck?

/system/bin/e2fsck

please try to set selinux permissive with setenforce/getenforce. Now lazy umount, kill system_server, re-mount sda9 to another dir and check again

today got Mecool KII Pro S905D on my hands. realized these tv box are shipped with busybox pre-rooted userdebug builds. selinux is permissive but namespaces are isolated. with no superuser app at all no clue how to set global

The /data partition was indeed corrupted.
After running e2fsck -p /dev/block/sda9, here was the updated du and df (again, after doing an adb root):
$ adb shell du -s /data
1.3G    /data
$ adb shell df -H /data
Filesystem      Size  Used Avail Use% Mounted on
/dev/block/sda9  10G  1.5G  8.9G  15% /data

After fixing the file system, the device ran properly and updated successfully thereafter.
(Note that I found that I had to run e2fsck with the -p option; it wouldn't run interactively for some reason.)
A portion of the output of the above e2fsck command is
data contains a file system with errors, check forced.
data: Deleted inode 163845 has zero dtime.  FIXED.
data: Deleted inode 163847 has zero dtime.  FIXED.
data: Deleted inode 163849 has zero dtime.  FIXED.
   . . . [snip ] . . .
data: Deleted inode 213003 has zero dtime.  FIXED.
data: Deleted inode 262223 has zero dtime.  FIXED.
data: Deleted inode 303108 has zero dtime.  FIXED.
data: 5203/655360 files (2.0% non-contiguous), 186831/2621440 blocks

There were a total of 140 lines of the sort data: Deleted inode...
FWIW, we are guessing that this problem was possibly caused by the filesystem becoming full with logs, which then caused corruption during the next attempted download of OTA updates: Those downloads failed, but thereafter left the file system in a corrupted state. Subsequent attempts at those downloads seemed to further corrupt the file system.
Thanks very much to @alecxs for your persistence and relevant details. (However, please note that to run e2fsck, the partition /dev/block/sda9 had to be UNmounted.)

df stands for "Disk Free". That means, it just needs to check with the "global file system information" about free space (accessible for all users). The size of the file system itself is also "globally available". The difference logically is the "used space". Done.
du works differently: not on file system level but on file level. It needs to look up each directory and file separately, gather it's size, and sum that up. So it can only take into account what it has access to.
Now you've run both commands as "normal user" – who has no permission to traverse e.g. /data/data (where all the apps' data is stored). So it can only sum up a portion of what space is occupied on /data. Would you run both commands as root user (as the screenshot in the comment by alecxs shows), numbers would be much closer together – as usually root can access all files. Though as again Alex correctly points out: there is still SELinux which might deny full access – which according to him is a known issue for mtk-su on the Amazon FireTV stick, and might be the culprit here, and isolated mount namespaces could be yet another reason for invisible files.
TL;DR: there's neither a file system corruption, nor a broken du binary necessarily causing the difference. All might work as designed. If you want to make sure, you can run fsck (if you prefer, in read-only mode) to rule out the former – and set up a test case on a different place for the latter.

per the comment in my description, I already ran du and df as root. Here is confirmation:
$ adb shell
Z:/ # su
Z:/ # whoami
root
Z:/ # du -sh /data
389M    /data
Z:/ # df -H /data
Filesystem      Size  Used Avail Use% Mounted on
/dev/block/sda9  10G  9.2G  1.1G  89% /data

Yes, apologies – I missed that in the last paragraphs (got distracted by those huge images in the comments below – no idea why SE meanhile displays them inline, bad idea IMHO). If you want I can hence remove my answer as "invalid". Or I can leave it as it might help those not being aware of the different approaches.

I prefer that you delete it because it doesn't directly address the question (and I had found that these procedures need to be done as root elsewhere). Thanks.

Conflicting wishes. @zippy does my edit change your mind?


text:
Applications on Android are not using Certificate Pinning
I'm doing a study for university and part of this study is to gather a group of android applications and check which of these applications use Cert Pinning. I am doing this by using fiddler as a proxy(I have also download fiddler certificate on my Android Phone) the applications which work normally do not have certificate pinning while the others who stop working do have certificate pinning.
The problem is that all the applications are working normally, this include applications such as youtube, gmail, play store. This means I can capture the traffic on Fiddler from these apps. My friend tried this as well on a more modern Android device and he is not able to capture any traffic from the mentioned apps and also from other apps which most probably have cert pinning. However I am able to capture from most applications ( but not from facebook, instagram and tiktok).
Does this have to do with my Android version, I have android 5.1.1. Does anyone have an idea what is the causing this, and if there's a way to enable certificate pinning ?
TIA

You are lucky, because of your very old Android version you have at least some apps that work. Starting with Android 6 the certificate you installed is useless as apps ignore it by default. If you want to bypass certificate pinning try Xposed + TrustMeAlready plugin or Frida/Objection (both require a rooted device). For more details please read https://stackoverflow.com/q/57568571/150978

At this stage I am not trying to bypass certificate pinning, I know how to do that with objection and frida. My issue is that I want to analyze which apps use certificate pinning or not, but having that all apps are working I cannot do this. But I guess you still answered my question, If I update to a more modern  Android version this will not happen.

Also kindly note to use objection and Frida there is no need to root the phone. Just use objection and frida gadget.


text:
Alphanumeric symbols in the data/app directory?
Why are the names of the applications replaced with alphanumeric characters in the data/app directory? I am seeing this when accessing the directory through an adb shell.

See this question, it's answer and the comment for answer to your question.


text:
How do I stop remote access?
I have a Samsung Galaxy 10. Somehow, my ex has gained access and is able to see my texts and video calls in Whatsapp and Telegram, etc. He is listening to or watching every conversation. I became suspicious when he mentioned details from private conversations. He admitted to mirroring my device but will not provide details and says he has stopped. However, I believe it is still happening. When I am on video calls in WhatsApp and Telegram, the calls freeze and it seems the signal is bad even when I am on WiFi or have full bars. How can I stop this? Please help.

remove all google/samsung accounts from settings. even if you are using another phone it still might possible to mirror WhatsApp web. therefore i recommend to unregister all services and change all passwords. use another phone number for Whatsapp Telegram etc. besides this, inform all your friends and contacts about your phone probably has been compromised and they might receive fake messages from attacker in your name

You may also contact the support form WhatsApp and Telegram, to check if they can see anything suspicious happening with your accounts.And also the police, since eavesdropping is a serious offense! In most countries, recording a a conversation is illegal even if is it your own (if other parties do not consent)!

It all depends on how far your ex went with installing unwanted software on your device.
In most cases a factory restore would remove unwanted software.
Just make sure to copy your important data (photos/messages/etc.) somewhere else before doing it.

If someone has gained remote access to your Android device, it is compromised.  The only way to likely remove the malware is to perform a factory reset.

Backup your data.
Perform a factory reset.

I would not backup all your apps, just the data itself, as you really can't trust anything on the device.
If you don't need any of the data on the device, just factory reset it.  That's the second safest thing you can do without buying a new device.  (Outside of buying a new device, the safest thing is wiping all the non-volatile storage, but that's a more in-depth procedure.)
Note that even a factory reset does not truly reset the entire device (reportedly true on iPhones and Android devices).  See: With Android, does a factory reset truly reset the device to the same as it was when it left the factory (unlike an iPhone)?

@alecxs Your recommendation to not use the same Google/Samsung account is a good one.  Why do you recommend removing all accounts before a factory reset since the factory reset will remove them from the device?

behavior depends on how factory reset is performed. on some devices factory reset from recovery won't remove google account. instead factory reset protection (FRP lock) is activated (requires unlocking with bonded google account which survived factory reset). on Xiaomi devices we have additional fun with Mi account (even on already unlocked bootloader) therefore assume for samsung account it's similar protection (but don't know for sure)

@alecxs Thanks for the info.  They really should rename "factory reset" to "kinda sorta reset".

@rockpaperlz-mask-it-or-casket A true factory reset would require manually re-flashing an older version of your device firmware. This may not be safe if the bootloader has been updated by a system update, or even impossible without voiding warranty... There is a reason to the madness though... If you reset to a vulnerable version of your OS, your device could (in some circumstances) get targeted and quickly be compromized as soon as you connect it to anything (wifi, mobile data, etc).

@svin83 Thanks.  It's one of the (many) things I find concerning about Microsoft's Windows.  Millions of users connect it to the internet while it is in an extremely vulnerable state in order to download updates to reduce some of the vulnerabilities.  The obvious solution for all operating systems (Android, Windows, Linux, macOS, et. al.) is to obtain the updates from a more secure device or directly from an external storage medium (e.g. DVD-ROM or CD-ROM).

@svin83 Regarding the bootloader, wouldn't a true factory reset perform a reset of that as well, removing that possible risk?  And regarding warranties, those are arbitrarily written by the manufacturer, so they could certainly allow a true factory reset.  It might actually save them in support and warranty costs, because a true factory reset would make the device to be identical to how it was when it was new out of the box.

Production systems should fetch the first, and most critical updates from a trusted local repository. Withdrawing administrative privileges from all users on Windows will block MANY attack vectors.

@rockpaperlz-mask-it-or-casket Boot loaders are often protected from flashing except by vendor approved updates. It may be possible if devices come with extra immutable storage containing the original OS, but who wants to pay for that?

@svin83 I agree completely that security updates should be fetched from a trusted local repo, but unfortunately Windows 10 isn't designed that way at all for the hundreds of millions (are they up to billions yet?) of home and small business users on Win10.  I think it's a safe estimate that well under 1% of home and small business Windows 10 users get their updates that way.

@svin83 Good point about having an immutable copy of the OS.  I wonder if it's more of a physical space issue rather than cost.  I haven't priced ROM chips in years... any idea of the size & cost (when purchased in bulk) of ROM chips these days (sufficient in size to store Android)?


text:
With Android, does a factory reset truly reset the device to the same as it was when it left the factory (unlike an iPhone)?
When you reset an iPhone, my understanding is that the device does not truly get reset to how it was when it exited the factory.
What about with an Android device?  Does performing a factory reset on an Android device always reset the device to how it actually left the factory?
I decided to ask this question to help our community generate accurate answers to this other one.

Only the user data partition is reset. The system partition stays and therefore all updates. But this is the same for iPhone. If an app manages to get root permissions e.g. using a vulnerability of the installed system software it can manipulate the system partition and make changes that are persistent to factory reset.

android has factory reset protection (FRP) therefore some partitions will survive

@alecxs Thanks. Which partitions?

idk. that differs. frp at least, maybe misc param persist? on mediatek maybe nvram seccfg para proinfo flashinfo?

Basically every partition that is not user accessible is untouched and persists... There are 20+ partitions on same Android devices, /data is the primary mount point cleared with a factory reset.

@acejavelin Answers beget more questions! :)  Many apps store databases that are not user-accessible (without root).  Is the partition where those are stored deleted?

That is user data, those are all cleared out. They are not directly user accessible, but are user specific data... All files in that base partition of /data are cleared.

@acejavelin Got it. Thank you.  It's 30 seconds too late to be able to edit your comment above, but I think if we replace "user accessible" with "user data" it would be accurate, correct?

@acejavelin of course, i am talking about partitions which contain userdata (like frp) or partitions with temp data (like fota/misc) or partitions with device specific data (calibration data, bad blocks info etc) which can survive, i think we can safely exclude partitions which are included in stock ROM. afaik only cache userdata metadata is wiped for sure on factory reset

If the OS is hacked (like a custom firmware or similar), then anything goes. It can present you a fake "factory reset" menu point, then pretend it is cleaning (by showing you some images on the screen that look like a real factory reset process) but really not erase anything. Reflashing a new firmware (colloquially known as "custom ROM", or an original one) might solve this for most cases.

It is the same as an iPhone I believe. A "factory reset" removes all information in the data and user partition, but leaves everything in the system and associated partitions as is. That means if you got an upgrade or update that changed anything in the system partition, it would remain after a "factory reset".
The reality is that a "factory reset" is kind of a misnomer in this case, it's more of a "user reset" than anything else if we were being more accurate.

So that means that if someone installed a malicious ROM on an Android, it would persist after a "factory reset"?

@RockPaperLz-MaskitorCasket Yes, but for this to occur they would need to unlock the bootloader, so there would be evidence of tampering. Most modern phones cannot have their bootloader unlocked though, and without that and root access to the device, the system partition contents cannot be modified.

Thanks.  I haven't installed a custom ROM in a few years.  If unlocking the bootloader is required to do this, and most modern Android devices cannot have their bootloaders unlocked, does that mean that custom ROMs are not available on most modern Android devices?

@RockPaperLz-MaskitorCasket Sadly, that is correct. Very few new(ish) devices outside of Google Pixel, OnePlus, some Samsungs and Moto devices, and a few others, allow the bootloader to be unlocked and rooting to occur, and if it does then tampering is evident as once the bootloader is unlocked, it cannot be relocked without flashing a signed factory image (meaning it is stock), so the evidence of tampering is very easy to determine.

Interesting. Thanks. Does the bootloader need to unlocked for the device to rooted?  Also, is there a good list anywhere of which devices allow unlocking the bootloader?

@RockPaperLz-MaskitorCasket Yes... Rooting cannot occur unless the bootloader is unlocked, and I don't know of a list. There are always exceptions, but each year that list gets smaller and smaller. Basically, if you are looking for a phone to root or use custom ROMs on, do your research ahead of time, because the list of phones that can do it is miniscule compared to the ones that cannot. A safe bet is always Google Pixel or OnePlus retail phones, but even some carrier branded Pixels cannot be unlocked.

Thank you for the additional info!  I had no idea that the carrier branded Pixels could not be unlocked.  Good to know.  Those Pixels are tempting, but a 12MP camera is just not making the cut in 2021, as I like to print enlargements.

@RockPaperLz-MaskitorCasket Honestly, I own and use a Pixel 4a... Once you get above 8 or so MP, the pixels don't matter, but how the software handles them is the primary issue. My 12MP Pixel will easily take better shots in most conditions than most cameras with double it's native resolution... There is a reason Pixel cameras are still among the best rated cell phone cameras of all time. But we are getting off track and getting "chatty" warnings from Stack Exchange, as this is not a discussion forum. But honestly I still feel Pixel devices are the best value out there.

@RockPaperLz-MaskitorCasket If you feel my answer to question is correct and complete, please accept it. If you think it needs more clarification to the original question, let me know and I will adjust it.

Sure.  I upvoted your answer right away, but was waiting to see if any other answers trickled in before accepting it.  Can you expand your answer a little on what you mean by data and user partition?  When I look at the root folder of an Android device I see data, but not user.

@RockPaperLz-MaskitorCasket In most devices the user folder is inside /data and is /data/user or /data/usr or /mnt/user, and some devices have them somewhere else, which is why I did not not reference "/data" specifically, but said the data and user partition as their exact location can vary from device to device and even between Android versions.

Thanks.  Do the programmers of the ROM decide which folder to use?

@RockPaperLz-MaskitorCasket Partially, it also depends on the Android version and the current file structure recommendations by Google.

Thanks.  I have accepted your answer.  Thanks for your help and for sharing your knowledge.


text:
My samsung a20 was dropped and the screen is black, can't get the alarm to shut off
My samsung a20 was dropped and screen cracked,it worked for a hour or so then screen went completely black...hey google works but can't get the alarm to shut off now...i need all my important information off that device..how do I get the alarm to shut off and if I replaced the screen will everything be the same as before

if only screen is replaced (but not main pcb board) your data will survive until someone does factory reset. your data is encrypted and protected with screen lock credentials and therefore not accessable


text:
Lg G5 sa recovery
Love my phone but old, have had it 'die' on me twice now in last 6 weeks. Just got it working after screen showed Fileware upload do not unplug for an hour. I disconnected battery whilst it was plugged in. bingo....working again but what if it dies and I cant get it working. How and where do I back everything up?

Does this answer your question? How to fully back up a phone's content to a PC, possibly for restoring on a similar phone


text:
How to open big EPUB files?
Just found out that Play Books has a limit of 100MB for each .EPUB file one wants to upload.

Are there alternative eReaders for Android that would allow to upload/read bigger .EPUB files?
This one has around 400MB.
I am wondering how should one open these files?

Have you tried Perfect! Viewer?

Check out moon + reader pro.

eReader prestigio, but ideally chrome must add support for epub spec, it is part of W3C after all.

authors: Валерий Заподовников


text:
Android 7.1 certificates are going to expire, anyway to renew them?
starting from September android 7.1 and below users are going to have issues with the internet
so is there anyway to renew those certificates so i can use my phone properly?

Kind of related: Let's Encrypt: Is there a workaround for the 2021 SSL “cutoff” for pre-7.1.1 Android devices?

Could you please be a bit more specific about what certificates you are talking about?


text:
How does Android interpret physical keyboard inputs?
I thought I had a grasp of how they work in a general sense, but I've been trying out several keyboards lately and have run into some inexplicable behavior.  For example, pressing the ESC key on one keyboard will functionally trigger the back function in Android, but on another keyboard it does not.  Same with mouse inputs' right clicks, seeing incongruemt behavior.  I know some keyboards have proprietary technologies that render special keys non-interoperable, but I thought the basic standard keys all trigger the same scan codes?  Why is this not the case?

Android seems to contain multiple key layout files may be those layout files had an impact in your case?

@Robert I select the same layout in all cases though?  I've also just noticed, the behavior seems to be application-specific, particularly Chrome.


text:
Turn off "Unfortunately [app] has stopped" popup
I'm wondering if it's possible to disable this popup. I've an old phone that I use rarely where I uninstalled some critical apps, that I don't use. Phone works flawlessly apart from constant popups. Maybe there is a Magisk module or something. Thanks


text:
Can factory reset recover deleted built-in apps?
If ill root my phone and delete the browser and the play store for example... and then ill go into recovery mode and make a factory reset, will those app will come back?
If yes, is there a way to prevent simple factory rest to recover those app?
ty

If you have deleted those apps from system partition using root permissions (via su) then a factory reset will not restore those apps (see also this question for details).
Only installing a new firmware or manually installing an "firmware update" via recovery that contains the deleted apps (e.g. a OpenGApps package containing PlayStore) can restore them.

Is this app will do the job, or do i need to delete specific files manually? https://play.google.com/store/apps/details?id=com.jumobile.manager.systemapp

@Joe For deleting a system app you need to remount the system partition writable. How to do so can differ from device to device, therefore such apps can work or not. You only know if it works if you have tried it. Note that deleting the wrong app can make your system unbootable, hence you would have to reflash the system firmware (if it is available).

I'm speaking about a rooted phone, i know how to do that, its very easy on Pixel and OnePluse phone's. in my old phone that i already rooted i use this app and give her SU permissions. and it deleted the system app's i wanted. My question is, if this app delete those app properly to prevent recovery by factory reset or not?

@Joe Sorry but I cant' answer you the question if an app works "properly" or not. Try it out and check what it modifies. Usually a system app is just an .apk file and an .odex file of the same name in the same directory.

The last sentence you said was the answer I was looking for! ty man!

I have anther question.. maybe you'll know... I want to disable the recovery mode, It happened to me once without intention... I hade a Homtom phone, and i rooted him, and then i tried to put TWRP recovery. I didn't succeed, but what happened was a black screen every time i tried to enter recovery mode. that's what im looking for, something like that.. replace the stock recovery with a broken recovery mode or whatever will do the same work.

@Joe You can do so and "lock" the recovery but someone who has access to your device can simple flash a different recovery and thus make it work again.

I know that with an access to my device you can flash a different recovery, but most people where i live don't know how to do that, and even they don't know to root or even to unlock the bootloader. most people won't know to recognize the problem, they are not so smart. Of course there are those who know and can do it, but it does add a lot of security to my phone, and besides that there are other reasons I want to do it besides security. What I do not know is how to do it in the simplest way. what happened to me then was by mistake or by luck

Let us continue this discussion in chat.


text:
block particular apps from accessing vibration
I'm using Samsung S9 ( OneUI version 2.5, Android version 10 ).
Is there any way to stop a particular app from accessing the vibration feature of the phone?
Even if I turn on the silent mode and turn off the vibration for all notifications, certain apps keep on vibrating the phone even for minor actions. I find this really annoying and I want to block these apps from having access to the vibration feature. How to do this?
In detail :
I'm the kind of person who doesn't like the concept of vibration haptic feedback. I'm okay with my phone vibrating for essential notifications such as calls and texts when I'm in a meeting and my phone is in silent mode. However, I don't like the phone vibrating for silly things such as a key-press, or forwarding a video etc. It gives me a weird feeling and also vibration consumes the battery.
Recently this problem became really annoying, as Youtube introduced segments in videos. Now, when I try to forward the video using the progress bar, the phone gives a really strong vibration, Which is annoying and consumes a lot of power.
I looked in the settings of the Youtube app and there is no way to stop it from vibrating. Is there any way to block the youtube app from having access to the vibration motor?

Does this answer your question? How to determine which app is causing vibration?. The question title doesn't include but my answer addresses "how to stop vibrations" as well.

Hi, Can you please post that as an answer here? Because the titles are so different, It would be easier for future references to find it if you answer it here.


text:
Android ePos caller ID app help!
Hi basically I have a new ePos system at my shop, they have a feature where it automatically inputs the callers number into the system to bring up their ‘profile’ from previous orders they’ve made.
However their caller ID app runs from Android phones and obviously we use landline phones.
I just wondered if anyone knows a way to have the android app triggered by a landline phone without having to do call forwarding? The invoxia VoiceBridge would have been perfect but of course they have discontinued it.
I just want a cell phone to receive a call alongside the landline phone.
Thanks!

In a lot of countries landline phones are are more and more converted into (DSL) internet connections with VoIP phones. If your landline connection is already using those techniques you could install a VoIP app on your phone and connect it via Wifi to the internet connection. Then you just have to enter the VoIP credentials of your telephone number from the landline into the VoIP client. Or use a router that handles the VoIP connection but let local analog/DECT and Smartphones connect and use the VoIP feature.

So I’d get a VoIP line and phone in then install the VoIP app on my smartphone or the landline phone?

Typically the router is the VoIP end point and the old phone is connected to the router + the VoIP client on the smartphone, too.


text:
Getting devices with custom system app
So, I am looking into getting devices with a custom app pre-installed from factory on the system image in a "device as a service" scenario. I am specifically interested in the app having system privileges without rooting the device. From some initial research, I believe solutions like Knox (MDMs) would not be able to cover this. What kind of solution would this be? What is the correct industry terminology here?

The device manufacturer will welcome you if you are a mobile network provider or another bigger company with 30k+ customers and may be order a few thousand branded devices for a lot of money.

@Robert, So what I'm really looking for at this point is custom device manufacturing?


text:
Detect which type of SSL Pinning is being used on Android Applications
Is there a way to detect what the Android Application is using as SSL Pinning. Whether it is certificate Pinning , Public Key Pinning or Hash Pinning ?
I am doing a study on local Android Applications and would like to collect data on what type of Pinning these applications are using.
TIA

Reverse engineer the apps using Jadx, apktool, JEB, Ida, Ghidra, .... But that is more a topic for https://reverseengineering.stackexchange.com Of course you need sufficient programming skills to understand the decompiled code. The more you know about Android development and reverse engineering the easier you will understand the decompiled code.

The official documentation for Android Developer mentions a little bit about this. Btw, I know an app that uses public-key pinning. However, there's no easy way except to reverse engineer the app and analyze the code.