Question and Answer about Android from Stack Exchange network.

In the Files app of stock Android 10 (Pixel 2 XL), there is a "Recent" category. For privacy reasons, I wanted to delete a file in this category. As far as I have searched for this file by filename, and it doesn't seem to exist on my system, but still appears in the list. I've tried clearing the cache/storage for the "Files" app, but it still remains. How can I remove this item from the recent list, clear the entire list, or get the file's folder location so I can delete the real file?

While YouTube Kids app is allowed on my daughter's Android phone, YouTube app is blocked. Recently I realised she still accesses youtube.com through her web browser so she can follow her favourite gaming YouTubers (on YouTube Kids app she can't follow their channels, she can only find their videos one by one through a general search, which is extremely annoying and unsatisfying).

Is there a way to either follow a channel in YouTube kids or to allow the following of a channel in YouTube app or in web youtube.com while blocking YouTube in general?

i want to use genymotion in android studio. i have installed genymoiton and oracle virtualbox. in android studio i went to: File> settings> plugins , and installed genymotion. i should say that, previously, i have create a virtual device in genymotion. the problem is: i expect that the genymotion icon to appear in android studio but: nothing appears

any help is highly appreciated...

I had more than 200 tabs open on opera and they would normally reopen again, even after reboots.

My phone broke, but I have a backup of the external SD Card, internal SD Card, and a backup from TWRP which is of a size of 23.7 GB but does not have an obviously accessible structure.

Following the advice from another QA, it is possible to concatenate the data.ext4.win000 to data.ext4.win009 files and access them as a tar archive (It's a good idea to cd to where you want the backup to be extracted to first):

bash cat data.ext4.win??? | tar xvfi -

What this does is concatenate each file matching the pattern data.ext4.win??? and then pipe the concatenated files to tar for extraction. the - as the filename tells tar to extract from stdin. The i option ignores zero blocks which will be in between each archive file concatenated.

In this example I used the ext4 formatted data partition. Change data.ext4 to match the partition you are extracting.

Although the tar command exits with

/data/magisk_backup_bd5d0aa87b96353c78a3bf3a455121d0c767089c/boot.img.gz
tar: Exiting with failure status due to previous errors

it extracts quite a few files before this hapens.

However, it is probably better to simply extract each of those files on their own without concatenating them, as in the comment by alecxs:

side note: concatenating win* files is wrong, that files are standalone tarball archives

Now that I have my /data directory again, I have access to /data/data/com.opera.browser and /data/app/com.opera.browser-2. What do I do with them to extract a list of urls that were open?

Directory Structures

data/data/com.opera.browser

├───app_opera
│   ├───Application Cache
│   │   └───Cache
│   │       └───index-dir
│   ├───blob_storage
│   │   └───9b46839e-470e-4a3a-aa32-e9bc919a25f0
│   ├───databases
│   ├───databases-incognito
│   ├───File System
│   │   ├───026
│   │   │   └───t
│   │   │       └───Paths
│   │   └───Origins
│   ├───GCM Store
│   │   └───Encryption
│   ├───GPUCache
│   │   └───index-dir
│   ├───IndexedDB
│   │   ├───https_hackernoon.com_0.indexeddb.leveldb
│   │   ├───https_mobile.twitter.com_0.indexeddb.leveldb
│   │   ├───https_www.epicgames.com_0.indexeddb.leveldb
│   │   └───https_www.independent.co.uk_0.indexeddb.leveldb
│   ├───Local Storage
│   │   └───leveldb
│   ├───paks
│   ├───Platform Notifications
│   ├───saved_pages
│   ├───Service Worker
│   │   ├───CacheStorage
│   │   │   ├───5a6f7e336992bc24678958dc2f1f9b9eec83593b
│   │   │   │   ├───281ffb34-a074-4397-a60c-e3dc55aee5e5
│   │   │   │   │   └───index-dir
│   │   │   │   └───8d34090e-e00a-4f69-9450-bbe1b4b0dc9d
│   │   │   │       └───index-dir
│   │   │   ├───96f3041722d8f6857b95786ee88fa6a107a86943
│   │   │   │   └───11ccf6ea-9e2a-4648-8c61-a635e1cca5c5
│   │   │   │       └───index-dir
│   │   │   └───e60030e2e5440743857a39cacd108634434c91f1
│   │   │       ├───0045349f-4331-4037-bf9d-e9711e515a08
│   │   │       │   └───index-dir
│   │   │       ├───4a447cca-f7ca-41f1-9464-e40337cd7ed1
│   │   │       │   └───index-dir
│   │   │       └───907b2396-da18-4880-a0df-e3608abac640
│   │   │           └───index-dir
│   │   ├───Database
│   │   └───ScriptCache
│   │       └───index-dir
│   ├───Session Storage
│   ├───shared_proto_db
│   │   └───metadata
│   ├───Sync Data
│   │   └───LevelDB
│   └───VideoDecodeStats
├───app_optimized
├───app_textures
├───app_webview
│   ├───blob_storage
│   │   └───3f7cc261-4c0e-41cc-947b-2dc712733f49
│   ├───GPUCache
│   │   └───index-dir
│   └───Local Storage
│       └───leveldb
├───cache
│   ├───cache
│   │   └───index-dir
│   ├───Crashpad
│   │   ├───attachments
│   │   ├───completed
│   │   ├───new
│   │   └───pending
│   ├───crash_dumps
│   ├───distiller
│   │   └───index-dir
│   └───okhttp
├───code_cache
├───databases
├───files
│   ├───AFRequestCache
│   ├───ds
│   │   ├───10
│   │   └───E
│   ├───images
│   │   └───share
│   ├───keychain
│   │   └───0
│   ├───reading
│   └───recently_closed_tabs
├───no_backup
└───shared_prefs

data/app/com.opera.browser-2

├───lib
│   ├───arm
│   └───arm64
└───oat
    ├───arm
    └───arm64

data/data/com.opera.browser/files/

# 332 files of the nameformat "thumbnail_-214748????"
# 3   files of the nameformat "searchengine_j_<UUID>"
AFRequestCache             
appstate.bin                    
audience_network.dex     
cards_settings.dat           
ds                                  
favorite_25                     
favorite_29                     
favorite_31                     
favorites.json                  
images                           
keychain                        
newsfeedback                 
permissions.bin               
reading                          
recently_closed_tabs       
reksio.ini   

System Info

I think I was on Android 7.1.1
Rooted with Magisk, but stock ROM

Recently Closed Tabs

Not what I am looking for right now, but I stumbled upon the location of those, in case a future viewer is looking for them:

data/data/com.opera.browser/files/recently_closed_tabs/state-2147481796

Related Links

• How can I export all my open Firefox Tabs to a text file? is posed about doing so on a living phone, but also points out where the file is located. The relevant file is called sessionstore.js.
  That does not seem useful for opera. grepping find for "session" only finds shared_prefs/sessionrestore.xml which contains nothing useful for my purposes.

• How can I export the list of open Chrome tabs?

Promising Files appstate.bin

data/data/com.opera.browser/files/appstate.bin contains at least some urls and their titles, separated by a null-byte. strings appstate.bin outputs more than just the urls that were open though. And some of those doubly or not completely. I shall document my journy with this file below.

Looking at data/data/com.opera.browser/files/appstate.bin shows that it's a binary data file, but it contains readable strings. Open it with vim appstate.bin or look at hexdump -C appstate.bin.

strings appstate.bin | grep -A3 reader_mode_state

already spits out quite a few urls. But it's not yet obvious to me how the structure of that file actually works.

Some entries prefix the url with l or O or K or ] or not at all.
In some entries the first line after "reader_mode_state" is the url, in others it is "operaui://startpage" and the url follows further below.

But what stands out is that the urls all seem to start with http or https - unless you had some ftp or such open, which I'm pretty confident I did not.

strings appstate.bin | grep http

outputs 1506 lines though. some links are duplicates, others are links I do not care about. e.g. like so:

Qhttps://www.linuxuprising.com/2018/06/fix-no-sound-dummy-output-issue-in.html?m=1
Qhttps://www.linuxuprising.com/2018/06/fix-no-sound-dummy-output-issue-in.html?m=1
https://www.linuxuprising.com
https://www.linuxuprising.com
https://www.linuxuprising.com
https://www.linuxuprising.com
https://www.linuxuprising.com
https://www.linuxuprising.com
https://www.linuxuprising.com
https://www.linuxuprising.com
https://www.linuxuprising.com
https://www.linuxuprising.com
https://www.linuxuprising.com

Since I don't care about duplicates, we can apply uniq to reduce that number down to 967 urls. With sort -u we would get down to 833 instead. But both are still too many. It seems to me like opera also stores the tab's history in there.

Removing some obviously unwanted lines gives 523 lines, so ~260 urls:

 strings appstate.bin | grep -v -e 'operaui://startpage' -e 'Speed Dial' | grep -A2 reader_mode_state | uniq | grep -v 'reader_mode_state'

As a target number to consider:

strings appstate.bin | grep reader_mode_state | wc -l
231

That means - assuming this target number is a good estimate of how many tabs were open - that I have about thirty urls too many. I think I can live with that.

I live in a country where some sites such as Reddit are blocked. On wifi I can change my DNS to Cloudflare (1.1.1.1) and be able to access those sites, but on mobile network my ISP doesn't seem to allow me to do so. All the solutions I see are for non-rooted devices and only affect wifi networks. My device happens to be rooted Android 10, is there anything I can do to be able to access Reddit without wifi?

Thank you for your time.

I am trying to use an LTE modem connected to an Android 7 device over an OTG cable. The kernel recognizes the device and registers it with cdc_ether, but I am unable to use the connection from the device. Is this because it is subsequently mounted as USB storage?

The device does not show up as a device in the Android UI / status bar.

If I disable MTP support, then the device wont register cdc_ether at all.

dmesg:

[10946.408785] usb 1-1.3: new high-speed USB device number 21 using msm_hsusb_host
[10946.525287] usb 1-1.3: New USB device found, idVendor=19d2, idProduct=1225
[10946.525306] usb 1-1.3: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[10946.525316] usb 1-1.3: Product: ZTE Mobile Broadband
[10946.525325] usb 1-1.3: Manufacturer: ZTE,Incorporated
[10946.525335] usb 1-1.3: SerialNumber: MF8610ZTED000000
[10946.529662] usb-storage 1-1.3:1.0: USB Mass Storage device detected
[10946.532702] scsi host19: usb-storage 1-1.3:1.0
[10947.538579] scsi 19:0:0:0: CD-ROM            ZTE      USB SCSI CD-ROM  2.31 PQ: 0 ANSI: 2
[10952.740595] usb 1-1.3: USB disconnect, device number 21
[10953.087891] usb 1-1.3: new high-speed USB device number 22 using msm_hsusb_host
[10953.232955] usb 1-1.3: New USB device found, idVendor=19d2, idProduct=1405
[10953.232969] usb 1-1.3: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[10953.232977] usb 1-1.3: Product: ZTE Mobile Broadband
[10953.232984] usb 1-1.3: Manufacturer: ZTE,Incorporated
[10953.232991] usb 1-1.3: SerialNumber: MF8610ZTED000000
[10953.260856] cdc_ether 1-1.3:1.0 usb0: register 'cdc_ether' at usb-msm_hsusb_host-1.3, CDC Ethernet Device, 36:4b:50:b7:ef:da
[10953.262322] usb-storage 1-1.3:1.2: USB Mass Storage device detected
[10953.262652] scsi host20: usb-storage 1-1.3:1.2
[10954.261139] scsi 20:0:0:0: CD-ROM            ZTE      USB SCSI CD-ROM  2.31 PQ: 0 ANSI: 2

dmesg with MTP disabled:

[10664.987934] usb 1-1.3: new high-speed USB device number 19 using msm_hsusb_host
[10665.105272] usb 1-1.3: New USB device found, idVendor=19d2, idProduct=1225
[10665.105291] usb 1-1.3: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[10665.105301] usb 1-1.3: Product: ZTE Mobile Broadband
[10665.105310] usb 1-1.3: Manufacturer: ZTE,Incorporated
[10665.105320] usb 1-1.3: SerialNumber: MF8610ZTED000000
[10665.110339] usb-storage 1-1.3:1.0: USB Mass Storage device detected
[10665.111320] scsi host17: usb-storage 1-1.3:1.0
[10666.110748] scsi 17:0:0:0: CD-ROM            ZTE      USB SCSI CD-ROM  2.31 PQ: 0 ANSI: 2
[10671.223090] usb 1-1.3: USB disconnect, device number 19
[10671.407859] msm_otg 78db000.usb: OTG runtime idle
[10671.407887] msm_otg 78db000.usb: OTG runtime suspend

ifconfig:

TB-8504F:/ # ifconfig                                                                                                                  
wlan0     Link encap:Ethernet  HWaddr 40:a1:08:36:5b:0d
          inet addr:192.168.1.133  Bcast:192.168.1.255  Mask:255.255.255.0 
          inet6 addr: 2605:a601:ab2b:9900:b19e:4f2e:5d28:5fa9/64 Scope: Global
          inet6 addr: fe80::42a1:8ff:fe36:5b0d/64 Scope: Link
          inet6 addr: 2605:a601:ab2b:9900:42a1:8ff:fe36:5b0d/64 Scope: Global
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:27906 errors:0 dropped:4 overruns:0 frame:0 
          TX packets:17795 errors:0 dropped:0 overruns:0 carrier:0 
          collisions:0 txqueuelen:1000 
          RX bytes:14342222 TX bytes:8697917 

dummy0    Link encap:Ethernet  HWaddr c6:b9:c8:82:8f:7e
          inet6 addr: fe80::c4b9:c8ff:fe82:8f7e/64 Scope: Link
          UP BROADCAST RUNNING NOARP  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0 
          TX packets:3 errors:0 dropped:0 overruns:0 carrier:0 
          collisions:0 txqueuelen:0 
          RX bytes:0 TX bytes:210 

p2p0      Link encap:Ethernet  HWaddr 42:a1:08:36:5b:0d
          UP BROADCAST MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0 
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0 
          collisions:0 txqueuelen:1000 
          RX bytes:0 TX bytes:0 

lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Mask:255.0.0.0 
          inet6 addr: ::1/128 Scope: Host
          UP LOOPBACK RUNNING  MTU:65536  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0 
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0 
          collisions:0 txqueuelen:0 
          RX bytes:0 TX bytes:0 

ip l:

255|TB-8504F:/ # ip l
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT group default 
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: dummy0: <BROADCAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN mode DEFAULT group default 
    link/ether c6:b9:c8:82:8f:7e brd ff:ff:ff:ff:ff:ff
3: sit0@NONE: <NOARP> mtu 1480 qdisc noop state DOWN mode DEFAULT group default 
    link/sit 0.0.0.0 brd 0.0.0.0
20: wlan0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP mode DORMANT group default qlen 1000
    link/ether 40:a1:08:36:5b:0d brd ff:ff:ff:ff:ff:ff
21: p2p0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc mq state DOWN mode DORMANT group default qlen 1000
    link/ether 42:a1:08:36:5b:0d brd ff:ff:ff:ff:ff:ff
31: usb0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000
    link/ether 36:4b:50:b7:ef:da brd ff:ff:ff:ff:ff:ff

The device does show up as usb0 with the MAC address that was listed in dmesg.

The app WhatsApp would like to have permission to access my device's photos, media and files.

If I grant permission, exactly what can (could) the application access?
Can it access all of the photos on my phone? Or just the photos I have shared or downloaded with the app? Can it access all of the phone's media?
Can it access all of the files on the phone?

Or does Android restrict what it can access? If so, what does it restrict it to and how?

I'm not interested in what WhatsApp says it will or won't access, or even what it has promised in its EULA. I'm more interested in what it could access, if it wanted to when granted the access.

The GPS is sporadically enabled on my phone without my consent or even a notification. I have to keep an eye on it and turn it off when I notice it's on. Is there a "global" setting I can use to prevent this or at least ensure I get a notification when it's about to be enabled?

Apps like Youtube, NetFlix, prime video do not have a "Store to SD Card" option. I have tried 3 different sd cards with my phone, formatted them but still, apps are unable to detect the sd card and do not have an option to download to external storage. However, file managers and apps like vlc, album, and basically any media app can access and browse files stored in the sd card. How do I fix this?

I want youtube to store downloaded videos to sd card same for NetFlix and prime video. I also tried uninstalling the apps and reinstalling them on my phone. I haven't found a fix yet.

My phone is running Android 8

I use G-Suite for business. I have the main domain (Let's call it example.com) and a number of secondary domains (we'll use example.co.uk for this). I have set up aliases so that I can receive email sent to [email protected] and also [email protected].

Using GMail on the web I can select a default email address for outgoing email. So, although my primary address is [email protected] my outgoing email appears to come from [email protected]

So far, so good.

Now I want to do the same thing on my Android phone and tablet.

How can I set up Gmail for Android to use my alias [email protected] instead of my primary address [email protected]?

Note that I don't want to reset the phone and sign in with a different address. I just want to change the GMail alias.

One answer to this question suggests it's not possible, but that was five years ago. Has anything changed?

I am out of ideas. The following MP3 does not play correctly on many Android-devices: https://www.heimatmuseum-zinnowitz.de/app/download/12553824899/Kino%20Audiodatei%20Deutsch.mp3?t=1590484494

It contains a German female voice. But on several devices, it does only play over the headphones. If I use the normal speaker, I do only get some noise.

I tried many different things:

• Used different devices (works fine on a Samsung-tablet (Android 8.1), but does only work over headphones on my Huawei P20 Pro (Android 9) and another older phone (Android 7)).
• On Windows, it works just fine.
• I converted the file a different format (OGG and WAV)
• I changed the sampling-rate from 48.0 kHz to 44.1 kHz
• I switched between constant and variable bitrate
• I tried the default-player and a different app (MusicFolderPlayer)
• I used different converters (Audacity and several online-converters)

The problem is always the same: I hear everything using headphones, I do only get noise with the speaker. How can I get this to work?

Needless to say that all devices used for testing are working fine with other files.

My phone (a Samsung A3 2016) used to allow me to move some apps to the SD card under its stock ROM (Android 7).

Last year I updated to Android 9 using LineageOS 16.0 and more recently to Android 10 with LineageOS 17.1.

However, ever since I made the switch I've lost the ability to move apps to the SD card. I go into Settings>Apps and notifications>App Info, choose an app that I know can be transferred, and the option is no longer there. I was hoping that the upgrade to Android 10 would fix this but it hasn't.

Does Android 10 no longer support this feature? Is it just the custom ROM I've used? Or is there a way to re-enable this feature. I would really like to get it working again as my phone only has 16GB of internal storage.

While using Google family link I am unable to block some websites. Maybe it's a bug, but for some reason for website like Instagram is blocked from being accessed but reddit is not. Does anyone have any idea why that might be

Discord talk channel stays broadcasting indefinitely in background even if the screen is locked.

Note that I write "background" from the user's point of view. The app has a persistent notification so that makes it technically non-background on Android.

I would like to know if there is a setting or app that could be used to prevent this privacy issue.

For example to stop apps on screen lock, or to auto-disable microphone after some time.

I tried a call recorder on my Android 7.1.2 phone, but only my voice was recorded, not those on the other side. Does it mean that my phone doesn't support something or should I try to find an application that may work?

I trying to build custom kernel for my Nexus 7 (2012 Wifi) device. Changed few things builded successfull, no bootloop. But I enable this in menuconfig: Device Drivers -> Network device support -> Wireless LAN -> Ralink driver support. After flashing got bootloop. How can i get some log about a problem?

As widely reported on different sites, and also discussed on this site (here and here), earlier this year, Google made changes to SafetyNet so that it could detect bootloader/verified boot status even with MagiskHide enabled. The developer of Magisk, John Wu, at that time tweeted that because Google was using the Trusted Execution Environment (TEE), its check on bootloader status could not be defeated. For example, he wrote:

this new update utilizes hardware-based key attestation. It will send an unmodified keystore certificate to SafetyNet servers, verify its legitimacy, and check certificate extension data to know whether your device have verified boot enabled (bootloader status)

Unless there is serious implementation bugs in your ARM TrustZone (or security co-processor like Google's Titan M), you cannot break the cryptography.

He basically concluded:

Let's face it. Fun is over guys.

Yet, on March 14, John Wu tweeted:

So apparently CTS is just passing again out of nowhere? Maybe Google is still testing things out?

I'm over it anyways. Google is apparently willing to use key attestation for detection. Since MagiskHide is still there, people can still always use it as usual.

And another tweet from him on April 3 that I didn't quite understand:

THE BIG GOOGLE HAMMER IS BACK! Say bye bye to SafetyNet, we'll (not) miss you...

Did that mean Google would somehow be removing SafetyNet, or at least not utilizing its capabilities to detect bootloader status?

So there was some doubt beginning to surface in mid March. In my own test in late May 2020, with MagiskHide not enabled, SafetyNet failed, but with MagiskHide enabled and targetting my test app, SafetyNet passed, meaning that MagishHide could still defeat SafetyNet. The test was run on a Pixel 3 with android 10.

So, Google may have the capability to detect MagiskHide, and it was working out in the field with real devices, but they have somehow stopped doing that? Does anyone know what is going on with SafetyNet? Was the feature temporarily reverted? Will it be coming back to SafetyNet, and if so, when?

My original Li-ion has 3000 mAh capacity. I've modded my device to have a total of 7000 mAh capacity now.

The enhanced capacity means that my percentage is not displayed accurately anymore.

About 2000 mAh charge displays 75% charge. That means 5000 mAh are located in the top 25% of my battery indicator.

(Charging times confirm: 1 Hour @1800 mA goes from 25% to 75%, but 75 to 83 takes almost the same time and so on.)

I know a lot is possible with a rooted Android device but I'm not too much of a software person.

How can I change the percentages that display? There has to be some kind of lookup table where the Vbatt→"%" conversion is done.

Edit: If no one can help me, I am going to add a bunch of tp4056 chips to enable actually charging.

The software seems to mess around quite a bit.

Now my phone is charging the 2nd time, and (I assume because it is calculated that the battery should be “full” by now in terms of mAh) it has reached “100%” despite the Vbatt being 3.95 Volts. Actual charge is ~ 70% at max!

Here you can see it charged more than 2000 mAh after reaching “100%”. I stopped the charge at 4.2 V.

The lower portion reached 75% after 1000mAh and took 900 more for the rest. So this has lost all it's 'linearity'.

Can I (additionally to changing the display behavior) also change the charging algorithm?

Do I have to compile a kernel by myself? Is there settings for this? I want higher current first and very low current for the charging above 4.1 V.

The status bar at the top of my Samsung S9+ does not show the am/pm after the time. The picture below was taken at 3:23 pm local time but you would not know that unless I told you. It could be 3:23 am. If I were using a 24-hour clock, I would expect that there not be an am/pm. However, my time setting is for 12-hour clock and could have an am/pm. How do I add the am/pm after the time?

Some may say that I can easily tell whether it is am or pm... just look outside. That may be true at 3:23 am or pm. However, at 8 pm during the summer time, the sunlight is about the same whether it is morning or evening. I would have to walk outside to find the sun and then know. During the winter time, 6 am and pm is completely dark. There is no sun to help me know.

Let's say I am very tired during the winter and start a nap at 4 pm. I wake up at 6. I do not know if I slept for 2 hours or 14 hours. Most likely I slept for 2 hours but it depends on how much sleep debt I have.

I own a Oneplus 7T, which runs Android 10 and therefore has no working TWRP to flash ROMs with. It's bootloader is unlocked and is rooted.

When installing a new ROM, whether it is a custom ROM or an update to the current ROM, I install them by extracting the ROM zip, extracting payload.bin, and flashing certain .img files in fastboot, following the instructions found here under the 'Manual Flash' section.

However, I'd like to understand more about this process. The instructions flash less .img files than were extracted. For example, in the recent Oneplus 7T OOS 10.0.11 update, the the number of .img files extracted (31) is less than what was flashed according to the instructions (19). Furthermore, the instructions passed the arguments --disable-verity when flashing two of the .imgs, but not the others.

Therefore, I'm wondering:

1. What does each .img file do?
2. Which files must be flashed and in what order?
3. Why are certain files flashed with certain arguments?