I'm trying to modify the hosts file on my android phone and I am using adb for this on Ubuntu 20.04 to pull the file, modify it and push it back as suggested here. I was able to pull the file but when I try to push it I get an error
adb: error: failed to copy 'Documents/hosts' to '/system/etc/hosts': remote couldn't create file: Read-only file system
One suggestion seems to be to run adb remount or adb shell mount -o rw,remount /system (I'm not sure if these meant to be run on the android device itself) and this doesn't work for me, I get
/system/bin/sh: /system/bin/remount: inaccessible or not found
To this, there seems to be a suggestion to run adb root which returns adbd cannot run as root in production builds. Now I'm not sure how to proceed. There are some threads online saying what to do about this but I feel this is way above my head already. I just want to push the hosts file back to the phone. Is there a simple way to do this?
This is fairly a very old question but I am surprised that none of the solutions are working for me. I need to run an android app as system app in an AVD (in emulator) created for Android version 7.0. For this, I want to push apk file to system partition but I keep getting error saying it is read only file system. I found many similar questions on stackoverflow but nothing is working for me. I restarted adb in root, executed it with remount as suggested in answers to similar questions, but system partition file system permissions do not change. Here is a sample session:
mvsagar#mvslt:~/sw/android_sdk/platform-tools$ ./adb root
restarting adbd as root
mvsagar#mvslt:~/sw/android_sdk/platform-tools$ ./adb remount
remount succeeded
mvsagar#mvslt:~/sw/android_sdk/platform-tools$ ./adb push /home/mvsagar/projects/AndroidStudioProjects/LcnApps/app/LCNUE.apk /system/app/LCNUE.apk
adb: error: failed to copy '/home/mvsagar/projects/AndroidStudioProjects/LcnApps/app/LCNUE.apk' to '/system/app/LCNUE.apk': couldn't create file: Read-only file system
I have tried manually remounting with read/write(rw) options using adb shell, but the remounting fails.
Is there any way to have read/write permission on system partition?
My dev env is Android Studio on Ubuntu.
In my case, I use a avd( Based on: Android 8.0 (Oreo) Tag/ABI: google_apis/x86_64 ).
$ emulator -avd Nexus_5X_API_26_APIs -writable-system
$ adb root
$ adb remount
Then, /system is writeable.
$ adb push somefile /system/bin/ is work.
When working with Q, this is the only solution that worked for me: https://stackoverflow.com/a/64397712/1898527
Adding here the steps for completion (kudos to the original author):
> emulator -avd Pixel_3a_XL_API_29 -writable-system
> adb shell avbctl disable-verification
> adb disable-verity
Now reboot your emulator so that the changes take effect.
> adb root
> adb remount
> adb shell "su 0 mount -o rw,remount /system"
Note: you will need an emulator without Google Play, otherwise this won't work. You can get it by following the steps described here: https://stackoverflow.com/a/45668555/1898527
use genymotion emulator, which is faster, light weight and pre rooted. (which means you can access system directory)
For the benefit of others, answer to the question was answered a long ago by #Ishamael in another stackoverflow question Read only file system on Android
Recently I designed my own android bootanimation.zip file. I'm very proud of it and would like to make it my boot animation (the graphic that shows up when you start up your phone). However, I ran into a complication that I can't seem to solve or find any solutions to online.
Info: I'm running Cyanogen 12 on a Motorola Nexus 6. I placed my bootanimation.zip in the /system/media folder (and /data/local, but that didn't work).
The issue (read carefully please!):
I have confirmed that my bootanimation.zip file IS formatted correctly and DOES display properly. When I enter my phone's shell as root I can properly execute the /system/bin/bootanimation command. This command simply previews bootanimation. However, I can't execute the binary as non-root (which I should be able to do). I even went as far as changing the ownership of bootanimation to the shell (non-root account). Basically, I see something like this.
shell> bootanimation #/system/bin/bootanimation should by in my $PATH
/system/bin/sh: bootanimation: not found
shell> cd /system/bin
shell:/system/bin> ls bootanimation
bootanimation: Permission denied
shell:system/bin> ./bootanimation
/system/bin/sh: ./bootanimation: not found
shell:system/bin> su #log in as root
root> cd /system/bin
root:/system/bin> ls -l bootanimation
-rwxr-xr-x shell shell 34252 2015-11-03 11:07 bootanimation
Finally, the device is clearly unable to execute this on startup because the boot animation is never displayed, instead a silver 'google' is displayed.
I appreciate any input, thanks.
I rooted my unlocked Galaxy S3 (SGH-T999)
Now, I'm trying to run adb root from Windows Command Prompt, however, I'm getting adbd cannot run as root in production builds error. So, the very first thing I checked was whether my phone was really rooted?
So I tried the following:
Open Command prompt
$adb devices // lists my device
$adb shell //goes to shell
$su // opens a 'SuperSu' prompt on my phone and I 'Grant' permission
# // Before following the rooting instructions, I was getting 'no su command found' in the previous step. So, I believe my phone is ROOTED. **Correct me if I'm wrong.**
However, when I do adb root, I get adbd cannot run as root in production builds error.
So, I thought, I might have to do some additional stuff beyond what I did above. I tried all the solutions in the following SO questions:
Launch a script as root through ADB
adb remount permission denied, but able to access super user in shell -- android
Unable to run 'adb root' on a rooted Android phone
None of the above worked for me. All they do is give the ROOT access INSIDE of SHELL. I want adb root to work so that I can execute various adb commands WITHOUT going into shell.
By design adb root command works in development builds only (i.e. eng and userdebug which have ro.debuggable=1 by default). So to enable the adb root command on your otherwise rooted device just add the ro.debuggable=1 line to one of the following files:
/system/build.prop
/system/default.prop
/data/local.prop
If you want adb shell to start as root by default - then add ro.secure=0 as well.
Alternatively you could use modified adbd binary (which does not check for ro.debuggable)
From https://android.googlesource.com/platform/system/core/+/master/adb/daemon/main.cpp
#if defined(ALLOW_ADBD_ROOT)
// The properties that affect `adb root` and `adb unroot` are ro.secure and
// ro.debuggable. In this context the names don't make the expected behavior
// particularly obvious.
//
// ro.debuggable:
// Allowed to become root, but not necessarily the default. Set to 1 on
// eng and userdebug builds.
//
// ro.secure:
// Drop privileges by default. Set to 1 on userdebug and user builds.
In some developer-friendly ROMs you could just enable Root Access in Settings > Developer option > Root access. After that adb root becomes available. Unfortunately it does not work for most stock ROMs on the market.
I ran into this issue when trying to root the emulator, I found out it was because I was running the Nexus 5x emulator which had Google Play on it. Created a different emulator that didn't have google play and adb root will root the device for you. Hope this helps someone.
I use for enter su mode in abd shell
adb shell "su"
I have a rooted Samsung Galaxy Trend Plus (GT-S7580).
Running 'adb root' gives me the same 'adbd cannot run as root in production builds' error.
For devices that have Developer Options -> Root access, choose "ADB only" to provide adb root access to the device (as suggested by NgaNguyenDuy).
Then try to run the command as per the solution at Launch a script as root through ADB.
In my case, I just wanted to run the 'netcfg rndis0 dhcp' command, and I did it this way:
adb shell "su -c netcfg rndis0 dhcp"
Please check whether you are making any mistakes while running it this way.
If it still does not work, check whether you rooted the device correctly.
If still no luck, try installing a custom ROM such as Cyanogen Mod in order for 'adb root' to work.
You need to replace the adbd binary in the boot.img/sbin/ folder to one that is su capable. You will also have to make some default.prop edits too.
Samsung seems to make this more difficult than other vendors. I have some adbd binaries you can try but it will require the knowledge of de-compiling and re-compiling the boot.img with the new binary. Also, if you have a locked bootloader... this is not gonna happen.
Also Chainfire has an app that will grant adbd root permission in the play store: https://play.google.com/store/apps/details?id=eu.chainfire.adbd&hl=en
Lastly, if you are trying to write a windows script with SU permissions you can do this buy using the following command style... However, you will at least need to grant (on the phone) SU permissions the frist time its ran...
adb shell "su -c ls" <-list working directory with su rights.
adb shell "su -c echo anytext > /data/test.file"
These are just some examples. If you state specifically what you are trying to accomplish I may be able to give more specific advice
-scosler
adbd has a compilation flag/option to enable root access: ALLOW_ADBD_ROOT=1.
Up to Android 9: If adbd on your device is compiled without that flag, it will always drop privileges when starting up and thus "adb root" will not help at all.
I had to patch the calls to setuid(), setgid(), setgroups() and the capability drops out of the binary myself to get a permanently rooted adbd on my ebook reader.
With Android 10 this changed; when the phone/tablet is unlocked (ro.boot.verifiedbootstate == "orange"), then adb root mode is possible in any case.
If you really need to have ADB running as root, the quickest and easiest way is to install Android Custom ROMs and the most popular is CyanogenMod for it has the Root Access options in developer options menu where you can choose to give root access to apps and ADB. I used CM before but since it wasn't developed anymore, I tried looking for some solutions out there. Although CyanogenMod is still a good alternative because it does not have bloatware.
One alternative I found out from a friend is using adbd insecure app which you could try from here: https://forum.xda-developers.com/showthread.php?t=1687590. In my case, it works perferct with an Android custom kernel, but not with the Android stock ROM (vanilla android only). You may try other alternatives too like modifying boot.img of the Android ROM.
in my case, ( device is rooted )
linux$ adb shell # in linux shell
mobile$ su root #=> notice the $ will become #
mobile# whoami #=> root
if you installed "adb root" module in Magisk, you still have to manually switch to root by su root, otherwise, it just LOOKS LIKE you are root, but actually you are NOT root.
I have a Samsung Galaxy Tab S2 running Android 7.0.
Here's how I rooted it today:
Root the device using Odin
Read Alex P.'s answer in this thread regarding editing system\build.prop file.
download onto your tablet: v1.3.9 System Tools Android: All-In-One toolbox
run the app; under "System Utilities" confirm your Odin root worked using "Root Check"
in the same app goto "Root Manager" and use the "Build.prop editor" to effect the changes in the system\build.prop (as specified by Alex P.).
Final Confirmation:
C:\Android\sdk\platform-tools>adb shell
gts28vewifi:/ $ whoami
shell
gts28vewifi:/ $ su
gts28vewifi:/ # su root
gts28vewifi:/ # whoami
root
Upvote Alex P.'s answer.
Further info
and here
and here too
Root Access in Windows Command: adb shell su
Root Access in MacOS Command: ./adb shell su
I'm trying to build Android Jellybean from source for the Measy U2C HDMI stick. I've managed to build and install all the partitions (boot, kernel, misc, recovery, system...). The problem I'm having is that the system partition doesn't seem to be mounting. When I run
adb ls /system
I get the following output:
000041ed 00000400 51301410 .
000041c0 00000800 00000003 lost+found
000041ed 00000000 00000001 ..
I'd like to adb shell into the device and try to debug why the system partition is not mounting but adb wants there to be a working shell in /system/bin/sh.
$ adb shell
- exec '/system/bin/sh' failed: No such file or directory (2) -
My question is, how can I get adb to look elsewhere for the shell command so i can get this working? Or is there an alternate way to remote into the device and debug this? There is a busybox install at /sbin/busybox so if I can just invoke that somehow, I can figure this out.
"SHELL_COMMAND" appears to be hardcoded in adb/services.c an unofficial copy of which is browsable at
https://github.com/android/platform_system_core/blob/master/adb/services.c
Given that you are building from source you should be able to change this. But since you want to point it to a shorter path, you could also probably edit the binary and move up the terminating null.
Another approach to investigating your problem could be to see if you can get a working adb shell after booting to the recovery partition, and try manually mounting the problematic system partition there to see what errors result.
Still another idea would be to put something in the startup scripts which launches an alternate shell listening on something which you could forward a socket to using adb - I'm not thinking of an obvious reason why setting up adb forwards would depend on the device side shell, but I haven't verified that by experiment or examining the code.
If you wanted to get really clever, I believe that you could create a /system/bin containing a copy of sh on the root filesystem. My recollection is that you can mount a filesystem over a non-empty directory - not sure if there would be an issue with open file descriptors to that directory, such as for the running sh itself, but your mount is failing anyway, and you could try doing a manual mount elsewhere in order to debug that issue.