Develop Reference

How to root or GPIO access on custom android-based development board

I have this development board Open-Q 820
It is running an Android 7.0 based on some sources from CodeAurora (that seem based on AOSP sources). Seems it uses proprietary bootloader that can not be changed. I need to access GPIO (/system/class/gpio) from my android app to control an external device. Problem is I can not do this from android app - seems only root can access this files.
I can call "adb root" command from PC and then call from "adb shell" something like
echo 0 > /sys/class/gpio/export
echo out > /sys/class/gpio/gpio0/direction
echo 1 > /sys/class/gpio/gpio0/value
and it is working. But I need to do the same from my android app. I know how to access terminal and su from android app. I just dont know how to root custom device. I tried to install SuperSU.apk app and its corresponding su native app manually. It starts and says it need to update su binaries. After installing binaries and reboot the system then it becomes broken - infinite android logo. If I not install binaries update then SuperSU can grant permissions to my app but actully app still can not use su (I dont know why - I use this library inside my app: https://github.com/Chrisplus/RootManager). And after reboot SuperSU not working longer.
So may be you know some SuperSU alternatives (Knigroot not working too) or steps how to correctly install some superuser management app. Or may be I can use su directly (I tried but my app has not rights to access /system/xbin/su). Or may be I can make /sys/class/gpio accessible by android apps somehow (I tried chmod 777 on it - not works). May be some SElinux rights, but I have no experience with this.
Thank you

Magisk helped me. Since it is have option to patch custom boot image. I used this option and now root access works.

aggressive adware irremovable apk on android

A few days ago I received complaints from several customers who told me that "adware is installed automatically on your device Krono NET K5". I made invesigar and found a few apk on / system / app that had different permissions to the usual "rw-r - r--". I could erase the few simple steps in a shell:
adb shell "su -c 'mount -o rw, remount /'"
adb shell "su -c 'rm /system/app/156.apk'"
adb shell "su -c 'rm /system/app/Launcher0607wxDjbOa.apk'"
adb shell "su -c 'rm /system/app/Sync.apk'"
adb shell "su -c 'rm /system/app/SettingProvider.apk'"
(Note that a suspect name as there is a apk using the system call SettingsProvider.apk with letter s)
So far everything worked properly, however there is a apk which is the main cause of all adware and causing the discharge cone apk other battery savers, system cleaners, among others. This application is:
"/system/app/providerdown.apk" Permits "rwsr-sr-x"
I tried to remove it by the above method, I tried to change the permissions to remove it and it has not worked. I tried to install a recovery to eliminate apk thence Aroma File Manager (CWM, TWRP) MTK but this device does not support any custom recovery for devices MTK.
Any idea? Thanks in advance (sorry for my bad english)

I have same problem. You will have to be rooted for this, but i guess you have root because of that code you wrote, and the fact that app somehow gains root access and installs itself in system. Only thing I did to make things easier is:
Download Avast to your phone.
Download Clean Master to your phone and with Clean master make backup of your avast apk.
Go to your stock recovery. I used an app from google store to boot to recovery but any way is good.
Clean cache and do a factory reset.
Boot the device.
DO NOT CONNECT DEVICE TO ANY NETWORK.
Just skip all the stuff like login to your google account and other settings.
Find your Avast apk in the sd card and install it.
Turn on firewall and block all acces to TimeService-that is the name that apk uses when seen from android system.
Go to android system and disable time service. It is probably version 1.1.6
You will still have malware in your device but it wont make mess anymore.
I would like the permanent solution too.

Android: adbd cannot run as root in production builds

I have an Android-based phone (2.3.6) with unlocked root privileges.
Since i'd like to have access to my phone through my computer, today i've installed QtAdb and Android SDK.
If i open a command prompt and i do
adb shell su
i get
#
And so I am able to copy, remove, push files on my phone (on the phone i get a notification using the app "SuperSU".)
But if i launch QtAdb - under Windows 7 - i get the following error: "adbd cannot run as root in production builds". I miss something? There's something wrong with QtAdb?

The problem is that, even though your phone is rooted, the 'adbd' server on the phone does not use root permissions. You can try to bypass these checks or install a different adbd on your phone or install a custom kernel/distribution that includes a patched adbd.
Or, a much easier solution is to use 'adbd insecure' from chainfire which will patch your adbd on the fly. It's not permanent, so you have to run it before starting up the adb server (or else set it to run every boot). You can get the app from the google play store for a couple bucks:
https://play.google.com/store/apps/details?id=eu.chainfire.adbd&hl=en
Or you can get it for free, the author has posted a free version on xda-developers:
http://forum.xda-developers.com/showthread.php?t=1687590
Install it to your device (copy it to the device and open the apk file with a file manager), run adb insecure on the device, and finally kill the adb server on your computer:
% adb kill-server
And then restart the server and it should already be root.

For those who rooted the Android device with Magisk, you can install adb_root from https://github.com/evdenis/adb_root. Then adb root can run smoothly.

Use adb shell; su;
I still have not found any other solution for android 12 rooted with magisk. adb_root does not work with android 12. adbd insecure does not work for me and throws error could not patch adbd.

if anyone is still having issues, heres how i fixed it
you have to start the shell with the phone and go into the magisk app and in the superuser tab (bottom) you have to enable root access for the shell and it works!

You have to grant the Superuser right to the shell app (com.anroid.shell).
In my case, I use Magisk to root my phone Nexsus 6P (Oreo 8.1). So I can grant Superuser right in the Magisk Manager app, whih is in the left upper option menu.

android dumpsys permission denial

I have an application where I create a process and call the dumpsys telephony.registry command to get information about the mobile network status.
String[] cmds={"dumpsys telephony.registry"};
Process p = Runtime.getRuntime().exec(cmds [0]+"\n");
and then after that I parse the result of the command. For "ls" or other commands it works fine. For dupmsys I get Permission Denial: can't dump telephony.registry from pid-953, uid=10090. I get the same error results for dumpsys power or other dumpsys commands.
I have set DUMP permissions android.permission.DUMP in the android Manifest like suggested here
I think that I am doing this right since Android offers this feature here
I have also done the step described here to force eclipse to allow me to give my application DUMP permission in the manifest.
When I execute the dumpsys command I always get the same result
Permission Denial: can't dump telephony.registry from pid-953, uid=10090
Am I doing something wrong? Why does android OS still deny me access to the dump service ?
PS I have set min API 8 and I am testing the application on device running (ICS)
API 15

Why does android OS still deny me access to the dump service ?
Because that permission is flagged as android:protectionLevel="signature|system|development" (or signatureOrSystem using the old syntax) on Android 2.3+, and therefore cannot be held by ordinary Android SDK applications.

There's another (hacky) way to access dumpsys without rooting your device - through adb shell.
This will require allowing USB debugging, and finding the port of the adb service.
Enable USB debugging on your device. This option is found under Settings -> Developer Options.
Connect your device to a PC, and run the following command from the PC's shell/command line:
adb tcpip 12345. Then, from your devices shell, issue the command adb connect localhost:12345 from your application. You can now disconnect the device from USB.
Alternatively, you can scan the ports on your device one by one without USB connection, using adb connect localhost:<portnum> and find the port adb service is listening to.
Authorize USB debugging from the pop up confirmation dialog, if prompted. Check the "always" checkbox to do not require this step again.
Now, when you have access to the adb service, use adb shell dumpsys ... from your application code to get whatever service dump you need.
NOTE: You don't need the DUMP permission for that to work.

The android dev team decided to stop granting these permissions to third-party apps. Only system apps can now get them.
more details:https://code.google.com/p/acra/issues/detail?id=100

It reports private values of core Android services that you would never be able to typically obtain. Official document says "Not for use by third-party applications".

Add permission on your manifest "android.permission.DUMP". I have not tried it yet but it shows on adb shell that it is missing that permission

How to connect to a dev phone and gain the root permission through "adb shell"

I'm using a dev phone (Nexus One). I connected to it through "adb shell" but I couldn't get the root permission. When I run "su" in the shell, I got
$ su
su: permission denied
Actually I cannot access "/sbin" at all.
When I used the "root" option in "adb", I got errors too:
./adb root -s xxx shell
adbd cannot run as root in production builds
I got this error no matter I used a downloaded SDK or I compiled an SDK from the source. I'm not sure about what "production builds" actually means. Does it mean that I need to compile Android and put it on the phone? I thought a dev phone already has the root permission unlocked.
Thanks for your help.

You should unlock your phone - root it. Nexus One comes with this option, but you have to enable it. You can read this article or google for more.