Database Users

Cannot for the life of me get system r/w permissions

I've been running cm7 nightlies and now stable 7.0 for some time now. I have the new radio, ladios' kernel, and the sdcard read fix flashed.
I installed super manager and successfully deleted some of the stock cm7 media off my phone last week. Today, I came across the new GPS.conf files and wanted to try them.
Super manager couldn't switch the system to r/w despite saying "ok"
When I try to delete or write in the system with EStrongs file explorer, ghost commander, or android mate, they all give strange errors. The deleted files disappear but reappear after reboot. If I try to paste a file in system/etc I only get an error.
Superuser is successfully allowing permissions. I have the latest busybox. I have r/w enabled in each file manager.
I even tried an adb push test which first said "system is r/o only". The next try was "successful" but didn't do anything.
I'm still new with adb so I probably did something wrong. I typed in that r/w command, mount now shows: /dev/block/mtdblock3 on /system type yaffs2 (rw,relatime)
I can't figure out what changed and what I need to do to get r/w permissions. My only theory is that i had uninstalled and reinstalled super manager earlier and that somehow messed with my permissions.

You cannot permanently modify the system partition while the phone is booted into Android. The only way is to use adb while the phone is in recovery mode. Any changes you make while the phone is booted will be lost after a reboot.
Go check on those media files you thought you deleted. I bet you'll find they are still there.

Yes that worked. Thank you.
I thought I had read somewhere that you had to be booted to adb push.
I also thought that root managers advertising r/w capability would make permanent changes.
Next question:
Can I add and remove files from the cm7 zip before flashing it? Do I have to rezip it in any special or can windows 7 manage it fine?
EDIT: Ok I guess i need to sign it... lets see...

jamus28 said:
Yes that worked. Thank you.
I thought I had read somewhere that you had to be booted to adb push.
I also thought that root managers advertising r/w capability would make permanent changes.
Next question:
Can I add and remove files from the cm7 zip before flashing it? Do I have to rezip it in any special or can windows 7 manage it fine?
EDIT: Ok I guess i need to sign it... lets see...
Click to expand...
Click to collapse
You don't need to sign them on the aria
Sent from my Liberty using XDA App

jamus28 said:
Yes that worked. Thank you.
I thought I had read somewhere that you had to be booted to adb push.
I also thought that root managers advertising r/w capability would make permanent changes.
Click to expand...
Click to collapse
Those programs will work on some phones but not the Aria.
Next question:
Can I add and remove files from the cm7 zip before flashing it? Do I have to rezip it in any special or can windows 7 manage it fine?
EDIT: Ok I guess i need to sign it... lets see...
Click to expand...
Click to collapse
It really is as simple as adding or removing a few files from the zip file if you want to modify it.

Modify the system partition on Android Nougat?

Hi all,
has anyone been able to do this? Following the guide here, no longer works for Android N. The phone boots, but ignores all changes to system. How do I modify both build.prop and hosts? It seems that there are now possibly two system partitions?
Thanks!

Same issue on Nexus 5X

No answer on this? How is it that nobody else seems to be having this issue?

What I've done
It looks to me like everyone has moved to systemless and the /system partition cannot be adequately modified in this way anymore.
Maybe this will help others:
I was modifying the system directory for two reasons: 1. modify /system/etc/hosts to remove ads and modifying build.prop to increase lcd.density. I found that here are the alternatives for each:
Removing Ads
Using something similar to AdAway_systemless_hosts_v2.zip (google it for a copy) and modifying the hosts file in that zip file to be the one I use (and rezipping, deploying on the Android device). This basically mounts over /system/etc/hosts with a custom hosts file instead of actually modifying the system specific hosts file which is no longer writable.
The alternative is to use Netguard which routes non https network traffic through a private VPN where you can block ads according to a hosts file. This seems to work OK, but I have noticed that websites seem to take longer to load.
Modifying lcd.density
You can use the same trick as AdAway_systemless_hosts_v2.zip uses, but modify it to also mount a modified copy of build.prop. Alternatively just use the Android N Display settings that are small (what I did anyhow).

I have been able to edit build.prop and still maintain systemless root.
Sent from my Nexus 6P using XDA-Developers mobile app

I was able to modify my system partition; by installing busy box to /su/xbin and running "su busybox mount -o rw,remount system" (no quotes) in material terminal with root

ArminasAnarion said:
I was able to modify my system partition; by installing busy box to /su/xbin and running "su busybox mount -o rw,remount system" (no quotes) in material terminal with root
Click to expand...
Click to collapse
Have you been able to do this with simply fastboot boot <twrp-image>, mounting system in rw mode and modifying it? I did that as I didn't want to root the phone, and while it looks like it did the write, it does not affect the system partition that is used by the phone after boot. I think there are two system partitions, and twrp mounts only one in rw mode. It does seem like it may be possible to do what you say using adb though after the phone is fully booted up. I'll try that!

dontblinkwatchout said:
Have you been able to do this with simply fastboot boot <twrp-image>, mounting system in rw mode and modifying it? I did that as I didn't want to root the phone, and while it looks like it did the write, it does not affect the system partition that is used by the phone after boot. I think there are two system partitions, and twrp mounts only one in rw mode. It does seem like it may be possible to do what you say using adb though after the phone is fully booted up. I'll try that!
Click to expand...
Click to collapse
I had the same problem. I don't want to root but I do make a few changes to my /system partition through adb in recovery such as the hosts file and some font files (namely the Emoji font file). I had modified stock boot image to not enforce encryption. I would boot back up into the system and couldn't see any changes made. The only thing I found that worked was installing a custom kernel (I use ElementalX). After that, changes I made to /system in TWRP were reflected in the OS. I don't know enough about kernel development to understand why on (mostly) stock kernel my changes couldn't be seen but on a custom one they were.
I never had this "problem" prior to Nougat.

Same issue here. Something has changed with how this is handled in Nougat.
I don't want to root just to overwrite the hosts file...
I'll keep debugging but my capability in this is definitely limited!

I use a similar approach as described in the OP's linked guide except I use my own recovery image that I compiled as an engineering build from source, and I am also experiencing the same behavior. Modifying the hosts file seems to have no impact on the system though the changes persist. Comparing the host file I installed and the host file from the latest Nexus 5X image with 'ls -lZ' the SELinux info looks to be the same. The only information that appears to differ is the modified date and one additional line in the file itself for testing. I thought I was doing something wrong with my hosts file, even though I have been using this approach since Android 6.0. However, I agree, it appears that changes to system are being ignored. Further, changing the system partition no longer shows the red warning at boot about the system being corrupted.
---------- Post added at 09:58 PM ---------- Previous post was at 09:38 PM ----------
DanRyb;68654939 I would boot back up into the system and couldn't see any changes made.[/QUOTE said:
Oooh. You're right. Neither /etc/hosts or /system/etc/hosts is modified in the booted OS after I modify it from live image, but the change is retained when I reboot into live image and mount system. Hmm, so either:
1) Need to figure out where the the system files are being loaded from and modify them from live image if possible
2) Use a mechanism similar to what dontblinkwatchout described AdAway is using of having a custom mount setup (have to reverse engineer AdAway I guess to see what it's doing)
3) ?
Click to expand...
Click to collapse

There's absolutely no way to modify or mount system partition r+w unless you disable dm-verity
Enviado desde mi Nexus 6P mediante Tapatalk

alexiuss said:
There's absolutely no way to modify or mount system partition r+w unless you disable dm-verity
Enviado desde mi Nexus 6P mediante Tapatalk
Click to expand...
Click to collapse
dm-verity has been around since Android 4.4. Are you saying there is something new around this in Android 7.0?
You can modify the system partition by compiling an engineering build of Android and booting it, then mounting the system partition and modifying it. I've been doing this to update the hosts file since Android 6.0 for every OTA update (since more recently OTA updates bomb out unless you reflash the clean "uncorrupted" system.img first). Changing the system image before Android 7.0 did result in an extra screen with a red warning about a corrupted something or other (I'm sure because dm-verity checking failed). Regardless, you can still change the system partition, the information just no longer seems to be used, which is a bit perplexing to me atm.

crashenx said:
dm-verity has been around since Android 4.4. Are you saying there is something new around this in Android 7.0?
Click to expand...
Click to collapse
Android 7.0 introduced redundant bits for reed solomon forward error correction into the system and vendor partitions and code in the kernel to perform the error correction.
Your changes are being written to emmc but when you boot with 7.0 kernel with dm-verity enabled your changes are being treated as data corruption and on-the-fly error corrected back to original.
You can see your changes if you boot into twrp because it has dm-verity disabled. However if you boot into android with dm-verity enabled it will look like original image again even though your changes are technically still there.
It took me a day to figure out what was really going on because i initially had no idea they added this feature to Android N.
The simple way to disable dm-verity is to install SuperSU, but you can also accomplish the same patching your own kernel, installing pre-patched kernel, installing custom kernel, etc.

sfhub said:
Android 7.0 introduced redundant bits for reed solomon forward error correction into the system and vendor partitions and code in the kernel to perform the error correction.
Your changes are being written to emmc but when you boot with 7.0 kernel with dm-verity enabled your changes are being treated as data corruption and on-the-fly error corrected back to original.
You can see your changes if you boot into twrp because it has dm-verity disabled. However if you boot into android with dm-verity enabled it will look like original image again even though your changes are technically still there.
It took me a day to figure out what was really going on because i initially had no idea they added this feature to Android N.
The simple way to disable dm-verity is to install SuperSU, but you can also accomplish the same patching your own kernel, installing pre-patched kernel, installing custom kernel, etc.
Click to expand...
Click to collapse
That's good info and makes total sense. Thanks! Pretty neat actually, just a bummer for me.
Yeah so SuperSU path is not really one I want to pursue. I could learn how to update the dm-verity shas used for verification. That'd probably be the most secure, but it's gonna be a PITA I bet. I imagine I'd need to compile my own image similar to how I made my live image and update a few things. Might have to deal with encryption which is probably an even bigger headache. Also, I bet it would break OTA and have to reflash to update, though that's true now.
I'm really curious what AdAway is doing. Maybe I should pursue reverse engineering that.
I really appreciate you pointing us in the right direction.

I am glad found this thread..willing to assist here without permanent root..

Ericarthurc said:
I was able to modify my system partition; by installing busy box to /su/xbin and running "su busybox mount -o rw,remount system" (no quotes) in material terminal with root
Click to expand...
Click to collapse
I was trying to create a /system/xbin/post-boot but couldn't remount /system, and so I added busybox to the front of my command. I am not using adb so I cut that part off. Thanks a lot!

Magiks on Moto Z play

I managed to have magisk and magiskhide working sucessfully, with some manual tricks and workarounds
There is a bug in f2fs that prevents /data/magisk.img to me mounted writable, so the tweek is just moving that file to the /cache partition, which is ext4 and creating a symlink to the original file.
So the steps for a working magisk is.
- Unlock your bootloader
- Install Twrp
- Flash magisk without mounting data partition and boot once.
- Reboot to recovery and open terminal (advanced)
- move magisk.img to /cache partition, changing name ( example: mv /data/magisk.img /cache/magisk_2.img)
- Create a symlink between_files ( ln -s /cache/magisk_2.img /data/magisk.img)
Would be nice if anybody can try to reproduce.

Ah, so there is a way after all. I gather it works normally afterwards, with phh superuser, xposed and everything? I'm willing to try and reproduce your steps if so, maybe tweak the installer script so it does this automagically as well.

lpchaim said:
Ah, so there is a way after all. I gather it works normally afterwards, with phh superuser, xposed and everything? I'm willing to try and reproduce your steps if so, maybe tweak the installer script so it does this automagically as well.
Click to expand...
Click to collapse
I did not installed Xposed because I wanted to pass SafetyNet, but I cannot think a reason why it shouldn't work.

jblancoperez said:
I did not installed Xposed because I wanted to pass SafetyNet, but I cannot think a reason why it shouldn't work.
Click to expand...
Click to collapse
Right. I think I'll try this out today and see how things turn out. As for SafetyNet, I though the unlocked bootloader alone was enough reason for it not to work, is this only for some models?
Update: So, @jblancoperez, I've reproduced your steps and Magisk Manager tells me it's installed but root isn't activated and it doesn't let me do anything else as a result.

Things to have a look,
Please confirm in the terminal if /magisk is mounted.
Go back to TWRP terminal and also confirm if the symlink is OK.
Nice to get the output from /cache/magisk.log
It took me a while to have everything right, doing it on TWRP is not the easiest places to move things around.

So, an update. Your method just wouldn't work for me at all, no matter how many times I tried. What worked was following the first part only, as in unmounting data and then flashing Magisk afterwards. I've tried Xposed and Viper4Android; they worked, but both did have to be flashed through twrp as opposed to Magisk Manager, which would throw an error. Not sure if that's on them or on this particular method. I should mention though that SafetyNet wouldn't pass even before xposed and with the hiding settings, not sure why.

You may want to try the kernel where the f2fs bug is fixed, which may be the cause when Magisk hide is not working which would cause Safetynet to fail.

Is there anyone wanting to test brand new Magisk 11.0 if it runs fine on Moto Z Play? With and/or without that f2fs fix?

tag68 said:
Is there anyone wanting to test brand new Magisk 11.0 if it runs fine on Moto Z Play? With and/or without that f2fs fix?
Click to expand...
Click to collapse
I got bootloop when I install magiks 11.0.

Do you have a logfile of that action in /cache or /cache/recovery which we could show in the Magisk thread?

I was able to upgrade the 10.2 installation.
Will try a new clean installation on the weekend with the f2fs fixed kernel.
I think I got why my procedure is not working for other people. Please try to copy the image instead of moving with the flags preserving de selinux attributes.

jblancoperez said:
Please try to copy the image instead of moving with the flags preserving de selinux attributes.
Click to expand...
Click to collapse
Keeping attributes when copying or moving is what my guide regarding timestamp is about. It's not that easy using Android.

tag68 said:
Keeping attributes when copying or moving is what my guide regarding timestamp is about. It's not that easy using Android.
Click to expand...
Click to collapse
I used the same cp commands @topjohnwu used in the magisk script, cp -afc orig dest.

jblancoperez said:
I used the same cp commands @topjohnwu used in the magisk script, cp -afc orig dest.
Click to expand...
Click to collapse
cp -a tries to copy attributes including timestamps. But it only succeeds if you are currently running as root.

persistant changes to hosts file following reboot?

Hi everyone. I'm scratching my head here and struggling to find a solution that doesn't require root.
I've got a hosts file that I love as it blocks nearly all advert servers on my phone.
I know there are several adblocking apps but they all require root.
I have had to remove root as I have some critical apps that still don;t work, even after hiding magisk from the apps within the Magisk Manager.
I've got a magisk patched image that I can "fastboot boot" with and can edit the hosts file (after remounting /system as rw) but when I then reboot afterwards, the hosts file has been overwritten.
Can anyone help me please or give me a pointer of how to make the hosts edits remain following a reboot?
edit2add
I am using stock ROM with latest August patches on my Mi A1

You can't without root even if you do it your system partition will be modified and it will result in phone not booting or just safetynet won't pass.
Use a vpn or I'm pretty sure there's app that can fake a vpn with a ad ban list

Dead-neM said:
You can't without root even if you do it your system partition will be modified and it will result in phone not booting or just safetynet won't pass.
Use a vpn or I'm pretty sure there's app that can fake a vpn with a ad ban list
Click to expand...
Click to collapse
Interesting idea regarding spoof VPN.
Do you know how the hosts file is generated? If it's copied over from somewhere during boot then could I edit the source file it's copied from?
If it's generated procedurally, might I be able to script it to add my edits during creation?

wodgey said:
Interesting idea regarding spoof VPN.
Do you know how the hosts file is generated? If it's copied over from somewhere during boot then could I edit the source file it's copied from?
If it's generated procedurally, might I be able to script it to add my edits during creation?
Click to expand...
Click to collapse
System partition ? so that's a good idea but you'll have to compile a rom to change this file. On Linux distro the host file is a thing you can modify easily. On android it's just deprecated by google as it's use mostly used as an adfilter. And google is an ad company. That's my guess.
Anyway host file will always need root even on Linux.
Simply because it can be used against you.
The problem is more on apps that blocks you because you're rooted than being rooted for changing this file.
If any app could modify host then bang you go to YouTube and it redirect you to something else.
Maybe for you it's just an adblock file but it's a little more than that.
So sorry but it's root or vpn.

Dead-neM said:
System partition ? so that's a good idea but you'll have to compile a rom to change this file. On Linux distro the host file is a thing you can modify easily. On android it's just deprecated by google as it's use mostly used as an adfilter. And google is an ad company. That's my guess.
Anyway host file will always need root even on Linux.
Simply because it can be used against you.
The problem is more on apps that blocks you because you're rooted than being rooted for changing this file.
If any app could modify host then bang you go to YouTube and it redirect you to something else.
Maybe for you it's just an adblock file but it's a little more than that.
So sorry but it's root or vpn.
Click to expand...
Click to collapse
So? Could I possibly extract the system.img from the stock ROM, make the edits there and then recompile?
(I've got a copy of payload.bin that I extracted a few weeks ago, when trying to flash the August security patches (this was before I did a compete flash of stock ROM using fastboot)
That actually seems like it wouldn't take too much effort

wodgey said:
So? Could I possibly extract the system.img from the stock ROM, make the edits there and then recompile?
(I've got a copy of payload.bin that I extracted a few weeks ago, when trying to flash the August security patches (this was before I did a compete flash of stock ROM using fastboot)
That actually seems like it wouldn't take too much effort
Click to expand...
Click to collapse
This will lead to a corrupt system partition modified. As i said the worse thing is you could not boot and the good just won't pass safetynet.

Dead-neM said:
This will lead to a corrupt system partition modified. As i said the worse thing is you could not boot and the good just won't pass safetynet.
Click to expand...
Click to collapse
Ok I understand.
How does the device 'know' that the system partition is corrupt? Does it perform a hash check perhaps?
How would compiling my own custom ROM avoid this same problem?

wodgey said:
Ok I understand.
How does the device 'know' that the system partition is corrupt? Does it perform a hash check perhaps?
How would compiling my own custom ROM avoid this same problem?
Click to expand...
Click to collapse
It does many thing to know that its have been touched. You'll have to modify some stuff and it will work. You'll loose certification but you'll have you own rom.

Dead-neM said:
It does many thing to know that its have been touched. You'll have to modify some stuff and it will work. You'll loose certification but you'll have you own rom.
Click to expand...
Click to collapse
Any chance you can outline the other stuff I'd need to change?
If it's really in-depth then don't worry but if it's just a few bullet-points that I can Google more info on, I'd appreciate it.

wodgey said:
Any chance you can outline the other stuff I'd need to change?
If it's really in-depth then don't worry but if it's just a few bullet-points that I can Google more info on, I'd appreciate it.
Click to expand...
Click to collapse
Search "dm-verity" and "safetynet". The first one is what will look at any r/o partition like system and kernel. It's been a long time since i dig into this. I'm not into this anymore.
But You can disable it but you'll loose safetynet, encrypted partition etc... (i may be wrong but you got the idea). And safetynet look if partition have been modified and you are a certified device if it won't pass the banking app and apps like Pokemon go etc won't work.
Magisk hide the fact that the kernel img have been touch and most app that detect it detect just the app itself. That means magisk capability (su, hide and module)
So you could maybe compile stock rom with a custom host file. Never touch vendor partition! Make a backup before! By booting and not flashing twrp. Do not flash twrp just use the "fastboot boot command"
You'll need to make a custom kernel and system img to flash in order to do it.
I'll try to do a rom without anything modded except kernel without dm verity and system with your host and i guess it needs change too.
I dunno if it will pass safetynet after.
Just don't brick your phone ?
Keep in mind that you'll loose ota. There's a chance that the rom work with just some changes but i can be a mess to do.
Why not trying a custom rom like lineage os?
Using their supersu zip won't you be able to replace the host file then remove root?
Once you make a backup a move it to a pc as a savestate. You are free to try different solution

Dead-neM said:
Search "dm-verity" and "safetynet". The first one is what will look at any r/o partition like system and kernel. It's been a long time since i dig into this. I'm not into this anymore.
But You can disable it but you'll loose safetynet, encrypted partition etc... (i may be wrong but you got the idea). And safetynet look if partition have been modified and you are a certified device if it won't pass the banking app and apps like Pokemon go etc won't work.
Magisk hide the fact that the kernel img have been touch and most app that detect it detect just the app itself. That means magisk capability (su, hide and module)
So you could maybe compile stock rom with a custom host file. Never touch vendor partition! Make a backup before! By booting and not flashing twrp. Do not flash twrp just use the "fastboot boot command"
You'll need to make a custom kernel and system img to flash in order to do it.
I'll try to do a rom without anything modded except kernel without dm verity and system with your host and i guess it needs change too.
I dunno if it will pass safetynet after.
Just don't brick your phone ?
Keep in mind that you'll loose ota. There's a chance that the rom work with just some changes but i can be a mess to do.
Why not trying a custom rom like lineage os?
Using their supersu zip won't you be able to replace the host file then remove root?
Once you make a backup a move it to a pc as a savestate. You are free to try different solution
Click to expand...
Click to collapse
Thanks for info I'll investigate later in the week when I have more time. Monday has arrived too quickly!
Appreciated though

boot animation

I'm wanting to change the boot animation on my OnePlus 6T but when I go to move a new bootanimation.zip to
/system/media it say task failed and the .zip file that's there has 0 bytes.
Anyone got any idea why it's not working? Didn't have this issue with any other phone.
Cheers

Newrooter22 said:
I'm wanting to change the boot animation on my OnePlus 6T but when I go to move a new bootanimation.zip to
/system/media it say task failed and the .zip file that's there has 0 bytes.
Anyone got any idea why it's not working? Didn't have this issue with any other phone.
Cheers
Click to expand...
Click to collapse
A couple of reasons.
OnePlus left zero room on system partition. You'd need to remove something beforehand.
Many file explorers, titanium backup, etc are having issues modifying the system partition. Best luck I've had is using the built in file explorer in TWRP.

I literally replaced my bootanimation yesterday. I used a Magisk module for a bootanimation and repalced the bootanimation in the module install location which is on your data partition. This way, you can remove the module and still keep your original bootanimation should you wish to revert back. The bootanimation I used was originally for a 720p screen so I had to modify it for the dimensions of the OP6T (1080 x 2340). I am still trying to work on modifying the Magisk module so it has my bootanimation instead. It didn't work when I tried it yesterday and had to replace the file manually after, which then worked.

ffejy462 said:
A couple of reasons.
OnePlus left zero room on system partition. You'd need to remove something beforehand.
Many file explorers, titanium backup, etc are having issues modifying the system partition. Best luck I've had is using the built in file explorer in TWRP.
Click to expand...
Click to collapse
You can increase the size of the system partition with this tool: https://forum.xda-developers.com/oneplus-6/how-to/tool-epr-enchilada-partition-resizer-t3963587

I would avoid trying to resize the partitions as suggested above unless you fully understand what it is doing and what issues may arise from messing with the partition tables.
I just put my bootanimation.zip into the system-less hosts Magisk module. I have been using that module for any system files I need to replace. It's nice and simple plus you can revert the changes by just disabling the module.

Jager said:
I would avoid trying to resize the partitions as suggested above unless you fully understand what it is doing and what issues may arise from messing with the partition tables.
I just put my bootanimation.zip into the system-less hosts Magisk module. I have been using that module for any system files I need to replace. It's nice and simple plus you can revert the changes by just disabling the module.
Click to expand...
Click to collapse
Can you tell me the name of the module I searched for "system-less host" module but magisk never showed anything. Thanks

Newrooter22 said:
Can you tell me the name of the module I searched for "system-less host" module but magisk never showed anything. Thanks
Click to expand...
Click to collapse
It's built into Magisk. In the settings...
Edit:
Also if you understand what I am doing then you will see that you can basically use any Magisk module to accomplish this. It just has to be mounting files against the /system partition. I used the system-less hosts since it literally is only replacing one file on the /system partition so nothing complex was going on with this module.