Mount /system on Android 10 with Magisk

Question

I am using Magisk 20.4 and trying to mount /system on a Google Pixel (1st gen) running Android 10.

I have tried using:

adb shell su -c mount -o rw,remount /system

that gives:

mount: '/system' not in /proc/mounts

The following also do not work:

adb shell su -c mount -o rw,remount /

'/dev/root' is read-only

adb shell su -c mount -o rw,remount /sbin/.magisk/mirror/system_root

'/sbin/.magisk/block/system_root' is read-only

I was also curious whether stuff in /sbin/.magisk/rootdir/system/ can actually override stuff in /system/ but that doesn't seem to be the case..

Has anyone managed to mount /system on Android 10? Is this issue specific to Google Pixel?

Cheers, Paschalis

Trying Hack5 suggestion gives me:

mount: '/system' not in /proc/mounts

Since I knew that /sbin/.magisk/mirror/system_root was a valid mount point, Ive tried the following, which still fails:

mount -wo remount /dev/block/bootdevice/by-name/system$(getprop
 ro.boot.slot_suffix)  /sbin/.magisk/block/system_root

mount: '/sbin/.magisk/block/system_root' not in /proc/mounts

UPDATE:

Turns out it's impossible to mount /system on a factory image of Google Pixel. But, I was missing the whole point of Magisk! So I made a few modules and I can override/add the system libs and bins that I need. There is even support for apex on Android 10!

score 1 · Answer 1 · answered Apr 11 '20 at 18:05

1

Your second command is correct, but the virtual block device is read only. IIRC, this is caused by the a/b mapping virtualisations.

Referring to https://android.stackexchange.com/a/158890/171244, you can see that specifying the correct block device will help. Try:

adb shell
su -c mount -wo remount /dev/block/bootdevice/by-name/system$(getprop ro.boot.slot_suffix) /system

This will switch from the virtual mapper (/dev/root) which is read-only, to the actual partition block device, making it writable

answered Apr 11 '20 at 18:05

Hack5

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Thanks for the reply. Unfortunately it does not work (see my updated question). – Paschalis Apr 11 '20 at 18:31
sorry, i made a typo, the final /system should just be / – Hack5 Apr 11 '20 at 18:34
I had also tested that and I haven't included on my edited answer. Still no luck :/ At this point I'm wondering even if it's possible! – Paschalis Apr 11 '20 at 18:38
It's definitely possible from TWRP – Hack5 Apr 11 '20 at 21:42
TWRP isn't supported on android10, but even temporarily booting into it gives: '/dev/block/bootdevice/by-name/system_a' is read-only. – Paschalis Apr 12 '20 at 15:04
1

I've never had a device with A/B so I'm stumped. – Hack5 Apr 13 '20 at 09:22

score 0 · Answer 2 · answered Apr 14 '20 at 09:26

0

ext4-dedup/logical partitions are ro by design

answered Apr 14 '20 at 09:26

alecxs

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score 0 · Answer 3 · edited Apr 06 '24 at 08:18

0

I think the problem is from Magisk.

I have a boot.img that I patched using Magisk 7.2.3. The latest 7.5.1 keeps giving me that error msg. Try using the old Magisk and you won't have that "mount: '/system' not in /proc/mounts" error.

edited Apr 06 '24 at 08:18

Andrew T.

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answered May 21 '20 at 22:48

user323757

1

you recommend to install magisk manager 7.2.3 right ? and I can see only 7.2.0 versions only..is that right you mentioned or it is 7.3.2 Magisk Manager version ? – Prabhakaran May 28 '20 at 03:18

Mount /system on Android 10 with Magisk

Trying Hack5 suggestion gives me:

UPDATE:

3 Answers3

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