How to mount system as rw (read,write)

Mount system partition as read-write

To modify the system partition in rooted devices it is necessary that system is mounted in read-write mode. For mounting system partition as read-write User will need root access and a adb shell or in device shell. 

Steps for Rooting -

1. Bootloader Unlock - First step to root devices with android 7.0 or above is a bootloader unlocking, unlocked bootloader allows to flash any custom images/files in the device. stock bootloader can be unlocked with fastboot commands. First enable USB debugging and OEM unlocking in your device and give the following commands.

command -    adb roboot bootloader 

command -    fastboot flashing unlock  or  fastboot oem unlock                                                               

2. Install custom recovery - Second step to root the android device is a installing custom recovery in a device. The most popular custom recovery is a TWRP recovery. To install custom recovery reboot the device in bootloader/fastboot mode and give the following commands. 

command - fastboot flash recovery <recovery image file name with location>    

                                          
3. Install magisk/ su binary -  download and store magisk  file in your device storage and flash that file by booting in TWRP/ custom recover, this will add su binary in your device's /system/bin directory and user/allowed applications can access root permission in the device. 

Note - some devices can be rooted without bootloader unlock and custom recovery with the help of rooting application like kingroot, kingoroot, towelroot, etc.

Setup Adb in pc -

To use adb shell user need to setup adb in pc. follow the link for instuction how to install adb? 

https://www.customrom.co.in/2021/01/how-to-use-adb-and-fastboot.html

Adb shell can be used without pc in rooted smartphones with the help of terminal applications available in play store

Steps for mounting system as rw -

1.First Open terminal/cmd and type command 

•  adb shell 
• su

2. then type the command 

• mount

 this command with show all mounted partition with permissions, search for the system partition 

in above image the highlighted line show the mounted system partition

where /dev/block/platform/msm_sdcc.1/by-name/system  is a device name and it is mounted at /system directory and ext4  is a type of partition ro is (read only) shows the permission of the partition 

3. Now to remount the system as rw type the following command 

• mount -o remount,rw -t ext4 /dev/block/platform/msm_sdcc.1/by-name/system /system

User needs to change the above command as their mount point, partition device and type differs 

4. To check system is mounted as rw successfully give the the command 

• mount 

the highlighted line shows the system is mounted in rw mode.