So you have an old android device?? and you want to change/modify/update it’s system files to fit your fancy requirements and considering the fact that android system is highly modular, customization is hyped a lot about but first, you will need to mount your read only android system for write and modify operations.
Here is one of the way :
1) Install the Android Software Development Kit and
2) USB drivers which is specific to your Android Device
3) USB debugging must be enabled. Check you Application Development section of your android phone.
Set the SDK path in the Advance System Settings such that “adb.exe” is accessible through command
prompt. Alternatively you can go the installed files location of your AndroidSDK to access “adb.exe”
a) Open Command Prompt and type “adb shell”. This will brings out the shell prompt.
b) Typing “mount” will show the list of current partitions on your android device. Note the system block(the block with the “/system” tag) and its permissions “ro”(i.e read only file system)
c) Type “su” for super user.
d) Type “mount -o rw, remount -t yaffs2 (your “/system” block name which in my case is “/dev/block/mtdblock7(space)/system”)”
e) Typing “mount” will diplay all the current partitions again but now the “/system” block should show “rw” (i.e read and write)
Now your system block is mounted for write and modify operations. The rest is pretty much easy.
Navigate around and change or modify your files.The “rm” command deletes a file and in my case as shown in the picture got rid of my ATT tone that plays every time i switch on my phone.
So, first of all you might be asking what is ADB ?
It’s basically a tool through which you can issue shell commands via your computer to your phone. ADB stands for Android Debug Bridge. It comes as a part of the standard Android SDK, which you can grab here. Basically, it provides a terminal-based interface for interacting with your phone’s operating system. Since Android platform is based on Linux, command-line is the only way to obtain and manipulate root access often required to perform certain advanced operations on your device using root access.
You can also directly issue commands by installing a terminal applications like terminal emulator, but it’s not handy to execute complex commands on such a small screen.
So, want to get into the android era?
So, first step is to get the android SDK on your computer from here. Just download the installer and install it to any drive, in this guide I am installing to a folder called android in C drive i.e (C:\android).
after installation has completed just click finish and it will automatically launch the SDK Manager. Now select both the option i.e platform tools and SDK tools and accept it and click Install. Once the process is done, you will have a ‘platform-tools’ folder inside your (C:\android) folder. That folder will have your ADB and all its dependencies.
Now, set the path variable. So, that you can easily issue commands via any location in cmd.To make ADB along with other Android SDK tools and platform tools easily accessible from anywhere at the command line, we shall add their paths to the PATH environment variable.
Right-click on the ‘Computer’ icon and click ‘Properties’. Now click ‘Advanced System Settings’ from the options in the left pane to bring up the ‘System Properties’ window. In the ‘System Properties’ window, click the ‘Environment Variables’ button on the ‘Advanced’tab.
Go-to the ‘Path’ in the ‘System variables’ section and double-click it to edit it and click on the text box and bring the cursor to the last.
Just add the below lines at the end of it, including both the semi-colons:
Note:If you have installed the SDK’s contents to another directory, make sure to use that one for your PATH variable.
Notice that the semi-colons are necessary to separate each path variable entry from the next and previous ones.
Reboot your machine.
USB Driver installation (Optional if you already have your driver software pre-installed).
The first step will be to download the USB drivers. To do this, launch SDK Manager from the SDK(android) folder and click on ‘Available packages’ in the left pane.
Expand ‘Third party Add-ons’ followed by ‘Google Inc. add-ons’ and check ‘Google Usb Driver package’,
Click ‘Install Selected’ and in the window that pops up, click the ‘Accept all’radio button followed by the ‘Install’ button. After the installations completed. The drivers for both 32 bit and 64 bit systems will now be present in the SDK(C:\android) folder under ‘usb_driver\x86′ and ‘usb_driver\x64′ sub-folders respectively.
Now, on the device(your mobile) go to Menu, select Settings > Applications > Development and enable USB Debugging.
Manually browse to the location of the driver and select whether it’s x64 or x86 depending on your OS version and click OK then Next. Now open Device manager and manually install the driver.
Once drivers have installed, you can verify successful installation by going to Device Manager. Your phone should be showing under ‘ADB Interface’, like the below screenshot.
Now, all the settings has been done. So, now it’s time to verify your ADB is working properly.
Open Command prompt by pressing WinKey+R > type “cmd” > type” adb devices “.
Now, it should list your android devices with the serial ID as shown.