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.