Make persistent changes to init.rc

Question

I want to change the init.rc file of an android pad. But after I change it and reboot the system, the original init.rc comes back.

How can

Answer 1

Please note that it may be easier for you to use an app like Scripter to run a script at boot time than modify this file.

Before following @tripler's instructions above you need a file called boot.img which can be extracted by (run on rooted Android device, untested without root):

dd if=/dev/block/platform//by-name/boot of=/sdcard/boot.img

Then connect your Android to your computer and copy the boot.img file from there.

Script:

http://linuxclues.blogspot.ca/2012/11/split-bootimg-python-android.html

Here is a modified, easier to see version of tripler's instructions (assuming boot.img is in tmp):

cd /tmp
mkdir fs
# Now use the linked script above to split the boot.img file into ramdisk.gz and kernel
python split_boot_img.py -i boot.img -o parts
cd fs
gunzip -c ../parts/ramdisk.gz | cpio -id
# make changes to init.rc

At that point you will have to rebuild the boot.img back together before reflashing, which will be device-specific. Can't help you with that, sorry!