[GUIDE] Update CM without losing custom /system changes (ex Swype, keymap)

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There's a really simple way to prevent CyanogenMod from overwriting your custom /system changes during an update. Create the file '/system/etc/custom_backup_list.txt' with a list of files within /system that you don't want to be overwritten.

For example, to prevent CM from wiping out Swype, open adb shell and type this:

mount -o remount,rw /system
cd /system/etc
echo lib/libSwypeCore.so >custom_backup_list.txt
echo app/Swype.apk >>custom_backup_list.txt
cd /
mount -o remount,ro /system

If you use teferi's custom keymap, do this:

mount -o remount,rw /system
cd /system/etc
echo lib/libSwypeCore.so >custom_backup_list.txt
echo app/Swype.apk >>custom_backup_list.txt
echo usr/keylayout/vision-keypad.kl >>custom_backup_list.txt
echo usr/keychars/vision-keypad.kcm.bin >>custom_backup_list.txt
cd /
mount -o remount,ro /system

Then the next time you flash CM, your changes to /system will still be there. If you want to see why this works, take a look at /system/bin/backuptool.sh

Hope this helps

Thanks! This is great; now I can easily keep my Email.apk that doesn't require me to enter a alphanumeric password every time I want to use the phone.

CM probably needs to overwrite build.prop but I've been changing the LCD density in this file. Is there a way to use a seperate file to override the lcd density so that i can let CM overwrite build.prop but still maintain lcd density after a flash?

Whatever commands you put in /data/local/userinit.sh will run at boot. So in adb shell, type this for a density of 215:

cd /data/local
echo setprop qemu.sf.lcd_density 215 >userinit.sh

awesome! thank you!

Don't suppose you would know how to get the CM update to not install/auto delete after installation apks like ADWLauncher and wifi calling?

Thank you!

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This may be the long lost solution to my Swype and Cyan Problems. The new Release Candidates are destroying my swype and not liking it's return after installing the new Cyan. So, if this can basically help me update without losing much, it's a god send. Especially the LCD density.

You're a genius.

Thank you.


Hmm, seems the issue is still persistent. Thanks though.

Should userinit.sh and custom_backup_list.txt survive the upgrade or should they both be included in the backup list file?

Sent from my HTC Vision using XDA App

If you look at the actual script, it seems that it ignores the backuptool if .installscript exists, and in practice, I've noticed that nothing gets saved when flashing via ROM Manager. Is this, in fact, what's happening, and is there a way around it?

Originally Posted by sundar2012

awesome! thank you!

Don't suppose you would know how to get the CM update to not install/auto delete after installation apks like ADWLauncher and wifi calling?

You can put the following in /data/local/userinit.sh:

mount -o rw,remount /system

for apk in ADWLauncher.apk MS-HTCVISION-KNT20-02.apk
do
rm -f /system/app/$apk
done

for package in com.android.launcher
do
pm uninstall $package
done

mount -o ro,remount /system
exit 0

I haven't tried this for removing the Wifi Calling app, so ymmv. I remove a much larger set of apps myself (facebook, email, live wallpapers, amazon mp3 store, DSPManager, FileManager, Browser). http://wiki.cyanogenmod.com/index.php?title=Barebones has a list of apps that can be removed safely.

@cparekh -- what e-mail app is that? Or did you just use the pre-OTA's Email.apk app?