update.zip just for fixing file permissions, possible? I soft bricked my colorfly g808 by following this guide (Japanese)

http://bl.oov.ch/2012/12/android-421-mvno-sim.html

I didnt do it using adb shell but using a terminal emulator in the phone itself, so I don't have ADB debug mode enabled.

the file in question is 

/data/resource-cache/vendor@overlay@framework@framework-res.apk@idmap

I need to set its permissions to "644"

I have access to adb sideload by pressing the volume key while booting while connected by USB. 

I tried several tutorials for making a custom updater-script but I always get the message "Installation aborted." when I try to install it. I tried signed and unsigned, by the way. 

Is it possible at all to create an update.zip for just setting a permission on a file? do I need an "update-binary" also present? (I tried including one from here http://pan.baidu.com/share/link?shareid=92493&amp;uk=252038779  which I thought was targeted for my device)

My android version is 4.2.2... I think..

What I see in the computer:

$ adb sideload update-signed.zip 
loading: 'update-signed.zip'
sending: 'update-signed.zip'  100%  


What I see in the device:

Now send the package you want to apply 
to the device with "adb sideload &lt;filename&gt;"...
Installation aborted.


The "Installation aborted" appears right after I send the file. It looks like it doesn't even try to analyze it.
I tried simplifying the script using just 

ui_print("Next time don't forget to enable debug mode before playing with fire!");
sleep(5);


(I'm taking care of leaving an empty line at the end also...)

The zip file I'm using:
http://s000.tinyupload.com/index.php?file_id=79008422714753153826

Another trial:
http://s000.tinyupload.com/index.php?file_id=00027545588116868142
Sure. Just put it in the updater-script which is usually located in META-INF/com/google/android/updater-script

Make sure your script mounts the data partition and executes something like this:

set_perm(0, 0, 0644, "/data/resource-cache/vendor@overlay@framework@framework-res.apk@idmap");

Not sure if the @ chars are not causing trouble in recovery though.

And yes, you need updater-script etc. in there.