[FIX]Fix external SD Card permissions (updated 2012-02-05)

NOTE: Please see the following post for the original modification (as far as I'm aware) and the manual method of doing the same thing: http://xdaforums.com/showpost.php?p=20869996&postcount=7

This "update.zip" style installer simply automates the process of modifying /system/etc/permissions/platform.xml to make the tablet permissions act the same as previous versions of android.

In particular, programs with the WRITE_EXTERNAL_STORAGE permission will be able to write to the removable storage card. (Honeycomb changes this to require WRITE_MEDIA_STORAGE which very few, if any, 3rd party programs use.)

If you are having issues with programs writing to your storage card, this might fix it.

This uses 'sed' to make the edits. If this is installed twice, it won't re-modifying the file. (However, if you have manually edited the platform.xml file, and then run this script, it might make create duplicate, but harmless, <group> entries. Before making the modification to platform.xml, it will create a backup of the file (called platform.xml.backup) in the /system/etc/permissions directory (if the backup doesn't already exist.)

Instructions:

Download the file, and place on your sdcard. Reboot into recovery and install .zip from sdcard. Choose this file. Done..

(I've tested this with my CWM based recovery and it works. It _should_ work with the factory recovery as well, but I haven't tested... Please reply with your results.)

Support:

None. If you aren't familiar with using recovery to install updates, you should research the topic before continuing.

More info:

If you are curious, here is the sed command I'm sending, using busybox compiled from the cyanogenmod sources: What that means is: do an "in-place" edit on /system/etc/permissions/platform.xml, and find the line containing "WRITE_EXTERNAL_STORAGE >", then if the next line contains some whitespace followed by "<group gid="sdcard_rw" />", replace that sdcard_rw line with two new lines, the first being "<group gid="media_rw" />" and the second being the exact line that contained "sdcard_rw". I purposely put the media_rw line before the sdcard_rw line to prevent this same sed command from finding the same match again. In other words, if you run this sed command 50 times on the same file, it'll only make the change the first time.

(I'm not fluent with sed, so if someone knows a better way to do that, please feel free to educate me.)

File is attached below...

UPDATED Feb 5th, 2012: the script will change the filesystem permissions of the platform.xml file before attempting to edit it. This MAY overcome issues people have been having with non-rooted devices, but I'm unable to test so I don't know. Okay, well, it appears that this won't work for a device that doesn't have CWM Recovery installed. Not sure why, but at least I've repeated it.


Take care
Gary

ringnutz said:

I assume this is for the 6210, but will it work for all versions?

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Click to collapse

It should, but I have no way to test. I can tell you that it won't cause any harm. Go ahead and install it, and then (using adb or a file explorer tool) copy the /system/etc/permissions/platform.xml (and platform.xml.backup) files and compare them (or send them to me and I'll compare them) to verify.

pacmanftw said:

Sweet, thinking about flashing this. Will it work on non-root systems?

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Click to collapse

It should, but I haven't tested it. It shouldn't cause any harm, however, so feel free to try it.

Brightxda said:

It does not work on non-root P6210.

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Click to collapse

That doesn't make sense. What leads you to believe that it didn't work? Which program/option isn't working how you expect (and how do you expect it to work?) (sorry for all the questions, but if I can't repeat exactly what you are experiencing, I can't really help you.)

Do you have some kind of file explorer installed? If so, please browse to /system/etc/permissions and view the "platform.xml" file. Scroll down to find the line with "WRITE_EXTERNAL_STORAGE". There should be two lines below that that start with "<group gid". One should have the string "media_rw" and the other "sdcard_rw". If so, then the fix DID apply properly.

"root" shouldn't matter for this...

Okay, if the attributes of the file aren't allowing writing, then I'm obviously not allowing for that in the package. It seemed like a reasonable assumption that the file was writable, being that it worked for so many people...

I wonder why samsung isn't being consistant with the file permissions. Well, that's something I can probably fix in an update. Not a big deal to change perms on a file.

(It's also not a high priority, as this is working for the majority of people without me tinkering with file permissions.)

take care
Gary