[HowTo] [for cooks] preload partition / how and why you should use it!

[eybee1970]

Hi folks,

an other very short tutorial for the people (cooks), who do not know how to use the preload (hidden) partition and symlink system apps to it.

Some basics on preload-partition and why you should use it:

We have the so called 'hidden/preload partition' (mmcblk0p12) on our device. Besides the system partition with around 840 mb space, this hidden partition has additional 500 mb...this 500 mb were thought from sammy in the beginning mainly for their own crap like gamehub apps or learning hub and so on. But as system partition is on the edge right now with jelly bean they also use it for placing system apps inside --> the reason is that 840 mb in system is far to less for all files!

Usually most cooks just transfered system apps to data partition (located on your usb storage) to get out of this mess. This method with using hidden partition just gives great opportunity to keep your system partition smaller and you can transfer apps to it which you can not move to data! Your device will probably also perform faster with less space used inside system-partition. Our kernel dev Phil also made it possible now to backup/restore preload-partition within nandroid on his newer CWM-recoveries --> so now you can do a full backup/restore including this preload-partition....before it was not possible!

How to symlink system-apps to preload-partition:

just take the app 'Notepad++' (google for it) on your PC/Laptop, open it, create a new file and put the following inside ('nameofapp.apk' is just an example for any app you wanna symlink):

Link: /preload/symlink/system/app/nameofapp.apk

save and close as 'nameofapp.apk' --> this is the one to put inside /system/app to symlink to the original one you put inside /preload/symlink/system/app.

Now do this steps with every system app you wanna symlink...

This is the manual way to this, though I know scripts can be used to do these steps automatically... But this way you at least get a basic understanding how it works!

I won't tell you how to push apps to preload-partition inside CWM-flashable ROM in general, cause this is basic knowledge when you wanna cook a ROM - but you could download any ROM already using this method and look inside 'META-INF\com\google\android\updater-script' and you will know how to do this.

 

[not-i]

Thanks for the guide mate. I'm sure this will help a lot of us out

 

[ThaiDai]

In dsixda's Kitchen the symlinks are automatically generated with a few lines of code in updater-script.
I'll will try to extract them when continuing to work with my Rom/Tutorial, so non-kitchen-builders can user it in their updater-scripts.

Have to say: it's very nice that you share your knowledge and experience with us, eybee. Thanks for that.

 

[bizmarck]

Thanks for the knowledge.
You're the man..

Sent from my GT-N7000 using Tapatalk 2

 

[maskerwsk]

Hey eybee. Nice guide.
One question. I'm using dsixda kitchen to build a rom but the zipaligning falls over when it reaches the nameofapk.apk text file. Anyway round this?

Sent from my GT-N7000 using xda premium

 

[ThaiDai]

Hey eybee. Nice guide.
One question. I'm using dsixda kitchen to build a rom but the zipaligning falls over when it reaches the nameofapk.apk text file. Anyway round this?

Sent from my GT-N7000 using xda premium

What do you mean by "nameofapk.apk"?
Maps.apk? (Then I know what you mean).

eybee won't give explanations for that because he doesn't use the kitchen.

 

[maskerwsk]

What do you mean by "nameofapk.apk"?
Maps.apk? (Then I know what you mean).

eybee won't give explanations for that because he doesn't use the kitchen.

yeah for example i moved MusicPlayer.apk to preload and created notepad++ file for MusicPlayer.apk which i put in system/app.

but when zipaligning apks in kitchen, when it reached the system/app/MusicPlayer.apk it fails

 

[eybee1970]

yeah for example i moved MusicPlayer.apk to preload and created notepad++ file for MusicPlayer.apk which i put in system/app.

but when zipaligning apks in kitchen, when it reached the system/app/MusicPlayer.apk it fails

of course i fails...you can not zipalign a symlink
just zipalign before, when all apps are still in /system/app and move to /preload afterwards

 

[ThaiDai]

of course i fails...you can not zipalign a symlink
just zipalign before, when all apps are still in /system/app and move to /preload afterwards

The problem is explained in the kitchen itself. You get a warning to move all apps first before de-odexing.
But I didn't get any mistake like this when zipaligning - I think the related script checks if there are symlinks. I move the apps before the de-odexing step in the Advanced options but not when zipaligning. So maybe he has some other problems.

 

[eybee1970]

The problem is explained in the kitchen itself. You get a warning to move all apps first before de-odexing.
But I didn't get any mistake like this when zipaligning - I think the related script checks if there are symlinks. I move the apps before the de-odexing step in the Advanced options but not when zipaligning. So maybe he has some other problems.

As explained: he is trying to zopalign the symlink in /system/app which of course fails (it is just a link named .apk!)...the original app he already moved to preload

 

[maskerwsk]

of course i fails...you can not zipalign a symlink
just zipalign before, when all apps are still in /system/app and move to /preload afterwards

Awesome. Thats what I was after

Sent from my GT-N7000 using xda premium

 

[shoey63]

This is excellent! We can now take control of an extra 500mb that Samsung thought we would never have access to

Sent from my GT-N7000 using xda app-developers app

 

[eybee1970]

This is excellent! We can now take control of an extra 500mb that Samsung thought we would never have access to

Sent from my GT-N7000 using xda app-developers app

this partition is well known since Galaxy S2 (paulobrien was talking about it back in Aug 2011)....but was not really needed til now

 

[Robbie Hood]

As explained: he is trying to zopalign the symlink in /system/app which of course fails (it is just a link named .apk!)...the original app he already moved to preload

Using a simple more powerfull line in update script

symlink("/preload/symlink/system/app", "/system/app");

this symlinks the whole folder to system/app so all that is in preload is also visible and active in a linked system/app folder.

This removes the whole functionality of the /system/app folder though but you have a very fast and clean system saves a lot of typing/ copypasting though

 

[eybee1970]

Using a simple more powerfull line in update script

symlink("/preload/symlink/system/app", "/system/app");

this symlinks the whole folder to system/app so all that is in preload is also visible and active in a linked system/app folder.

This removes the whole functionality of the /system/app folder though but you have a very fast and clean system

yes, I saw in your script already

 

[Robbie Hood]

yes, I saw in your script already

Always finding ways to improve :highfive:
So there is NO /system/app folder in my rom

 

[shoey63]

@RobbieHood. How would you do in user space? Using linux commands in terminal for example?

Sent from my GT-N7000 using xda app-developers app

 

[eybee1970]

Always finding ways to improve :highfive:
So there is NO /system/app folder in my rom

for all: but there will be one after installation, but just containing symlinks...

 

[Robbie Hood]

for all: but there will be one after installation, but just containing symlinks...

well not exactly
The folder is linked so when you open it via /system/app or any browser you are virtually in /preload/symlink/system/app with the real apks
its somewhat the same principle as the sdcard on galaxy s3 which is linked to /data/media and does not have its own partition

 

[eybee1970]

well not exactly
The folder is linked so when you open it via /system/app or any browser you are virtually in /preload/symlink/system/app with the real apks
its somewhat the same principle as the sdcard on galaxy s3 which is linked to /data/media and does not have its own partition

Ok...this is the correct way to say it
Just did not want anybody coming in here then and say "hey, when i open with Root Explorer i still can see /system/app and all apps inside..."