= Modify Internal SDcard storage to External SDcard =

The Samsung Galaxy XCover2 (S7710) has only roughly 500MB left on emulated internal storage which is not enough these days if you like to install a lot of applications. There are many tricks around to move data/cache/applications to the external SD card, but all of them has it quirks. Since large SDcard these days are fast and cheap enough having I think this could be done better, by simply discarding the internal /data storage and use an sdcard partition instead.

= Requirements =
* Linux envirionment with compiler tools
* split-bootimg.pl found ar [[http://www.enck.org/tools.html]]
* Android Tools mkbootfs mkbootimg (optional simg2img)
* Android SDK Environment
* Heimdall [[http://glassechidna.com.au/heimdall/]]
* Stock S7710 firmware [[http://live.samsung-updates.com/index.php?device=GT-S7710]]


What I will do is modify the {{{/fstab.samsungskomer}}} to change the mount of the ext4 {{{/data}}} of the internal location {{{/dev/block/mmcblk0p25}}} to the second partition of the external SDCard {{{/dev/block/mmcblk1p2}}}. Technically speaking you do not even need to root your device, but by flashing firmware you will need to do some pretty advanced stuff.

= Steps =

== Format SD Card ==
Format 32GB class 10 or higher SDcard with two partitions:

1. 20GB vfat partition, this will serve as the normal extSdCard
2. 12GB ext4 partition, this will serve as the new /data partition (make sure it is the second and last partition)


== Compile Android Tools ==
{{{
 $ git clone https://android.googlesource.com/platform/system/core
 $ cd core
 $ git checkout android-4.2.1_r1

 $ cd libmincrypt
 $ gcc -c *.c -I../include
 $ ar rcs libmincrypt.a *.o
 $ cd ../mkbootimg
 $ gcc mkbootimg.c -o mkbootimg -I../include ../libmincrypt/libmincrypt.a

 $ cd ../mkbootfs
 $ gcc mkbootfs.c  -o mkbootfs -I../include


 $ cd ../libsparse
 $ gcc -o simg2img -Iinclude -lz simg2img.c sparse_crc32.c backed_block.c output_file.c sparse.c sparse_err.c sparse_read.c
}}}
== Modify stock kernel ==
I assume you have a stock kernel laying around if not download it from the links below.

{{{
 $ ./split_bootimg.pl boot.img

 $ mkdir ramdisk; cd ramdisk
 $ gzip -dc ../boot.img-ramdisk.gz | cpio -i

 # Alter {{{ fstab.samsungskomer }}} and change /data mountpoint from {{{/dev/block/mmcblk0p25}}} to {{{/dev/block/mmcblk1p2}}} 
 $ vim fstab.samsungskomer

 $ cd ..
 $ mkbootfs ./ramdisk | gzip > ramdisk-new.gz
 $ mkbootimg --cmdline 'no_console_suspend=1 console=null' \
  	    --kernel boot.img-kernel \
	    --ramdisk ramdisk-new.gz \
            -o boot-new.img
}}}
== Upload kernel ==
1. Put device in download mode (VolumeDown+Home+Power) on power-on.
1. $ sudo heimdall flash --pit S7710.pit --Kernel ./boot-new.img # FYI: Pit file retrieval below

== Enjoy your new device ==
The phone will need to be rebooted a few times and it will be complaining about corruption and encryption, just go will the flow and acknowledge the notifications. Ones completed enjoy your improved Samsung Galaxy XCover 2 (S7710).


= Misc =
== Retrieve PIT file ==
1. Put device in download mode (VolumeDown+Home+Power) on power-on.
1. $ sudo heimdall download-pit --output S7710.pit
1. Reboot device to perform other heimdall actions as other actions will fail after this.

= References = 
* Heimdall 1.3.1 is NOT working, make sure to use a higher version.
* Disable power on by home key: [[http://forum.xda-developers.com/showthread.php?t=2204889&page=15]]
* Rooting guide hints (windows only): [[http://forum.xda-developers.com/showpost.php?p=40232503&postcount=45]]
* Compile simg2img and make_ext4fs [[http://muzso.hu/2012/08/10/how-to-pack-and-unpack-system.img-and-userdata.img-from-an-android-factory-image]]