android improve internal storage

You need to change the layout of the device

You need to build a specific rom and a specific recovery to adopt the sdcard

What do the specific rom and specific recovery means ?

Let me start by how android manages storage

As per kitakat the storage is determined by the fstab and the storage-list.xml

This define what blocks should be used for what purpose more specifically they determine the partition

To adopt the storage

• You need to build a new rom with modified fstab and
  
  storage-list.xml (till lollipop because android 6 uses only the
  
  fstab)




• Then build twrp (or any other recovery) with modified fstab and
  
  storage-list.xml




• Then flash twrp and wipe everything using advanced wipe a word of
  
  caution this will wipe your sdcard

Enjoy