These tutorial ar for them who know about rom porting!
Porting MiUi to mediatek.
You have to take MiUi rom compalitable with your Soc.
MT6577 to MT6575
MT6589 to MT6577
MT6582 to MT6572
Better is to port from the same SOc like MT6572 to MT6572
For porting MiUi,Lewa,Oppo
To port for MT6572 to MT6572 just copy and replace these files from your stock rom to port rom.
Done now decompile boot.img of your stock rom also the MiUi rom you are porting !
Now copy and replace int.rc to stock boot.img ramdisk folder from ramdisk folder of MiUi boot.img after decompiling.
You have to change the mount point of updater script of the rom you are porting.
Open updater script of port rom find these lines
format("ext4", "EMMC", "/dev/block/mmcblk0p5", "0");
mount("ext4", "EMMC", "/dev/block/mmcblk0p5", "/system");
Now change the mmcblkop_ with your phones partition.
To know about your phones mount point download partition table from google play!(system,data,each does not have the same mount point)
Done now again zip your rom and flash.
To port MiUi,Lewa,Oppo from different chip mentioned above and MT6582 to MT6582,MT6589 to MT6589
Copy and replace these files from stock rom to port rom
Now do the same work to boot.img and updater script ! Now zip your rom and flash!