[Without PC] Unpack, Edit, Repack boot.img

Thanks bigsupersquid for all your support.
From the beginning I said I must have to share my work with interested so they can help me as especially that is the first version of this the apk already as was the case.
Then I will thread it and I think to make it open source because I believe that work under Linux must be OPEN SOURCE.

---------- Post added at 09:03 PM ---------- Previous post was at 09:02 PM ----------

Sorry for my English

You are too hasty , not easy work program overnight , just be passiont , these are some screenshots for you my prince

Well, I don't know the specifics of your device but you definitely need an unlocked bootloader and S-Off. Then you need to figure out the sizes of your system, data and cache partitions (you can use "Partition Table" from the Play Store). Create three additional partitions at the end of your SD card with the sizes you found. You can either use AParted on your phone or MiniTool and a card adapter on your PC . The partitions must be all primary and formatted to ext3 or ext4 depending on what your kernel supports. Then you have to unzip the ROM file you want to install, find the updater-script and edit all lines that contain mmcblk0px (where x is your system partition number) to mmcblk1p2 (your SD system partition). You also need to unpack the boot.img, find the fstab.nick in the ramdisk (nick is the nickname of your device) and edit the sysyem, data and cache mountpoints to /dev/block/mmcblk1p2, 3 and 4 accordingly. Pack and zip everything back and reboot to recovery (if you need to flash GApps, then you must also modify that zip first). Make a backup of your current ROM and flash your modified zip(s). When you reboot, your device should load your secondary ROM. To switch back to the primary you need to reflash your primary kernel (from the backup you took). Use dd if=path/backup.boot.img of=/dev/block/mmcblk0px (where x is your boot partition) and reboot. To boot back to your secondary ROM, just use the above command to flash the boot.img extracted from your modified ROM.zip.
This should theoretically work on any device with any ROM as primary and a Jellybean or above ROM as secondary. All I have done is to automate the editing of zips so that they can be directly flashed.

PS: Sorry for the long off-topic but it is directly related to your work.

Sent from the 3rd dimension!

Hi again, I recently opened a new thread that explains Dual-Boot in more detail. I believe you'll find it interesting.

Sent from the 3rd dimension!

Well, i start a new tread and I would like everyone to participate.
http://xdaforums.com//android/software/utility-android-image-kitchen-flasher-t3339856/post65916523