[Galaxy Note 4 General] ananjaser1211:
Dualboot patcher 101

Device : Galaxy Note 4

Difficulty level : Easy

This is a full guide to understand and use Dualboot Patcher App
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Download latest app snapshot from : Noobdev

Files » DualBootPatcherAndroid-9.1.0.r80.gd5920b2-snapshot.apk

Latest as of Jan 8 2017

Install it like a normal apk

Dualbooting begins here ---

Main things to do are

Setup Dualboot boot enviroment

Setup Dualboot files

Flashing

Switch between roms

App sharing

Part 1

Setting up for first time use

-Open dualboot patcher app and do the following

-Go to Roms tab then click the 3 dot menu on "Primary"

-Press Set Kernel {if it didnt ask you at the beginning}

-Then press "Update RamDisk"

Part 2

Patching Files for dualboot

-Download the rom you want to dualboot / any mods for it / xposed or whatever flashableZIP you want to install on your secondary rom

-Go to "Patch Zip File" Press the + and click "Add Flashable Zip"

-Select your ROM Zip

-Select your Device (Trelte For exynos or Trlte For Snapdragon)

-Select "Data slot" in Partition Configuration

-The ID is your parition name , basicly SAME ID for zips = Same flash location, Type rom1 for example [No caps]

-Do the same for any other zips (making sure the ID is the excat same)

Part 3

Flashing

Once you are done patching files , you will end up with a duplicate collection of your original files, but they end with _data-slot-[ID].zip suffix

-Grab those files and go flash them in your recovery

-in the recovery screen you will see [Multiboot] prefix behind most scripts, that means you are flashing a patched zip

-Once you are done flashing just hit reboot from the recovery

Part 4

Switching

You will be greated with your new rom , do the first setup and you are now running your secondary rom

Now, to switch roms do the following

-Install your dualboot patcher app on your secondary rom

-Open it and go to "Roms" Section

-Suprise, you will see Primary and below it [ID] (Data Slot)

-Press the primary and reboot , thats it

Part 5

App Sharing

Lets say you want your app data to be available on all your roms , Whatsapp data , telegram data , game data etc

-Open the app on your primary rom , go to "App Sharing" Section and enable " Share Individual applications"

-Press "manage shared applications"

-Click on an app "whatsapp for example"

-Tick "Use shared data"

-Hit ok then Then go back after selecting all your apps

-It must show a toast saying "The changes will take effect next reboot"

-Reboot your device to the secondary rom and do the same thing for the same apps

App data is now shared across both roms,

F.A.Q please read before attempting this

1- Faild to set kernel due to unrecognized device

-Common issue with custom roms, you can fix it by editing your Buid.prop , changing device name , code etc and ro.patcher

2- Flashing files via recovery , will it affect my primary rom ?

- No , all the files are directed to your new rom enviroment , the only things that can affect dualboot is kernel changes

3- How to change primary / secondary kernel ?

-To change primary , just flash the new kernel , then follow " Part 1 " of the guide again

-To Change Secondary , Follow " Part 2 " of the guide to patch the Kernel zip then flash in recovery

4- Where are the files located ?

-your secondary system can be found under /data/multiboot/data-slot[ID]/System (only seen when you are using primary rom or Recovery file manager)

-Your shared app data can be found under /data/multiboot/_Appsharing

5- Enabling app sharing, my data for the app is gone.

-When you enable app sharing it changes the data location, so whatever data you had need to be moved with it, best thing to do is to backup the app you want to share with titaniumbackup (before enabling shared data for it) then restore it when you enable data sharing and rebooting

6- How many roms can i "dualboot"

-As much as you like aslong as you have storage in your data partition i had 4 roms dualbooted at one point

7- How much storage does it consume ?

-CM roms are usually around 1GB for system + few GBs for data (total of 3GB-4GB For normal user with some apps)

-TW roms are heavier around 2-3GB for system (most bloated AF roms) and same for data

8- My secondary rom broke due to a mod or something, how can i switch roms in recovery ?

-Download dualboot utilites

-Files » Utilities : DualBootUtilities-9.1.0.r80.gd5920b2.zip

-Flash in recovery and it will give you an aroma installer enviroment to select your roms

9- Switch roms without aroma

-In TWRP select flash IMG option instead of zip

-Navigate to /internalmem/Multiboot/[ID]/boot.img

-select flash boot

-swipe to flash then reboot

10- Can i install a rom with aroma installer ?

-Yes , just make sure that the aroma does NOT reboot your device after completion as the dualboot script needs to run after the rom script is done to set the new kernel etc

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Hope this helps whoever wants to use this app , its very simple ,it might look complicated but its easy, GL and have fun

This guide can be used for other devices , Dont forget to hit thanks and reply if it helped.

All thanks for the original devoloper and poster [MENTION=6083514]Anik_khan[/MENTION]