Install Custom ROM

gistfile1.txt

Special boot modes

    Recovery: With the device powered off, hold Volume Up + Power. Keep holding both buttons until the “MI” logo appears on the screen, then release.

    Download: With the device powered off, hold Volume Down + Power. Keep holding both buttons until the word “FASTBOOT” appears on the screen, then release.



Steps.

# Prerequisites

Install fastboot and adb.
You will need the platform-tools from the Android SDK on your computer.
http://developer.android.com/sdk/index.html#linux-bundle-size

# Unlocking the bootloader

Note: The steps below only need to be run once per device.

See brand official unlocking site.

Developer Options = On / OEM Locking = On / USB Debugging = On
On your device, go into Settings -> About and find the Build Number and tap on it 7 times to enable developer settings. Press back and go into Developer Options and enable USB debugging. From your computer, open a command prompt and type:

adb reboot bootloader

You should now be in fastboot mode.

# Installing a custom recovery 


Popular custom revovery tool: TWRP. Download: <recovery_filename>.img

adb reboot bootloader
fastboot devices
sudo fastboot flash recovery <recovery_filename>.img
sudo fastboot reboot

Sometimes recovery is persistent:

sudo fastboot flash antirbpass dummy.img 
fastboot format userdata


#Installing custom ROM from recovery

From custom recovery: Wipe and Format Data, Select Cache and System partitions and Swipe to Wipe

Method 1: SIDELOADING

Sideload the <custom-rom-package>.zip

From custom recovery Advanced > ADB Sideload
From command line: 
adb sideload <custom-rom-package>.zip
adb sideload <open_gapps-arm64-9.0-nano-xxx.zip>
adb sideload <addonsu-15.1-arm64-signed.zip>

Method 2: PUSHING

adb push <custom-rom-package>.zip /sdcard/
adb push open_gapps-arm64-9.0-pico-xxx.zip /sdcard/
adb push addonsu-15.1-arm64-signed.zip /sdcard/