Install Lineage OS on Asus Zenfone Selfie: a slim guide.

Asus Zenfone Selfie (Build Number. ZD551KL)is a budget smart phone priced below INR 12000. The default Android version is Lollipop with Zen UI. Zenfone Selfie can give good performance, if we install custom ROM.  Lineage OS is the leading custom ROM project and it offers official build for Zenfone Selfie. User can install Lineage OS over default Android. Lineage OS can improve the performance of Zenfone Selfie.

Necessary skill set
Basic knowledge on adb and fastboot, TWRP custom recovery installation, flash packages from TWRP. Finally you need the confidence to take the risk of unbrick phone (Void warranty)!!.

[I will not be responsible to what happens to your device while trying following steps.]


Download
Following are the necessary packages to download before the installation process. Copy the downloaded packages to the external storage (SD Card) of your phone:

Marshmallow firmware
Lineage OS
Open GAAps (ARM64) Pico
su (arm64)

Steps to follow
Links along with each step leads to concerned instructions in Lineage OS wiki.

1. Unlock Asus Zenfone Selfie.
2. Install adb and fastboot.
3. Install TWRP custom recovery.
3. Flash the Marshmallow firmware using TWRP recovery [Very important]
4. Install Lineage OS, OpenGAAps and su add-on from TWRP recovery.
5. Restart phone.

Note
How to enter recovery mode of Zenfone Selfie?
Power Off phone.
Long press Power button+Volume down button.

References
https://forum.xda-developers.com/zenfone-2-laser/orig-development/rom-cyanogenmod-13-0-t3317515/page225

http://wiki.lineageos.org/Z00T_info.html#build-guide

Screen brightness problem with Acer ES1-131 and Debian 8 (Jessie)

I installed Debian 8 (Jessie) XFCE and LXDE desktop on Acer ES1-131 Netbook. I could successfully installed Debian. But problem is that, not able reduce the brightness of screen. Short cut key for brightness control not working.

The real problem with the Linux kernel. Default kernel version could not identify the Intel driver. You can find that /sys/class/backlight will be empty. Brightness control folder and files should be reside here.

How to solve it?
Solution is that upgrade the kernel of Debian.

Enable sudo in Debian

Sudo is a tool default with Ubuntu, which allows users to execute administrative tasks (e.g. installation, remove etc). sudo is not available with Debian default. Ubuntu user may feel difficult while work with Debian without sudo. User has to install sudo tool first.

Open terminal and apply following commands,

su
apt-get install sudo
adduser username sudo


Logout from desktop.
Login again.

Install Linux ISO file in a USB stick

Its easy to write ISO file to USB pen drive. This process erase all data in your USB drive.

Copy Linux iso file in home folder.
Open a terminal and become root user and apply following commands,
  
cat debian.iso > /dev/sdb; sync

Disable Grub2 theme in Ubuntu MATE

Gurb 2 has GUI theme.

It may lag the boot time. User can remove it to get back legacy Grub theme.
Apply following command to remove Grub 2 theme.

sudo apt-get remove grub2-themes-ubuntu-mate

Then update Grub

update-grub