There had been many scenarios where I wished if mobile phone could be used as a development machine. Scenarios such as quick SSHing to servers or pushing a hotfix to Github while on the roads, testing out a snippet which just popped in mind while jogging, etc.

I tried to make Nexus 5 as a pocket development machine. I was able to set it up, but with some limitations. Here is what all I did:

TWRP Installation

1. Connect phone to laptop via USB. Verify by listing connected devices:

   $ adb devices
   

2. Reboot phone to bootloader screen:

   $ adb reboot bootloader
   

3. Flash TWRP image for Nexus 5:

   $ fastboot devices
   $ fastboot oem unlock
   $ fastboot flash recovery twrp-3.2.3-0-hammerhead.img
   

4. Now, from bootloader screen, reboot in recovery mode. This would load TWRP app.

Lineage OS

Sideload Lineage OS & gapps files:

• Lineage OS 15.1 can be downloaded from XDA - unofficial build. (Current official build is 14.1)
• For Nexus 5 GApps, I downloaded ARM 8.1 pico package.

(Optionally you can wipe existing data from TWRP’s Wipe option.)

$ adb sideload lineage-15.1-20180923-UNOFFICIAL-hammerhead.zip
$ adb sideload open_gapps-arm-8.1-pico-20190312.zip

Then reboot the system. You’ll have to go through OS initial setup process.

SU Addon for root access

1. Download su addon arm 15.1 and copy to phone.

   $ adb push addonsu-15.1-arm-signed.zip /sdcard
   

2. Reboot in recovery mode to go to TWRP app, Install > select addonsu-15.1-arm-signed.zip

After that reboot the system. Lineage OS with root access is ready now!

Part B: Development Setup

There are many terminal apps available in Google Playstore. I chose Termux, which has powerful terminal emulation with essential Linux package collection.

The default location of Termux’s bash is /data/data/com.termux/files/home.

Few basic commands:

$ pkg search <term>
$ pkg show <packages>

$ pkg list-all
$ pkg list-installed

$ pkg install <packages>
$ pkg reinstall <packages>
$ pkg uninstall <packages>

$ apt list --upgradable
$ pkg upgrade

$ pkg help

1. Text Editor

pkg search editor can help you to get a glimpse of available editors in termux package repo.

vim, nano, emacs are few choices.

$ pkg install -y vim

2. Git

Install git:

$ pkg install -y git

Github setup:

Add public key to your Github account.

$ pkg install -y hub
$ git config --global user.email "<email>"
$ git config --global user.name "<username>"

3. zsh

1. Installation:

   $ pkg install -y zsh
   

2. oh-my-zsh:

   $ git clone git://github.com/robbyrussell/oh-my-zsh.git $HOME/.oh-my-zsh --depth 1
   $ cp $HOME/.oh-my-zsh/templates/zshrc.zsh-template $HOME/.zshrc
   

   Create $HOME/.termux folder & add the following files for theme customization:

   $HOME/.termux/colors.properties - example

   $HOME/.termux/font.ttf example

   
   

3. Restart Termux to make zsh as default shell.

   $ chsh -s zsh
   $ exit
   

4. SSH

$ pkg install -y openssh
$ ssh-keygen -t rsa -b 4096 -C "<email>"

Connect to remote servers from phone:

$ ssh [email protected]

SSH into phone:

1. Start SSH server daemon in phone:

   $ sshd
   

2. Password SSHing is difficult, add your public key to ~/.ssh/authorized_keys file.

3. Then, from any other device:

   $ ssh -p 8022 <IP_address_of_phone>
   

4. Stop SSH daemon:

   $ pkill sshd
   

5. Programming languages

Language packages such as clang, python, nodejs, ruby, golang, rust, erlang, lua, perl, etc. are available.

Now we can clone any repo, edit in vim & commit to Github, SSH to a remote server and do a quick snippet compilation. Pretty much what all I needed 🎉

Limitations:

• Since Termux has access to only /data/data/com.termux, we can’t create our projects/ folder outside of that location.
• Since project files are in app specific location, we can’t use any code editor apps such as DroidEdit which is running outside of that user scope.
• su root shell can’t run termux packages directly.

A workaround for using termux packages in root shell is to export LD_LIBRARY_PATH pointing to termux’s /usr/lib/ and execute package binaries by specifying path:

$ export LD_LIBRARY_PATH=/data/data/com.termux/files/usr/lib/

$ /data/data/com.termux/files/usr/bin/python --version
$ /data/data/com.termux/files/usr/bin/vim test.txt

If there is a way to solve these limitations, please let me know in comments.