Posted by The Samsung Galaxy SIII, also called i9300 is a phone released in 2012. It has 4 cores, 1GB of memory, 16GB for the local storage and a Micro SD card reader. This tutorial will also work for the other phones, the main difference will be for Kernel dependent software (like Docker).
Material
Cables
You will need a charger, my official one is 1.5A. Unfortunately I haven’t found any easy way to use the micro-USB port both for charging and connecting devices. A possibility could be to use a Qi module but I don’t recommend it because of the bad thermal dissipation and the higher electrical consumption.
Internet access
We will need a WiFi router connected to Internet.
System
We will use PostmarketOS, a GNU/Linux distribution based on Alpine Linux. You can follow the tutorial from the official website. On my side, I have used the Micro SD card to install the system to don’t use too much the internal NAND. I also recommend you to compile using the armv7 architecture instead of the default armhf choice. We will use the edge channel to get more recent software and disable the graphical interface.
pmbootstrap init
#work path default
#edge
#samsung
#i9305
#y
#yourusername
#none
#n
#none
#y
#yourfuturehostname
#y
#Run now the armv7 script
pmbootstrap install --no-fde --sdcard=/dev/mmcblk0
#Plug the card and restart your phone in download mode
pmbootstrap flasher flash_kernel
#It will reboot and display "Loading..." on the screenYou can now connect to your device using ssh
ssh yourusername@172.16.42.1Services
WiFi
Use nmcli to connect to your WiFi
sudo nmcli device wifi list ifname wlan0
sudo nmcli --ask dev wifi connect YOURSSIDContainers
Unfortunately because of the old 3.0 kernel, Docker and LXC won’t start on our device.
Conclusion
Our Galaxy SIII is now alive, with Alpine Linux. Except the kernel problem, I think it’s quite interesting. Our server is able to run basic/light services and has a battery to prevent electricity cut.