Posted by The Samsung Galaxy SIII (code name: i9300), is a smartphone released in 2012. It has 4 cores, 1GB of memory and 16GB of storage. PostmarketOS is a GNU/Linux distribution mobile oriented, based on Alpine Linux. This tutorial has been tested only on the i9300 device but should also work on i9305 and samsung-shv-e210s.
The tutorial on PostmarketOS‘s website is really good, but using armhf even if the i9300 is compatible with armv7. This modification will allow us to use all the specificity of its CPU and software like Plasma Mobile. Follow the official tutorial and run the following script after “pmbootstrap init”.
cd ~/.local/var/pmbootstrap/cache_git/pmaports
cp device/testing/linux-samsung-i9305/config-samsung-i9305.armhf device/testing/linux-samsung-i9305/config-samsung-i9305.armv7
OLD=$(sha512sum device/testing/device-samsung-i9305/deviceinfo | cut -d" " -f1)
sed -i 's/armhf/armv7/g' device/testing/device-samsung-i9305/* firmware/firmware-samsung-i9305/APKBUILD device/testing/linux-samsung-i9305/APKBUILD
NEW=$(sha512sum device/testing/device-samsung-i9305/deviceinfo | cut -d" " -f1)
sed -i "s/${OLD}/${NEW}/g" device/testing/device-samsung-i9305/APKBUILD
You can now continue the tutorial and build PostmarketOS for the i9300 using the armv7 architecture.