Files and instructions for unattended/automatic setup of a Raspberry Pi using only the boot partition which you can see on a flashed SD card on windows.
This project borrows quite heavily from Jim Danner on GitLab: https://gitlab.com/JimDanner/pi-boot-script/-/tree/master
I could never get his version working properly, I made a lot of changes and wanted to share them here.
init=/bin/bash -c "mount -t proc proc /proc; mount -t sysfs sys /sys; mount /boot; source /boot/unattended"
Tested on Rpi4 and Pi Zero W With Raspberry Pi OS - Release date: May 7th 2021