This post is for some background knowledge and preparation for tinkering my OnePlus 6. In the end, my OnePlus 6 would be dual-booting both Android 15 (LineageOS 22 on slot A) and PostmarketOS (on slot B). Preparation On the computer You will need a computer with fastboot tools(SDK platform tools). This can be obtained by installing the android-tools package on Linux or by installing the Android SDK Platform-Tools on Windows, Mac (or …