Update README

README.md

@@ -2,7 +2,7 @@
 
 This repository contains the instructions and configuration to build a SD image with a bigger /boot partition size and my SSH public keys
 
-## Usage
+## Building
 
 1. Enable QEMU on the host machine by adding the following option
 
@@ -15,3 +15,17 @@ boot.binfmt.emulatedSystems = [ "aarch64-linux" ];
 ```{bash}
 nix-build '<nixpkgs/nixos>' -A config.system.build.sdImage -I nixos-config=./sd-image.nix --argstr system aarch64-linux
 ```
+
+## Usage
+
+1. Extract the image
+
+```{bash}
+nix-shell -p zstd --run "unzstd rp4-image.img.zst"
+```
+
+2. Burn it to an SD card
+
+``` bash
+sudo dd if=rp4-image.img of=/dev/mmcblk0 bs=1M status=progress conv=fsync
+```