README: document how to install for raspberry pi

README.md

@@ -36,6 +36,23 @@ This repo is managed with Nix + GNU stow
   # profit
   ```
 
+## Installation for Raspberry Pi
+Raspberry Pi uses the same configuration as the installer.
+The `(modulesPath + "/installer/sd-card/sd-image-aarch64.nix")` allows this.
+
+- Build the image `nixosConfigurations.<name>.config.system.build.sdImage`.
+  Disable stuff like Lix to build this.
+  You might want to use raw password once so you don't have agenix decryption
+  problem while trying to have wpa_supplicant have the right passwords.
+
+- Burn the image to the sd card.
+  ```bash
+  zstdcat result/sd-image/nixos-image-sd-card-<hash>-aarch64-linux.img.zst |
+        doas dd of=/dev/sdb status=progress
+  ```
+
+- profit
+
 # Pitfalls
 ## `users.mutableUsers`
 NEVER set this to true without declaratively setting the passwords.