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nix-configs/configuration-pi4b.nix

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+{ config, pkgs, lib, ... }:
+
+{
+ # This configuration worked on 08-20-2022 nixos-unstable
+ # The image used https://hydra.nixos.org/build/188033711
+
+  boot = {
+    kernelPackages = pkgs.linuxPackages_rpi4;
+    tmpOnTmpfs = true;
+    initrd.availableKernelModules = [ "usbhid" "usb_storage" ];
+    # ttyAMA0 is the serial console broken out to the GPIO
+    kernelParams = [
+        "8250.nr_uarts=1"
+        "console=ttyAMA0,115200"
+        "console=tty1"
+        # A lot GUI programs need this, nearly all wayland applications
+        "cma=128M"
+    ];
+  };
+
+  boot.loader.raspberryPi = {
+    enable = true;
+    version = 4;
+  };
+  boot.loader.grub.enable = false;
+
+  # Required for the Wireless firmware
+  hardware.enableRedistributableFirmware = true;
+
+  networking = {
+    hostName = "nixos-raspi-4"; # Define your hostname.
+    networkmanager = {
+      enable = true;
+    };
+  };
+
+  nix = {
+    autoOptimiseStore = true;
+    gc = {
+      automatic = true;
+      dates = "weekly";
+      options = "--delete-older-than 30d";
+    };
+    # Free up to 1GiB whenever there is less than 100MiB left.
+    extraOptions = ''
+      min-free = ${toString (100 * 1024 * 1024)}
+      max-free = ${toString (1024 * 1024 * 1024)}
+    '';
+  };
+  system.stateVersion = "20.09";
+}