move old nixos-config over here

common/base.nix

@@ -0,0 +1,42 @@
+{ pkgs, ... }:
+
+{
+  boot = {
+    loader.systemd-boot.enable = true;
+    loader.efi.canTouchEfiVariables = true;
+    kernelPackages = pkgs.linuxPackages_zen;
+  };
+
+  time.timeZone = "Europe/Stockholm";
+
+  environment.systemPackages = with pkgs; [
+    btrfs-progs
+    btrfs-snap
+    git
+    glibcLocales
+    qemu_kvm
+    qemu-utils
+    vim
+    zstd
+  ];
+
+  # Use fish, but not in /etc/passwd . See https://nixos.wiki/wiki/Fish#Setting_fish_as_your_shell
+  programs.bash = {
+    interactiveShellInit = ''
+      if [[ $(${pkgs.procps}/bin/ps --no-header --pid=$PPID --format=comm) != "fish" && -z ''${BASH_EXECUTION_STRING} ]]
+      then
+        shopt -q login_shell && LOGIN_OPTION='--login' || LOGIN_OPTION=""
+        exec ${pkgs.fish}/bin/fish $LOGIN_OPTION
+      fi
+    '';
+    shellInit = ''
+      export NIX_LD=$(nix eval --impure --raw --expr 'let pkgs = import <nixpkgs> {}; NIX_LD = pkgs.lib.fileContents "${pkgs.stdenv.cc}/nix-support/dynamic-linker"; in NIX_LD')
+    '';
+  };
+
+  # Open ports in the firewall.
+  # networking.firewall.allowedTCPPorts = [ ... ];
+  # networking.firewall.allowedUDPPorts = [ ... ];
+  # Or disable the firewall altogether.
+  # networking.firewall.enable = false;
+}