flashrom: Install udev-rules file

Add the udev-rules file from flashrom source to the out directory. The
file contains rules for programmers used by flashrom. Members of the
`flashrom` system group are allowed to access these devices.

Also, add a module for installing flashrom and adding flashrom to udev
packages. The module can be used by setting `programs.flashrom.enable`
to `true`.

Signed-off-by: Felix Singer <felixsinger@posteo.net>

1 files changed, 26 insertions, 0 deletions

diff --git a/nixos/modules/programs/flashrom.nix b/nixos/modules/programs/flashrom.nix
new file mode 100644
index 00000000000..f026c2e31cd
--- /dev/null
+++ b/nixos/modules/programs/flashrom.nix
@@ -0,0 +1,26 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+
+let
+  cfg = config.programs.flashrom;
+in
+{
+  options.programs.flashrom = {
+    enable = mkOption {
+      type = types.bool;
+      default = false;
+      description = ''
+        Installs flashrom and configures udev rules for programmers
+        used by flashrom. Grants access to users in the "flashrom"
+        group.
+      '';
+    };
+  };
+
+  config = mkIf cfg.enable {
+    services.udev.packages = [ pkgs.flashrom ];
+    environment.systemPackages = [ pkgs.flashrom ];
+    users.groups.flashrom = { };
+  };
+}