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>

nixos/doc/manual/from_md/release-notes/rl-2111.section.xml

@@ -48,6 +48,14 @@
           <link xlink:href="options.html#opt-networking.ucarp.enable">networking.ucarp</link>.
         </para>
       </listitem>
+      <listitem>
+        <para>
+          Users of flashrom should migrate to
+          <link xlink:href="options.html#opt-programs.flashrom.enable">programs.flashrom.enable</link>
+          and add themselves to the <literal>flashrom</literal> group to
+          be able to access programmers supported by flashrom.
+        </para>
+      </listitem>
     </itemizedlist>
   </section>
   <section xml:id="sec-release-21.11-incompatibilities">

nixos/doc/manual/release-notes/rl-2111.section.md

@@ -16,6 +16,8 @@ In addition to numerous new and upgraded packages, this release has the followin
 
 - [ucarp](https://download.pureftpd.org/pub/ucarp/README), an userspace implementation of the Common Address Redundancy Protocol (CARP). Available as [networking.ucarp](options.html#opt-networking.ucarp.enable).
 
+- Users of flashrom should migrate to [programs.flashrom.enable](options.html#opt-programs.flashrom.enable) and add themselves to the `flashrom` group to be able to access programmers supported by flashrom.
+
 ## Backward Incompatibilities {#sec-release-21.11-incompatibilities}
 
 - The `staticjinja` package has been upgraded from 1.0.4 to 2.0.0

nixos/modules/module-list.nix

@@ -138,6 +138,7 @@
   ./programs/file-roller.nix
   ./programs/firejail.nix
   ./programs/fish.nix
+  ./programs/flashrom.nix
   ./programs/flexoptix-app.nix
   ./programs/freetds.nix
   ./programs/fuse.nix

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 = { };
+  };
+}

pkgs/tools/misc/flashrom/default.nix

@@ -19,11 +19,17 @@ stdenv.mkDerivation rec {
     sha256 = "0ax4kqnh7kd3z120ypgp73qy1knz47l6qxsqzrfkd97mh5cdky71";
   };
 
+  postPatch = ''
+    substituteInPlace util/z60_flashrom.rules \
+      --replace "plugdev" "flashrom"
+  '';
+
   # Meson build doesn't build and install manpage. Only Makefile can.
   # Build manpage from source directory. Here we're inside the ./build subdirectory
   postInstall = ''
     make flashrom.8 -C ..
     installManPage ../flashrom.8
+    install -Dm644 ../util/z60_flashrom.rules $out/etc/udev/rules.d/flashrom.rules
   '';
 
   mesonFlags = lib.optionals stdenv.isAarch64 [ "-Dpciutils=false" ];