From 1c58cdbeed880e99d816c234a954d4cdfc073b6c Mon Sep 17 00:00:00 2001
From: Luflosi <luflosi@luflosi.de>
Date: Sun, 7 Nov 2021 20:49:45 +0100
Subject: nixos/modprobe: add boot.initrd.extraModprobeConfig option

This option behaves exactly like `boot.extraModprobeConfig`, except that it also includes the generated modprobe.d file in the initrd.
Many years ago, someone tried to include the normal modprobe.d/nixos.conf file generated by `boot.extraModprobeConfig` in the initrd: 0aa2c1dc46779a3df6c4e02d3fae39b0de297be8. This file contains a reference to a directory with firmware files inside. Including firmware in the initrd made it too big, so the commit was reverted again in 4a4c051a95b6b8da3a13d7955087e915e6dd4bf7.
The `boot.extraModprobeConfig` option not changing the initrd caused me much confusion because I tried to set the maximum cache size for ZFS and it didn't work.
Closes https://github.com/NixOS/nixpkgs/issues/25456.
---
 nixos/modules/system/boot/modprobe.nix | 20 ++++++++++++++++++++
 nixos/modules/system/boot/stage-1.nix  |  3 +++
 2 files changed, 23 insertions(+)

(limited to 'nixos/modules/system')

diff --git a/nixos/modules/system/boot/modprobe.nix b/nixos/modules/system/boot/modprobe.nix
index c75f32c4d99..7426d148891 100644
--- a/nixos/modules/system/boot/modprobe.nix
+++ b/nixos/modules/system/boot/modprobe.nix
@@ -34,6 +34,23 @@ with lib;
       type = types.lines;
     };
 
+    boot.initrd.extraModprobeConfig = mkOption {
+      default = "";
+      example =
+        ''
+          options zfs zfs_arc_max=1073741824
+        '';
+      description = ''
+        Does exactly the same thing as
+        <option>boot.extraModprobeConfig</option>, except
+        that the generated <filename>modprobe.conf</filename>
+        file is also included in the initrd.
+        This is useful for setting module options for kernel
+        modules that are loaded during early boot in the initrd.
+      '';
+      type = types.lines;
+    };
+
   };
 
 
@@ -50,6 +67,9 @@ with lib;
         '')}
         ${config.boot.extraModprobeConfig}
       '';
+    environment.etc."modprobe.d/nixos-initrd.conf".text = ''
+        ${config.boot.initrd.extraModprobeConfig}
+      '';
     environment.etc."modprobe.d/debian.conf".source = pkgs.kmod-debian-aliases;
 
     environment.systemPackages = [ pkgs.kmod ];
diff --git a/nixos/modules/system/boot/stage-1.nix b/nixos/modules/system/boot/stage-1.nix
index 6dfe6b939ab..9c684fbada2 100644
--- a/nixos/modules/system/boot/stage-1.nix
+++ b/nixos/modules/system/boot/stage-1.nix
@@ -338,6 +338,9 @@ let
         { object = pkgs.writeText "mdadm.conf" config.boot.initrd.mdadmConf;
           symlink = "/etc/mdadm.conf";
         }
+        { object = config.environment.etc."modprobe.d/nixos-initrd.conf".source;
+          symlink = "/etc/modprobe.d/nixos-initrd.conf";
+        }
         { object = pkgs.runCommand "initrd-kmod-blacklist-ubuntu" {
               src = "${pkgs.kmod-blacklist-ubuntu}/modprobe.conf";
               preferLocalBuild = true;
-- 
cgit 1.4.1