From d36077c0b686c91cea9d20edd58da632d4f28318 Mon Sep 17 00:00:00 2001
From: nikstur <nikstur@outlook.com>
Date: Tue, 7 Apr 2026 00:01:29 +0200
Subject: [PATCH 01/35] nixos/systemd: fix modprobe

Upstream systemd changed how modprobe is discovered. It is now searched
for on path. Thus, add the kmod package to the ExecSearchPath of the
modprobe@.service.
---
 nixos/modules/system/boot/systemd.nix | 4 ++++
 nixos/tests/systemd-misc.nix          | 5 +++++
 2 files changed, 9 insertions(+)

diff --git a/nixos/modules/system/boot/systemd.nix b/nixos/modules/system/boot/systemd.nix
index 0b9124709f85..56b87de1f394 100644
--- a/nixos/modules/system/boot/systemd.nix
+++ b/nixos/modules/system/boot/systemd.nix
@@ -792,6 +792,10 @@ in
       path = [ pkgs.util-linux ];
       overrideStrategy = "asDropin";
     };
+    systemd.services."modprobe@" = {
+      restartIfChanged = false;
+      serviceConfig.ExecSearchPath = lib.makeBinPath [ pkgs.kmod ];
+    };
     systemd.services.systemd-random-seed.restartIfChanged = false;
     systemd.services.systemd-remount-fs.restartIfChanged = false;
     systemd.services.systemd-update-utmp.restartIfChanged = false;
diff --git a/nixos/tests/systemd-misc.nix b/nixos/tests/systemd-misc.nix
index 2623f78add63..30f9fe720059 100644
--- a/nixos/tests/systemd-misc.nix
+++ b/nixos/tests/systemd-misc.nix
@@ -60,5 +60,10 @@ in
     machine.succeed("systemctl status example.service | grep 'Active: active'")
 
     machine.succeed("systemctl show --property TasksMax --value user-1000.slice | grep 100")
+
+    with subtest("modprobe@ services work"):
+      modprobe_service_status = machine.succeed("systemctl show --property ExecMainStatus modprobe@configfs.service")
+      print(modprobe_service_status)
+      t.assertEqual("ExecMainStatus=0\n", modprobe_service_status)
   '';
 }

From 0d7de04c0c246ea33ee9c4764781be9752c29bf1 Mon Sep 17 00:00:00 2001
From: Will Fancher <elvishjerricco@gmail.com>
Date: Sun, 5 Apr 2026 17:11:38 -0400
Subject: [PATCH 02/35] nixos/systemd-stage-1: Enable dbus by default

Also fix the scary dbus warning when using systemctl
---
 nixos/modules/services/system/dbus.nix | 21 ++++++++++++++++++++-
 1 file changed, 20 insertions(+), 1 deletion(-)

diff --git a/nixos/modules/services/system/dbus.nix b/nixos/modules/services/system/dbus.nix
index 1e21fe20d714..8cb03b08c2f6 100644
--- a/nixos/modules/services/system/dbus.nix
+++ b/nixos/modules/services/system/dbus.nix
@@ -32,7 +32,19 @@ in
   options = {
 
     boot.initrd.systemd.dbus = {
-      enable = mkEnableOption "dbus in stage 1";
+      enable = mkEnableOption "dbus in stage 1" // {
+        # TODO: This isn't really necessary, but it avoids a very
+        # common red herring error message:
+        #
+        # $ systemctl ...
+        # Failed to connect to system scope bus via local transport: No such file or directory.
+        #
+        # When systemctl tries and fails to control the system manager
+        # over dbus, it fals back to a private bus socket after
+        # printing this message. It works, but users often think it is
+        # the source of their problem when it isn't.
+        default = true;
+      };
     };
 
     services.dbus = {
@@ -163,6 +175,13 @@ in
           "${config.boot.initrd.systemd.package}/share/dbus-1/system.d"
         ];
         targets.sockets.wants = [ "dbus.socket" ];
+
+        # Otherwise, dbus waits on cryptsetup, and systemctl says the
+        # bus couldn't be found. This isn't an error (systemctl will
+        # fall back to a private bus with PID 1), but it's confusing
+        # to unaware users.
+        services.dbus.unitConfig.DefaultDependencies = false;
+        sockets.dbus.unitConfig.DefaultDependencies = false;
       };
     })
 

From 2af908228dff2083cff13b5d2c4a95931dc79b0d Mon Sep 17 00:00:00 2001
From: Will Fancher <elvishjerricco@gmail.com>
Date: Mon, 6 Apr 2026 05:26:12 -0400
Subject: [PATCH 03/35] nixos/systemd-stage-1: Support rd.systemd.break=

---
 nixos/modules/system/boot/systemd/initrd.nix | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/nixos/modules/system/boot/systemd/initrd.nix b/nixos/modules/system/boot/systemd/initrd.nix
index 2c59d224176e..f61d94b7851a 100644
--- a/nixos/modules/system/boot/systemd/initrd.nix
+++ b/nixos/modules/system/boot/systemd/initrd.nix
@@ -29,6 +29,10 @@ let
 
   upstreamUnits = [
     "basic.target"
+    "breakpoint-pre-udev.service"
+    "breakpoint-pre-basic.service"
+    "breakpoint-pre-mount.service"
+    "breakpoint-pre-switch-root.service"
     "ctrl-alt-del.target"
     "debug-shell.service"
     "emergency.service"

From 1ea02ad83f1229cb630317895548c60ee0deee45 Mon Sep 17 00:00:00 2001
From: Will Fancher <elvishjerricco@gmail.com>
Date: Fri, 15 Aug 2025 15:43:01 -0400
Subject: [PATCH 04/35] nixos/tests/boot-stage2: Explicitly disable systemd
 stage 1

---
 nixos/tests/boot-stage2.nix | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/nixos/tests/boot-stage2.nix b/nixos/tests/boot-stage2.nix
index c2aa3730ed4b..08c00d46c6c6 100644
--- a/nixos/tests/boot-stage2.nix
+++ b/nixos/tests/boot-stage2.nix
@@ -54,6 +54,9 @@
 
       boot = {
         initrd = {
+          # TODO: Switch to systemd initrd
+          systemd.enable = false;
+
           # Format the upper Nix store.
           postDeviceCommands = ''
             ${pkgs.e2fsprogs}/bin/mkfs.ext4 /dev/vdb

From 8cd4240c6c053df53deb5f3a70c5396d022ca3cf Mon Sep 17 00:00:00 2001
From: Will Fancher <elvishjerricco@gmail.com>
Date: Fri, 15 Aug 2025 15:43:01 -0400
Subject: [PATCH 05/35] nixos/tests/initrd-network: Explicitly disable systemd
 stage 1

---
 nixos/tests/initrd-network.nix | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/nixos/tests/initrd-network.nix b/nixos/tests/initrd-network.nix
index b84588f1d250..b43e62db0a52 100644
--- a/nixos/tests/initrd-network.nix
+++ b/nixos/tests/initrd-network.nix
@@ -1,3 +1,5 @@
+# Tests networking in scripted stage 1. Remove in 26.11.
+
 { pkgs, lib, ... }:
 {
   name = "initrd-network";
@@ -8,6 +10,7 @@
     { ... }:
     {
       imports = [ ../modules/profiles/minimal.nix ];
+      boot.initrd.systemd.enable = false;
       boot.initrd.network.enable = true;
       boot.initrd.network.postCommands = ''
         ip addr show

From e7a9b6a1a2fdc37f97f122ebe388402d787dfd96 Mon Sep 17 00:00:00 2001
From: Will Fancher <elvishjerricco@gmail.com>
Date: Fri, 15 Aug 2025 15:43:01 -0400
Subject: [PATCH 06/35] nixos/tests/iscsi: Explicitly disable systemd stage 1

---
 nixos/tests/iscsi-multipath-root.nix | 1 +
 nixos/tests/iscsi-root.nix           | 2 ++
 2 files changed, 3 insertions(+)

diff --git a/nixos/tests/iscsi-multipath-root.nix b/nixos/tests/iscsi-multipath-root.nix
index ba17ac64058e..90723bdbb604 100644
--- a/nixos/tests/iscsi-multipath-root.nix
+++ b/nixos/tests/iscsi-multipath-root.nix
@@ -186,6 +186,7 @@ in
         boot.initrd.extraFiles."etc/multipath/wwids".source =
           pkgs.writeText "wwids" "/3600140592b17c3f6b404168b082ceeb7/";
 
+        boot.initrd.systemd.enable = false;
         boot.iscsi-initiator = {
           discoverPortal = "target";
           name = initiatorName;
diff --git a/nixos/tests/iscsi-root.nix b/nixos/tests/iscsi-root.nix
index e8c98a39931c..571dbecad244 100644
--- a/nixos/tests/iscsi-root.nix
+++ b/nixos/tests/iscsi-root.nix
@@ -142,6 +142,8 @@ in
           };
         };
 
+        # No SCSI support in systemd stage 1 at present.
+        boot.initrd.systemd.enable = false;
         boot.iscsi-initiator = {
           discoverPortal = "target";
           name = initiatorName;

From a261a22e18f6d98c46a7e6135f0c20ae3f915022 Mon Sep 17 00:00:00 2001
From: Will Fancher <elvishjerricco@gmail.com>
Date: Fri, 15 Aug 2025 15:43:01 -0400
Subject: [PATCH 07/35] nixos/tests/boot-stage1: Explicitly disable systemd
 stage 1

---
 nixos/tests/boot-stage1.nix | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/nixos/tests/boot-stage1.nix b/nixos/tests/boot-stage1.nix
index e76af3e1dc6f..2fda8355086a 100644
--- a/nixos/tests/boot-stage1.nix
+++ b/nixos/tests/boot-stage1.nix
@@ -1,3 +1,6 @@
+# Remove in 26.11. This test guards against problems with
+# stage-1-init.sh, which will be removed with scripted stage 1.
+
 { pkgs, ... }:
 {
   name = "boot-stage1";
@@ -10,6 +13,8 @@
       ...
     }:
     {
+      boot.initrd.systemd.enable = false;
+
       boot.extraModulePackages =
         let
           compileKernelModule =

From 482da791bfe649278e988f7414a322d7a43897c9 Mon Sep 17 00:00:00 2001
From: Will Fancher <elvishjerricco@gmail.com>
Date: Fri, 15 Aug 2025 15:43:01 -0400
Subject: [PATCH 08/35] nixos/tests/initrd-network-ssh: Explicitly disable
 systemd stage 1

---
 nixos/tests/initrd-network-ssh/default.nix | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/nixos/tests/initrd-network-ssh/default.nix b/nixos/tests/initrd-network-ssh/default.nix
index 510a9f7ef4e5..60b888b69a86 100644
--- a/nixos/tests/initrd-network-ssh/default.nix
+++ b/nixos/tests/initrd-network-ssh/default.nix
@@ -1,3 +1,5 @@
+# This tests SSH in scripted stage 1. Remove in 26.11.
+
 import ../make-test-python.nix (
   { lib, pkgs, ... }:
 
@@ -14,6 +16,7 @@ import ../make-test-python.nix (
           boot.kernelParams = [
             "ip=${config.networking.primaryIPAddress}:::255.255.255.0::eth1:none"
           ];
+          boot.initrd.systemd.enable = false;
           boot.initrd.network = {
             enable = true;
             ssh = {

From de7ea54d822f6af969fff218689f11a085439fe9 Mon Sep 17 00:00:00 2001
From: Will Fancher <elvishjerricco@gmail.com>
Date: Wed, 27 Aug 2025 01:40:34 -0400
Subject: [PATCH 09/35] nixos/tests/luks: Explicitly disable systemd stage 1

systemd stage 1 is covered by
`nixos.tests.systemd-initrd-luks-password`, but we should still test
scripted stage 1 for the time being.
---
 nixos/tests/luks.nix | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/nixos/tests/luks.nix b/nixos/tests/luks.nix
index 7440d110ad28..db2672eefdc0 100644
--- a/nixos/tests/luks.nix
+++ b/nixos/tests/luks.nix
@@ -1,3 +1,5 @@
+# Tests LUKS specifically with scripted stage 1. Remove in 26.11.
+
 { lib, pkgs, ... }:
 {
   name = "luks";
@@ -6,6 +8,8 @@
     { pkgs, ... }:
     {
 
+      boot.initrd.systemd.enable = false;
+
       # Use systemd-boot
       virtualisation = {
         emptyDiskImages = [

From fef6d22a872d14381771490b9e3c872fad3084ff Mon Sep 17 00:00:00 2001
From: Will Fancher <elvishjerricco@gmail.com>
Date: Fri, 15 Aug 2025 15:43:01 -0400
Subject: [PATCH 10/35] nixos/tests/predictable-interface-names: Explicitly set
 'boot.initrd.systemd.enable'

---
 nixos/tests/predictable-interface-names.nix | 26 +++++++++++----------
 1 file changed, 14 insertions(+), 12 deletions(-)

diff --git a/nixos/tests/predictable-interface-names.nix b/nixos/tests/predictable-interface-names.nix
index 8ab29a73cd4f..0bf2afce7a39 100644
--- a/nixos/tests/predictable-interface-names.nix
+++ b/nixos/tests/predictable-interface-names.nix
@@ -63,18 +63,20 @@ pkgs.lib.listToAttrs (
             # Check if predictable interface names are working in stage-1
             boot.initrd.postDeviceCommands = lib.mkIf (!systemdStage1) script;
 
-            boot.initrd.systemd = lib.mkIf systemdStage1 {
-              enable = true;
-              initrdBin = [ pkgs.iproute2 ];
-              services.systemd-udev-settle.wantedBy = [ "initrd.target" ];
-              services.check-interfaces = {
-                requiredBy = [ "initrd.target" ];
-                after = [ "systemd-udev-settle.service" ];
-                serviceConfig.Type = "oneshot";
-                path = [ pkgs.iproute2 ];
-                inherit script;
-              };
-            };
+            boot.initrd.systemd = lib.mkMerge [
+              { enable = systemdStage1; }
+              (lib.mkIf systemdStage1 {
+                initrdBin = [ pkgs.iproute2 ];
+                services.systemd-udev-settle.wantedBy = [ "initrd.target" ];
+                services.check-interfaces = {
+                  requiredBy = [ "initrd.target" ];
+                  after = [ "systemd-udev-settle.service" ];
+                  serviceConfig.Type = "oneshot";
+                  path = [ pkgs.iproute2 ];
+                  inherit script;
+                };
+              })
+            ];
           };
 
         testScript = ''

From 1718e9f745006f167c9566bc29e13ece087b02ae Mon Sep 17 00:00:00 2001
From: Will Fancher <elvishjerricco@gmail.com>
Date: Wed, 10 Sep 2025 02:00:08 -0400
Subject: [PATCH 11/35] nixos/tests/initrd-luks-empty-passphrase: Explicitly
 set 'boot.initrd.systemd.enable'

---
 nixos/tests/all-tests.nix                    | 5 ++++-
 nixos/tests/initrd-luks-empty-passphrase.nix | 8 +++-----
 2 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/nixos/tests/all-tests.nix b/nixos/tests/all-tests.nix
index 1eed27e00a54..894ed9020894 100644
--- a/nixos/tests/all-tests.nix
+++ b/nixos/tests/all-tests.nix
@@ -769,7 +769,10 @@ in
   };
   influxdb = runTest ./influxdb.nix;
   influxdb2 = runTest ./influxdb2.nix;
-  initrd-luks-empty-passphrase = runTest ./initrd-luks-empty-passphrase.nix;
+  initrd-luks-empty-passphrase = runTest {
+    imports = [ ./initrd-luks-empty-passphrase.nix ];
+    _module.args.systemdStage1 = false;
+  };
   initrd-network-openvpn = handleTestOn [ "x86_64-linux" "i686-linux" ] ./initrd-network-openvpn { };
   initrd-network-ssh = handleTest ./initrd-network-ssh { };
   initrd-secrets = handleTest ./initrd-secrets.nix { };
diff --git a/nixos/tests/initrd-luks-empty-passphrase.nix b/nixos/tests/initrd-luks-empty-passphrase.nix
index 3a906685f0ca..56a92a827ff4 100644
--- a/nixos/tests/initrd-luks-empty-passphrase.nix
+++ b/nixos/tests/initrd-luks-empty-passphrase.nix
@@ -14,8 +14,6 @@ in
 {
   name = "initrd-luks-empty-passphrase";
 
-  _module.args.systemdStage1 = lib.mkDefault false;
-
   nodes.machine =
     { pkgs, ... }:
     {
@@ -31,9 +29,9 @@ in
       };
 
       boot.loader.systemd-boot.enable = true;
-      boot.initrd.systemd = lib.mkIf systemdStage1 {
-        enable = true;
-        emergencyAccess = true;
+      boot.initrd.systemd = {
+        enable = systemdStage1;
+        emergencyAccess = lib.mkIf systemdStage1 true;
       };
       environment.systemPackages = with pkgs; [ cryptsetup ];
 

From ee5dd90859c7a5dd76603d60f02c9a472f25d942 Mon Sep 17 00:00:00 2001
From: Will Fancher <elvishjerricco@gmail.com>
Date: Mon, 6 Apr 2026 03:07:19 -0400
Subject: [PATCH 12/35] nixos/tests/initrd-network-opentvpn: Explicit
 systemdStage1 arg

---
 nixos/tests/all-tests.nix                      | 4 +++-
 nixos/tests/initrd-network-openvpn/default.nix | 2 +-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/nixos/tests/all-tests.nix b/nixos/tests/all-tests.nix
index 894ed9020894..5d684cfe119a 100644
--- a/nixos/tests/all-tests.nix
+++ b/nixos/tests/all-tests.nix
@@ -773,7 +773,9 @@ in
     imports = [ ./initrd-luks-empty-passphrase.nix ];
     _module.args.systemdStage1 = false;
   };
-  initrd-network-openvpn = handleTestOn [ "x86_64-linux" "i686-linux" ] ./initrd-network-openvpn { };
+  initrd-network-openvpn = handleTestOn [ "x86_64-linux" "i686-linux" ] ./initrd-network-openvpn {
+    systemdStage1 = false;
+  };
   initrd-network-ssh = handleTest ./initrd-network-ssh { };
   initrd-secrets = handleTest ./initrd-secrets.nix { };
   initrd-secrets-changing = handleTest ./initrd-secrets-changing.nix { };
diff --git a/nixos/tests/initrd-network-openvpn/default.nix b/nixos/tests/initrd-network-openvpn/default.nix
index f685e46dc467..0e4edcb4f70c 100644
--- a/nixos/tests/initrd-network-openvpn/default.nix
+++ b/nixos/tests/initrd-network-openvpn/default.nix
@@ -2,7 +2,7 @@
   system ? builtins.currentSystem,
   config ? { },
   pkgs ? import ../.. { inherit system config; },
-  systemdStage1 ? false,
+  systemdStage1,
 }:
 
 import ../make-test-python.nix (

From 0f146213ded8979a4cc323edc8c081ba6b5f4542 Mon Sep 17 00:00:00 2001
From: Will Fancher <elvishjerricco@gmail.com>
Date: Mon, 6 Apr 2026 04:53:33 -0400
Subject: [PATCH 13/35] nixos/tests/hibernate: Explicit systemdStage1 arg

---
 nixos/tests/all-tests.nix | 4 +++-
 nixos/tests/hibernate.nix | 2 +-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/nixos/tests/all-tests.nix b/nixos/tests/all-tests.nix
index 5d684cfe119a..02f1fd0e5583 100644
--- a/nixos/tests/all-tests.nix
+++ b/nixos/tests/all-tests.nix
@@ -727,7 +727,9 @@ in
   # 9pnet_virtio used to mount /nix partition doesn't support
   # hibernation. This test happens to work on x86_64-linux but
   # not on other platforms.
-  hibernate = handleTestOn [ "x86_64-linux" ] ./hibernate.nix { };
+  hibernate = handleTestOn [ "x86_64-linux" ] ./hibernate.nix {
+    systemdStage1 = false;
+  };
   hibernate-systemd-stage-1 = handleTestOn [ "x86_64-linux" ] ./hibernate.nix {
     systemdStage1 = true;
   };
diff --git a/nixos/tests/hibernate.nix b/nixos/tests/hibernate.nix
index 9b840a4e14da..53daec48d6c0 100644
--- a/nixos/tests/hibernate.nix
+++ b/nixos/tests/hibernate.nix
@@ -4,7 +4,7 @@
   system ? builtins.currentSystem,
   config ? { },
   pkgs ? import ../.. { inherit system config; },
-  systemdStage1 ? false,
+  systemdStage1,
 }:
 
 with import ../lib/testing-python.nix { inherit system pkgs; };

From 8a6ac4af8d4301a0aac6e582627abeae997a85f9 Mon Sep 17 00:00:00 2001
From: Will Fancher <elvishjerricco@gmail.com>
Date: Mon, 6 Apr 2026 04:58:24 -0400
Subject: [PATCH 14/35] nixos/tests/systemd-shutdown: Explicit systemdStage1
 arg

---
 nixos/tests/all-tests.nix        | 5 ++++-
 nixos/tests/systemd-shutdown.nix | 2 --
 2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/nixos/tests/all-tests.nix b/nixos/tests/all-tests.nix
index 02f1fd0e5583..99c897c23bbe 100644
--- a/nixos/tests/all-tests.nix
+++ b/nixos/tests/all-tests.nix
@@ -1608,7 +1608,10 @@ in
   systemd-pstore = runTest ./systemd-pstore.nix;
   systemd-repart = handleTest ./systemd-repart.nix { };
   systemd-resolved = runTest ./systemd-resolved.nix;
-  systemd-shutdown = runTest ./systemd-shutdown.nix;
+  systemd-shutdown = runTest {
+    imports = [ ./systemd-shutdown.nix ];
+    _module.args.systemdStage1 = false;
+  };
   systemd-ssh-proxy = runTest ./systemd-ssh-proxy.nix;
   systemd-sysupdate = runTest ./systemd-sysupdate.nix;
   systemd-sysusers-immutable = runTest ./systemd-sysusers-immutable.nix;
diff --git a/nixos/tests/systemd-shutdown.nix b/nixos/tests/systemd-shutdown.nix
index 827cbac300d8..7439c9331182 100644
--- a/nixos/tests/systemd-shutdown.nix
+++ b/nixos/tests/systemd-shutdown.nix
@@ -11,8 +11,6 @@ in
   name = "systemd-shutdown";
   meta.maintainers = with lib.maintainers; [ das_j ];
 
-  _module.args.systemdStage1 = lib.mkDefault false;
-
   nodes.machine = {
     imports = [ ../modules/profiles/minimal.nix ];
     systemd.shutdownRamfs.contents."/etc/systemd/system-shutdown/shutdown-message".source =

From 58dc3d61dc022b93e548614103e0b37fed9b51b6 Mon Sep 17 00:00:00 2001
From: Will Fancher <elvishjerricco@gmail.com>
Date: Mon, 6 Apr 2026 04:59:37 -0400
Subject: [PATCH 15/35] nixos/tests/envfs: Explicit systemdStage1 arg

---
 nixos/tests/envfs.nix | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/nixos/tests/envfs.nix b/nixos/tests/envfs.nix
index 78946285ed68..a209b2c8db2c 100644
--- a/nixos/tests/envfs.nix
+++ b/nixos/tests/envfs.nix
@@ -1,6 +1,6 @@
 {
   pkgs,
-  systemdStage1 ? false,
+  systemdStage1,
   ...
 }:
 

From 94a06492e2848085389bbc5242c381bc876e2265 Mon Sep 17 00:00:00 2001
From: Will Fancher <elvishjerricco@gmail.com>
Date: Fri, 15 Aug 2025 15:43:01 -0400
Subject: [PATCH 16/35] nixos/tests/non-default-filesystems/btrfs: Use systemd
 stage 1

---
 nixos/tests/non-default-filesystems.nix | 108 ++++++++++++------------
 1 file changed, 56 insertions(+), 52 deletions(-)

diff --git a/nixos/tests/non-default-filesystems.nix b/nixos/tests/non-default-filesystems.nix
index 11bf2070464f..2c578c94da53 100644
--- a/nixos/tests/non-default-filesystems.nix
+++ b/nixos/tests/non-default-filesystems.nix
@@ -34,66 +34,70 @@ with pkgs.lib;
     '';
   };
 
-  btrfs = makeTest {
-    name = "non-default-filesystems-btrfs";
+  btrfs =
+    let
+      disk = "/dev/vda";
+      partition = "/dev/disk/by-label/storage";
+    in
+    makeTest {
+      name = "non-default-filesystems-btrfs";
 
-    nodes.machine =
-      {
-        config,
-        pkgs,
-        lib,
-        ...
-      }:
-      let
-        disk = config.virtualisation.rootDevice;
-      in
-      {
-        virtualisation.rootDevice = "/dev/vda";
-        virtualisation.useDefaultFilesystems = false;
+      nodes.machine =
+        { ... }:
+        {
+          virtualisation.rootDevice = disk;
+          virtualisation.useDefaultFilesystems = false;
 
-        boot.initrd.availableKernelModules = [ "btrfs" ];
-        boot.supportedFilesystems = [ "btrfs" ];
-
-        boot.initrd.postDeviceCommands = ''
-          FSTYPE=$(blkid -o value -s TYPE ${disk} || true)
-          if test -z "$FSTYPE"; then
-            modprobe btrfs
-            ${pkgs.btrfs-progs}/bin/mkfs.btrfs ${disk}
-
-            mkdir /nixos
-            mount -t btrfs ${disk} /nixos
-
-            ${pkgs.btrfs-progs}/bin/btrfs subvolume create /nixos/root
-            ${pkgs.btrfs-progs}/bin/btrfs subvolume create /nixos/home
-
-            umount /nixos
-          fi
-        '';
-
-        virtualisation.fileSystems = {
-          "/" = {
-            device = disk;
-            fsType = "btrfs";
-            options = [ "subvol=/root" ];
+          systemd.repart.partitions."00-root" = {
+            Type = "linux-generic";
+            Format = "btrfs";
+            Label = "storage";
+            Subvolumes = [
+              "/root"
+              "/home"
+            ];
+            MakeDirectories = [
+              "/root"
+              "/home"
+            ];
           };
 
-          "/home" = {
-            device = disk;
-            fsType = "btrfs";
-            options = [ "subvol=/home" ];
+          boot.initrd.supportedFilesystems = [ "btrfs" ];
+
+          boot.initrd.systemd = {
+            enable = true;
+            repart = {
+              enable = true;
+              device = disk;
+              empty = "allow";
+            };
+          };
+
+          virtualisation.fileSystems = {
+            "/" = {
+              device = partition;
+              fsType = "btrfs";
+              options = [ "subvol=/root" ];
+            };
+
+            "/home" = {
+              device = partition;
+              fsType = "btrfs";
+              options = [ "subvol=/home" ];
+            };
           };
         };
-      };
 
-    testScript = ''
-      machine.wait_for_unit("multi-user.target")
+      testScript = ''
+        machine.wait_for_unit("multi-user.target")
 
-      with subtest("BTRFS filesystems are mounted correctly"):
-        print("output of \"grep -E '/dev/vda' /proc/mounts\":\n" + machine.execute("grep -E '/dev/vda' /proc/mounts")[1])
-        machine.succeed("grep -E '/dev/vda / btrfs rw,.*subvolid=[0-9]+,subvol=/root 0 0' /proc/mounts")
-        machine.succeed("grep -E '/dev/vda /home btrfs rw,.*subvolid=[0-9]+,subvol=/home 0 0' /proc/mounts")
-    '';
-  };
+        with subtest("BTRFS filesystems are mounted correctly"):
+          realdev = machine.succeed("realpath '${partition}'")
+          print(f"output of \"grep -E '{realdev}' /proc/mounts\":\n" + machine.execute(f"grep -E '{realdev}' /proc/mounts")[1])
+          machine.succeed(f"grep -E '{realdev} / btrfs rw,.*subvolid=[0-9]+,subvol=/root 0 0' /proc/mounts")
+          machine.succeed(f"grep -E '{realdev} /home btrfs rw,.*subvolid=[0-9]+,subvol=/home 0 0' /proc/mounts")
+      '';
+    };
 
   erofs =
     let

From 61305d14147e05b60c6bad4e7c8d91dfcc7a6e37 Mon Sep 17 00:00:00 2001
From: Will Fancher <elvishjerricco@gmail.com>
Date: Fri, 15 Aug 2025 15:43:01 -0400
Subject: [PATCH 17/35] nixos/tests/initrd-secrets: Use systemd stage 1

---
 nixos/tests/initrd-secrets-changing.nix | 21 ++++++++++++++-------
 nixos/tests/initrd-secrets.nix          | 15 +++++++++------
 2 files changed, 23 insertions(+), 13 deletions(-)

diff --git a/nixos/tests/initrd-secrets-changing.nix b/nixos/tests/initrd-secrets-changing.nix
index f0d6bc4c28b4..1ff8a9aabdcb 100644
--- a/nixos/tests/initrd-secrets-changing.nix
+++ b/nixos/tests/initrd-secrets-changing.nix
@@ -24,14 +24,19 @@ testing.makeTest {
 
       boot.initrd.secrets = {
         "/test" = secret1InStore;
-        "/run/keys/test" = secret1InStore;
+        "/run/test" = secret1InStore;
+      };
+      boot.initrd.systemd = {
+        enable = true;
+        tmpfiles.settings."00-copy-secret" = {
+          "/sysroot/secret-from-initramfs".C.argument = "/test";
+        };
       };
-      boot.initrd.postMountCommands = "cp /test /mnt-root/secret-from-initramfs";
 
       specialisation.secrets2System.configuration = {
         boot.initrd.secrets = lib.mkForce {
           "/test" = secret2InStore;
-          "/run/keys/test" = secret2InStore;
+          "/run/test" = secret2InStore;
         };
       };
     };
@@ -40,21 +45,23 @@ testing.makeTest {
     start_all()
 
     machine.wait_for_unit("multi-user.target")
-    print(machine.succeed("cat /run/keys/test"))
+    print(machine.succeed("cat /run/test"))
     machine.succeed(
         "cmp ${secret1InStore} /secret-from-initramfs",
-        "cmp ${secret1InStore} /run/keys/test",
+        "cmp ${secret1InStore} /run/test",
     )
     # Select the second boot entry corresponding to the specialisation secrets2System.
     machine.succeed("grub-reboot 1")
+    # Remove the rootfs secret so tmpfiles will copy the new one next time
+    machine.succeed("rm /secret-from-initramfs")
     machine.shutdown()
 
     with subtest("Check that the specialisation's secrets are distinct despite identical kernels"):
         machine.wait_for_unit("multi-user.target")
-        print(machine.succeed("cat /run/keys/test"))
+        print(machine.succeed("cat /run/test"))
         machine.succeed(
             "cmp ${secret2InStore} /secret-from-initramfs",
-            "cmp ${secret2InStore} /run/keys/test",
+            "cmp ${secret2InStore} /run/test",
         )
         machine.shutdown()
   '';
diff --git a/nixos/tests/initrd-secrets.nix b/nixos/tests/initrd-secrets.nix
index e19ac4d6f3dc..ce0a54dac6c0 100644
--- a/nixos/tests/initrd-secrets.nix
+++ b/nixos/tests/initrd-secrets.nix
@@ -24,12 +24,15 @@ let
           boot.initrd.secrets = {
             "/test" = secretInStore;
 
-            # This should *not* need to be copied in postMountCommands
-            "/run/keys/test" = secretInStore;
+            # This should *not* need to be copied
+            "/run/test" = secretInStore;
+          };
+          boot.initrd.systemd = {
+            enable = true;
+            tmpfiles.settings."00-copy-secret" = {
+              "/sysroot/secret-from-initramfs".C.argument = "/test";
+            };
           };
-          boot.initrd.postMountCommands = ''
-            cp /test /mnt-root/secret-from-initramfs
-          '';
           boot.initrd.compressor = compressor;
           # zstd compression is only supported from 5.9 onwards. Remove when 5.10 becomes default.
           boot.kernelPackages = pkgs.linuxPackages_latest;
@@ -40,7 +43,7 @@ let
         machine.wait_for_unit("multi-user.target")
         machine.succeed(
             "cmp ${secretInStore} /secret-from-initramfs",
-            "cmp ${secretInStore} /run/keys/test",
+            "cmp ${secretInStore} /run/test",
         )
       '';
     };

From 1288734d0986dd2f63f172ffd9f0969650b15315 Mon Sep 17 00:00:00 2001
From: Will Fancher <elvishjerricco@gmail.com>
Date: Fri, 15 Aug 2025 15:43:01 -0400
Subject: [PATCH 18/35] nixos/tests/swap: Use systemd stage 1

---
 nixos/tests/swap-partition.nix         | 47 ++++++++++++------------
 nixos/tests/swap-random-encryption.nix | 49 ++++++++++++++------------
 2 files changed, 51 insertions(+), 45 deletions(-)

diff --git a/nixos/tests/swap-partition.nix b/nixos/tests/swap-partition.nix
index d6310be61202..fa370be079c8 100644
--- a/nixos/tests/swap-partition.nix
+++ b/nixos/tests/swap-partition.nix
@@ -1,33 +1,35 @@
-{ lib, pkgs, ... }:
+{ ... }:
 {
   name = "swap-partition";
 
   nodes.machine =
-    {
-      config,
-      pkgs,
-      lib,
-      ...
-    }:
+    { config, ... }:
     {
       virtualisation.useDefaultFilesystems = false;
 
       virtualisation.rootDevice = "/dev/vda1";
 
-      boot.initrd.postDeviceCommands = ''
-        if ! test -b /dev/vda1; then
-          ${pkgs.parted}/bin/parted --script /dev/vda -- mklabel msdos
-          ${pkgs.parted}/bin/parted --script /dev/vda -- mkpart primary 1MiB -250MiB
-          ${pkgs.parted}/bin/parted --script /dev/vda -- mkpart primary -250MiB 100%
-          sync
-        fi
-
-        FSTYPE=$(blkid -o value -s TYPE /dev/vda1 || true)
-        if test -z "$FSTYPE"; then
-          ${pkgs.e2fsprogs}/bin/mke2fs -t ext4 -L root /dev/vda1
-          ${pkgs.util-linux}/bin/mkswap --label swap /dev/vda2
-        fi
-      '';
+      boot.initrd.systemd = {
+        enable = true;
+        repart = {
+          enable = true;
+          device = "/dev/vda";
+          empty = "allow";
+        };
+      };
+      systemd.repart.partitions = {
+        "00-root" = {
+          Type = "linux-generic";
+          Format = "ext4";
+          Label = "root";
+        };
+        "10-swap" = {
+          Type = "linux-generic";
+          Label = "swap";
+          SizeMinBytes = "250M";
+          SizeMaxBytes = "250M";
+        };
+      };
 
       virtualisation.fileSystems = {
         "/" = {
@@ -38,7 +40,8 @@
 
       swapDevices = [
         {
-          device = "/dev/disk/by-label/swap";
+          device = "/dev/disk/by-partlabel/swap";
+          options = [ "x-systemd.makefs" ];
         }
       ];
     };
diff --git a/nixos/tests/swap-random-encryption.nix b/nixos/tests/swap-random-encryption.nix
index 80601e89d108..f977104d8dff 100644
--- a/nixos/tests/swap-random-encryption.nix
+++ b/nixos/tests/swap-random-encryption.nix
@@ -1,14 +1,9 @@
-{ lib, pkgs, ... }:
+{ ... }:
 {
   name = "swap-random-encryption";
 
   nodes.machine =
-    {
-      config,
-      pkgs,
-      lib,
-      ...
-    }:
+    { pkgs, ... }:
     {
       environment.systemPackages = [ pkgs.cryptsetup ];
 
@@ -16,19 +11,27 @@
 
       virtualisation.rootDevice = "/dev/vda1";
 
-      boot.initrd.postDeviceCommands = ''
-        if ! test -b /dev/vda1; then
-          ${pkgs.parted}/bin/parted --script /dev/vda -- mklabel msdos
-          ${pkgs.parted}/bin/parted --script /dev/vda -- mkpart primary 1MiB -250MiB
-          ${pkgs.parted}/bin/parted --script /dev/vda -- mkpart primary -250MiB 100%
-          sync
-        fi
-
-        FSTYPE=$(blkid -o value -s TYPE /dev/vda1 || true)
-        if test -z "$FSTYPE"; then
-          ${pkgs.e2fsprogs}/bin/mke2fs -t ext4 -L root /dev/vda1
-        fi
-      '';
+      boot.initrd.systemd = {
+        enable = true;
+        repart = {
+          enable = true;
+          device = "/dev/vda";
+          empty = "allow";
+        };
+      };
+      systemd.repart.partitions = {
+        "00-root" = {
+          Type = "linux-generic";
+          Format = "ext4";
+          Label = "root";
+        };
+        "10-swap" = {
+          Type = "linux-generic";
+          Label = "swap";
+          SizeMinBytes = "250M";
+          SizeMaxBytes = "250M";
+        };
+      };
 
       virtualisation.fileSystems = {
         "/" = {
@@ -39,7 +42,7 @@
 
       swapDevices = [
         {
-          device = "/dev/vda2";
+          device = "/dev/disk/by-partlabel/swap";
 
           randomEncryption = {
             enable = true;
@@ -60,7 +63,7 @@
 
     with subtest("Swap device has 4k sector size"):
       import json
-      result = json.loads(machine.succeed("lsblk -Jo PHY-SEC,LOG-SEC /dev/mapper/dev-vda2"))
+      result = json.loads(machine.succeed("lsblk -Jo PHY-SEC,LOG-SEC /dev/mapper/dev-disk-by\\x2dpartlabel-swap"))
       block_devices = result["blockdevices"]
       if len(block_devices) != 1:
         raise Exception ("lsblk output did not report exactly one block device")
@@ -72,7 +75,7 @@
     with subtest("Swap encrypt has assigned cipher and keysize"):
       import re
 
-      results = machine.succeed("cryptsetup status dev-vda2").splitlines()
+      results = machine.succeed("cryptsetup status dev-disk-by\\x2dpartlabel-swap").splitlines()
 
       cipher_pattern = re.compile(r"\s*cipher:\s+aes-xts-plain64\s*")
       if not any(cipher_pattern.fullmatch(line) for line in results):

From 5e0a4d739ddd85e045e684a74660b6f8e0b9f705 Mon Sep 17 00:00:00 2001
From: Will Fancher <elvishjerricco@gmail.com>
Date: Sat, 23 Aug 2025 10:31:15 -0400
Subject: [PATCH 19/35] nixos/tests/installer: Support both stage 1
 implementations

---
 nixos/tests/all-tests.nix                 |  4 +-
 nixos/tests/installer-systemd-stage-1.nix | 52 -----------------------
 nixos/tests/installer.nix                 | 34 ++++++++++-----
 3 files changed, 26 insertions(+), 64 deletions(-)
 delete mode 100644 nixos/tests/installer-systemd-stage-1.nix

diff --git a/nixos/tests/all-tests.nix b/nixos/tests/all-tests.nix
index 99c897c23bbe..a927794c0108 100644
--- a/nixos/tests/all-tests.nix
+++ b/nixos/tests/all-tests.nix
@@ -785,8 +785,8 @@ in
   input-remapper = runTest ./input-remapper.nix;
   inspircd = runTest ./inspircd.nix;
   installed-tests = recurseIntoAttrs (handleTest ./installed-tests { });
-  installer = handleTest ./installer.nix { };
-  installer-systemd-stage-1 = handleTest ./installer-systemd-stage-1.nix { };
+  installer = handleTest ./installer.nix { systemdStage1 = true; };
+  installer-systemd-stage-1 = handleTest ./installer.nix { systemdStage1 = true; };
   intune = runTest ./intune.nix;
   invidious = runTest ./invidious.nix;
   invoiceplane = runTest ./invoiceplane.nix;
diff --git a/nixos/tests/installer-systemd-stage-1.nix b/nixos/tests/installer-systemd-stage-1.nix
deleted file mode 100644
index d007b3caf397..000000000000
--- a/nixos/tests/installer-systemd-stage-1.nix
+++ /dev/null
@@ -1,52 +0,0 @@
-{
-  system ? builtins.currentSystem,
-  config ? { },
-  pkgs ? import ../.. { inherit system config; },
-}:
-
-{
-  # Some of these tests don't work with systemd stage 1 yet. Uncomment
-  # them when fixed.
-  inherit
-    (import ./installer.nix {
-      inherit system config pkgs;
-      systemdStage1 = true;
-    })
-    # bcache
-    bcachefsSimple
-    bcachefsEncrypted
-    btrfsSimple
-    btrfsSubvolDefault
-    btrfsSubvolEscape
-    btrfsSubvols
-    encryptedFSWithKeyfile
-    # grub1
-    luksroot
-    luksroot-format1
-    luksroot-format2
-    lvm
-    separateBoot
-    separateBootFat
-    separateBootZfs
-    simple
-    simpleLabels
-    simpleProvided
-    simpleSpecialised
-    simpleUefiGrub
-    simpleUefiGrubSpecialisation
-    simpleUefiSystemdBoot
-    stratisRoot
-    swraid
-    zfsroot
-    clevisLuks
-    clevisLuksFallback
-    clevisZfs
-    clevisZfsFallback
-    clevisZfsParentDataset
-    clevisZfsParentDatasetFallback
-    gptAutoRoot
-    clevisBcachefs
-    clevisBcachefsFallback
-    ;
-
-}
diff --git a/nixos/tests/installer.nix b/nixos/tests/installer.nix
index 892c066c568b..80148997bff0 100644
--- a/nixos/tests/installer.nix
+++ b/nixos/tests/installer.nix
@@ -2,7 +2,7 @@
   system ? builtins.currentSystem,
   config ? { },
   pkgs ? import ../.. { inherit system config; },
-  systemdStage1 ? false,
+  systemdStage1,
 }:
 
 with import ../lib/testing-python.nix { inherit system pkgs; };
@@ -42,7 +42,7 @@ let
         # To ensure that we can rebuild the grub configuration on the nixos-rebuild
         system.extraDependencies = with pkgs; [ stdenvNoCC ];
 
-        ${optionalString systemdStage1 "boot.initrd.systemd.enable = true;"}
+        boot.initrd.systemd.enable = ${boolToString systemdStage1};
 
         ${optionalString (bootLoader == "grub") ''
           boot.loader.grub.extraConfig = "serial; terminal_output serial";
@@ -640,6 +640,7 @@ let
       clevisFallbackTest ? false,
       disableFileSystems ? false,
       selectNixPackage ? pkgs: pkgs.nixVersions.stable,
+      broken ? false,
     }:
     let
       isEfi = bootLoader == "systemd-boot" || (bootLoader == "grub" && grubUseEfi);
@@ -656,6 +657,7 @@ let
           "x86_64-darwin"
           "i686-linux"
         ];
+        inherit broken;
       };
       nodes =
         let
@@ -846,14 +848,23 @@ let
             "mount LABEL=boot /mnt/boot",
         )
       '';
-      extraConfig = ''
-        boot.kernelParams = lib.mkAfter [ "console=tty0" ];
-      '';
-      enableOCR = true;
-      postBootCommands = ''
-        target.wait_for_text("[Pp]assphrase for")
-        target.send_chars("supersecret\n")
-      '';
+      # The serial console is much more reliable than OCR, but
+      # scripted stage 1 doesn't forward logs / password prompts to
+      # it. (TODO: The test framework should use 'console=ttyS0'
+      # anyway, but currently it uses 'console=tty0' for the sake of
+      # the interactive driver)
+      enableOCR = !systemdStage1;
+      postBootCommands =
+        if systemdStage1 then
+          ''
+            target.wait_for_console_text("passphrase for")
+            target.send_console("supersecret\n")
+          ''
+        else
+          ''
+            target.wait_for_text("[Pp]assphrase for")
+            target.send_chars("supersecret\n")
+          '';
     };
 
   # The (almost) simplest partitioning scheme: a swap partition and
@@ -879,11 +890,13 @@ let
 
   simple-test-config-by-attr = simple-test-config // {
     testByAttrSwitch = true;
+    broken = true;
   };
 
   simple-test-config-from-by-attr-to-flake = simple-test-config // {
     testByAttrSwitch = true;
     testFlakeSwitch = true;
+    broken = true;
   };
 
   simple-uefi-grub-config = {
@@ -1387,6 +1400,7 @@ in
   # Full disk encryption (root, kernel and initrd encrypted) using GRUB, GPT/UEFI,
   # LVM-on-LUKS and a keyfile in initrd.secrets to enter the passphrase once
   fullDiskEncryption = makeInstallerTest "fullDiskEncryption" {
+    broken = true;
     createPartitions = ''
       installer.succeed(
           "flock /dev/vda parted --script /dev/vda -- mklabel gpt"

From 0b198b61f6e739bca7451793d53aa5601b0674ec Mon Sep 17 00:00:00 2001
From: Will Fancher <elvishjerricco@gmail.com>
Date: Tue, 26 Aug 2025 01:43:34 -0400
Subject: [PATCH 20/35] nixos/tests/ec2-nixops: Support both stage 1
 implementations

---
 nixos/tests/ec2.nix | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/nixos/tests/ec2.nix b/nixos/tests/ec2.nix
index ae9a79db5403..1a84033ffed5 100644
--- a/nixos/tests/ec2.nix
+++ b/nixos/tests/ec2.nix
@@ -19,9 +19,13 @@ let
         ../modules/profiles/qemu-guest.nix
         {
           # Hack to make the partition resizing work in QEMU.
-          boot.initrd.postDeviceCommands = mkBefore ''
-            ln -s vda /dev/xvda
-            ln -s vda1 /dev/xvda1
+          boot.initrd.services.udev.rules = ''
+            KERNEL==vda, SYMLINK+=xvda
+            KERNEL==vda1, SYMLINK+=xvda1
+          '';
+          services.udev.extraRules = ''
+            KERNEL==vda, SYMLINK+=xvda
+            KERNEL==vda1, SYMLINK+=xvda1
           '';
 
           amazonImage.format = "qcow2";

From 65090b23f6ec329bcc1d54eb970299395ed85ccd Mon Sep 17 00:00:00 2001
From: Will Fancher <elvishjerricco@gmail.com>
Date: Wed, 10 Sep 2025 06:10:57 -0400
Subject: [PATCH 21/35] nixos/tests/qemu-vm-external-disk-image: Increase
 bootSize

The systemd initrd is a little larger and it's gone over the threshold.
---
 nixos/tests/qemu-vm-external-disk-image.nix | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/nixos/tests/qemu-vm-external-disk-image.nix b/nixos/tests/qemu-vm-external-disk-image.nix
index b01cabbadb5d..6b6a2ef29a28 100644
--- a/nixos/tests/qemu-vm-external-disk-image.nix
+++ b/nixos/tests/qemu-vm-external-disk-image.nix
@@ -32,7 +32,7 @@ let
         label = rootFslabel;
         partitionTableType = "efi";
         format = "qcow2";
-        bootSize = "32M";
+        bootSize = "128M";
         additionalSpace = "0M";
         copyChannel = false;
       };

From 222ee6e2451960162ef53b5c0c30bc8e64d2c8a3 Mon Sep 17 00:00:00 2001
From: Will Fancher <elvishjerricco@gmail.com>
Date: Fri, 26 Sep 2025 02:17:56 -0400
Subject: [PATCH 22/35] nixos/luksroot: Unhide crypttabExtraOpts

---
 nixos/modules/system/boot/luksroot.nix | 1 -
 1 file changed, 1 deletion(-)

diff --git a/nixos/modules/system/boot/luksroot.nix b/nixos/modules/system/boot/luksroot.nix
index e925a1e7d2d0..02e39df724c1 100644
--- a/nixos/modules/system/boot/luksroot.nix
+++ b/nixos/modules/system/boot/luksroot.nix
@@ -999,7 +999,6 @@ in
                   type = with types; listOf singleLineStr;
                   default = [ ];
                   example = [ "_netdev" ];
-                  visible = false;
                   description = ''
                     Only used with systemd stage 1.
 

From 5312ce1bae2879cc2ff7a3e2851bf32918099079 Mon Sep 17 00:00:00 2001
From: Will Fancher <elvishjerricco@gmail.com>
Date: Sun, 5 Apr 2026 17:11:38 -0400
Subject: [PATCH 23/35] nixos/systemd-stage-1/users-groups: Assert against
 cryptsetup-askpass

---
 nixos/modules/config/users-groups.nix | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/nixos/modules/config/users-groups.nix b/nixos/modules/config/users-groups.nix
index 461c219ee807..56ff03aefec1 100644
--- a/nixos/modules/config/users-groups.nix
+++ b/nixos/modules/config/users-groups.nix
@@ -1143,6 +1143,16 @@ in
           '';
         }
       ]
+      ++ flip mapAttrsToList config.boot.initrd.systemd.users (
+        name: user: {
+          assertion = config.boot.initrd.systemd.enable -> (baseNameOf user.shell != "cryptsetup-askpass");
+          message = ''
+            cryptsetup-askpass is not available in systemd stage 1. Please remove it from: boot.initrd.systemd.users.${name}.shell
+
+            Use `systemctl default` instead; see the NixOS 26.05 release notes for details. If you want to continue restricting the command for SSH login, you can use `command="systemctl default"` in SSH authorized keys instead; see `sshd(8)`.
+          '';
+        }
+      )
       ++ flatten (
         flip mapAttrsToList cfg.users (
           name: user:

From 5620d245adf03c58b74f803031ba2a85d204db31 Mon Sep 17 00:00:00 2001
From: Will Fancher <elvishjerricco@gmail.com>
Date: Fri, 15 Aug 2025 15:43:01 -0400
Subject: [PATCH 24/35] nixos/systemd-stage-1: Enable by default

---
 .../administration/boot-problems.section.md   | 84 ++++++++++++-------
 .../installing-from-other-distro.section.md   |  9 +-
 nixos/doc/manual/redirects.json               |  3 +
 .../manual/release-notes/rl-2605.section.md   | 10 +++
 nixos/modules/system/boot/stage-1.nix         |  4 +
 nixos/modules/system/boot/systemd/initrd.nix  | 84 +++++++++++--------
 nixos/release-combined.nix                    | 20 +++++
 7 files changed, 143 insertions(+), 71 deletions(-)

diff --git a/nixos/doc/manual/administration/boot-problems.section.md b/nixos/doc/manual/administration/boot-problems.section.md
index bca4fdc3fb38..357c6e5ea0ef 100644
--- a/nixos/doc/manual/administration/boot-problems.section.md
+++ b/nixos/doc/manual/administration/boot-problems.section.md
@@ -1,41 +1,61 @@
 # Boot Problems {#sec-boot-problems}
 
-If NixOS fails to boot, there are a number of kernel command line parameters that may help you to identify or fix the issue. You can add these parameters in the GRUB boot menu by pressing “e” to modify the selected boot entry and editing the line starting with `linux`. The following are some useful kernel command line parameters that are recognised by the NixOS boot scripts or by systemd:
+If NixOS fails to boot, there are a number of kernel command line parameters that may help you to identify or fix the issue. You can add these parameters in the GRUB boot menu by pressing “e” to modify the selected boot entry and editing the line starting with `linux`.
 
-`boot.shell_on_fail`
-
-: Allows the user to start a root shell if something goes wrong in stage 1 of the boot process (the initial ramdisk). This is disabled by default because there is no authentication for the root shell.
-
-`boot.debug1`
-
-: Start an interactive shell in stage 1 before anything useful has been done. That is, no modules have been loaded and no file systems have been mounted, except for `/proc` and `/sys`.
-
-`boot.debug1devices`
-
-: Like `boot.debug1`, but runs stage1 until kernel modules are loaded and device nodes are created. This may help with e.g. making the keyboard work.
-
-`boot.debug1mounts`
-
-: Like `boot.debug1` or `boot.debug1devices`, but runs stage1 until all filesystems that are mounted during initrd are mounted (see [neededForBoot](#opt-fileSystems._name_.neededForBoot)). As a motivating example, this could be useful if you've forgotten to set [neededForBoot](#opt-fileSystems._name_.neededForBoot) on a file system.
-
-`boot.trace`
-
-: Print every shell command executed by the stage 1 and 2 boot scripts.
-
-`single`
-
-: Boot into rescue mode (a.k.a. single user mode). This will cause systemd to start nothing but the unit `rescue.target`, which runs `sulogin` to prompt for the root password and start a root login shell. Exiting the shell causes the system to continue with the normal boot process.
-
-`systemd.log_level=debug` `systemd.log_target=console`
-
-: Make systemd very verbose and send log messages to the console instead of the journal. For more parameters recognised by systemd, see systemd(1).
-
-In addition, these arguments are recognised by the live image only:
+{manpage}`kernel-command-line(7)` documents the kernel parameters accepted by systemd. Those include many that are helpful for debugging boot issues, such as `systemd.debug_shell` and `rescue`. Some also have `rd.`‐prefixed variants that apply to stage 1.
 
 `live.nixos.passwd=password`
 
 : Set the password for the `nixos` live user. This can be used for SSH access if there are issues using the terminal.
 
-Notice that for `boot.shell_on_fail`, `boot.debug1`, `boot.debug1devices`, and `boot.debug1mounts`, if you did **not** select "start the new shell as pid 1", and you `exit` from the new shell, boot will proceed normally from the point where it failed, as if you'd chosen "ignore the error and continue".
+If no login prompts or X11 login screens appear (e.g. due to hanging dependencies), you can press Alt+ArrowUp. If you’re lucky, this will start `rescue.target` (described in {manpage}`systemd.special(7)`). (Also note that since most units have a 90-second timeout before systemd gives up on them, the `agetty` login prompts should appear eventually unless something is very wrong.)
 
-If no login prompts or X11 login screens appear (e.g. due to hanging dependencies), you can press Alt+ArrowUp. If you’re lucky, this will start rescue mode (described above). (Also note that since most units have a 90-second timeout before systemd gives up on them, the `agetty` login prompts should appear eventually unless something is very wrong.)
+## Scripted stage 1 {#sec-boot-problems-scripted-stage-1}
+
+The scripted implementation of stage 1 also understands these boot parameters.
+
+::: {.warning}
+The scripted implementation of stage 1 is disabled by default and deprecated. These parameters have no effect, unless systemd stage 1 is explicitly disabled with `boot.initrd.systemd.enable = false;`.
+:::
+
+`boot.shell_on_fail`
+
+: Allows the user to start a root shell if something goes wrong in stage 1 of the boot process (the initial ramdisk). This is disabled by default because there is no authentication for the root shell.
+
+  ::: {.note}
+  systemd stage 1 alternative: `SYSTEMD_SULOGIN_FORCE=1` for rescue mode, or `rd.systemd.debug_shell` for shell on tty9.
+  :::
+
+`boot.debug1`
+
+: Start an interactive shell in stage 1 before anything useful has been done. That is, no modules have been loaded and no file systems have been mounted, except for `/proc` and `/sys`.
+
+  ::: {.note}
+  systemd stage 1 alternative: `rd.systemd.break=pre-udev`
+  :::
+
+`boot.debug1devices`
+
+: Like `boot.debug1`, but runs stage1 until kernel modules are loaded and device nodes are created. This may help with e.g. making the keyboard work.
+
+  ::: {.note}
+  systemd stage 1 alternative: `rd.systemd.break=pre-mount`
+  :::
+
+`boot.debug1mounts`
+
+: Like `boot.debug1` or `boot.debug1devices`, but runs stage1 until all filesystems that are mounted during initrd are mounted (see [neededForBoot](#opt-fileSystems._name_.neededForBoot)). As a motivating example, this could be useful if you've forgotten to set [neededForBoot](#opt-fileSystems._name_.neededForBoot) on a file system.
+
+  ::: {.note}
+  systemd stage 1 alternative: `rd.systemd.break=pre-switch-root`
+  :::
+
+`boot.trace`
+
+: Print every shell command executed by the stage 1 and 2 boot scripts.
+
+  ::: {.note}
+  systemd stage 1 alternative: `rd.systemd.log_level=debug`
+  :::
+
+Notice that for `boot.shell_on_fail`, `boot.debug1`, `boot.debug1devices`, and `boot.debug1mounts`, if you did **not** select "start the new shell as pid 1", and you `exit` from the new shell, boot will proceed normally from the point where it failed, as if you'd chosen "ignore the error and continue".
diff --git a/nixos/doc/manual/installation/installing-from-other-distro.section.md b/nixos/doc/manual/installation/installing-from-other-distro.section.md
index 56b1cca00e05..2b9d3171264a 100644
--- a/nixos/doc/manual/installation/installing-from-other-distro.section.md
+++ b/nixos/doc/manual/installation/installing-from-other-distro.section.md
@@ -149,6 +149,10 @@ The first steps to all these are the same:
     `NIXOS_LUSTRATE`:
     :::
 
+    ::: {.warning}
+    The lustrate process will not work if the [](#opt-boot.initrd.systemd.enable) option is set to `true`, which is now the default. Setting this to `false` is deprecated and scheduled for removal in NixOS 26.11, along with `NIXOS_LUSTRATE`. Other installation methods, such as the one outlined above, or installing from [kexec](#sec-booting-via-kexec), are recommended instead.
+    :::
+
     Generate your NixOS configuration:
 
     ```ShellSession
@@ -167,11 +171,6 @@ The first steps to all these are the same:
     If the current system and NixOS's bootloader configuration don't agree on where the [EFI System Partition](https://en.wikipedia.org/wiki/EFI_system_partition) is to be mounted, you'll need to manually alter the mount point in `hardware-configuration.nix` before building the system closure.
     :::
 
-    ::: {.note}
-    The lustrate process will not work if the [](#opt-boot.initrd.systemd.enable) option is set to `true`.
-    If you want to use this option, wait until after the first boot into the NixOS system to enable it and rebuild.
-    :::
-
     You'll likely want to set a root password for your first boot using
     the configuration files because you won't have a chance to enter a
     password until after you reboot. You can initialize the root password
diff --git a/nixos/doc/manual/redirects.json b/nixos/doc/manual/redirects.json
index 7bf88472148e..feb535c2142c 100644
--- a/nixos/doc/manual/redirects.json
+++ b/nixos/doc/manual/redirects.json
@@ -151,6 +151,9 @@
   "module-virtualisation-xen-introduction": [
     "index.html#module-virtualisation-xen-introduction"
   ],
+  "sec-boot-problems-scripted-stage-1": [
+    "index.html#sec-boot-problems-scripted-stage-1"
+  ],
   "sec-nixos-test-vms-vs-containers": [
     "index.html#sec-nixos-test-vms-vs-containers"
   ],
diff --git a/nixos/doc/manual/release-notes/rl-2605.section.md b/nixos/doc/manual/release-notes/rl-2605.section.md
index 5220d49e71e2..c0caa51bd18f 100644
--- a/nixos/doc/manual/release-notes/rl-2605.section.md
+++ b/nixos/doc/manual/release-notes/rl-2605.section.md
@@ -4,6 +4,16 @@
 
 <!-- To avoid merge conflicts, consider adding your item at an arbitrary place in the list instead. -->
 
+- Stage 1 (a.k.a. initrd) is now based on systemd by default, and the old scripted implementation is deprecated and scheduled for removal in 26.11. If you run into issues migrating, you can [get help from the community](https://nixos.org/community/) or report an issue on GitHub.
+
+  You can temporarily revert to the scripted stage 1 implementation by disabling [](#opt-boot.initrd.systemd.enable), but this is discouraged.
+
+  Most incompatibilities will be explained with assertions during configuration evaluation, but be aware of the following that can't be automatically detected:
+
+  - If you use LUKS disk encryption, ensure that `fileSystems."/".device` is set to `"/dev/mapper/<name>"`, where `<name>` matches the name in your `boot.initrd.luks.devices.<name>` definition, to avoid systemd timing out while prompting for a passphrase. If you have a more complex setup, e.g. with LVM on top of LUKS, you may need to add `"x-systemd.device-timeout=infinity"` to `fileSystems."/".options` instead. If you need to disable the timeout before you can boot into the system, pass `systemd.default_device_timeout_sec=infinity` on the kernel command line.
+  - The `cryptsetup-askpass` program is not available; use `systemctl default` instead, which will prompt for passphrases as necessary. If you pipe password responses into SSH over stdin, use `ssh -o RequestTTY=force` to ensure `systemctl default` gets a TTY to prompt on.
+  - Many kernel parameters have been replaced with native systemd versions; see [](#sec-boot-problems).
+
 - The system.nix file has been added has an alternative entry point to configuration.nix (and flake.nix) that allows to configure NixOS without using `nix-channel`.
   This file must evaluate to a NixOS system derivation or an attribute set of such derivations, in which case the attribute to build has to be selected with the `--attr` option of `nixos-rebuild` or `nixos-install`.
   For example,
diff --git a/nixos/modules/system/boot/stage-1.nix b/nixos/modules/system/boot/stage-1.nix
index 343777d05c3a..a2594b3e9ab3 100644
--- a/nixos/modules/system/boot/stage-1.nix
+++ b/nixos/modules/system/boot/stage-1.nix
@@ -727,6 +727,10 @@ in
   };
 
   config = mkIf config.boot.initrd.enable {
+    warnings = lib.optional (!config.boot.initrd.systemd.enable) ''
+      Scripted initrd is deprecated and scheduled for removal in 26.11. See the NixOS 26.05 release notes.
+    '';
+
     assertions = [
       {
         assertion = !config.boot.initrd.systemd.enable -> any (fs: fs.mountPoint == "/") fileSystems;
diff --git a/nixos/modules/system/boot/systemd/initrd.nix b/nixos/modules/system/boot/systemd/initrd.nix
index f61d94b7851a..c3713c026b0e 100644
--- a/nixos/modules/system/boot/systemd/initrd.nix
+++ b/nixos/modules/system/boot/systemd/initrd.nix
@@ -157,6 +157,7 @@ in
 
   options.boot.initrd.systemd = {
     enable = mkEnableOption "systemd in initrd" // {
+      default = true;
       description = ''
         Whether to enable systemd in initrd. The unit options such as
         {option}`boot.initrd.systemd.services` are the same as their
@@ -427,42 +428,57 @@ in
   };
 
   config = mkIf (config.boot.initrd.enable && cfg.enable) {
-    assertions = [
-      {
-        assertion =
-          cfg.root == "fstab" -> any (fs: fs.mountPoint == "/") (builtins.attrValues config.fileSystems);
-        message = "The ‘fileSystems’ option does not specify your root file system.";
-      }
-    ]
-    ++
-      map
-        (name: {
-          assertion = lib.attrByPath name (throw "impossible") config.boot.initrd == "";
-          message = ''
-            systemd stage 1 does not support 'boot.initrd.${lib.concatStringsSep "." name}'. Please
-              convert it to analogous systemd units in 'boot.initrd.systemd'.
-
-                Definitions:
-            ${lib.concatMapStringsSep "\n" ({ file, ... }: "    - ${file}")
-              (lib.attrByPath name (throw "impossible") options.boot.initrd).definitionsWithLocations
-            }
-          '';
-        })
-        [
-          [ "preFailCommands" ]
-          [ "preDeviceCommands" ]
-          [ "preLVMCommands" ]
-          [ "postDeviceCommands" ]
-          [ "postResumeCommands" ]
-          [ "postMountCommands" ]
-          [ "extraUdevRulesCommands" ]
-          [ "extraUtilsCommands" ]
-          [ "extraUtilsCommandsTest" ]
+    assertions =
+      let
+        obsoleteOpt =
+          opts: msgFn:
+          lib.flip map opts (opt: {
+            assertion = lib.attrByPath opt (throw "impossible") config.boot.initrd == "";
+            message = ''
+              ${msgFn (lib.concatStringsSep "." opt)}
+                  Definitions:
+              ${lib.concatMapStringsSep "\n" ({ file, ... }: "    - ${file}")
+                (lib.attrByPath opt (throw "impossible") options.boot.initrd).definitionsWithLocations
+              }
+            '';
+          });
+      in
+      [
+        {
+          assertion =
+            cfg.root == "fstab" -> any (fs: fs.mountPoint == "/") (builtins.attrValues config.fileSystems);
+          message = "The ‘fileSystems’ option does not specify your root file system.";
+        }
+      ]
+      ++
+        obsoleteOpt
           [
-            "network"
-            "postCommands"
+            [ "preFailCommands" ]
+            [ "preDeviceCommands" ]
+            [ "preLVMCommands" ]
+            [ "postDeviceCommands" ]
+            [ "postResumeCommands" ]
+            [ "postMountCommands" ]
+            [
+              "network"
+              "postCommands"
+            ]
           ]
-        ];
+          (name: ''
+            systemd stage 1 does not support `boot.initrd.${name}`. Instead, create systemd services using the `boot.initrd.systemd.services` options, which has an API matching the stage 2 `systemd.services` options. Refer to `bootup(7)`, specifically the sections on "Bootup in the Initrd" and "System Manager Bootup", for information about when various units happen, and order services accordingly.
+          '')
+      ++
+        obsoleteOpt
+          [
+            [ "extraUtilsCommands" ]
+            [ "extraUtilsCommandsTest" ]
+          ]
+          (name: ''
+            systemd stage 1 does not support `boot.initrd.${name}`. Instead, use `boot.initrd.systemd.initrdBin`, `boot.initrd.systemd.extraBin`, `boot.initrd.systemd.contents`, or `boot.initrd.systemd.storePaths` to add files to the initrd.
+          '')
+      ++ obsoleteOpt [ [ "extraUdevRulesCommands" ] ] (name: ''
+        systemd stage 1 does not support `boot.initrd.${name}`. Instead, use `boot.initrd.services.udev` to configure udev.
+      '');
 
     system.build = { inherit initialRamdisk; };
 
diff --git a/nixos/release-combined.nix b/nixos/release-combined.nix
index d299ead82a1b..40eb4a0d34ae 100644
--- a/nixos/release-combined.nix
+++ b/nixos/release-combined.nix
@@ -103,6 +103,24 @@ rec {
         (onFullSupported "nixos.tests.gnome")
         (onSystems [ "x86_64-linux" ] "nixos.tests.hibernate")
         (onFullSupported "nixos.tests.i3wm")
+        (onSystems [ "aarch64-linux" ] "nixos.tests.installer-systemd-stage-1.simpleUefiSystemdBoot")
+        (onSystems [ "x86_64-linux" ] "nixos.tests.installer-systemd-stage-1.btrfsSimple")
+        (onSystems [ "x86_64-linux" ] "nixos.tests.installer-systemd-stage-1.btrfsSubvolDefault")
+        (onSystems [ "x86_64-linux" ] "nixos.tests.installer-systemd-stage-1.btrfsSubvolEscape")
+        (onSystems [ "x86_64-linux" ] "nixos.tests.installer-systemd-stage-1.btrfsSubvols")
+        (onSystems [ "x86_64-linux" ] "nixos.tests.installer-systemd-stage-1.luksroot")
+        (onSystems [ "x86_64-linux" ] "nixos.tests.installer-systemd-stage-1.lvm")
+        (onSystems [ "x86_64-linux" ] "nixos.tests.installer-systemd-stage-1.separateBootZfs")
+        (onSystems [ "x86_64-linux" ] "nixos.tests.installer-systemd-stage-1.separateBootFat")
+        (onSystems [ "x86_64-linux" ] "nixos.tests.installer-systemd-stage-1.separateBoot")
+        (onSystems [ "x86_64-linux" ] "nixos.tests.installer-systemd-stage-1.simpleLabels")
+        (onSystems [ "x86_64-linux" ] "nixos.tests.installer-systemd-stage-1.simpleProvided")
+        (onSystems [ "x86_64-linux" ] "nixos.tests.installer-systemd-stage-1.simpleUefiSystemdBoot")
+        (onSystems [ "x86_64-linux" ] "nixos.tests.installer-systemd-stage-1.simple")
+        (onSystems [ "x86_64-linux" ] "nixos.tests.installer-systemd-stage-1.swraid")
+        (onSystems [ "x86_64-linux" ] "nixos.tests.installer-systemd-stage-1.zfsroot")
+        (onSystems [ "x86_64-linux" ] "nixos.tests.nixos-rebuild-specialisations")
+        # Scripted stage 1 installer tests, remove in 26.11
         (onSystems [ "aarch64-linux" ] "nixos.tests.installer.simpleUefiSystemdBoot")
         (onSystems [ "x86_64-linux" ] "nixos.tests.installer.btrfsSimple")
         (onSystems [ "x86_64-linux" ] "nixos.tests.installer.btrfsSubvolDefault")
@@ -166,6 +184,8 @@ rec {
         (onFullSupported "nixos.tests.nfs4.simple")
         (onSystems [ "x86_64-linux" ] "nixos.tests.oci-containers.podman")
         (onFullSupported "nixos.tests.openssh")
+        (onFullSupported "nixos.tests.systemd-initrd-networkd-ssh")
+        # Scripted stage 1 SSH test, remove in 26.11
         (onFullSupported "nixos.tests.initrd-network-ssh")
         (onFullSupported "nixos.tests.pantheon")
         (onFullSupported "nixos.tests.php.fpm")

From 1e4eb2df3fe59c4ef9a20830a18ae2771b8bfa45 Mon Sep 17 00:00:00 2001
From: rnhmjoj <rnhmjoj@inventati.org>
Date: Sat, 28 Mar 2026 21:35:49 +0100
Subject: [PATCH 25/35] nixos: completely remove systemd-udev-settle.service

This service is essentially a random sleep() call that old software that
is unable to properly handle modern hardware initialisation being
asynchronous can use to *mostly* get by.

Over the years is has caused so many issues in NixOS, like introducing
long delays in the boot process[1], complete deadlocks[2] and even failures
when reloading services or activating a new configuration[3].

systemd has been discouraging its use since 2011 (15 years ago!), then
it officially deprecated it in 2018 and since 2020 it started to show on
every boot a huge wall of text calling out all the offending services
that still use it.

Around 2021 we managed to fix around 15 NixOS modules[4] that were
relying on systemd-udev-settle and practically ZFS[5] was the only
remaining one. However, since then, people have actually started to
bring it back with new services[6][7][8]. This is not acceptable.

So, to prevent any more (lazy) uses of systemd-udev-settle, we stop
providing the systemd-udev-settle.service unit entirely. For existing
modules that unfortunately still need it, we replace it with the command
`udevadm settle --timeout=180`, which is all that the service does.
Hopefully this will also increase the awareness that it's bad and
something to be fixed.

Note: I tested this change using

 - `nixosTests.zfs`,
 - `nixosTests.ifstate`,
 - `nixosTests.misc`,
 - `nixosTests.openvswitch`,
 - `nixosTests.predictable-interface-names`
 - `nixosTests.nvidia-container-toolkit`

and making sure that none of the 165 packages that provide upstream
units (via the `systemd.packages` option) had a dependency on
systemd-udev-settle.service.

[1]: https://github.com/NixOS/nixpkgs/pull/25311
[2]: https://github.com/NixOS/nixpkgs/issues/107341
[3]: https://github.com/NixOS/nixpkgs/pull/113804
[4]: https://github.com/NixOS/nixpkgs/issues/73095
[5]: https://github.com/openzfs/zfs/issues/10891
[6]: https://github.com/NixOS/nixpkgs/pull/257525#discussion_r1442702970
[7]: https://github.com/NixOS/nixpkgs/pull/460075
[8]: https://github.com/NixOS/nixpkgs/pull/284507
---
 .../hardware/nvidia-container-toolkit/default.nix |  6 +++++-
 nixos/modules/services/hardware/udev.nix          |  1 -
 nixos/modules/services/networking/ifstate.nix     | 11 ++++++++---
 nixos/modules/system/boot/systemd.nix             |  2 --
 nixos/modules/tasks/filesystems/zfs.nix           | 15 ++++++---------
 nixos/modules/virtualisation/openvswitch.nix      |  1 -
 nixos/tests/misc.nix                              |  3 +--
 nixos/tests/predictable-interface-names.nix       |  3 ++-
 8 files changed, 22 insertions(+), 20 deletions(-)

diff --git a/nixos/modules/services/hardware/nvidia-container-toolkit/default.nix b/nixos/modules/services/hardware/nvidia-container-toolkit/default.nix
index 475a5122fd4e..1a1365c5d420 100644
--- a/nixos/modules/services/hardware/nvidia-container-toolkit/default.nix
+++ b/nixos/modules/services/hardware/nvidia-container-toolkit/default.nix
@@ -320,7 +320,6 @@
 
       systemd.services.nvidia-container-toolkit-cdi-generator = {
         description = "Container Device Interface (CDI) for Nvidia generator";
-        after = [ "systemd-udev-settle.service" ];
         requiredBy = lib.mkMerge [
           (lib.mkIf config.virtualisation.docker.enable [ "docker.service" ])
           (lib.mkIf config.virtualisation.podman.enable [ "podman.service" ])
@@ -329,6 +328,11 @@
         serviceConfig = {
           RuntimeDirectory = "cdi";
           RemainAfterExit = true;
+          # We wait for the udev events queue to empty in the *hope* that the
+          # devices needed here become available. This is terribly broken and
+          # essentially no better than a random sleep(). See PR #452645 for
+          # an attempt to fix this issue.
+          ExecStartPre = "-${lib.getExe' pkgs.systemd "udevadm"} settle --timeout=180";
           ExecStart =
             let
               script = pkgs.callPackage ./cdi-generate.nix {
diff --git a/nixos/modules/services/hardware/udev.nix b/nixos/modules/services/hardware/udev.nix
index 6e779df94e77..1299a5115a5f 100644
--- a/nixos/modules/services/hardware/udev.nix
+++ b/nixos/modules/services/hardware/udev.nix
@@ -455,7 +455,6 @@ in
       "systemd-udevd-control.socket"
       "systemd-udevd-kernel.socket"
       "systemd-udevd.service"
-      "systemd-udev-settle.service"
       "systemd-udev-trigger.service"
     ];
     boot.initrd.systemd.storePaths = [
diff --git a/nixos/modules/services/networking/ifstate.nix b/nixos/modules/services/networking/ifstate.nix
index 051322fc1ce5..ef44463ba9cf 100644
--- a/nixos/modules/services/networking/ifstate.nix
+++ b/nixos/modules/services/networking/ifstate.nix
@@ -69,7 +69,6 @@ let
   # https://github.com/systemd/systemd/blob/main/units/systemd-networkd.service.in
   commonServiceConfig = {
     after = [
-      "systemd-udev-settle.service"
       "network-pre.target"
       "systemd-sysusers.service"
       "systemd-sysctl.service"
@@ -88,6 +87,12 @@ let
       "network.target"
     ];
 
+    # We wait for the udev events queue to empty in the *hope* that the
+    # devices needed here become available. This is terribly broken and
+    # essentially no better than a random sleep().
+    # FIXME: use .device units dependecies instead.
+    serviceConfig.ExecStartPre = "-${lib.getExe' pkgs.systemd "udevadm"} settle --timeout=180";
+
     unitConfig = {
       # Avoid default dependencies like "basic.target", which prevents ifstate from starting before luks is unlocked.
       DefaultDependencies = "no";
@@ -173,7 +178,7 @@ in
         etc."ifstate/ifstate.yaml".source = settingsFormat.generate "ifstate.yaml" cfg.settings cfg.package;
       };
 
-      systemd.services.ifstate = commonServiceConfig // {
+      systemd.services.ifstate = lib.recursiveUpdate commonServiceConfig {
         description = "IfState";
 
         wantedBy = [
@@ -263,7 +268,7 @@ in
             "remote-fs.target"
           ];
 
-          services.ifstate-initrd = commonServiceConfig // {
+          services.ifstate-initrd = lib.recursiveUpdate commonServiceConfig {
             description = "IfState initrd";
 
             wantedBy = [
diff --git a/nixos/modules/system/boot/systemd.nix b/nixos/modules/system/boot/systemd.nix
index 56b87de1f394..99d7f13af5e9 100644
--- a/nixos/modules/system/boot/systemd.nix
+++ b/nixos/modules/system/boot/systemd.nix
@@ -65,7 +65,6 @@ let
     "systemd-udevd-control.socket"
     "systemd-udevd-kernel.socket"
     "systemd-udevd.service"
-    "systemd-udev-settle.service"
   ]
   ++ (optional (!config.boot.isContainer) "systemd-udev-trigger.service")
   ++ [
@@ -799,7 +798,6 @@ in
     systemd.services.systemd-random-seed.restartIfChanged = false;
     systemd.services.systemd-remount-fs.restartIfChanged = false;
     systemd.services.systemd-update-utmp.restartIfChanged = false;
-    systemd.services.systemd-udev-settle.restartIfChanged = false; # Causes long delays in nixos-rebuild
     systemd.targets.local-fs.unitConfig.X-StopOnReconfiguration = true;
     systemd.targets.remote-fs.unitConfig.X-StopOnReconfiguration = true;
     systemd.services.systemd-importd.environment = proxy_env;
diff --git a/nixos/modules/tasks/filesystems/zfs.nix b/nixos/modules/tasks/filesystems/zfs.nix
index a4f27ed840a9..48f85a913779 100644
--- a/nixos/modules/tasks/filesystems/zfs.nix
+++ b/nixos/modules/tasks/filesystems/zfs.nix
@@ -158,16 +158,8 @@ let
     }:
     lib.nameValuePair "zfs-import-${pool}" {
       description = "Import ZFS pool \"${pool}\"";
-      # We wait for systemd-udev-settle to ensure devices are available,
-      # but don't *require* it, because mounts shouldn't be killed if it's stopped.
-      # In the future, hopefully someone will complete this:
-      # https://github.com/zfsonlinux/zfs/pull/4943
-      wants = [
-        "systemd-udev-settle.service"
-      ]
-      ++ lib.optional (config.boot.initrd.clevis.useTang) "network-online.target";
+      wants = lib.optional (config.boot.initrd.clevis.useTang) "network-online.target";
       after = [
-        "systemd-udev-settle.service"
         "systemd-modules-load.service"
         "systemd-ask-password-console.service"
       ]
@@ -189,6 +181,11 @@ let
       serviceConfig = {
         Type = "oneshot";
         RemainAfterExit = true;
+        # We wait for the udev events queue to empty in the *hope* that the
+        # devices needed by the pool become available. This is terribly broken
+        # and essentially no better than a random sleep(), but we can't do any
+        # better, see upstream issue https://github.com/openzfs/zfs/issues/10891
+        ExecStartPre = "${lib.getExe' pkgs.systemd "udevadm"} settle --timeout=180";
       };
       environment.ZFS_FORCE = lib.optionalString force "-f";
       script =
diff --git a/nixos/modules/virtualisation/openvswitch.nix b/nixos/modules/virtualisation/openvswitch.nix
index 5a231fb5888c..4e75d1677955 100644
--- a/nixos/modules/virtualisation/openvswitch.nix
+++ b/nixos/modules/virtualisation/openvswitch.nix
@@ -67,7 +67,6 @@ in
       systemd.services.ovsdb = {
         description = "Open_vSwitch Database Server";
         wantedBy = [ "multi-user.target" ];
-        after = [ "systemd-udev-settle.service" ];
         path = [ cfg.package ];
         restartTriggers = [
           db
diff --git a/nixos/tests/misc.nix b/nixos/tests/misc.nix
index 3e296d8d428c..12c0275b3a23 100644
--- a/nixos/tests/misc.nix
+++ b/nixos/tests/misc.nix
@@ -106,8 +106,7 @@ in
         assert "machine" == machine.succeed("hostname -s").strip()
 
     with subtest("whether systemd-udevd automatically loads modules for our hardware"):
-        machine.succeed("systemctl start systemd-udev-settle.service")
-        machine.wait_for_unit("systemd-udev-settle.service")
+        machine.succeed("udevadm settle --timeout=180")
         assert "mousedev" in machine.succeed("lsmod")
 
     with subtest("whether systemd-tmpfiles-clean works"):
diff --git a/nixos/tests/predictable-interface-names.nix b/nixos/tests/predictable-interface-names.nix
index 0bf2afce7a39..6282c433bae7 100644
--- a/nixos/tests/predictable-interface-names.nix
+++ b/nixos/tests/predictable-interface-names.nix
@@ -43,9 +43,10 @@ pkgs.lib.listToAttrs (
         meta = { };
 
         nodes.machine =
-          { lib, ... }:
+          { pkgs, lib, ... }:
           let
             script = ''
+              ${lib.getExe' pkgs.systemd "udevadm"} settle --timeout=180
               ip link
               if ${lib.optionalString predictable "!"} ip link show eth0; then
                 echo Success

From 35c3b96ba86853397b4b5b17b317cc7f85042774 Mon Sep 17 00:00:00 2001
From: rnhmjoj <rnhmjoj@inventati.org>
Date: Wed, 8 Apr 2026 10:28:29 +0200
Subject: [PATCH 26/35] nixos/zfs: remove udev settle hack

It may not be actually needed, at least anymore.
All nixosTests.zfs are passing.
---
 nixos/modules/tasks/filesystems/zfs.nix | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/nixos/modules/tasks/filesystems/zfs.nix b/nixos/modules/tasks/filesystems/zfs.nix
index 48f85a913779..9ee7a5ff86dc 100644
--- a/nixos/modules/tasks/filesystems/zfs.nix
+++ b/nixos/modules/tasks/filesystems/zfs.nix
@@ -181,11 +181,6 @@ let
       serviceConfig = {
         Type = "oneshot";
         RemainAfterExit = true;
-        # We wait for the udev events queue to empty in the *hope* that the
-        # devices needed by the pool become available. This is terribly broken
-        # and essentially no better than a random sleep(), but we can't do any
-        # better, see upstream issue https://github.com/openzfs/zfs/issues/10891
-        ExecStartPre = "${lib.getExe' pkgs.systemd "udevadm"} settle --timeout=180";
       };
       environment.ZFS_FORCE = lib.optionalString force "-f";
       script =

From 9a0ea0689bcbf7ab854d3c5c605d7eb3df572dfb Mon Sep 17 00:00:00 2001
From: Will Fancher <elvishjerricco@gmail.com>
Date: Wed, 8 Apr 2026 19:45:31 -0400
Subject: [PATCH 27/35] nixos/tests: Fix installer systemdStage1 argument

---
 nixos/tests/all-tests.nix | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/nixos/tests/all-tests.nix b/nixos/tests/all-tests.nix
index c66beaf27766..9a059c30563c 100644
--- a/nixos/tests/all-tests.nix
+++ b/nixos/tests/all-tests.nix
@@ -785,7 +785,7 @@ in
   input-remapper = runTest ./input-remapper.nix;
   inspircd = runTest ./inspircd.nix;
   installed-tests = recurseIntoAttrs (handleTest ./installed-tests { });
-  installer = handleTest ./installer.nix { systemdStage1 = true; };
+  installer = handleTest ./installer.nix { systemdStage1 = false; };
   installer-systemd-stage-1 = handleTest ./installer.nix { systemdStage1 = true; };
   intune = runTest ./intune.nix;
   invidious = runTest ./invidious.nix;

From afd024ffa386f1674785bd5751f3cda60d196ce0 Mon Sep 17 00:00:00 2001
From: Jost Alemann <alemann@posteo.com>
Date: Thu, 9 Apr 2026 20:39:24 +0200
Subject: [PATCH 28/35] ruff: 0.15.9 -> 0.15.10

Changelog: https://github.com/astral-sh/ruff/releases/tag/0.15.10
Diff: https://github.com/astral-sh/ruff/compare/0.15.9...0.15.10
---
 pkgs/by-name/ru/ruff/package.nix | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/pkgs/by-name/ru/ruff/package.nix b/pkgs/by-name/ru/ruff/package.nix
index 1b7deaaa92d7..6241410abaf8 100644
--- a/pkgs/by-name/ru/ruff/package.nix
+++ b/pkgs/by-name/ru/ruff/package.nix
@@ -16,18 +16,18 @@
 
 rustPlatform.buildRustPackage (finalAttrs: {
   pname = "ruff";
-  version = "0.15.9";
+  version = "0.15.10";
 
   src = fetchFromGitHub {
     owner = "astral-sh";
     repo = "ruff";
     tag = finalAttrs.version;
-    hash = "sha256-ePivGE8izhG1fj6efV/UdN8P/KdWVCUGCYGP9abLN5w=";
+    hash = "sha256-x+zqgIJATDWimxbh/VGt94HFiUSD4H9QD/49hnHgfuQ=";
   };
 
   cargoBuildFlags = [ "--package=ruff" ];
 
-  cargoHash = "sha256-DCTFjFl/fCbXwj7AGPNnrjvSTqxNW6PVWsUhbSGe/wI=";
+  cargoHash = "sha256-EQERi5NSMUK7qfFYWilzhacYlK4ShQl9Koz8t/8I6+U=";
 
   nativeBuildInputs = [ installShellFiles ];
 

From 24941111e4530c1b2104b0f3612c55b659e22ec6 Mon Sep 17 00:00:00 2001
From: Markus Theil <theil.markus@gmail.com>
Date: Fri, 10 Apr 2026 19:35:24 +0200
Subject: [PATCH 29/35] kernel: enable CONFIG_HW_RANDOM to be built-in

Starting with kernels around 6.18 and 6.19 I noticed,
that /dev/hwrng was no longer present and the TPM 2.0
usually found in modern computers did therefore not automatically
seed the kernel RNG with the hw random subsystem.

Enabling CONFIG_HW_RANDOM to yes fixes this. The subsystem
is rather small and should not increase the default kernel size
too much.

Signed-off-by: Markus Theil <theil.markus@gmail.com>
---
 pkgs/os-specific/linux/kernel/common-config.nix | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/pkgs/os-specific/linux/kernel/common-config.nix b/pkgs/os-specific/linux/kernel/common-config.nix
index 70dfebee57b9..6d1015afdcfe 100644
--- a/pkgs/os-specific/linux/kernel/common-config.nix
+++ b/pkgs/os-specific/linux/kernel/common-config.nix
@@ -825,6 +825,8 @@ let
         whenOlder "6.2" yes
       ); # allow RDRAND to seed the RNG
       RANDOM_TRUST_BOOTLOADER = whenOlder "6.2" yes; # allow the bootloader to seed the RNG
+      # only when compiled as yes, TPM 2.0 will automatically seed the kernel RNG
+      HW_RANDOM = yes;
 
       MODULE_SIG = no; # r13y, generates a random key during build and bakes it in
       # Depends on MODULE_SIG and only really helps when you sign your modules

From 721dd9c62459d1f60fd5bb6a80aa87ac2cef9238 Mon Sep 17 00:00:00 2001
From: zowoq <59103226+zowoq@users.noreply.github.com>
Date: Sat, 11 Apr 2026 12:54:52 +0000
Subject: [PATCH 30/35] linux_testing: 7.0-rc6 -> 7.0-rc7

---
 pkgs/os-specific/linux/kernel/kernels-org.json | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/pkgs/os-specific/linux/kernel/kernels-org.json b/pkgs/os-specific/linux/kernel/kernels-org.json
index adf23aea9dbc..a5112d3484a5 100644
--- a/pkgs/os-specific/linux/kernel/kernels-org.json
+++ b/pkgs/os-specific/linux/kernel/kernels-org.json
@@ -1,7 +1,7 @@
 {
     "testing": {
-        "version": "7.0-rc6",
-        "hash": "sha256:085bc06mbav64rmsm6a34j2y75nrqpqp4qd8ld8mb9acf1i4iw45",
+        "version": "7.0-rc7",
+        "hash": "sha256:0d4199hy9z3md6ia1p2awy89y2fqpwvgadn0j850f4xckz2hqdgf",
         "lts": false
     },
     "6.1": {

From ca1e1fbc50c9a0be6facfd3c12882671ff2c7cd9 Mon Sep 17 00:00:00 2001
From: zowoq <59103226+zowoq@users.noreply.github.com>
Date: Sat, 11 Apr 2026 13:02:33 +0000
Subject: [PATCH 31/35] linux_6_19: 6.19.11 -> 6.19.12

---
 pkgs/os-specific/linux/kernel/kernels-org.json | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/pkgs/os-specific/linux/kernel/kernels-org.json b/pkgs/os-specific/linux/kernel/kernels-org.json
index a5112d3484a5..eeb2ec75d5c4 100644
--- a/pkgs/os-specific/linux/kernel/kernels-org.json
+++ b/pkgs/os-specific/linux/kernel/kernels-org.json
@@ -35,8 +35,8 @@
         "lts": true
     },
     "6.19": {
-        "version": "6.19.11",
-        "hash": "sha256:16ymkc5r3hw05z7l7ih3qw406qlszz1l7b4g5yz0hv15ddxrs0r0",
+        "version": "6.19.12",
+        "hash": "sha256:1md8b270pdyk9d8cq0qyr8qmymcijmj3gc39nn394wpr0l94yp6f",
         "lts": false
     }
 }

From c25eab496979a9283a37e559fb95ad8eb311aeae Mon Sep 17 00:00:00 2001
From: zowoq <59103226+zowoq@users.noreply.github.com>
Date: Sat, 11 Apr 2026 12:54:54 +0000
Subject: [PATCH 32/35] linux_6_18: 6.18.21 -> 6.18.22

---
 pkgs/os-specific/linux/kernel/kernels-org.json | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/pkgs/os-specific/linux/kernel/kernels-org.json b/pkgs/os-specific/linux/kernel/kernels-org.json
index eeb2ec75d5c4..833b8a07b517 100644
--- a/pkgs/os-specific/linux/kernel/kernels-org.json
+++ b/pkgs/os-specific/linux/kernel/kernels-org.json
@@ -30,8 +30,8 @@
         "lts": true
     },
     "6.18": {
-        "version": "6.18.21",
-        "hash": "sha256:0ks735y6jq4yy3jaicjsj4dn4n3kk2skf9dqh9dyifipn57j2f0w",
+        "version": "6.18.22",
+        "hash": "sha256:0nazlm6j5blyd4qgl0z6xc3qk00vz3cfvx5mqv18awv5ygx94g52",
         "lts": true
     },
     "6.19": {

From c9c2a2b5753618a9fcb98032cb5918e4a293a269 Mon Sep 17 00:00:00 2001
From: zowoq <59103226+zowoq@users.noreply.github.com>
Date: Sat, 11 Apr 2026 12:54:56 +0000
Subject: [PATCH 33/35] linux_6_12: 6.12.80 -> 6.12.81

---
 pkgs/os-specific/linux/kernel/kernels-org.json | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/pkgs/os-specific/linux/kernel/kernels-org.json b/pkgs/os-specific/linux/kernel/kernels-org.json
index 833b8a07b517..ddf254194439 100644
--- a/pkgs/os-specific/linux/kernel/kernels-org.json
+++ b/pkgs/os-specific/linux/kernel/kernels-org.json
@@ -25,8 +25,8 @@
         "lts": true
     },
     "6.12": {
-        "version": "6.12.80",
-        "hash": "sha256:0lrylj87bb8ky29pbplpncrfhmgqqbq3d49iqgdwv7p7jvc929f9",
+        "version": "6.12.81",
+        "hash": "sha256:0iw84bqdbh9dlaqd1bqgldg50riw2b5is7ipqnbp0sll8cv9rc62",
         "lts": true
     },
     "6.18": {

From 6ad3e8add4b5e27ff1f24b47d11a51702687125d Mon Sep 17 00:00:00 2001
From: zowoq <59103226+zowoq@users.noreply.github.com>
Date: Sat, 11 Apr 2026 12:54:58 +0000
Subject: [PATCH 34/35] linux_6_6: 6.6.132 -> 6.6.134

---
 pkgs/os-specific/linux/kernel/kernels-org.json | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/pkgs/os-specific/linux/kernel/kernels-org.json b/pkgs/os-specific/linux/kernel/kernels-org.json
index ddf254194439..0f0f14a8bbc0 100644
--- a/pkgs/os-specific/linux/kernel/kernels-org.json
+++ b/pkgs/os-specific/linux/kernel/kernels-org.json
@@ -20,8 +20,8 @@
         "lts": true
     },
     "6.6": {
-        "version": "6.6.132",
-        "hash": "sha256:1d1fdd5wpphlm68yb16csaaijv0lf38ynl3gpvvdspsg22xjpdn5",
+        "version": "6.6.134",
+        "hash": "sha256:1grp1wqgzjsk6xyl0nvd2hxlxjj0wgz04x544zkz8srp6rxnjy33",
         "lts": true
     },
     "6.12": {

From 6f3463230872eb1c491d292aaa3d3208cfdbf87d Mon Sep 17 00:00:00 2001
From: zowoq <59103226+zowoq@users.noreply.github.com>
Date: Sat, 11 Apr 2026 12:55:00 +0000
Subject: [PATCH 35/35] linux_6_1: 6.1.167 -> 6.1.168

---
 pkgs/os-specific/linux/kernel/kernels-org.json | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/pkgs/os-specific/linux/kernel/kernels-org.json b/pkgs/os-specific/linux/kernel/kernels-org.json
index 0f0f14a8bbc0..d0581ef08f29 100644
--- a/pkgs/os-specific/linux/kernel/kernels-org.json
+++ b/pkgs/os-specific/linux/kernel/kernels-org.json
@@ -5,8 +5,8 @@
         "lts": false
     },
     "6.1": {
-        "version": "6.1.167",
-        "hash": "sha256:1jwqwp2fg3wdsh9w663rbnbv1rvsvksv1pj4bzns8swp0wy0a618",
+        "version": "6.1.168",
+        "hash": "sha256:0vkp75sfnjvfqxjh6gqcx24h2m6qj6xkwlw6b118cja43vjnz1g0",
         "lts": true
     },
     "5.15": {