[PATCH v2 2/3] host/rootfs: Switch to systemd-udevd

[Demi Marie Obenour <demiobenour@gmail.com>]

This replaces the mdevd uevent daemon with systemd-udevd, which supports
much more hardware and is therefore to be preferred for a full desktop
environment.  Various Wayland compositors integrate with systemd-udevd,
allowing them to discover devices as they appear rather than having to
only use devices plugged in when the compositor is started.
Additionally, systemd-udevd has quirks for various devices that are
needed to support the wide variety of hardware end-users have.

The dependency on /dev/dri/card0 being present is eliminated, and
whatever devices the user has are now picked up by the compositor.  New
dependencies are added to ensure that udev coldplug has finished before
any non-trivial services are started.  systemd-udev-trigger.service runs
'udevadm trigger' and has Before=sysinit.target, so anything that is not
an early boot service can assume 'udevadm trigger' has run.

systemd-udevd doesn't set PATH to anything useful, presumably because
under NixOS this is handled some other way.  Therefore, explicitly set
it to /usr/bin in the scripts systemd-udevd calls.

The /etc/mdev/listen and /etc/mdev/wait scripts are replaced by
'udevadm wait', so they are deleted.  The whole static-nodes target also
goes away, as Linux handles that itself and systemd-udevd deals with
autoloading.

Signed-off-by: Demi Marie Obenour <demiobenour@gmail.com>
---
The changes to default.nix are so that I could use the binary cache,
which was necessary to test this in a reasonable amount of time.  I'm
also not sure what changes you (Alyssa) want in this file.  Feel free to
fix it up on commit.

Signed-off-by: Demi Marie Obenour <demiobenour@gmail.com>
---
 host/rootfs/Makefile                               |  29 +++---
 host/rootfs/default.nix                            | 112 +++++++--------------
 host/rootfs/image/etc/mdev.conf                    |   7 --
 host/rootfs/image/etc/mdev/listen                  |  11 --
 host/rootfs/image/etc/mdev/wait                    |  14 ---
 host/rootfs/image/etc/s6-rc/card0/type.license     |   2 -
 host/rootfs/image/etc/s6-rc/card0/up               |   4 -
 host/rootfs/image/etc/s6-rc/kvm/up                 |   5 +-
 host/rootfs/image/etc/s6-rc/mdevd-coldplug/type    |   1 -
 host/rootfs/image/etc/s6-rc/mdevd-coldplug/up      |   4 -
 .../image/etc/s6-rc/mdevd/notification-fd.license  |   2 -
 host/rootfs/image/etc/s6-rc/mdevd/run              |   5 -
 host/rootfs/image/etc/s6-rc/ok-all/contents        |   2 +-
 .../dependencies.d/systemd-udevd}                  |   0
 .../s6-rc/{card0 => systemd-udevd-coldplug}/type   |   0
 .../type.license                                   |   0
 .../image/etc/s6-rc/systemd-udevd-coldplug/up      |   3 +
 .../card0 => systemd-udevd/flag-essential}         |   0
 .../s6-rc/{mdevd => systemd-udevd}/notification-fd |   0
 .../s6-rc/systemd-udevd/notification-fd.license    |   2 +
 host/rootfs/image/etc/s6-rc/systemd-udevd/run      |  11 ++
 .../image/etc/s6-rc/{mdevd => systemd-udevd}/type  |   0
 .../s6-rc/{mdevd => systemd-udevd}/type.license    |   0
 host/rootfs/image/etc/s6-rc/vm-env/contents        |   1 +
 host/rootfs/image/etc/s6-rc/vm-env/type.license    |   2 -
 host/rootfs/image/etc/s6-rc/vmm-env/contents       |   5 +-
 .../weston/dependencies.d/systemd-udevd-coldplug   |   0
 .../image/etc/udev/rules.d/99-spectrum.rules       |   9 ++
 host/rootfs/image/usr/bin/vm-start                 |   2 +-
 .../{etc/mdev/net/add => usr/libexec/net-add}      |   0
 30 files changed, 86 insertions(+), 147 deletions(-)

diff --git a/host/rootfs/Makefile b/host/rootfs/Makefile
index 322d75026dbcba4301f26abfbf74efa8cc68cdfd..db142f290a1efd3884d8c5a114b26fa0f42ef5f1 100644
--- a/host/rootfs/Makefile
+++ b/host/rootfs/Makefile
@@ -13,10 +13,6 @@ FILES = \
 	image/etc/group \
 	image/etc/init \
 	image/etc/login \
-	image/etc/mdev.conf \
-	image/etc/mdev/listen \
-	image/etc/mdev/net/add \
-	image/etc/mdev/wait \
 	image/etc/parse-devname \
 	image/etc/passwd \
 	image/etc/s6-linux-init/env/WAYLAND_DISPLAY \
@@ -52,9 +48,9 @@ FILES = \
 	image/etc/s6-linux-init/run-image/service/xdg-desktop-portal-spectrum-host/template/notification-fd \
 	image/etc/s6-linux-init/run-image/service/xdg-desktop-portal-spectrum-host/template/run \
 	image/etc/s6-linux-init/scripts/rc.init \
+	image/etc/udev/rules.d/99-spectrum.rules \
 	image/etc/xdg/weston/autolaunch \
 	image/etc/xdg/weston/weston.ini \
-	image/usr/share/dbus-1/services/org.freedesktop.portal.Documents.service \
 	image/usr/bin/assign-devices \
 	image/usr/bin/create-vm-dependencies \
 	image/usr/bin/run-appimage \
@@ -63,12 +59,15 @@ FILES = \
 	image/usr/bin/vm-import \
 	image/usr/bin/vm-start \
 	image/usr/bin/vm-stop \
-	image/usr/bin/xdg-open
+	image/usr/bin/xdg-open \
+	image/usr/libexec/net-add \
+	image/usr/share/dbus-1/services/org.freedesktop.portal.Documents.service
 
 DIRS = \
 	dev \
 	etc/s6-linux-init/env \
 	etc/s6-linux-init/run-image/configs \
+	etc/s6-linux-init/run-image/sd-notify-wrapper \
 	etc/s6-linux-init/run-image/service/dbus/instance \
 	etc/s6-linux-init/run-image/service/dbus/instances \
 	etc/s6-linux-init/run-image/service/dbus/template/data \
@@ -93,7 +92,6 @@ DIRS = \
 	etc/s6-linux-init/run-image/user \
 	etc/s6-linux-init/run-image/vm/by-id \
 	etc/s6-linux-init/run-image/vm/by-name \
-	etc/s6-linux-init/run-image/wait \
 	ext \
 	run \
 	proc \
@@ -129,19 +127,11 @@ build/empty:
 	mkdir -p $@
 
 S6_RC_FILES = \
-	image/etc/s6-rc/card0/type \
-	image/etc/s6-rc/card0/up \
 	image/etc/s6-rc/core/type \
 	image/etc/s6-rc/core/up \
 	image/etc/s6-rc/kvm/timeout-up \
 	image/etc/s6-rc/kvm/type \
 	image/etc/s6-rc/kvm/up \
-	image/etc/s6-rc/mdevd-coldplug/dependencies.d/mdevd \
-	image/etc/s6-rc/mdevd-coldplug/type \
-	image/etc/s6-rc/mdevd-coldplug/up \
-	image/etc/s6-rc/mdevd/notification-fd \
-	image/etc/s6-rc/mdevd/run \
-	image/etc/s6-rc/mdevd/type \
 	image/etc/s6-rc/ok-all/contents \
 	image/etc/s6-rc/ok-all/type \
 	image/etc/s6-rc/static-nodes/type \
@@ -149,11 +139,18 @@ S6_RC_FILES = \
 	image/etc/s6-rc/sys-vmms/dependencies.d/vmm-env \
 	image/etc/s6-rc/sys-vmms/type \
 	image/etc/s6-rc/sys-vmms/up \
+	image/etc/s6-rc/systemd-udevd-coldplug/dependencies.d/systemd-udevd \
+	image/etc/s6-rc/systemd-udevd-coldplug/type \
+	image/etc/s6-rc/systemd-udevd-coldplug/up \
+	image/etc/s6-rc/systemd-udevd/flag-essential \
+	image/etc/s6-rc/systemd-udevd/notification-fd \
+	image/etc/s6-rc/systemd-udevd/run \
+	image/etc/s6-rc/systemd-udevd/type \
 	image/etc/s6-rc/vm-env/contents \
 	image/etc/s6-rc/vm-env/type \
 	image/etc/s6-rc/vmm-env/contents \
 	image/etc/s6-rc/vmm-env/type \
-	image/etc/s6-rc/weston/dependencies.d/card0 \
+	image/etc/s6-rc/weston/dependencies.d/systemd-udevd-coldplug \
 	image/etc/s6-rc/weston/notification-fd \
 	image/etc/s6-rc/weston/run \
 	image/etc/s6-rc/weston/type
diff --git a/host/rootfs/default.nix b/host/rootfs/default.nix
index 116b55232b0b9f0ef2d04a4b15ba6f198cfb832c..12d1a72a7365cb4a2cda477fe231725103fbe2c4 100644
--- a/host/rootfs/default.nix
+++ b/host/rootfs/default.nix
@@ -6,88 +6,47 @@ import ../../lib/call-package.nix (
 { callSpectrumPackage, lseek, src, pkgsMusl, pkgsStatic, linux_latest }:
 pkgsStatic.callPackage (
 
-{ spectrum-host-tools
-, lib, stdenvNoCC, nixos, runCommand, writeClosure, erofs-utils, s6-rc
-, busybox, cloud-hypervisor, cryptsetup, dbus, execline, inkscape
-, iproute2, inotify-tools, jq, kmod, mdevd, s6, s6-linux-init, socat
-, util-linuxMinimal, virtiofsd, xorg, xdg-desktop-portal-spectrum-host
+{ busybox, cloud-hypervisor, cryptsetup, dbus, erofs-utils, execline
+, inkscape, inotify-tools, iproute2, jq, kmod, lib, mdevd, nixos
+, runCommand, s6, s6-linux-init, s6-rc, socat, spectrum-host-tools
+, stdenvNoCC, util-linuxMinimal, virtiofsd, writeClosure
+, xdg-desktop-portal-spectrum-host, xorg
 }:
-
 let
-  inherit (nixosAllHardware.config.hardware) firmware;
   inherit (lib)
     concatMapStringsSep concatStrings escapeShellArgs fileset optionalAttrs
-    mapAttrsToList systems trivial;
-
+    mapAttrsToList systems trivial lists;
   pkgsGui = pkgsMusl.extend (
     final: super:
-    (optionalAttrs (systems.equals pkgsMusl.stdenv.hostPlatform super.stdenv.hostPlatform) {
-      flatpak = super.flatpak.override {
-        withMalcontent = false;
-      };
-
-      libgudev = super.libgudev.overrideAttrs ({ ... }: {
-        # Tests use umockdev, which is not compatible with libudev-zero.
-        doCheck = false;
-      });
-
-      qt6 = super.qt6.overrideScope (_: prev: {
-        qttranslations = prev.qttranslations.override {
-          qttools = prev.qttools.override {
-            qtbase = prev.qtbase.override {
-              qttranslations = null;
-              systemdSupport = false;
-            };
-            qtdeclarative = null;
-          };
-        };
-
-        qtbase = prev.qtbase.override {
-          systemdSupport = false;
-        };
-      });
-
-      systemd = super.systemd.overrideAttrs ({ meta ? { }, ... }: {
+    (lib.optionalAttrs (systems.equals pkgsMusl.stdenv.hostPlatform super.stdenv.hostPlatform) {
+      malcontent = super.malcontent.overrideAttrs ({ meta ? { }, ... }: {
         meta = meta // {
           platforms = [ ];
         };
       });
+   }));
+in
+pkgsGui.callPackage (
+{ cosmic-files, crosvm, dejavu_fonts, foot, mesa
+, systemdMinimal, westonLite, xdg-desktop-portal
+, xdg-desktop-portal-gtk
+}:
 
-      upower = super.upower.override {
-        # Not ideal, but it's the best way to get rid of an installed
-        # test that needs umockdev.
-        withIntrospection = false;
-      };
-
-      udev = final.libudev-zero;
-
-      weston = super.weston.overrideAttrs ({ mesonFlags ? [], ... }: {
-        mesonFlags = mesonFlags ++ [
-          "-Dsystemd=false"
-        ];
-      });
-
-      xdg-desktop-portal = (super.xdg-desktop-portal.override {
-        enableSystemd = false;
-      }).overrideAttrs ({ ... }: {
-        # Tests use umockdev.
-        doCheck = false;
-      });
-    })
-  );
-
-  foot = pkgsGui.foot.override { allowPgo = false; };
+let
+  inherit (nixosAllHardware.config.hardware) firmware;
+  no_pgo_foot = foot.override { allowPgo = false; };
 
   packages = [
-    cloud-hypervisor cryptsetup dbus execline inotify-tools iproute2
-    jq kmod mdevd s6 s6-linux-init s6-rc socat spectrum-host-tools
-    virtiofsd xdg-desktop-portal-spectrum-host
+    cloud-hypervisor crosvm cryptsetup dbus execline inotify-tools
+    iproute2 jq kmod mdevd s6 s6-linux-init s6-rc socat
+    spectrum-host-tools virtiofsd xdg-desktop-portal-spectrum-host
 
     (busybox.override {
       extraConfig = ''
         CONFIG_CHATTR n
         CONFIG_DEPMOD n
         CONFIG_FINDFS n
+        CONFIG_HALT n
         CONFIG_INIT n
         CONFIG_INSMOD n
         CONFIG_IP n
@@ -98,10 +57,13 @@ let
         CONFIG_MODINFO n
         CONFIG_MODPROBE n
         CONFIG_MOUNT n
+        CONFIG_POWEROFF n
+        CONFIG_REBOOT n
         CONFIG_RMMOD n
+        CONFIG_SHUTDOWN n
       '';
     })
-  ] ++ (with pkgsGui; [ cosmic-files crosvm foot ]);
+  ];
 
   nixosAllHardware = nixos ({ modulesPath, ... }: {
     imports = [ (modulesPath + "/profiles/all-hardware.nix") ];
@@ -111,14 +73,14 @@ let
 
   kernel = linux_latest;
 
-  appvm = callSpectrumPackage ../../img/app { inherit (foot) terminfo; };
-  netvm = callSpectrumPackage ../../vm/sys/net { inherit (foot) terminfo; };
+  appvm = callSpectrumPackage ../../img/app { inherit (no_pgo_foot) terminfo; };
+  netvm = callSpectrumPackage ../../vm/sys/net { inherit (no_pgo_foot) terminfo; };
 
   # Packages that should be fully linked into /usr,
   # (not just their bin/* files).
   usrPackages = [
     appvm kernel.modules firmware netvm
-  ] ++ (with pkgsGui; [ mesa dejavu_fonts westonLite ]);
+    mesa dejavu_fonts westonLite ];
 
   appvms = {
     appvm-firefox = callSpectrumPackage ../../vm/app/firefox.nix {};
@@ -136,16 +98,16 @@ let
     # Weston doesn't support SVG icons.
     inkscape -w 20 -h 20 \
         -o $out/usr/share/icons/hicolor/20x20/apps/com.system76.CosmicFiles.png \
-        ${pkgsGui.cosmic-files}/share/icons/hicolor/24x24/apps/com.system76.CosmicFiles.svg
+        ${cosmic-files}/share/icons/hicolor/24x24/apps/com.system76.CosmicFiles.svg
 
     ln -st $out/usr/bin \
         ${concatMapStringsSep " " (p: "${p}/bin/*") packages} \
-        ${pkgsGui.xdg-desktop-portal}/libexec/xdg-document-portal \
-        ${pkgsGui.xdg-desktop-portal-gtk}/libexec/xdg-desktop-portal-gtk
+        ${xdg-desktop-portal}/libexec/xdg-document-portal \
+        ${xdg-desktop-portal-gtk}/libexec/xdg-desktop-portal-gtk
     ln -st $out/usr/share/dbus-1 \
         ${dbus}/share/dbus-1/session.conf
     ln -st $out/usr/share/dbus-1/services \
-        ${pkgsGui.xdg-desktop-portal-gtk}/share/dbus-1/services/org.freedesktop.impl.portal.desktop.gtk.service
+        ${xdg-desktop-portal-gtk}/share/dbus-1/services/org.freedesktop.impl.portal.desktop.gtk.service
 
     for pkg in ${escapeShellArgs usrPackages}; do
         lndir -ignorelinks -silent "$pkg" "$out/usr"
@@ -159,6 +121,10 @@ let
     # programs we want.
     # https://lore.kernel.org/util-linux/87zgrl6ufb.fsf@alyssa.is/
     ln -s ${util-linuxMinimal}/bin/{findfs,uuidgen,lsblk,mount} $out/usr/bin
+
+    # TODO: this is another hack and it should be possible
+    # to build systemd without this.
+    ln -s -- ${lib.escapeShellArg systemdMinimal}/bin/udevadm "$out/usr/bin"
   '';
 in
 
@@ -195,7 +161,7 @@ stdenvNoCC.mkDerivation {
   unsafeDiscardReferences = { out = true; };
 
   passthru = {
-    inherit appvm firmware kernel nixosAllHardware packagesSysroot pkgsGui;
+    inherit appvm firmware kernel nixosAllHardware packagesSysroot;
   };
 
   meta = with lib; {
@@ -203,4 +169,4 @@ stdenvNoCC.mkDerivation {
     platforms = platforms.linux;
   };
 }
-) {}) (_: {})
+) {}) {}) (_: {})
diff --git a/host/rootfs/image/etc/mdev.conf b/host/rootfs/image/etc/mdev.conf
deleted file mode 100644
index bddcfdc44ec2a8b1aa95e84cb88fdde625c766d8..0000000000000000000000000000000000000000
--- a/host/rootfs/image/etc/mdev.conf
+++ /dev/null
@@ -1,7 +0,0 @@
-# SPDX-License-Identifier: EUPL-1.2+
-# SPDX-FileCopyrightText: 2021-2022, 2024 Alyssa Ross <hi@alyssa.is>
-
-$PCI_CLASS=^2....$ 0:0 660 +/etc/mdev/net/add
--$MODALIAS=.* 0:0 660 +importas -Siu MODALIAS modprobe -q $MODALIAS
-kvm 0:0 660 +background { /etc/mdev/listen kvm }
-dri/card0 0:0 660 +background { /etc/mdev/listen card0 }
diff --git a/host/rootfs/image/etc/mdev/listen b/host/rootfs/image/etc/mdev/listen
deleted file mode 100755
index ab50ee8c5ed1139d1129bac56afa7263af150745..0000000000000000000000000000000000000000
--- a/host/rootfs/image/etc/mdev/listen
+++ /dev/null
@@ -1,11 +0,0 @@
-#!/bin/execlineb -S1
-# SPDX-License-Identifier: EUPL-1.2+
-# SPDX-FileCopyrightText: 2021 Alyssa Ross <hi@alyssa.is>
-
-foreground {
-  redirfd -w 2 /dev/null
-  mkfifo /run/wait/${1}
-}
-
-redirfd -w 1 /run/wait/${1}
-echo
diff --git a/host/rootfs/image/etc/mdev/wait b/host/rootfs/image/etc/mdev/wait
deleted file mode 100755
index 6bddb303d2671ce4e5b8581cd81235d7404916e7..0000000000000000000000000000000000000000
--- a/host/rootfs/image/etc/mdev/wait
+++ /dev/null
@@ -1,14 +0,0 @@
-#!/bin/execlineb -S1
-# SPDX-License-Identifier: EUPL-1.2+
-# SPDX-FileCopyrightText: 2021 Alyssa Ross <hi@alyssa.is>
-
-foreground {
-  redirfd -w 2 /dev/null
-  mkfifo /run/wait/${1}
-}
-
-foreground {
-  redirfd -w 1 /dev/null
-  head -1 /run/wait/${1}
-}
-rm /run/wait/${1}
diff --git a/host/rootfs/image/etc/s6-rc/card0/type.license b/host/rootfs/image/etc/s6-rc/card0/type.license
deleted file mode 100644
index c49c11b66262c7edc57ac06a486c1166d867c31d..0000000000000000000000000000000000000000
--- a/host/rootfs/image/etc/s6-rc/card0/type.license
+++ /dev/null
@@ -1,2 +0,0 @@
-SPDX-License-Identifier: CC0-1.0
-SPDX-FileCopyrightText: 2021 Alyssa Ross <hi@alyssa.is>
diff --git a/host/rootfs/image/etc/s6-rc/card0/up b/host/rootfs/image/etc/s6-rc/card0/up
deleted file mode 100644
index 703562e5442aea45198350afe86a8f38c11ed072..0000000000000000000000000000000000000000
--- a/host/rootfs/image/etc/s6-rc/card0/up
+++ /dev/null
@@ -1,4 +0,0 @@
-# SPDX-License-Identifier: EUPL-1.2+
-# SPDX-FileCopyrightText: 2021 Alyssa Ross <hi@alyssa.is>
-
-/etc/mdev/wait card0
diff --git a/host/rootfs/image/etc/s6-rc/kvm/up b/host/rootfs/image/etc/s6-rc/kvm/up
index c02e3f90245e005b98b4de8245a1863fb49c1158..a8436de58580f2a2a6f42bb69418a319f967df47 100644
--- a/host/rootfs/image/etc/s6-rc/kvm/up
+++ b/host/rootfs/image/etc/s6-rc/kvm/up
@@ -1,4 +1,3 @@
 # SPDX-License-Identifier: EUPL-1.2+
-# SPDX-FileCopyrightText: 2023 Alyssa Ross <hi@alyssa.is>
-
-/etc/mdev/wait kvm
+# SPDX-FileCopyrightText: 2025 Demi Marie Obenour <demiobenour@gmail.com>
+udevadm wait /dev/kvm
diff --git a/host/rootfs/image/etc/s6-rc/mdevd-coldplug/type b/host/rootfs/image/etc/s6-rc/mdevd-coldplug/type
deleted file mode 100644
index bdd22a1850ae6c03a414eeb8084998679a2cdf92..0000000000000000000000000000000000000000
--- a/host/rootfs/image/etc/s6-rc/mdevd-coldplug/type
+++ /dev/null
@@ -1 +0,0 @@
-oneshot
diff --git a/host/rootfs/image/etc/s6-rc/mdevd-coldplug/up b/host/rootfs/image/etc/s6-rc/mdevd-coldplug/up
deleted file mode 100644
index 8698f7d7988a017786fb91a584eafbfb23b3165d..0000000000000000000000000000000000000000
--- a/host/rootfs/image/etc/s6-rc/mdevd-coldplug/up
+++ /dev/null
@@ -1,4 +0,0 @@
-# SPDX-License-Identifier: EUPL-1.2+
-# SPDX-FileCopyrightText: 2020-2021 Alyssa Ross <hi@alyssa.is>
-
-mdevd-coldplug
diff --git a/host/rootfs/image/etc/s6-rc/mdevd/notification-fd.license b/host/rootfs/image/etc/s6-rc/mdevd/notification-fd.license
deleted file mode 100644
index 2b3b032142b7286bd317cf0abaa44fba3a9b8941..0000000000000000000000000000000000000000
--- a/host/rootfs/image/etc/s6-rc/mdevd/notification-fd.license
+++ /dev/null
@@ -1,2 +0,0 @@
-SPDX-License-Identifier: CC0-1.0
-SPDX-FileCopyrightText: 2020 Alyssa Ross <hi@alyssa.is>
diff --git a/host/rootfs/image/etc/s6-rc/mdevd/run b/host/rootfs/image/etc/s6-rc/mdevd/run
deleted file mode 100644
index 55899bbe674426e4591e866a4d0617361ba34305..0000000000000000000000000000000000000000
--- a/host/rootfs/image/etc/s6-rc/mdevd/run
+++ /dev/null
@@ -1,5 +0,0 @@
-#!/bin/execlineb -P
-# SPDX-License-Identifier: EUPL-1.2+
-# SPDX-FileCopyrightText: 2020-2022 Alyssa Ross <hi@alyssa.is>
-
-mdevd -D3 -O4 -b134217728
diff --git a/host/rootfs/image/etc/s6-rc/ok-all/contents b/host/rootfs/image/etc/s6-rc/ok-all/contents
index 9f8b0ed66ceedd591ed2f1a7e164d9abcc54cc53..c76a5af336c7f1c3f4b81bf1f6244a53e0399fe8 100644
--- a/host/rootfs/image/etc/s6-rc/ok-all/contents
+++ b/host/rootfs/image/etc/s6-rc/ok-all/contents
@@ -1,6 +1,6 @@
 # SPDX-License-Identifier: CC0-1.0
 # SPDX-FileCopyrightText: 2021 Alyssa Ross <hi@alyssa.is>
 #
-mdevd-coldplug
+systemd-udevd-coldplug
 sys-vmms
 vm-env
diff --git a/host/rootfs/image/etc/s6-rc/mdevd-coldplug/dependencies.d/mdevd b/host/rootfs/image/etc/s6-rc/systemd-udevd-coldplug/dependencies.d/systemd-udevd
similarity index 100%
rename from host/rootfs/image/etc/s6-rc/mdevd-coldplug/dependencies.d/mdevd
rename to host/rootfs/image/etc/s6-rc/systemd-udevd-coldplug/dependencies.d/systemd-udevd
diff --git a/host/rootfs/image/etc/s6-rc/card0/type b/host/rootfs/image/etc/s6-rc/systemd-udevd-coldplug/type
similarity index 100%
rename from host/rootfs/image/etc/s6-rc/card0/type
rename to host/rootfs/image/etc/s6-rc/systemd-udevd-coldplug/type
diff --git a/host/rootfs/image/etc/s6-rc/mdevd-coldplug/type.license b/host/rootfs/image/etc/s6-rc/systemd-udevd-coldplug/type.license
similarity index 100%
rename from host/rootfs/image/etc/s6-rc/mdevd-coldplug/type.license
rename to host/rootfs/image/etc/s6-rc/systemd-udevd-coldplug/type.license
diff --git a/host/rootfs/image/etc/s6-rc/systemd-udevd-coldplug/up b/host/rootfs/image/etc/s6-rc/systemd-udevd-coldplug/up
new file mode 100644
index 0000000000000000000000000000000000000000..1732c98158046d0fb6ba6e8fb2201444fcf9128a
--- /dev/null
+++ b/host/rootfs/image/etc/s6-rc/systemd-udevd-coldplug/up
@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: CC0-1.0
+# SPDX-FileCopyrightText: 2025 Demi Marie Obenour <demiobenour@gmail.com>
+udevadm trigger
diff --git a/host/rootfs/image/etc/s6-rc/weston/dependencies.d/card0 b/host/rootfs/image/etc/s6-rc/systemd-udevd/flag-essential
similarity index 100%
rename from host/rootfs/image/etc/s6-rc/weston/dependencies.d/card0
rename to host/rootfs/image/etc/s6-rc/systemd-udevd/flag-essential
diff --git a/host/rootfs/image/etc/s6-rc/mdevd/notification-fd b/host/rootfs/image/etc/s6-rc/systemd-udevd/notification-fd
similarity index 100%
rename from host/rootfs/image/etc/s6-rc/mdevd/notification-fd
rename to host/rootfs/image/etc/s6-rc/systemd-udevd/notification-fd
diff --git a/host/rootfs/image/etc/s6-rc/systemd-udevd/notification-fd.license b/host/rootfs/image/etc/s6-rc/systemd-udevd/notification-fd.license
new file mode 100644
index 0000000000000000000000000000000000000000..c4a0586a407fe14c3e0855749a7524ac3871dda4
--- /dev/null
+++ b/host/rootfs/image/etc/s6-rc/systemd-udevd/notification-fd.license
@@ -0,0 +1,2 @@
+SPDX-License-Identifier: CC0-1.0
+SPDX-FileCopyrightText: 2025 Demi Marie Obenour <demiobenour@gmail.com>
diff --git a/host/rootfs/image/etc/s6-rc/systemd-udevd/run b/host/rootfs/image/etc/s6-rc/systemd-udevd/run
new file mode 100644
index 0000000000000000000000000000000000000000..2501680b69eb0060b651146dffb6b3a99640c6fb
--- /dev/null
+++ b/host/rootfs/image/etc/s6-rc/systemd-udevd/run
@@ -0,0 +1,11 @@
+#!/bin/execlineb -P
+# SPDX-License-Identifier: EUPL-1.2+
+# SPDX-FileCopyrightText: 2025 Demi Marie Obenour <demiobenour@gmail.com>
+if { rm -f /run/sd-notify-wrapper/systemd-udevd }
+background {
+   s6-ipcserver-socketbinder -b0 -m -a 0600 /run/sd-notify-wrapper/systemd-udevd
+   fdmove 1 3
+   sd-notify-adapter
+}
+export NOTIFY_SOCKET /run/sd-notify-wrapper/systemd-udevd
+exec -a systemd-udevd udevadm
diff --git a/host/rootfs/image/etc/s6-rc/mdevd/type b/host/rootfs/image/etc/s6-rc/systemd-udevd/type
similarity index 100%
rename from host/rootfs/image/etc/s6-rc/mdevd/type
rename to host/rootfs/image/etc/s6-rc/systemd-udevd/type
diff --git a/host/rootfs/image/etc/s6-rc/mdevd/type.license b/host/rootfs/image/etc/s6-rc/systemd-udevd/type.license
similarity index 100%
rename from host/rootfs/image/etc/s6-rc/mdevd/type.license
rename to host/rootfs/image/etc/s6-rc/systemd-udevd/type.license
diff --git a/host/rootfs/image/etc/s6-rc/vm-env/contents b/host/rootfs/image/etc/s6-rc/vm-env/contents
index 580795b1b02bb7a8dff7f872723c678141d4bb70..ed8b5c410adfc17f5bbc33932ac79d97bd7b3115 100644
--- a/host/rootfs/image/etc/s6-rc/vm-env/contents
+++ b/host/rootfs/image/etc/s6-rc/vm-env/contents
@@ -2,4 +2,5 @@
 # SPDX-FileCopyrightText: 2021 Alyssa Ross <hi@alyssa.is>
 #
 static-nodes
+systemd-udevd-coldplug
 weston
diff --git a/host/rootfs/image/etc/s6-rc/vm-env/type.license b/host/rootfs/image/etc/s6-rc/vm-env/type.license
deleted file mode 100644
index 5a4063310c3d22dbf59b30792e8e6f55a57ec9c0..0000000000000000000000000000000000000000
--- a/host/rootfs/image/etc/s6-rc/vm-env/type.license
+++ /dev/null
@@ -1,2 +0,0 @@
-SPDX-License-Identifier: CC0-1.0
-SPDX-FileCopyrightText: 2022 Alyssa Ross <hi@alyssa.is>
diff --git a/host/rootfs/image/etc/s6-rc/vmm-env/contents b/host/rootfs/image/etc/s6-rc/vmm-env/contents
index ee1e3cfc39d1a6545bbefc3692782b9de6b3ade3..9a1aea63abd1b5c374e3ac9a9671e4c9341f8d16 100644
--- a/host/rootfs/image/etc/s6-rc/vmm-env/contents
+++ b/host/rootfs/image/etc/s6-rc/vmm-env/contents
@@ -3,4 +3,7 @@
 #
 core
 kvm
-static-nodes
+# systemd runs systemd-udev-trigger.service before sysinit.target.
+# Therefore, anything using libudev that isn't an early boot service
+# might expect udev coldplug to have finished.
+systemd-udevd-coldplug
diff --git a/host/rootfs/image/etc/s6-rc/weston/dependencies.d/systemd-udevd-coldplug b/host/rootfs/image/etc/s6-rc/weston/dependencies.d/systemd-udevd-coldplug
new file mode 100644
index 0000000000000000000000000000000000000000..e69de29bb2d1d6434b8b29ae775ad8c2e48c5391
diff --git a/host/rootfs/image/etc/udev/rules.d/99-spectrum.rules b/host/rootfs/image/etc/udev/rules.d/99-spectrum.rules
new file mode 100644
index 0000000000000000000000000000000000000000..ca91367529f39eebe009cc8acef782cf6a4516c1
--- /dev/null
+++ b/host/rootfs/image/etc/udev/rules.d/99-spectrum.rules
@@ -0,0 +1,9 @@
+# SPDX-License-Identifier: EUPL-1.2+
+# SPDX-FileCopyrightText: 2025 Demi Marie Obenour <demiobenour@gmail.com>
+
+# systemd-udevd has a built-in module loading feature,
+# but it seems to not work for some reason or another.
+# This works.
+ACTION!="remove", ENV{MODALIAS}!="", RUN+="/usr/bin/modprobe -q $env{MODALIAS}"
+# systemd-udevd unsets PATH, so fix that.
+ACTION!="remove", ENV{PCI_CLASS}=="2????", RUN+="/usr/bin/env PATH=/usr/bin /usr/libexec/net-add"
diff --git a/host/rootfs/image/usr/bin/vm-start b/host/rootfs/image/usr/bin/vm-start
index 67480e5215d8a8260ce3f03c67f71ba8f210c291..9725ef5ec549ff191606282a7b0ae56838f53f03 100755
--- a/host/rootfs/image/usr/bin/vm-start
+++ b/host/rootfs/image/usr/bin/vm-start
@@ -2,7 +2,7 @@
 # SPDX-License-Identifier: EUPL-1.2+
 # SPDX-FileCopyrightText: 2022-2023, 2025 Alyssa Ross <hi@alyssa.is>
 
-foreground { s6-rc -bu change vm-env }
+foreground { s6-rc -bu change weston }
 
 foreground {
   redirfd -w 2 /dev/null
diff --git a/host/rootfs/image/etc/mdev/net/add b/host/rootfs/image/usr/libexec/net-add
similarity index 100%
rename from host/rootfs/image/etc/mdev/net/add
rename to host/rootfs/image/usr/libexec/net-add

-- 
2.51.0