Take a different approach

Generate module blacklists instead when initramfs is loaded.

mkosi.extra/usr/lib/initcpio/install/nvidia-driver-selection

@@ -2,8 +2,8 @@
 # SPDX-License-Identifier: GPL-2.0-only OR GPL-3.0-only OR LicenseRef-KDE-Accepted-GPL
 # SPDX-FileCopyrightText: 2026 Thomas Duckworth <tduck@filotimoproject.org>
 
-# Necessary for letting udev control what GPUs get which drivers
-# using driver_override, so nouveau or nvidia can be dynamically selected.
+# Necessary for generating automatic modprobe blacklists before
+# drivers load so nouveau or nvidia can be dynamically selected.
 # Also gives us some certainty that these are included for kernel modesetting.
 
 build() {
@@ -11,8 +11,12 @@ build() {
     add_module "nvidia-drm"
     add_module "nvidia-modeset"
     add_module "nvidia-uvm"
-
     add_module "nouveau"
 
     add_checked_modules "/drivers/gpu/drm"
+
+    add_binary "/usr/lib/initcpio/nvidia-driver-selection"
+
+    add_systemd_unit "kde-linux-nvidia-driver-selection.service"
+    add_symlink "/etc/systemd/system/sysinit.target.wants/kde-linux-nvidia-driver-selection.service" "/usr/lib/systemd/system/kde-linux-nvidia-driver-selection.service"
 }

mkosi.extra/usr/lib/initcpio/nvidia-driver-selection

@@ -0,0 +1,42 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0-only OR GPL-3.0-only OR LicenseRef-KDE-Accepted-GPL
+# SPDX-FileCopyrightText: 2026 Thomas Duckworth <tduck@filotimoproject.org>
+
+# Checks sysfs for NVIDIA GPUs and generates a modprobe blacklist dynamically.
+
+mkdir -p /run/modprobe.d
+mkdir -p /run/modules-load.d
+USE_NVIDIA=0
+GPU_FOUND=0
+
+for dev in /sys/bus/pci/devices/*; do
+    [ -f "$dev/vendor" ] && [ -f "$dev/device" ] && [ -f "$dev/class" ] || continue
+
+    vendor=$(cat "$dev/vendor")
+    class=$(cat "$dev/class")
+
+    # 0x10de = NVIDIA. Class 0x03* = Display controllers
+    if [ "$vendor" = "0x10de" ] && [[ "$class" == 0x03* ]]; then
+        GPU_FOUND=1
+        device=$(cat "$dev/device")
+        dec_id=$(printf "%d" "$device")
+
+        # 7680 (0x1e00) is the Turing (NVIDIA driver) cutoff
+        if [ "$dec_id" -ge 7680 ]; then
+            USE_NVIDIA=1
+        fi
+    fi
+done
+
+if [ "$GPU_FOUND" -eq 1 ]; then
+    if [ "$USE_NVIDIA" -eq 1 ]; then
+        echo "blacklist nouveau" > /run/modprobe.d/05-dynamic-gpu.conf
+        modprobe nvidia-drm modeset=1
+    else
+        echo "blacklist nvidia" > /run/modprobe.d/05-dynamic-gpu.conf
+        echo "blacklist nvidia-drm" >> /run/modprobe.d/05-dynamic-gpu.conf
+        echo "blacklist nvidia-modeset" >> /run/modprobe.d/05-dynamic-gpu.conf
+        echo "blacklist nvidia-uvm" >> /run/modprobe.d/05-dynamic-gpu.conf
+        modprobe nouveau
+    fi
+fi

mkosi.extra/usr/lib/rebuild-efi

@@ -28,8 +28,8 @@ fi
 cat <<- EOF > mkinitcpio.conf
 MODULES=(overlay)
 BINARIES=()
-FILES=(/usr/lib/udev/rules.d/05-nvidia-module-selection.rules) # Determine which driver is used at boot with udev
-HOOKS=(base systemd nvidia-module-selection modconf kms keyboard block sd-encrypt filesystems fsck systemd-extension plymouth microcode sd-shutdown)
+FILES=()
+HOOKS=(base systemd nvidia-driver-selection modconf kms keyboard block sd-encrypt filesystems fsck systemd-extension plymouth microcode sd-shutdown)
 EOF
 
 echo "rw \

mkosi.extra/usr/lib/systemd/system/kde-linux-nvidia-driver-selection.service

@@ -0,0 +1,14 @@
+# SPDX-License-Identifier: GPL-2.0-only OR GPL-3.0-only OR LicenseRef-KDE-Accepted-GPL
+# SPDX-FileCopyrightText: 2025 Thomas Duckworth <tduck@filotimoproject.org>
+
+[Unit]
+Description=Dynamic NVIDIA Driver Selection
+DefaultDependencies=no
+Before=systemd-udevd.service systemd-modules-load.service
+ConditionPathExists=/sys/bus/pci/devices
+
+# This service and binary is included in the initramfs.
+[Service]
+Type=oneshot
+ExecStart=/usr/lib/initcpio/nvidia-driver-selection
+RemainAfterExit=yes

mkosi.postinst.chroot

@@ -146,40 +146,6 @@ if [ -f /usr/lib/modprobe.d/nvidia-utils.conf ]; then
     sed -i '/blacklist nouveau/d' /usr/lib/modprobe.d/nvidia-utils.conf
 fi
 
-# Generate a huge udev rule which selects the correct driver for NVIDIA graphics cards.
-# This gets included in the initrd - see mkosi.extra/usr/lib/rebuild-efi
-PCI_IDS="/usr/share/hwdata/pci.ids"
-UDEV_RULE="/usr/lib/udev/rules.d/05-nvidia-module-selection.rules"
-
-echo "# Generated by mkosi.postinst.chroot" > "$UDEV_RULE"
-echo "# Static driver overrides for NVIDIA GPUs based on ID ranges." >> "$UDEV_RULE"
-
-gawk '
-    BEGIN { IGNORECASE = 1 }
-    # Vendor line, e.g. "10de  NVIDIA Corporation".
-    /^10de\b/ { in_nvidia = 1; next }
-    # Any other vendor line (4 hex digits at start) disables in_nvidia.
-    /^[0-9A-Fa-f]{4}\s/ { in_nvidia = 0; next }
-
-    # device lines are indented and begin with a 4-hex-digit device id
-    in_nvidia && /^\s+[0-9A-Fa-f]{4}\b/ {
-        device_id = gensub(/^\s+([0-9A-Fa-f]{4}).*/, "\\1", "g")
-        dec_id = strtonum("0x" device_id)
-
-        # 0x1e00 (7680) is where Turing architecture begins (RTX 20-series / GTX 16-series).
-        # This is, currently, the cutoff for support in the open kernel modules.
-        if (dec_id >= 7680) {
-            driver = "nvidia"
-        } else {
-            driver = "nouveau"
-        }
-
-        # Match only Class 03 (Display Controllers) to avoid breaking Audio/USB/Bridges.
-        printf "ACTION==\"add\", SUBSYSTEM==\"pci\", ATTR{vendor}==\"0x10de\", ATTR{device}==\"0x%s\", ATTR{class}==\"0x03*\", ATTR{driver_override}=\"%s\"\n", device_id, driver
-    }
-' "$PCI_IDS" >> "$UDEV_RULE"
-
-
 cd /tmp
 /usr/lib/rebuild-efi
 mv -v ./*.efi /