diff --git a/arch/daedalus-v4l2-dkms/PKGBUILD b/arch/daedalus-v4l2-dkms/PKGBUILD
new file mode 100644
index 000000000..963f6a74d
--- /dev/null
+++ b/arch/daedalus-v4l2-dkms/PKGBUILD
@@ -0,0 +1,68 @@
+# Maintainer: Markus Fritsche <fritsche.markus@gmail.com>
+#
+# daedalus-v4l2-dkms — DKMS package for the daedalus_v4l2 out-of-tree
+# kernel module (V4L2 stateless decoder shim for Pi 5 / CM5).
+#
+# Pair to daedalus-v4l2 (userspace daemon).  When loaded, the module
+# registers /dev/videoNN (V4L2 m2m) + /dev/mediaNN (media controller) +
+# /dev/daedalus-v4l2 (chardev to the userspace daemon).  Userspace
+# clients drive the V4L2 m2m + request API path; the daemon does the
+# actual FFmpeg-backed decode on /dev/daedalus-v4l2.
+#
+# Project: https://git.reauktion.de/reauktion/daedalus-v4l2
+# Sibling userspace package: daedalus-v4l2
+# Sibling consumer: libva-v4l2-request-fourier
+
+pkgname=daedalus-v4l2-dkms
+_module=daedalus_v4l2
+
+# Same pin as arch/daedalus-v4l2 — keep kernel module + daemon
+# bit-versioned together so the chardev wire protocol stays in sync.
+_commit=f04d7000f858fe51d867aba14a529d3aef4fbd54
+
+pkgver=0.1.0.r15.f04d700
+pkgrel=1
+pkgdesc="V4L2 stateless decoder shim kernel module (DKMS) — Pi 5 / CM5"
+arch=('any')
+url="https://git.reauktion.de/reauktion/daedalus-v4l2"
+license=('GPL-2.0-or-later')
+depends=('dkms')
+makedepends=('git')
+
+source=("git+https://git.reauktion.de/reauktion/daedalus-v4l2.git#commit=${_commit}"
+        "dkms.conf")
+sha256sums=('SKIP'
+            'SKIP')
+
+pkgver() {
+    cd "${srcdir}/daedalus-v4l2"
+    printf '0.1.0.r%s.%s' \
+        "$(git rev-list --count HEAD)" \
+        "$(git rev-parse --short=7 HEAD)"
+}
+
+package() {
+    local _src="${pkgdir}/usr/src/${_module}-${pkgver}"
+
+    install -dm755 "${_src}"
+
+    # Install the kernel/ subdir and embed the shared proto header in
+    # the same tree.  The in-tree Makefile uses
+    # `ccflags-y += -I$(src)/../include` (assuming the parent
+    # daedalus-v4l2 layout); for DKMS we flatten by copying the header
+    # into kernel/include/ and patching the Makefile to point there.
+    cp -r "${srcdir}/daedalus-v4l2/kernel/." "${_src}/"
+    install -Dm644 "${srcdir}/daedalus-v4l2/include/daedalus_v4l2_proto.h" \
+        "${_src}/include/daedalus_v4l2_proto.h"
+    sed -i 's|-I\$(src)/\.\./include|-I$(src)/include|' "${_src}/Makefile"
+
+    # dkms.conf at the root of the source tree (DKMS convention).
+    # Substitute #MODULE_VERSION# placeholder with the actual pkgver
+    # so dkms install/uninstall match what's on disk.
+    install -Dm644 "${srcdir}/dkms.conf" "${_src}/dkms.conf"
+    sed -i "s/#MODULE_VERSION#/${pkgver}/" "${_src}/dkms.conf"
+
+    # License
+    install -Dm644 "${srcdir}/daedalus-v4l2/kernel/daedalus_v4l2_main.c" \
+        "${pkgdir}/usr/share/licenses/${pkgname}/SPDX-HEADER"
+}
diff --git a/arch/daedalus-v4l2-dkms/dkms.conf b/arch/daedalus-v4l2-dkms/dkms.conf
new file mode 100644
index 000000000..607c28c33
--- /dev/null
+++ b/arch/daedalus-v4l2-dkms/dkms.conf
@@ -0,0 +1,19 @@
+# DKMS configuration for daedalus_v4l2 — V4L2 stateless decoder shim.
+#
+# Built against /lib/modules/$kernelver/build with the in-tree Makefile.
+# The Makefile uses `obj-m := daedalus_v4l2.o` and links
+# daedalus_v4l2_main.o + daedalus_v4l2_chardev.o into the final .ko.
+
+PACKAGE_NAME="daedalus_v4l2"
+PACKAGE_VERSION="#MODULE_VERSION#"
+
+# Single module produced by the Makefile.
+BUILT_MODULE_NAME[0]="daedalus_v4l2"
+DEST_MODULE_LOCATION[0]="/updates"
+
+# Use the package's own Makefile — it already does
+# `$(MAKE) -C $(KERNELDIR) M=$(PWD) modules`.
+MAKE[0]="make KERNELDIR=/lib/modules/${kernelver}/build all"
+CLEAN="make KERNELDIR=/lib/modules/${kernelver}/build clean"
+
+AUTOINSTALL="yes"
diff --git a/arch/daedalus-v4l2/PKGBUILD b/arch/daedalus-v4l2/PKGBUILD
new file mode 100644
index 000000000..3e146f1f6
--- /dev/null
+++ b/arch/daedalus-v4l2/PKGBUILD
@@ -0,0 +1,105 @@
+# Maintainer: Markus Fritsche <fritsche.markus@gmail.com>
+#
+# daedalus-v4l2 — userspace daemon + V4L2 m2m test tools.
+#
+# Pair to daedalus-v4l2-dkms (kernel module).  Together they expose
+# /dev/videoNN + /dev/mediaNN as a V4L2 stateless decoder shim on Pi 5 /
+# CM5, decoding VP9 / AV1 / H.264 via dlopen'd FFmpeg in a single-
+# threaded daemon and shipping decoded NV12 / P010 back through dmabuf.
+# Consumed end-to-end by libva-v4l2-request-fourier (>= 1.0.0.r376) so
+# `ffmpeg -hwaccel vaapi` against vp9_small.ivf produces byte-exact NV12.
+#
+# Project: https://git.reauktion.de/reauktion/daedalus-v4l2
+# Sibling kernel package: daedalus-v4l2-dkms
+# Sibling consumer: libva-v4l2-request-fourier
+
+pkgname=daedalus-v4l2
+_upstreampkg=daedalus-v4l2
+
+# Pin the daedalus-v4l2 tip.  f04d700 = "Phase 8.13: byte-exact end-to-
+# end via libva (consumer target hit)" — first commit where the full
+# ffmpeg -hwaccel vaapi → libva → /dev/video0 → daemon path lands a
+# pixel-correct decoded frame back in ffmpeg.  Promote to a later pin
+# only after a future phase closes cleanly.
+_commit=f04d7000f858fe51d867aba14a529d3aef4fbd54
+
+# 0.1.0 (pre-1.0) + commit count + short sha.  Bump the .Y on each
+# Phase 8.x close.  pkgver() recomputes at build time.
+pkgver=0.1.0.r15.f04d700
+pkgrel=1
+pkgdesc="Userspace daemon for the daedalus-v4l2 V4L2 stateless decoder shim (VP9/AV1/H.264 on Pi 5 / CM5)"
+arch=('aarch64')
+url="https://git.reauktion.de/reauktion/daedalus-v4l2"
+license=('BSD-2-Clause' 'GPL-2.0-or-later')
+# Daemon dlopens libavformat.so.61 / libavcodec.so.61 / libavutil.so.59
+# at runtime (Option γ — see daemon/src/ffmpeg_loader.h).  ffmpeg
+# provides those; we don't link them.
+depends=('ffmpeg' 'libdrm')
+# Headers from libav*-dev needed at compile time for type-safe function
+# pointer signatures; pkg-config locates them.
+makedepends=('cmake' 'ninja' 'pkgconf' 'git' 'ffmpeg')
+optdepends=('daedalus-v4l2-dkms: kernel module providing /dev/video0 + /dev/daedalus-v4l2'
+            'libva-v4l2-request-fourier: VA-API consumer routing through this daemon')
+
+source=("git+https://git.reauktion.de/reauktion/daedalus-v4l2.git#commit=${_commit}")
+sha256sums=('SKIP')
+
+pkgver() {
+    cd "${srcdir}/${_upstreampkg}"
+    printf '0.1.0.r%s.%s' \
+        "$(git rev-list --count HEAD)" \
+        "$(git rev-parse --short=7 HEAD)"
+}
+
+build() {
+    cd "${srcdir}/${_upstreampkg}/daemon"
+    cmake -B build -G Ninja \
+        -DCMAKE_BUILD_TYPE=Release \
+        -DCMAKE_INSTALL_PREFIX=/usr
+    cmake --build build
+
+    cd "${srcdir}/${_upstreampkg}/tools"
+    make
+}
+
+package() {
+    cd "${srcdir}/${_upstreampkg}"
+
+    # Daemon binary
+    install -Dm755 daemon/build/daedalus_v4l2_daemon \
+        "${pkgdir}/usr/bin/daedalus_v4l2_daemon"
+
+    # Test tools (under /usr/libexec to keep them out of the default PATH
+    # — they're for verification, not daily use).
+    install -Dm755 tools/test_chardev_pingpong \
+        "${pkgdir}/usr/libexec/daedalus-v4l2/test_chardev_pingpong"
+    install -Dm755 tools/test_m2m_decode \
+        "${pkgdir}/usr/libexec/daedalus-v4l2/test_m2m_decode"
+    install -Dm755 tools/test_m2m_stream \
+        "${pkgdir}/usr/libexec/daedalus-v4l2/test_m2m_stream"
+
+    # Shared wire-protocol header (kernel ↔ daemon); useful for
+    # third-party clients of the chardev.
+    install -Dm644 include/daedalus_v4l2_proto.h \
+        "${pkgdir}/usr/include/daedalus_v4l2_proto.h"
+
+    # Documentation
+    install -Dm644 README.md \
+        "${pkgdir}/usr/share/doc/${pkgname}/README.md"
+    for d in docs/*.md; do
+        install -Dm644 "$d" "${pkgdir}/usr/share/doc/${pkgname}/$(basename "$d")"
+    done
+
+    # Licenses: BSD-2-Clause for daemon/tools, GPL for the kernel proto
+    # header; the SPDX headers in src/ are the canonical declaration but
+    # ship a short note here for package-manager-driven license queries.
+    install -dm755 "${pkgdir}/usr/share/licenses/${pkgname}"
+    cat > "${pkgdir}/usr/share/licenses/${pkgname}/LICENSE" <<'EOF'
+daedalus-v4l2 userspace components are BSD-2-Clause licensed.
+The shared kernel↔daemon wire protocol header
+(/usr/include/daedalus_v4l2_proto.h) is GPL-2.0-or-later WITH
+Linux-syscall-note for kernel-side compatibility.  See SPDX
+headers on individual source files for the canonical
+per-file declaration.
+EOF
+}
diff --git a/arch/libva-v4l2-request-fourier/PKGBUILD b/arch/libva-v4l2-request-fourier/PKGBUILD
index 32bdcc016..56a1772c8 100644
--- a/arch/libva-v4l2-request-fourier/PKGBUILD
+++ b/arch/libva-v4l2-request-fourier/PKGBUILD
@@ -23,20 +23,26 @@
 pkgname=libva-v4l2-request-fourier
 _upstreampkg=libva-v4l2-request
 
-# Pin the fork tip. 7ac934e = "iter38b: bounds check uses MAX_PROFILES
-# (11), not MAX_CONFIG_ATTRIBUTES (10)" — fresnel-fourier campaign
-# production tip 2026-05-14, sibling iter38 added multi-device probe so
-# a single libva session serves rkvdec + hantro without requiring
-# LIBVA_V4L2_REQUEST_VIDEO_PATH overrides. Promote to a later pin only
-# after a future iteration closes cleanly.
-_commit=7ac934e0c5420814c7a5fc3e2a2f08251d590d9e
+# Pin the fork tip. de27e95 = "v4l2: log error_idx + failing ctrl id
+# on S_EXT_CTRLS failure" — Phase 8.13 diagnostic that surfaced the
+# real root cause of the libva→daedalus_v4l2 request-completion
+# timeout (turned out the EINVAL libva was logging was a harmless
+# H264/HEVC probe; actual VP9 stateless control SET worked all along).
+#
+# Prior pin (7ac934e) was iter38b — fresnel-fourier multi-device probe
+# + MAX_PROFILES bounds-check fix. de27e95 adds the daedalus_v4l2
+# probe slot (b5b3acf), the meson option gate (2146341), and the
+# S_EXT_CTRLS diagnostic (de27e95 itself). Backward-compatible on
+# rkvdec / hantro / cedrus / rpi-hevc-dec hosts — daedalus probe is
+# off by default unless the kernel module is present.
+_commit=de27e95571b67ef34619c23a12db4698f9b3454e
 
 # Project version from meson.build (1.0.0) + commit count + short sha,
 # matching the ffmpeg-v4l2-request-fourier convention. Recomputed at
 # build time by pkgver() below; the static value here is a placeholder
 # so AUR-style consumers see something coherent before src/ exists.
-pkgver=1.0.0.r348.7ac934e
-pkgrel=2
+pkgver=1.0.0.r376.de27e95
+pkgrel=1
 pkgdesc="VA-API backend for V4L2 stateless decoders (multiplanar fork — fourier umbrella)"
 arch=('aarch64')
 url="https://git.reauktion.de/marfrit/libva-v4l2-request-fourier"
diff --git a/debian/daedalus-v4l2-dkms/build-deb.sh b/debian/daedalus-v4l2-dkms/build-deb.sh
new file mode 100755
index 000000000..c027e0395
--- /dev/null
+++ b/debian/daedalus-v4l2-dkms/build-deb.sh
@@ -0,0 +1,131 @@
+#!/bin/bash
+# Build daedalus-v4l2-dkms_<ver>_all.deb (kernel module via DKMS).
+#
+# Installs kernel/ source tree to /usr/src/daedalus_v4l2-${PKGVER}/
+# plus a dkms.conf.  Postinst registers with DKMS (dkms add + build +
+# install).  Prerm deregisters.  Result: the daedalus_v4l2 module
+# auto-rebuilds against any installed kernel headers without users
+# needing to remember to dkms-add it.
+#
+# Architecture: all.  The kernel module itself is per-kernel-version,
+# but the SOURCE package is arch-independent.
+#
+# Sibling Arch package: ../../arch/daedalus-v4l2-dkms/PKGBUILD
+# Sibling userspace package: ../daedalus-v4l2/build-deb.sh
+set -euo pipefail
+
+UPSTREAM_COMMIT=f04d7000f858fe51d867aba14a529d3aef4fbd54
+PKGVER=0.1.0+r15+gf04d700
+PKGREL=1
+MODULE_NAME=daedalus_v4l2
+
+HERE=$(dirname "$(readlink -f "$0")")
+
+# Reproducible build.  2026-05-18 23:00 UTC — Phase 8.13 close.
+export SOURCE_DATE_EPOCH=1779231600
+
+work=$(mktemp -d)
+trap "rm -rf $work" EXIT
+
+cd "$work"
+curl -sSLfo daedalus-v4l2.tar.gz \
+    "https://git.reauktion.de/reauktion/daedalus-v4l2/archive/${UPSTREAM_COMMIT}.tar.gz"
+tar xzf daedalus-v4l2.tar.gz
+SRCDIR=daedalus-v4l2
+
+ROOT="$work/pkgroot"
+SRCROOT="$ROOT/usr/src/${MODULE_NAME}-${PKGVER}"
+
+mkdir -p "$SRCROOT/include" \
+         "$ROOT/DEBIAN" \
+         "$ROOT/usr/share/doc/daedalus-v4l2-dkms"
+
+# Copy kernel/ source files to the DKMS source dir.
+cp -r "$work/$SRCDIR/kernel/." "$SRCROOT/"
+
+# Embed the shared protocol header inline (rather than referencing
+# ../include/ which doesn't exist after DKMS extracts the tree).
+# Patch the Makefile to find it at $SRCROOT/include/ instead.
+install -m 644 "$work/$SRCDIR/include/daedalus_v4l2_proto.h" \
+    "$SRCROOT/include/daedalus_v4l2_proto.h"
+sed -i 's|-I\$(src)/\.\./include|-I$(src)/include|' "$SRCROOT/Makefile"
+
+# Generate dkms.conf with the actual version substituted.
+cat > "$SRCROOT/dkms.conf" <<EOF
+PACKAGE_NAME="${MODULE_NAME}"
+PACKAGE_VERSION="${PKGVER}"
+
+BUILT_MODULE_NAME[0]="${MODULE_NAME}"
+DEST_MODULE_LOCATION[0]="/updates"
+
+MAKE[0]="make KERNELDIR=/lib/modules/\${kernelver}/build all"
+CLEAN="make KERNELDIR=/lib/modules/\${kernelver}/build clean"
+
+AUTOINSTALL="yes"
+EOF
+
+# Doc
+install -m 644 "$work/$SRCDIR/README.md" \
+    "$ROOT/usr/share/doc/daedalus-v4l2-dkms/README.md"
+install -Dm644 "$HERE/debian/copyright" "$ROOT/usr/share/doc/daedalus-v4l2-dkms/copyright"
+install -Dm644 "$HERE/debian/changelog" "$ROOT/usr/share/doc/daedalus-v4l2-dkms/changelog.Debian"
+gzip -9 -n "$ROOT/usr/share/doc/daedalus-v4l2-dkms/changelog.Debian"
+
+# DKMS post-install / pre-remove hooks.
+cat > "$ROOT/DEBIAN/postinst" <<EOF
+#!/bin/sh
+set -e
+
+NAME=${MODULE_NAME}
+VERSION=${PKGVER}
+
+if [ "\$1" = "configure" ] && command -v dkms >/dev/null 2>&1; then
+    dkms add "\$NAME/\$VERSION" 2>/dev/null || true
+    dkms autoinstall "\$NAME/\$VERSION" || true
+fi
+
+#DEBHELPER#
+EOF
+chmod 755 "$ROOT/DEBIAN/postinst"
+
+cat > "$ROOT/DEBIAN/prerm" <<EOF
+#!/bin/sh
+set -e
+
+NAME=${MODULE_NAME}
+VERSION=${PKGVER}
+
+if [ "\$1" = "remove" ] && command -v dkms >/dev/null 2>&1; then
+    dkms remove "\$NAME/\$VERSION" --all || true
+fi
+
+#DEBHELPER#
+EOF
+chmod 755 "$ROOT/DEBIAN/prerm"
+
+cat > "$ROOT/DEBIAN/control" <<EOF
+Package: daedalus-v4l2-dkms
+Version: ${PKGVER}-${PKGREL}
+Section: kernel
+Priority: optional
+Architecture: all
+Depends: dkms (>= 2.1.0.0)
+Recommends: daedalus-v4l2, linux-headers-generic | linux-headers
+Maintainer: Markus Fritsche <mfritsche@reauktion.de>
+Homepage: https://git.reauktion.de/reauktion/daedalus-v4l2
+Description: V4L2 stateless decoder shim kernel module (DKMS) — Pi 5 / CM5
+ Out-of-tree V4L2 m2m kernel module for the daedalus-v4l2 stack on
+ Raspberry Pi 5 / CM5.  Registers /dev/videoNN (V4L2 stateless m2m
+ decoder), /dev/mediaNN (media controller with request API), and
+ /dev/daedalus-v4l2 (chardev bridge to the userspace daemon).
+ .
+ The actual decode happens in the userspace daemon shipped by the
+ daedalus-v4l2 package — this module is just the kernel-side V4L2
+ plumbing.  Install both to actually serve VAAPI / V4L2 clients.
+ .
+ Built via DKMS against the running kernel's headers.
+EOF
+
+DEB_OUT="daedalus-v4l2-dkms_${PKGVER}-${PKGREL}_all.deb"
+dpkg-deb --root-owner-group --build "$ROOT" "$HERE/$DEB_OUT"
+echo "built: $HERE/$DEB_OUT"
diff --git a/debian/daedalus-v4l2-dkms/debian/changelog b/debian/daedalus-v4l2-dkms/debian/changelog
new file mode 100644
index 000000000..26c83642f
--- /dev/null
+++ b/debian/daedalus-v4l2-dkms/debian/changelog
@@ -0,0 +1,11 @@
+daedalus-v4l2-dkms (0.1.0+r15+gf04d700-1) bookworm trixie; urgency=medium
+
+  * Initial Debian DKMS packaging for the daedalus_v4l2 kernel module.
+  * Pinned to f04d700 (Phase 8.13 close): kernel-side framework
+    integration (V4L2 m2m, dmabuf-export, media controller, request
+    API, NV12 single-plane + NV12M + P010 CAPTURE) that closes the
+    libva→/dev/video0→daemon round-trip with byte-exact pixels.
+  * Auto-builds via DKMS against the running kernel's headers.
+  * Companion userspace package: daedalus-v4l2 (daemon + tools).
+
+ -- Markus Fritsche <mfritsche@reauktion.de>  Mon, 18 May 2026 23:00:00 +0000
diff --git a/debian/daedalus-v4l2-dkms/debian/control b/debian/daedalus-v4l2-dkms/debian/control
new file mode 100644
index 000000000..15ff67b35
--- /dev/null
+++ b/debian/daedalus-v4l2-dkms/debian/control
@@ -0,0 +1,24 @@
+Source: daedalus-v4l2-dkms
+Section: kernel
+Priority: optional
+Maintainer: Markus Fritsche <mfritsche@reauktion.de>
+Build-Depends: debhelper-compat (= 13)
+Standards-Version: 4.6.2
+Homepage: https://git.reauktion.de/reauktion/daedalus-v4l2
+
+Package: daedalus-v4l2-dkms
+Architecture: all
+Depends: ${misc:Depends}, dkms (>= 2.1.0.0)
+Recommends: daedalus-v4l2,
+            linux-headers-generic | linux-headers
+Description: V4L2 stateless decoder shim kernel module (DKMS) — Pi 5 / CM5
+ Out-of-tree V4L2 m2m kernel module for the daedalus-v4l2 stack on
+ Raspberry Pi 5 / CM5. Registers /dev/videoNN (V4L2 stateless m2m
+ decoder), /dev/mediaNN (media controller with request API), and
+ /dev/daedalus-v4l2 (chardev bridge to the userspace daemon).
+ .
+ The actual decode happens in the userspace daemon shipped by the
+ daedalus-v4l2 package — this module is just the kernel-side V4L2
+ plumbing. Install both to actually serve VAAPI / V4L2 clients.
+ .
+ Built via DKMS against the running kernel's headers.
diff --git a/debian/daedalus-v4l2-dkms/debian/copyright b/debian/daedalus-v4l2-dkms/debian/copyright
new file mode 100644
index 000000000..9870f0236
--- /dev/null
+++ b/debian/daedalus-v4l2-dkms/debian/copyright
@@ -0,0 +1,21 @@
+Format: https://www.debian.org/doc/packaging-manuals/copyright-format/1.0/
+Upstream-Name: daedalus-v4l2
+Upstream-Contact: Markus Fritsche <fritsche.markus@gmail.com>
+Source: https://git.reauktion.de/reauktion/daedalus-v4l2
+
+Files: *
+Copyright: 2026 Markus Fritsche <fritsche.markus@gmail.com>
+License: GPL-2.0-or-later
+Comment:
+ Kernel module (loadable into the Linux kernel) — GPL-2.0-or-later.
+ The shared protocol header carries an additional Linux-syscall-note
+ exception so userspace inclusion is BSD-clean.
+
+License: GPL-2.0-or-later
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2 of the License, or
+ (at your option) any later version.
+ .
+ On Debian systems, the complete text of the GNU General Public
+ License v2 can be found in `/usr/share/common-licenses/GPL-2'.
diff --git a/debian/daedalus-v4l2/build-deb.sh b/debian/daedalus-v4l2/build-deb.sh
new file mode 100755
index 000000000..e195c20dc
--- /dev/null
+++ b/debian/daedalus-v4l2/build-deb.sh
@@ -0,0 +1,106 @@
+#!/bin/bash
+# Build daedalus-v4l2_<ver>_arm64.deb (userspace daemon + test tools).
+#
+# Mirrors arch/daedalus-v4l2 (Arch Linux build).  The companion DKMS
+# package (debian/daedalus-v4l2-dkms) carries the kernel module
+# separately so apt/dpkg can split kernel-version-tied and userspace
+# upgrade cadence.
+#
+# Sibling Arch package: ../../arch/daedalus-v4l2/PKGBUILD
+# Sibling DKMS package: ../daedalus-v4l2-dkms/build-deb.sh
+# Upstream repo: https://git.reauktion.de/reauktion/daedalus-v4l2
+set -euo pipefail
+
+# Same pin as the Arch PKGBUILD.  f04d700 = "Phase 8.13: byte-exact
+# end-to-end via libva (consumer target hit)" — first commit where the
+# full ffmpeg -hwaccel vaapi → libva → /dev/video0 → daemon path lands
+# a pixel-correct decoded frame back in ffmpeg.
+UPSTREAM_COMMIT=f04d7000f858fe51d867aba14a529d3aef4fbd54
+PKGVER=0.1.0+r15+gf04d700
+PKGREL=1
+
+HERE=$(dirname "$(readlink -f "$0")")
+
+# Reproducible build.  2026-05-18 23:00 UTC — Phase 8.13 close.
+export SOURCE_DATE_EPOCH=1779231600
+
+work=$(mktemp -d)
+trap "rm -rf $work" EXIT
+
+cd "$work"
+curl -sSLfo daedalus-v4l2.tar.gz \
+    "https://git.reauktion.de/reauktion/daedalus-v4l2/archive/${UPSTREAM_COMMIT}.tar.gz"
+tar xzf daedalus-v4l2.tar.gz
+SRCDIR=daedalus-v4l2
+
+# Build daemon (CMake)
+cd "$SRCDIR/daemon"
+cmake -B build -G Ninja \
+    -DCMAKE_BUILD_TYPE=Release \
+    -DCMAKE_INSTALL_PREFIX=/usr
+cmake --build build
+
+# Build test tools (in-tree Makefile)
+cd "$work/$SRCDIR/tools"
+make
+
+# Stage
+ROOT="$work/pkgroot"
+mkdir -p "$ROOT/DEBIAN" \
+         "$ROOT/usr/bin" \
+         "$ROOT/usr/libexec/daedalus-v4l2" \
+         "$ROOT/usr/include" \
+         "$ROOT/usr/share/doc/daedalus-v4l2"
+
+install -m 755 "$work/$SRCDIR/daemon/build/daedalus_v4l2_daemon" \
+    "$ROOT/usr/bin/daedalus_v4l2_daemon"
+
+install -m 755 "$work/$SRCDIR/tools/test_chardev_pingpong" \
+    "$ROOT/usr/libexec/daedalus-v4l2/test_chardev_pingpong"
+install -m 755 "$work/$SRCDIR/tools/test_m2m_decode" \
+    "$ROOT/usr/libexec/daedalus-v4l2/test_m2m_decode"
+install -m 755 "$work/$SRCDIR/tools/test_m2m_stream" \
+    "$ROOT/usr/libexec/daedalus-v4l2/test_m2m_stream"
+
+install -m 644 "$work/$SRCDIR/include/daedalus_v4l2_proto.h" \
+    "$ROOT/usr/include/daedalus_v4l2_proto.h"
+
+install -m 644 "$work/$SRCDIR/README.md" \
+    "$ROOT/usr/share/doc/daedalus-v4l2/README.md"
+for d in "$work/$SRCDIR/docs/"*.md; do
+    install -m 644 "$d" "$ROOT/usr/share/doc/daedalus-v4l2/$(basename "$d")"
+done
+
+install -Dm644 "$HERE/debian/copyright" "$ROOT/usr/share/doc/daedalus-v4l2/copyright"
+install -Dm644 "$HERE/debian/changelog" "$ROOT/usr/share/doc/daedalus-v4l2/changelog.Debian"
+gzip -9 -n "$ROOT/usr/share/doc/daedalus-v4l2/changelog.Debian"
+
+cat > "$ROOT/DEBIAN/control" <<EOF
+Package: daedalus-v4l2
+Version: ${PKGVER}-${PKGREL}
+Section: video
+Priority: optional
+Architecture: arm64
+Depends: ffmpeg (>= 7.1), libdrm2
+Recommends: daedalus-v4l2-dkms
+Maintainer: Markus Fritsche <mfritsche@reauktion.de>
+Homepage: https://git.reauktion.de/reauktion/daedalus-v4l2
+Description: Userspace daemon for the daedalus_v4l2 stateless decoder shim
+ daedalus-v4l2 ships the userspace daemon that backs the daedalus_v4l2
+ out-of-tree V4L2 kernel module on Raspberry Pi 5 / CM5.  Together they
+ expose /dev/videoNN + /dev/mediaNN as a V4L2 stateless decoder for
+ VP9, AV1, and H.264 — actual decoding happens in this single-threaded
+ daemon via dlopen'd FFmpeg, with decoded NV12 / P010 frames shipped
+ back through dmabuf.
+ .
+ Consumed end-to-end by libva-v4l2-request-fourier (>= 1.0.0+r376) so
+ that 'ffmpeg -hwaccel vaapi' against vp9_small.ivf produces a
+ byte-exact NV12 frame.
+ .
+ The kernel module ships separately in daedalus-v4l2-dkms; install
+ both to actually serve V4L2 clients.
+EOF
+
+DEB_OUT="daedalus-v4l2_${PKGVER}-${PKGREL}_arm64.deb"
+dpkg-deb --root-owner-group --build "$ROOT" "$HERE/$DEB_OUT"
+echo "built: $HERE/$DEB_OUT"
diff --git a/debian/daedalus-v4l2/debian/changelog b/debian/daedalus-v4l2/debian/changelog
new file mode 100644
index 000000000..680fd670a
--- /dev/null
+++ b/debian/daedalus-v4l2/debian/changelog
@@ -0,0 +1,13 @@
+daedalus-v4l2 (0.1.0+r15+gf04d700-1) bookworm trixie; urgency=medium
+
+  * Initial Debian packaging for the daedalus-v4l2 userspace daemon.
+  * Pinned to f04d700 (Phase 8.13 close): first commit where the full
+    ffmpeg -hwaccel vaapi → libva-v4l2-request-fourier → /dev/video0
+    → daemon path lands a pixel-correct decoded NV12 frame back in
+    ffmpeg.
+  * Codecs: VP9, AV1, H.264 (all via dlopen'd FFmpeg 7.1.3).
+  * Capture formats: NV12M (2 plane), NV12 (1 plane, for libva),
+    P010 (10-bit single plane).
+  * Companion package: daedalus-v4l2-dkms (kernel module).
+
+ -- Markus Fritsche <mfritsche@reauktion.de>  Mon, 18 May 2026 23:00:00 +0000
diff --git a/debian/daedalus-v4l2/debian/control b/debian/daedalus-v4l2/debian/control
new file mode 100644
index 000000000..72ec51ae8
--- /dev/null
+++ b/debian/daedalus-v4l2/debian/control
@@ -0,0 +1,34 @@
+Source: daedalus-v4l2
+Section: video
+Priority: optional
+Maintainer: Markus Fritsche <mfritsche@reauktion.de>
+Build-Depends: debhelper-compat (= 13),
+               cmake,
+               ninja-build,
+               pkg-config,
+               libavformat-dev (>= 7.1),
+               libavcodec-dev (>= 7.1),
+               libavutil-dev (>= 7.1)
+Standards-Version: 4.6.2
+Homepage: https://git.reauktion.de/reauktion/daedalus-v4l2
+
+Package: daedalus-v4l2
+Architecture: arm64
+Depends: ${misc:Depends}, ${shlibs:Depends},
+         ffmpeg (>= 7.1),
+         libdrm2
+Recommends: daedalus-v4l2-dkms
+Description: Userspace daemon for the daedalus_v4l2 stateless decoder shim
+ daedalus-v4l2 ships the userspace daemon that backs the daedalus_v4l2
+ out-of-tree V4L2 kernel module on Raspberry Pi 5 / CM5. Together they
+ expose /dev/videoNN + /dev/mediaNN as a V4L2 stateless decoder for
+ VP9, AV1, and H.264 — actual decoding happens in this single-threaded
+ daemon via dlopen'd FFmpeg, with decoded NV12 / P010 frames shipped
+ back through dmabuf.
+ .
+ Consumed end-to-end by libva-v4l2-request-fourier (>= 1.0.0+r376) so
+ that 'ffmpeg -hwaccel vaapi' against vp9_small.ivf produces a
+ byte-exact NV12 frame.
+ .
+ The kernel module ships separately in daedalus-v4l2-dkms; install
+ both to actually serve V4L2 clients.
diff --git a/debian/daedalus-v4l2/debian/copyright b/debian/daedalus-v4l2/debian/copyright
new file mode 100644
index 000000000..90650d0ae
--- /dev/null
+++ b/debian/daedalus-v4l2/debian/copyright
@@ -0,0 +1,40 @@
+Format: https://www.debian.org/doc/packaging-manuals/copyright-format/1.0/
+Upstream-Name: daedalus-v4l2
+Upstream-Contact: Markus Fritsche <fritsche.markus@gmail.com>
+Source: https://git.reauktion.de/reauktion/daedalus-v4l2
+
+Files: *
+Copyright: 2026 Markus Fritsche <fritsche.markus@gmail.com>
+License: BSD-2-Clause
+
+Files: include/daedalus_v4l2_proto.h
+Copyright: 2026 Markus Fritsche <fritsche.markus@gmail.com>
+License: GPL-2.0-or-later WITH Linux-syscall-note
+Comment:
+ Shared kernel↔daemon wire-protocol header. GPL-2.0-or-later (matches
+ the kernel module that includes it) with the standard
+ Linux-syscall-note exception so userspace inclusion is BSD-clean.
+
+License: BSD-2-Clause
+ Redistribution and use in source and binary forms, with or without
+ modification, are permitted provided that the following conditions
+ are met:
+ .
+ 1. Redistributions of source code must retain the above copyright
+    notice, this list of conditions and the following disclaimer.
+ 2. Redistributions in binary form must reproduce the above copyright
+    notice, this list of conditions and the following disclaimer in
+    the documentation and/or other materials provided with the
+    distribution.
+ .
+ THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES ARE DISCLAIMED.
+
+License: GPL-2.0-or-later
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2 of the License, or
+ (at your option) any later version.
+ .
+ On Debian systems, the complete text of the GNU General Public
+ License v2 can be found in `/usr/share/common-licenses/GPL-2'.
diff --git a/debian/libva-v4l2-request-fourier/build-deb.sh b/debian/libva-v4l2-request-fourier/build-deb.sh
new file mode 100755
index 000000000..a3931ec54
--- /dev/null
+++ b/debian/libva-v4l2-request-fourier/build-deb.sh
@@ -0,0 +1,74 @@
+#!/bin/bash
+# Build libva-v4l2-request-fourier_<ver>_arm64.deb.
+#
+# Compiles the libva ICD from the marfrit/libva-v4l2-request-fourier
+# tip pinned in PKGVER below.  Mirrors arch/libva-v4l2-request-fourier
+# (Arch Linux build).  Output is a single arm64 .deb that ships the
+# VA-API driver as /usr/lib/aarch64-linux-gnu/dri/v4l2_request_drv_video.so.
+#
+# Sibling Arch package: ../../arch/libva-v4l2-request-fourier/PKGBUILD
+# Upstream fork: https://git.reauktion.de/marfrit/libva-v4l2-request-fourier
+set -euo pipefail
+
+# Same pin as the Arch PKGBUILD.  de27e95 = "v4l2: log error_idx +
+# failing ctrl id on S_EXT_CTRLS failure" (Phase 8.13 diagnostic).
+UPSTREAM_COMMIT=de27e95571b67ef34619c23a12db4698f9b3454e
+PKGVER=1.0.0+r376+gde27e95
+PKGREL=1
+
+HERE=$(dirname "$(readlink -f "$0")")
+
+# Reproducible build.  2026-05-18 23:00 UTC — Phase 8.13 close.
+export SOURCE_DATE_EPOCH=1779231600
+
+work=$(mktemp -d)
+trap "rm -rf $work" EXIT
+
+cd "$work"
+curl -sSLfo libva-fourier.tar.gz \
+    "https://git.reauktion.de/marfrit/libva-v4l2-request-fourier/archive/${UPSTREAM_COMMIT}.tar.gz"
+tar xzf libva-fourier.tar.gz
+SRCDIR=$(echo libva-v4l2-request-fourier)
+
+cd "$SRCDIR"
+meson setup build \
+    --buildtype=release \
+    --prefix=/usr \
+    --libdir=lib/aarch64-linux-gnu \
+    -Db_lto=false
+meson compile -C build
+
+ROOT="$work/pkgroot"
+DESTDIR="$ROOT" meson install -C build
+
+# Strip any non-package debug, then drop dependencies + control.
+install -Dm644 "$HERE/debian/copyright" "$ROOT/usr/share/doc/libva-v4l2-request-fourier/copyright"
+install -Dm644 "$HERE/debian/changelog" "$ROOT/usr/share/doc/libva-v4l2-request-fourier/changelog.Debian"
+gzip -9 -n "$ROOT/usr/share/doc/libva-v4l2-request-fourier/changelog.Debian"
+
+mkdir -p "$ROOT/DEBIAN"
+cat > "$ROOT/DEBIAN/control" <<EOF
+Package: libva-v4l2-request-fourier
+Version: ${PKGVER}-${PKGREL}
+Section: libs
+Priority: optional
+Architecture: arm64
+Depends: libva2, libdrm2
+Conflicts: libva-v4l2-request
+Replaces: libva-v4l2-request
+Provides: libva-driver, libva-v4l2-request (= ${PKGVER}-${PKGREL})
+Maintainer: Markus Fritsche <mfritsche@reauktion.de>
+Homepage: https://git.reauktion.de/marfrit/libva-v4l2-request-fourier
+Description: VA-API backend for V4L2 stateless decoders (fourier fork)
+ LibVA implementation for the Linux Video4Linux2 Request API, multiplanar
+ fork of bootlin/libva-v4l2-request.  Drives rkvdec / hantro / cedrus /
+ rpi-hevc-dec / daedalus_v4l2 stateless decoders for H.264, HEVC, VP8,
+ VP9, AV1, and MPEG-2.
+ .
+ Auto-detected by VAAPI consumers (ffmpeg -hwaccel vaapi, mpv --hwdec=vaapi,
+ Firefox VAAPI accel) when LIBVA_DRIVER_NAME=v4l2_request is set.
+EOF
+
+DEB_OUT="libva-v4l2-request-fourier_${PKGVER}-${PKGREL}_arm64.deb"
+dpkg-deb --root-owner-group --build "$ROOT" "$HERE/$DEB_OUT"
+echo "built: $HERE/$DEB_OUT"
diff --git a/debian/libva-v4l2-request-fourier/debian/changelog b/debian/libva-v4l2-request-fourier/debian/changelog
new file mode 100644
index 000000000..fcb6873df
--- /dev/null
+++ b/debian/libva-v4l2-request-fourier/debian/changelog
@@ -0,0 +1,15 @@
+libva-v4l2-request-fourier (1.0.0+r376+gde27e95-1) bookworm trixie; urgency=medium
+
+  * Initial Debian packaging (sibling to existing
+    arch/libva-v4l2-request-fourier).
+  * Pinned to fork tip de27e95: "v4l2: log error_idx + failing ctrl id
+    on S_EXT_CTRLS failure" — Phase 8.13 diagnostic that surfaced the
+    real root cause of the libva→daedalus_v4l2 request-completion
+    timeout.
+  * Includes daedalus_v4l2 probe slot (b5b3acf) and meson option gate
+    (2146341) for the Pi 5 daemon-backed decoder shim.
+  * Backward-compatible on rkvdec / hantro / cedrus / rpi-hevc-dec
+    hosts — daedalus probe is off by default unless the kernel module
+    is present.
+
+ -- Markus Fritsche <mfritsche@reauktion.de>  Mon, 18 May 2026 23:00:00 +0000
diff --git a/debian/libva-v4l2-request-fourier/debian/control b/debian/libva-v4l2-request-fourier/debian/control
new file mode 100644
index 000000000..6389b9baf
--- /dev/null
+++ b/debian/libva-v4l2-request-fourier/debian/control
@@ -0,0 +1,27 @@
+Source: libva-v4l2-request-fourier
+Section: libs
+Priority: optional
+Maintainer: Markus Fritsche <mfritsche@reauktion.de>
+Build-Depends: debhelper-compat (= 13),
+               libva-dev,
+               libdrm-dev,
+               meson (>= 0.43),
+               ninja-build,
+               pkg-config
+Standards-Version: 4.6.2
+Homepage: https://git.reauktion.de/marfrit/libva-v4l2-request-fourier
+
+Package: libva-v4l2-request-fourier
+Architecture: arm64
+Depends: ${misc:Depends}, ${shlibs:Depends}, libva2, libdrm2
+Conflicts: libva-v4l2-request
+Replaces: libva-v4l2-request
+Provides: libva-driver, libva-v4l2-request (= ${binary:Version})
+Description: VA-API backend for V4L2 stateless decoders (fourier fork)
+ LibVA implementation for the Linux Video4Linux2 Request API, multiplanar
+ fork of bootlin/libva-v4l2-request. Drives rkvdec / hantro / cedrus /
+ rpi-hevc-dec / daedalus_v4l2 stateless decoders for H.264, HEVC, VP8,
+ VP9, AV1, and MPEG-2.
+ .
+ Auto-detected by VAAPI consumers (ffmpeg -hwaccel vaapi, mpv --hwdec=vaapi,
+ Firefox VAAPI accel) when LIBVA_DRIVER_NAME=v4l2_request is set.
diff --git a/debian/libva-v4l2-request-fourier/debian/copyright b/debian/libva-v4l2-request-fourier/debian/copyright
new file mode 100644
index 000000000..684dc8dca
--- /dev/null
+++ b/debian/libva-v4l2-request-fourier/debian/copyright
@@ -0,0 +1,38 @@
+Format: https://www.debian.org/doc/packaging-manuals/copyright-format/1.0/
+Upstream-Name: libva-v4l2-request-fourier
+Upstream-Contact: Markus Fritsche <fritsche.markus@gmail.com>
+Source: https://git.reauktion.de/marfrit/libva-v4l2-request-fourier
+Comment:
+ Fork of bootlin/libva-v4l2-request with multi-codec / multi-device
+ enhancements for the fourier campaign (RK3399 / RK3588 / RK3566 / BCM2712).
+ Per-file SPDX headers are the canonical declaration; this summary
+ covers the aggregate.
+
+Files: *
+Copyright: 2018 Paul Kocialkowski <paul.kocialkowski@bootlin.com>
+           2018-2026 The libva-v4l2-request authors
+           2024-2026 Markus Fritsche <fritsche.markus@gmail.com>
+License: LGPL-2.1+ or MIT
+
+License: LGPL-2.1+
+ This package is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+ .
+ On Debian systems, the complete text of the GNU Lesser General
+ Public License v2.1 can be found in `/usr/share/common-licenses/LGPL-2.1'.
+
+License: MIT
+ Permission is hereby granted, free of charge, to any person obtaining
+ a copy of this software and associated documentation files (the
+ "Software"), to deal in the Software without restriction, including
+ without limitation the rights to use, copy, modify, merge, publish,
+ distribute, sublicense, and/or sell copies of the Software, and to
+ permit persons to whom the Software is furnished to do so, subject
+ to the following conditions:
+ .
+ The above copyright notice and this permission notice shall be
+ included in all copies or substantial portions of the Software.
+ .
+ THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND.