[PATCH 7/7] Support updates via systemd-sysupdate

Demi Marie Obenour
2025-10-29T10:14:36Z

Include a new 'update' command to update the system. This works as
follows:

1. Take a global, system-wide lock.
2. Create a BTRFS subvolume for the sys.updates VM to write the updates.
3. Bind-mount this subvolume into the VM's shared directory.
4. Start sys.updates to get the updates.
5. Wait for the VM to shut down.
6. Take a BTRFS snapshot of the subvolume.
7. Call syncfs() to flush all of the data on the subvolume.
8. Inspect the contents of the subvolume.
Check that everything is a regular file and that the names are reasonable.
Check that SHA256SUMS and SHA256SUMS.gpg are present.
9. Call systemd-sysupdate to run the actual update.

Signed-off-by: Demi Marie Obenour <demiobenour@gmail.com>
---
host/rootfs/Makefile | 8 ++-
host/rootfs/default.nix | 17 ++++---
host/rootfs/file-list.mk | 5 ++
host/rootfs/image/etc/fstab | 1 +
.../image/etc/sysupdate.d/50-verity.transfer | 21 ++++++++
host/rootfs/image/etc/sysupdate.d/60-root.transfer | 21 ++++++++
.../image/etc/sysupdate.d/70-kernel.transfer | 25 ++++++++++
host/rootfs/image/usr/bin/run-update | 54 ++++++++++++++++++++
host/rootfs/image/usr/bin/update | 56 +++++++++++++++++++++
host/rootfs/image/usr/bin/vm-start | 25 +++++++++-
host/rootfs/os-release.in | 13 +++++
host/rootfs/os-release.in.license | 2 +
host/rootfs/shell.nix | 2 +-
update-signing-keys.gpg | 1 +
update-signing-keys.gpg.license | 2 +
update-url | 1 +
update-url.license | 2 +
vm/app/sysupdate.d/50-verity.transfer | 18 +++++++
vm/app/sysupdate.d/60-root.transfer | 18 +++++++
vm/app/sysupdate.d/70-kernel.transfer | 18 +++++++
vm/app/updates.nix | 57 ++++++++++++++++++++++
21 files changed, 356 insertions(+), 11 deletions(-)

diff --git a/host/rootfs/Makefile b/host/rootfs/Makefile
index 4712d9063e9f2e3c9b8b7b4fb2a7e54d119c6840..2faa1e46c1a3bbbdf31baf1e972d9b4ecb389ae5 100644
--- a/host/rootfs/Makefile
+++ b/host/rootfs/Makefile
@@ -10,6 +10,7 @@ include file-list.mk
dest = build/rootfs.erofs

DIRS = \
+ boot \
dev \
etc/s6-linux-init/env \
etc/s6-linux-init/run-image/configs \
@@ -47,11 +48,13 @@ DIRS = \

FIFOS = etc/s6-linux-init/run-image/service/s6-svscan-log/fifo

-BUILD_FILES = build/etc/s6-rc
+BUILD_FILES = build/etc/s6-rc build/etc/os-release

$(dest): ../../scripts/make-erofs.sh $(PACKAGES_FILE) $(FILES) $(BUILD_FILES) build/empty build/fifo file-list.mk
+ set -euo pipefail; \
{ \
cat $(PACKAGES_FILE) ;\
+ printf '%s\n%s\n' ../../update-signing-keys.gpg /etc/systemd/import-pubring.gpg; \
for file in $(FILES) $(LINKS); do printf '%s\n%s\n' $$file "$${file#image/}"; done ;\
for file in $(BUILD_FILES); do printf '%s\n%s\n' $$file $${file#build/}; done ;\
printf 'build/empty\n%s\n' $(DIRS) ;\
@@ -99,6 +102,9 @@ debug:
$(VMLINUX)
.PHONY: debug

+build/etc/os-release: os-release.in build/etc
+ sed 's#@VERSION@#$(VERSION)#g' < os-release.in > $@
+
run: build/live.img $(EXT_FS) build/rootfs.verity.roothash ../../lib/kcmdline-utils.mk
@set -x && \
ext="$$(mktemp build/spectrum-rootfs-extfs.XXXXXXXXXX.img)" && \
diff --git a/host/rootfs/default.nix b/host/rootfs/default.nix
index cb39f0d77b6640198da3ab840a2c8ca7cc1c91a1..c412fe17f45bde79f1efa42cadb29cfd5fbc3991 100644
--- a/host/rootfs/default.nix
+++ b/host/rootfs/default.nix
@@ -8,10 +8,10 @@ import ../../lib/call-package.nix (
}:
pkgsStatic.callPackage (

-{ busybox, cloud-hypervisor, cryptsetup, dbus, erofs-utils, execline
-, inkscape, inotify-tools, iproute2, jq, lib, mdevd, nixos
-, runCommand, s6, s6-linux-init, s6-rc, socat, spectrum-host-tools
-, stdenvNoCC, util-linux, virtiofsd, writeClosure
+{ btrfs-progs, bash, busybox, cloud-hypervisor, cryptsetup, dbus
+, erofs-utils, execline, inkscape, inotify-tools, iproute2, jq, lib
+, mdevd, nixos, runCommand, s6, s6-linux-init, s6-rc, socat
+, spectrum-host-tools, stdenvNoCC, util-linux, virtiofsd, writeClosure
, xdg-desktop-portal-spectrum-host, xorg
}:
let
@@ -40,8 +40,8 @@ let
no_pgo_foot = foot.override { allowPgo = false; };

packages = [
- cloud-hypervisor crosvm cryptsetup dbus execline inotify-tools
- iproute2 jq mdevd s6 s6-linux-init s6-rc socat
+ btrfs-progs cloud-hypervisor crosvm cryptsetup dbus execline
+ inotify-tools iproute2 jq mdevd s6 s6-linux-init s6-rc socat
spectrum-host-tools virtiofsd xdg-desktop-portal-spectrum-host

(busybox.override {
@@ -90,6 +90,7 @@ let
appvm-firefox = callSpectrumPackage ../../vm/app/firefox.nix {};
appvm-foot = callSpectrumPackage ../../vm/app/foot.nix {};
appvm-gnome-text-editor = callSpectrumPackage ../../vm/app/gnome-text-editor.nix {};
+ appvm-updates = callSpectrumPackage ../../vm/app/updates.nix {};
};

packagesSysroot = runCommand "packages-sysroot" {
@@ -135,13 +136,15 @@ stdenvNoCC.mkDerivation {
../../lib/common.mk
../../lib/kcmdline-utils.mk
../../lib/verity.mk
+ ../../lib/kcmdline-utils.mk
../../scripts/make-erofs.sh
../../version
+ ../../update-signing-keys.gpg
]);
};
sourceRoot = "source/host/rootfs";

- nativeBuildInputs = [ erofs-utils spectrum-build-tools s6-rc ];
+ nativeBuildInputs = [ erofs-utils spectrum-build-tools s6-rc bash btrfs-progs ];

env = {
PACKAGES = runCommand "packages" {} ''
diff --git a/host/rootfs/file-list.mk b/host/rootfs/file-list.mk
index 9acaa1d90bed674814775becf89c1c847d0ce3e3..905422ebda0f70ce32def788e0c093527af293fc 100644
--- a/host/rootfs/file-list.mk
+++ b/host/rootfs/file-list.mk
@@ -42,13 +42,18 @@ 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/sysupdate.d/50-verity.transfer \
+ image/etc/sysupdate.d/60-root.transfer \
+ image/etc/sysupdate.d/70-kernel.transfer \
image/etc/udev/rules.d/99-spectrum.rules \
image/etc/xdg/weston/autolaunch \
image/etc/xdg/weston/weston.ini \
image/usr/bin/assign-devices \
image/usr/bin/create-vm-dependencies \
image/usr/bin/run-appimage \
+ image/usr/bin/run-update \
image/usr/bin/run-vmm \
+ image/usr/bin/update \
image/usr/bin/vm-console \
image/usr/bin/vm-import \
image/usr/bin/vm-start \
diff --git a/host/rootfs/image/etc/fstab b/host/rootfs/image/etc/fstab
index 6a82ecc85090a37b13603b29f74ca6e554a28c33..78cec99f29dda993ad97048771097121a0e42622 100644
--- a/host/rootfs/image/etc/fstab
+++ b/host/rootfs/image/etc/fstab
@@ -4,3 +4,4 @@ proc /proc proc defaults 0 0
devpts /dev/pts devpts defaults,gid=4,mode=620 0 0
tmpfs /dev/shm tmpfs defaults 0 0
sysfs /sys sysfs defaults 0 0
+tmpfs /tmp tmpfs defaults,mode=0700 0 0
diff --git a/host/rootfs/image/etc/sysupdate.d/50-verity.transfer b/host/rootfs/image/etc/sysupdate.d/50-verity.transfer
new file mode 100644
index 0000000000000000000000000000000000000000..07a698f3956e19f9f55efff52db51128c16a5b56
--- /dev/null
+++ b/host/rootfs/image/etc/sysupdate.d/50-verity.transfer
@@ -0,0 +1,21 @@
+# SPDX-License-Identifier: CC0-1.0
+# SPDX-FileCopyrightText: 2025 Demi Marie Obenour <demiobenour@gmail.com>
+
+# Uses example code from systemd man pages which is under MIT-0
+# (no attribution required).
+[Transfer]
+ProtectVersion=%A
+Verify=yes
+
+[Source]
+Type=url-file
+Path=file:///run/updater
+MatchPattern=Spectrum_OS_@v.verity
+
+[Target]
+Type=partition
+Path=auto
+MatchPattern=Spectrum_OS_@v.verity
+MatchPartitionType=root-verity
+PartitionFlags=0
+ReadOnly=1
diff --git a/host/rootfs/image/etc/sysupdate.d/60-root.transfer b/host/rootfs/image/etc/sysupdate.d/60-root.transfer
new file mode 100644
index 0000000000000000000000000000000000000000..ebc102d1d7f4341565cd452f1bd89ffe9640b361
--- /dev/null
+++ b/host/rootfs/image/etc/sysupdate.d/60-root.transfer
@@ -0,0 +1,21 @@
+# SPDX-License-Identifier: CC0-1.0
+# SPDX-FileCopyrightText: 2025 Demi Marie Obenour <demiobenour@gmail.com>
+
+# Uses example code from systemd man pages which is under MIT-0
+# (no attribution required).
+[Transfer]
+ProtectVersion=%A
+Verify=yes
+
+[Source]
+Type=url-file
+Path=file:///run/updater
+MatchPattern=Spectrum_OS_@v.root
+
+[Target]
+Type=partition
+Path=auto
+MatchPattern=Spectrum_OS_@v
+MatchPartitionType=root
+PartitionFlags=0
+ReadOnly=1
diff --git a/host/rootfs/image/etc/sysupdate.d/70-kernel.transfer b/host/rootfs/image/etc/sysupdate.d/70-kernel.transfer
new file mode 100644
index 0000000000000000000000000000000000000000..6f75dfb04abf5ae911be3ae95318685321a86f5f
--- /dev/null
+++ b/host/rootfs/image/etc/sysupdate.d/70-kernel.transfer
@@ -0,0 +1,25 @@
+# SPDX-License-Identifier: CC0-1.0
+# SPDX-FileCopyrightText: 2025 Demi Marie Obenour <demiobenour@gmail.com>
+
+# Uses example code from systemd man pages which is under MIT-0
+# (no attribution required).
+[Transfer]
+ProtectVersion=%A
+Verify=yes
+
+[Source]
+Type=url-file
+Path=file:///run/updater
+MatchPattern=Spectrum_OS_@v.efi
+
+[Target]
+Type=regular-file
+Path=/EFI/Linux
+PathRelativeTo=boot
+MatchPattern=Spectrum_OS_@v+@l-@d.efi \
+ Spectrum_OS_@v+@l.efi \
+ Spectrum_OS_@v.efi
+Mode=0644
+TriesLeft=3
+TriesDone=0
+InstancesLeft=2
diff --git a/host/rootfs/image/usr/bin/run-update b/host/rootfs/image/usr/bin/run-update
new file mode 100644
index 0000000000000000000000000000000000000000..c1938df01189c26f6c7ffd4c0010fabdc5fb3405
--- /dev/null
+++ b/host/rootfs/image/usr/bin/run-update
@@ -0,0 +1,54 @@
+#!/bin/execlineb -S1
+# SPDX-License-Identifier: EUPL-1.2+
+# SPDX-FileCopyrightText: 2024 Alyssa Ross <hi@alyssa.is>
+
+backtick -E dir { mktemp -d /run/vm/by-id/XXXXXX }
+backtick -E id { basename -- $dir }
+
+if { mkdir -p /run/configs/${id}/fs }
+if { redirfd -w 1 /run/configs/${id}/fs/type echo appimage }
+if { touch /run/configs/${id}/fs/run }
+if { mount --rbind $1 /run/configs/${id}/fs/run }
+if {
+ ln -s /usr/lib/spectrum/img/appvm/blk /usr/lib/spectrum/img/appvm/vmlinux
+ /run/configs/${id}
+}
+
+if { ln -s /run/configs/${id} ${dir}/config }
+
+if { create-vm-dependencies $id }
+
+piperw 4 3
+background {
+ fdclose 3
+ fdmove 0 4
+
+ # Wait for the VMM to be up, then start the VM.
+ if { redirfd -w 1 /dev/null head -1 }
+ vm-start $id
+}
+fdclose 4
+
+foreground { run-vmm $id }
+fdclose 3
+
+if {
+ forx -pE service {
+ dbus
+ vhost-user-fs
+ vhost-user-gpu
+ xdg-desktop-portal-spectrum-host
+ }
+ s6-instance-delete /run/service/${service} $id
+}
+
+if {
+ forx -E mount {
+ /run/configs/${id}/fs/run
+ ${dir}/fs/config
+ ${dir}/fs/doc
+ }
+ umount $mount
+}
+
+rm -r $dir /run/configs/${id}
diff --git a/host/rootfs/image/usr/bin/update b/host/rootfs/image/usr/bin/update
new file mode 100755
index 0000000000000000000000000000000000000000..8e147929cecbef5873cd02c946adf1355da444c6
--- /dev/null
+++ b/host/rootfs/image/usr/bin/update
@@ -0,0 +1,56 @@
+#!/bin/execlineb -WS1
+# SPDX-License-Identifier: EUPL-1.2+
+# SPDX-FileCopyrightText: 2025 Demi Marie Obenour <demiobenour@gmail.com>
+
+# Steps:
+#
+# 1. Take a global, system-wide lock.
+# 2. Create a BTRFS subvolume for the sys.updates VM to write the updates.
+# 3. Bind-mount this subvolume into the VM's shared directory.
+# 4. Start sys.updates to get the updates.
+# 5. Wait for the VM to shut down.
+# 6. Take a BTRFS snapshot of the subvolume.
+# 7. Call syncfs() to flush all of the data on the subvolume.
+# 8. Inspect the contents of the subvolume.
+# Check that everything is a regular file and that the names are reasonable.
+# Check that SHA256SUMS and SHA256SUMS.gpg are present.
+# 9. Call systemd-sysupdate to run the actual update.
+
+if { mkdir -p -m 0700 /run/updater }
+if {
+ case $1 {
+ /[0-9A-Za-z._/-]+ { true }
+ }
+ foreground { fdmove -c 1 2 echo 'Update directory path has forbidden characters or is not absolute' }
+ exit 1
+}
+execline-cd $1
+s6-setlock /run/update-lock
+foreground {
+ # This might fail with a "File exists" error, but that is fine.
+ foreground { redirfd -w 2 /dev/null btrfs subvolume create -- shared }
+ if { umask 0022 mkdir -p shared/etc/systemd shared/update-destination }
+ # TODO: use a safe copy program that is not vulnerable to symlink attacks.
+ # This should be okay as the directory has not been shared yet, but better
+ # safe than sorry. Also nosymfollow should be a mitigation, but still,
+ # better safe than sorry.
+ if { cp /etc/systemd/import-pubring.gpg shared/etc/systemd }
+ if {
+ if {
+ backtick -E update_vm_id {
+ backtick -E id_path { readlink /run/vm/by-name/sys.appvm-updates }
+ basename -- $id_path
+ }
+ vm-start $update_vm_id shared
+ }
+ if { btrfs subvolume snapshot -- shared private }
+ if { sync -- private }
+ if { updates-dir-check private/update-destination }
+ unshare --mount
+ if { mount --bind -o ro -- private/update-destination /run/updater }
+ /usr/lib/systemd/systemd-sysupdate update
+ }
+}
+importas -i sysupdate_exit_status "?"
+foreground { btrfs subvolume delete -- shared private }
+exit $sysupdate_exit_status
diff --git a/host/rootfs/image/usr/bin/vm-start b/host/rootfs/image/usr/bin/vm-start
index 67480e5215d8a8260ce3f03c67f71ba8f210c291..8ae8d94203345c4f3e8b6e46de0d139fda6c11d6 100755
--- a/host/rootfs/image/usr/bin/vm-start
+++ b/host/rootfs/image/usr/bin/vm-start
@@ -1,6 +1,24 @@
-#!/bin/execlineb -S1
+#!/bin/execlineb -Ws0
# SPDX-License-Identifier: EUPL-1.2+
# SPDX-FileCopyrightText: 2022-2023, 2025 Alyssa Ross <hi@alyssa.is>
+# SPDX-FileCopyrightText: 2025 Demi Marie Obenour <demiobenour@gmail.com>
+
+if {
+ case "${#}" {
+ 1 { true }
+ 2 {
+ multisubstitute {
+ define sourcedir ${2}
+ define fsdir /run/vm/by-id/${1}/fs/user
+ }
+ if { mkdir -p ${fsdir} }
+ foreground { redirfd -w 2 /dev/null umount ${fsdir} }
+ mount --bind -- ${sourcedir} ${fsdir}
+ }
+ }
+ foreground { fdmove -c 1 2 echo "Bad number of arguments ${#} (expected 1 or 3)" }
+ exit 100
+}

foreground { s6-rc -bu change vm-env }

@@ -20,4 +38,7 @@ foreground {
redirfd -w 2 /dev/null
s6-svwait -U /run/service/vmm/instance/${1}
}
-ch-remote --api-socket /run/vm/by-id/${1}/vmm boot
+if { ch-remote --api-socket /run/vm/by-id/${1}/vmm boot }
+case "${#}" {
+ 2 { s6-svwait -D /run/service/vmm/instance/${1} }
+}
diff --git a/host/rootfs/os-release.in b/host/rootfs/os-release.in
new file mode 100644
index 0000000000000000000000000000000000000000..8a167a39366dedc6ff9024efdb98383ec84618ec
--- /dev/null
+++ b/host/rootfs/os-release.in
@@ -0,0 +1,13 @@
+NAME="Spectrum OS"
+ID="spectrum"
+PRETTY_NAME="Spectrum OS @VERSION@"
+VERSION=@VERSION@
+VERSION_ID=@VERSION@
+IMAGE_ID=spectrum_os_@VERSION@
+IMAGE_VERSION=@VERSION@
+RELEASE_TYPE=development
+HOME_URL="https://www.spectrum-os.org"
+BUG_REPORT_URL="mailto:discuss@spectrum-os.org"
+ANSI_COLOR="1;34"
+VENDOR_NAME="Spectrum"
+VENDOR_URL="https://www.spectrum-os.org"
diff --git a/host/rootfs/os-release.in.license b/host/rootfs/os-release.in.license
new file mode 100644
index 0000000000000000000000000000000000000000..c4a0586a407fe14c3e0855749a7524ac3871dda4
--- /dev/null
+++ b/host/rootfs/os-release.in.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/shell.nix b/host/rootfs/shell.nix
index bd234e90ee19bdfa6591d29c518cb0dc393b01c8..b5ed566062da03944567dd610c88e1a58523e303 100644
--- a/host/rootfs/shell.nix
+++ b/host/rootfs/shell.nix
@@ -3,7 +3,7 @@
# SPDX-FileCopyrightText: 2022 Unikie

import ../../lib/call-package.nix (
-{ callSpectrumPackage, rootfs, pkgsStatic, srcOnly, stdenv
+{ callSpectrumPackage, rootfs, srcOnly, stdenv
, btrfs-progs, cryptsetup, jq, netcat, qemu_kvm, reuse, util-linux
}:

diff --git a/update-signing-keys.gpg b/update-signing-keys.gpg
new file mode 100644
index 0000000000000000000000000000000000000000..b4c15467614ee15deef02af05f4c6554a1f7a013
--- /dev/null
+++ b/update-signing-keys.gpg
@@ -0,0 +1 @@
+NOT A VALID KEY - UPDATES WILL NOT WORK
diff --git a/update-signing-keys.gpg.license b/update-signing-keys.gpg.license
new file mode 100644
index 0000000000000000000000000000000000000000..c4a0586a407fe14c3e0855749a7524ac3871dda4
--- /dev/null
+++ b/update-signing-keys.gpg.license
@@ -0,0 +1,2 @@
+SPDX-License-Identifier: CC0-1.0
+SPDX-FileCopyrightText: 2025 Demi Marie Obenour <demiobenour@gmail.com>
diff --git a/update-url b/update-url
new file mode 100644
index 0000000000000000000000000000000000000000..a5b28fe9b3bbeb5e823c9e17c4765a074a83b350
--- /dev/null
+++ b/update-url
@@ -0,0 +1 @@
+https://your-spectrum-os-update-server.invalid/download-directory/
diff --git a/update-url.license b/update-url.license
new file mode 100644
index 0000000000000000000000000000000000000000..c4a0586a407fe14c3e0855749a7524ac3871dda4
--- /dev/null
+++ b/update-url.license
@@ -0,0 +1,2 @@
+SPDX-License-Identifier: CC0-1.0
+SPDX-FileCopyrightText: 2025 Demi Marie Obenour <demiobenour@gmail.com>
diff --git a/vm/app/sysupdate.d/50-verity.transfer b/vm/app/sysupdate.d/50-verity.transfer
new file mode 100644
index 0000000000000000000000000000000000000000..e437860426b8a651ca20ee7bddff1a9b3cf39507
--- /dev/null
+++ b/vm/app/sysupdate.d/50-verity.transfer
@@ -0,0 +1,18 @@
+# SPDX-License-Identifier: CC0-1.0
+# SPDX-FileCopyrightText: 2025 Demi Marie Obenour <demiobenour@gmail.com>
+
+# Uses example code from systemd man pages which is under MIT-0
+# (no attribution required).
+[Transfer]
+Verify=yes
+
+[Source]
+Type=url-file
+Path=@UPDATE_URL@
+MatchPattern=Spectrum_OS_@v.verity
+
+[Target]
+Type=regular-file
+Path=/run/virtiofs/virtiofs0/user/update-destination
+MatchPattern=Spectrum_OS_@v.verity
+Mode=0644
diff --git a/vm/app/sysupdate.d/60-root.transfer b/vm/app/sysupdate.d/60-root.transfer
new file mode 100644
index 0000000000000000000000000000000000000000..84ab4cd693342bb1118aa9525c797080c5b356dc
--- /dev/null
+++ b/vm/app/sysupdate.d/60-root.transfer
@@ -0,0 +1,18 @@
+# SPDX-License-Identifier: CC0-1.0
+# SPDX-FileCopyrightText: 2025 Demi Marie Obenour <demiobenour@gmail.com>
+
+# Uses example code from systemd man pages which is under MIT-0
+# (no attribution required).
+[Transfer]
+Verify=yes
+
+[Source]
+Type=url-file
+Path=@UPDATE_URL@
+MatchPattern=Spectrum_OS_@v.root
+
+[Target]
+Type=regular-file
+Path=/run/virtiofs/virtiofs0/user/update-destination
+MatchPattern=Spectrum_OS_@v.root
+Mode=0644
diff --git a/vm/app/sysupdate.d/70-kernel.transfer b/vm/app/sysupdate.d/70-kernel.transfer
new file mode 100644
index 0000000000000000000000000000000000000000..931944ac68483d864600748e469de9cd4829ff4a
--- /dev/null
+++ b/vm/app/sysupdate.d/70-kernel.transfer
@@ -0,0 +1,18 @@
+# SPDX-License-Identifier: CC0-1.0
+# SPDX-FileCopyrightText: 2025 Demi Marie Obenour <demiobenour@gmail.com>
+
+# Uses example code from systemd man pages which is under MIT-0
+# (no attribution required).
+[Transfer]
+Verify=yes
+
+[Source]
+Type=url-file
+Path=@UPDATE_URL@
+MatchPattern=Spectrum_OS_@v.efi
+
+[Target]
+Type=regular-file
+Path=/run/virtiofs/virtiofs0/user/update-destination
+MatchPattern=Spectrum_OS_@v.efi
+Mode=0644
diff --git a/vm/app/updates.nix b/vm/app/updates.nix
new file mode 100644
index 0000000000000000000000000000000000000000..30beca30e578b5c869eaedf2fd7e8913bf616a0c
--- /dev/null
+++ b/vm/app/updates.nix
@@ -0,0 +1,57 @@
+# SPDX-License-Identifier: MIT
+# SPDX-FileCopyrightText: 2023 Alyssa Ross <hi@alyssa.is>
+
+import ../../lib/call-package.nix (
+{ callSpectrumPackage, lib, pkgsMusl, pkgsStatic, src, writeScript, systemd }:
+
+pkgsMusl.callPackage (
+{ stdenvNoCC, curl }:
+
+pkgsStatic.callPackage (
+{ execline, runCommand }:
+
+let
+ raw_update_url = builtins.readFile ../../update-url;
+ update-url =
+ if builtins.match "^https?://([[:alnum:]:./?=~-]|%[[:xdigit:]]{2})+/\n$" raw_update_url == null then
+ builtins.abort "Bad update URL"
+ else
+ builtins.substring 0 (builtins.stringLength raw_update_url - 1) raw_update_url;
+ sysupdate-d = stdenvNoCC.mkDerivation {
+ name = "spectrum-systemd-transfer-files";
+ src = ./.;
+ installPhase =
+ ''
+ mkdir -- "$out"
+ (
+ cd -- "$src" &&
+ for i in sysupdate.d/*.transfer; do
+ s=''${i#sysupdate.d/} &&
+ sed 's,@UPDATE_URL@,${update-url},g' < "$i" > "$out/$s" || exit
+ done
+ printf %s\\n '${update-url}' > "$out/update-url"
+ ) || exit
+ '';
+ };
+ l = lib.escapeShellArgs;
+ mountpoint = "/run/virtiofs/virtiofs0/user";
+ sysupdate-path = "${systemd}/lib/systemd/systemd-sysupdate";
+ runner = writeScript "update-run-script" (
+ "#!/bin/sh --\n" +
+ builtins.concatStringsSep " && \\\n" [
+ (l ["mount" "-toverlay" "-olowerdir=${mountpoint}/etc:/etc" "--" "overlay" "/etc"])
+ (l [sysupdate-path "--definitions=${sysupdate-d}" "update"])
+ (l ["${curl}/bin/curl" "-L" "--proto" "=http,https"
+ "-o" "${mountpoint}/update-destination/SHA256SUMS.gpg"
+ "--" "${update-url}SHA256SUMS.gpg"])
+ (l ["${curl}/bin/curl" "-L" "--proto" "=http,https"
+ "-o" "${mountpoint}/update-destination/SHA256SUMS"
+ "--" "${update-url}/SHA256SUMS"])
+ ]);
+in
+
+callSpectrumPackage ../make-vm.nix {} {
+ providers.net = [ "sys.netvm" ];
+ type = "nix";
+ run = "${runner}";
+}) {}) {}) (_: {})

--
2.51.2