[PATCH v2 3/3] host/rootfs: Simplify s6-rc dependencies

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

This moves almost all of the s6-rc dependencies into named, commented
bundles.  This makes the system much easier to understand.

Most of the explanation is in the bundle files themselves.

Signed-off-by: Demi Marie Obenour <demiobenour@gmail.com>
---
 host/rootfs/Makefile                                  |  8 ++++----
 host/rootfs/image/etc/s6-rc/basic/contents            | 18 ++++++++++++++++++
 host/rootfs/image/etc/s6-rc/{vmm-env => basic}/type   |  0
 .../image/etc/s6-rc/{vmm-env => basic}/type.license   |  0
 host/rootfs/image/etc/s6-rc/ok-all/contents           | 19 ++++++++++++++++---
 .../s6-rc/sys-vmms/dependencies.d/{vmm-env => vm-env} |  0
 host/rootfs/image/etc/s6-rc/systemd-udevd/run         |  9 ++++++---
 host/rootfs/image/etc/s6-rc/vm-env/contents           | 13 ++++++++++---
 host/rootfs/image/etc/s6-rc/vmm-env/contents          |  9 ---------
 .../dependencies.d/{systemd-udevd-coldplug => basic}  |  0
 10 files changed, 54 insertions(+), 22 deletions(-)

diff --git a/host/rootfs/Makefile b/host/rootfs/Makefile
index db142f290a1efd3884d8c5a114b26fa0f42ef5f1..9a9e533ad2433bce137dd73e7e9d519c5afab303 100644
--- a/host/rootfs/Makefile
+++ b/host/rootfs/Makefile
@@ -127,6 +127,8 @@ build/empty:
 	mkdir -p $@
 
 S6_RC_FILES = \
+	image/etc/s6-rc/basic/contents \
+	image/etc/s6-rc/basic/type \
 	image/etc/s6-rc/core/type \
 	image/etc/s6-rc/core/up \
 	image/etc/s6-rc/kvm/timeout-up \
@@ -136,7 +138,7 @@ S6_RC_FILES = \
 	image/etc/s6-rc/ok-all/type \
 	image/etc/s6-rc/static-nodes/type \
 	image/etc/s6-rc/static-nodes/up \
-	image/etc/s6-rc/sys-vmms/dependencies.d/vmm-env \
+	image/etc/s6-rc/sys-vmms/dependencies.d/vm-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 \
@@ -148,9 +150,7 @@ S6_RC_FILES = \
 	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/systemd-udevd-coldplug \
+	image/etc/s6-rc/weston/dependencies.d/basic \
 	image/etc/s6-rc/weston/notification-fd \
 	image/etc/s6-rc/weston/run \
 	image/etc/s6-rc/weston/type
diff --git a/host/rootfs/image/etc/s6-rc/basic/contents b/host/rootfs/image/etc/s6-rc/basic/contents
new file mode 100644
index 0000000000000000000000000000000000000000..54f58577ba9f125e7fc08dcdd69394e8a88ab622
--- /dev/null
+++ b/host/rootfs/image/etc/s6-rc/basic/contents
@@ -0,0 +1,18 @@
+# SPDX-License-Identifier: CC0-1.0
+# SPDX-FileCopyrightText: 2021 Alyssa Ross <hi@alyssa.is>
+# SPDX-FileCopyrightText: 2025 Demi Marie Obenour <demiobenour@gmail.com>
+
+# This file contains all atomics and bundles needed for basic system
+# initialization.  Everything that is not meant to run in early boot
+# should depend on this.
+
+# This ensures that core files are written to the right place.
+core
+
+# This ensures that static nodes are created.
+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/vmm-env/type b/host/rootfs/image/etc/s6-rc/basic/type
similarity index 100%
rename from host/rootfs/image/etc/s6-rc/vmm-env/type
rename to host/rootfs/image/etc/s6-rc/basic/type
diff --git a/host/rootfs/image/etc/s6-rc/vmm-env/type.license b/host/rootfs/image/etc/s6-rc/basic/type.license
similarity index 100%
rename from host/rootfs/image/etc/s6-rc/vmm-env/type.license
rename to host/rootfs/image/etc/s6-rc/basic/type.license
diff --git a/host/rootfs/image/etc/s6-rc/ok-all/contents b/host/rootfs/image/etc/s6-rc/ok-all/contents
index c76a5af336c7f1c3f4b81bf1f6244a53e0399fe8..edef03d2b6eae4fb0b92ac828436cd4572ca7acc 100644
--- a/host/rootfs/image/etc/s6-rc/ok-all/contents
+++ b/host/rootfs/image/etc/s6-rc/ok-all/contents
@@ -1,6 +1,19 @@
 # SPDX-License-Identifier: CC0-1.0
 # SPDX-FileCopyrightText: 2021 Alyssa Ross <hi@alyssa.is>
-#
-systemd-udevd-coldplug
+# SPDX-FileCopyrightText: 2025 Demi Marie Obenour <demiobenour@gmail.com>
+
+# This file contains the services that need to be started even
+# if nothing else depends on them.  It should not include services
+# that are only needed by other services.  For instance, it would
+# not be appropriate for this file to reference systemd-udevd.
+# However, services should be included in this file whenever they
+# are directly needed by the user, even if they depend on another
+# service in this files.  For instance, sys-vmms depends on weston,
+# but it is still included.
+
+# VMMs that should be started at boot.  In the future
+# it might make sense to start them only as needed.
 sys-vmms
-vm-env
+
+# The Wayland compositor.
+weston
diff --git a/host/rootfs/image/etc/s6-rc/sys-vmms/dependencies.d/vmm-env b/host/rootfs/image/etc/s6-rc/sys-vmms/dependencies.d/vm-env
similarity index 100%
rename from host/rootfs/image/etc/s6-rc/sys-vmms/dependencies.d/vmm-env
rename to host/rootfs/image/etc/s6-rc/sys-vmms/dependencies.d/vm-env
diff --git a/host/rootfs/image/etc/s6-rc/systemd-udevd/run b/host/rootfs/image/etc/s6-rc/systemd-udevd/run
index 2501680b69eb0060b651146dffb6b3a99640c6fb..f05804a6b3903a767f8e1400cf0153045dd3781f 100644
--- a/host/rootfs/image/etc/s6-rc/systemd-udevd/run
+++ b/host/rootfs/image/etc/s6-rc/systemd-udevd/run
@@ -1,11 +1,14 @@
 #!/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 }
+if { mkdir -p /run/sd-notify-wrapper }
+s6-setlock -d 4 /run/sd-notify-wrapper/systemd-udevd.lock
+if { rm -f /run/sd-notify-wrapper/systemd-udevd.sock }
 background {
-   s6-ipcserver-socketbinder -b0 -m -a 0600 /run/sd-notify-wrapper/systemd-udevd
+   s6-ipcserver-socketbinder -b0 -m -a 0600 /run/sd-notify-wrapper/systemd-udevd.sock
    fdmove 1 3
    sd-notify-adapter
 }
-export NOTIFY_SOCKET /run/sd-notify-wrapper/systemd-udevd
+fdclose 3
+export NOTIFY_SOCKET /run/sd-notify-wrapper/systemd-udevd.sock
 exec -a systemd-udevd udevadm
diff --git a/host/rootfs/image/etc/s6-rc/vm-env/contents b/host/rootfs/image/etc/s6-rc/vm-env/contents
index ed8b5c410adfc17f5bbc33932ac79d97bd7b3115..81bfd422d22bde582fe198e0778c1c93d0d0f329 100644
--- a/host/rootfs/image/etc/s6-rc/vm-env/contents
+++ b/host/rootfs/image/etc/s6-rc/vm-env/contents
@@ -1,6 +1,13 @@
 # SPDX-License-Identifier: CC0-1.0
 # SPDX-FileCopyrightText: 2021 Alyssa Ross <hi@alyssa.is>
-#
-static-nodes
-systemd-udevd-coldplug
+# SPDX-FileCopyrightText: 2025 Demi Marie Obenour <demiobenour@gmail.com>
+
+# This file contains s6 atomics and bundles that
+# need to be started before starting any VMs.
+
+# Basic initialization
+basic
+# KVM being available
+kvm
+# Wayland compositor ready
 weston
diff --git a/host/rootfs/image/etc/s6-rc/vmm-env/contents b/host/rootfs/image/etc/s6-rc/vmm-env/contents
deleted file mode 100644
index 9a1aea63abd1b5c374e3ac9a9671e4c9341f8d16..0000000000000000000000000000000000000000
--- a/host/rootfs/image/etc/s6-rc/vmm-env/contents
+++ /dev/null
@@ -1,9 +0,0 @@
-# SPDX-License-Identifier: CC0-1.0
-# SPDX-FileCopyrightText: 2021 Alyssa Ross <hi@alyssa.is>
-#
-core
-kvm
-# 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/basic
similarity index 100%
rename from host/rootfs/image/etc/s6-rc/weston/dependencies.d/systemd-udevd-coldplug
rename to host/rootfs/image/etc/s6-rc/weston/dependencies.d/basic

-- 
2.51.0