[initcpiocfg] Make using systemd hook optional

src/modules/initcpiocfg/initcpiocfg.conf

@@ -0,0 +1,11 @@
+# SPDX-FileCopyrightText: no
+# SPDX-License-Identifier: CC0-1.0
+#
+# The initcpiocfg module is responsible for the configuration of mkinitcpio.conf.  Typically this
+# module is used in conjunction with the initcpio module to generate the boot image when using mkinitcpio
+---
+#
+# Determines if the systemd versions of the hooks should be used.  This is false by default.mkinitcpio
+#
+# Please note that using the systemd hooks result in no access to the emergency recovery shell
+# useSystemdHook: false

src/modules/initcpiocfg/initcpiocfg.schema.yaml

@@ -0,0 +1,11 @@
+# SPDX-FileCopyrightText: 2023 Evan James <dalto@fastmail.com>
+# SPDX-License-Identifier: GPL-3.0-or-later
+---
+$schema: https://json-schema.org/schema#
+$id: https://calamares.io/schemas/initcpiocfg
+additionalProperties: false
+type: object
+properties:
+    useSystemdHook: { type: boolean }
+
+

src/modules/initcpiocfg/main.py

@@ -163,9 +163,12 @@ def find_initcpio_features(partitions, root_mount_point):
         "block",
         "keyboard",
     ]
-    uses_systemd = target_env_call(["sh", "-c", "which systemd-cat"]) == 0
 
-    if uses_systemd:
+    systemd_hook_allowed = libcalamares.job.configuration.get("useSystemdHook", False)
+
+    use_systemd = systemd_hook_allowed and target_env_call(["sh", "-c", "which systemd-cat"]) == 0
+
+    if use_systemd:
         hooks.insert(0, "systemd")
         hooks.append("sd-vconsole")
     else:
@@ -224,7 +227,7 @@ def find_initcpio_features(partitions, root_mount_point):
             hooks.append("usr")
 
     if encrypt_hook:
-        if uses_systemd:
+        if use_systemd:
             hooks.append("sd-encrypt")
         else:
             hooks.append("encrypt")