plymouth: add rd_NO_PLYMOUTH

dracut.8

@@ -251,6 +251,11 @@ get ip from dhcp server on a specific interface
 .B ip=<client-IP-number>:[<server-id>]:<gateway-IP-number>:<netmask>:<client-hostname>:<interface>:{none|off}
 explicit network configuration
 
+.SH Plymouth Boot Splash
+.TP
+.B rd_NO_PLYMOUTH
+do not start plymouth. This will not work with encrypted partitions.
+
 .SH Misc
 .TP
 .B rdblacklist=<drivername>

modules.d/50plymouth/plymouth-pretrigger.sh

@@ -1,18 +1,22 @@
 #!/bin/sh
 
-[ -c /dev/null ] || mknod /dev/null c 1 3
-# first trigger graphics subsystem
-udevadm trigger --attr-match=class=0x030000 >/dev/null 2>&1
-# first trigger graphics and tty subsystem
-udevadm trigger --subsystem-match=graphics --subsystem-match=drm --subsystem-match=tty >/dev/null 2>&1
+if ! getarg rd_NO_PLYMOUTH; then
+    [ -c /dev/null ] || mknod /dev/null c 1 3
+    # first trigger graphics subsystem
+    udevadm trigger --attr-match=class=0x030000 >/dev/null 2>&1
+    # first trigger graphics and tty subsystem
+    udevadm trigger --subsystem-match=graphics --subsystem-match=drm --subsystem-match=tty >/dev/null 2>&1
 
-udevadm settle --timeout=30 2>&1 | vinfo
-[ -c /dev/zero ] || mknod /dev/zero c 1 5
-[ -c /dev/systty ] || mknod /dev/systty c 4 0
-[ -c /dev/fb ] || mknod /dev/fb c 29 0
-[ -c /dev/hvc0 ] || mknod /dev/hvc0 c 229 0
+    udevadm settle --timeout=30 2>&1 | vinfo
+    [ -c /dev/zero ] || mknod /dev/zero c 1 5
+    [ -c /dev/systty ] || mknod /dev/systty c 4 0
+    [ -c /dev/fb ] || mknod /dev/fb c 29 0
+    [ -c /dev/hvc0 ] || mknod /dev/hvc0 c 229 0
 
-info "Starting plymouth daemon"
-[ -x /bin/plymouthd ] && /bin/plymouthd --attach-to-session
-/bin/plymouth --show-splash 2>&1 | vinfo
+    info "Starting plymouth daemon"
+    [ -x /bin/plymouthd ] && /bin/plymouthd --attach-to-session
+    /bin/plymouth --show-splash 2>&1 | vinfo
+fi
 
+
+# vim:ts=8:sw=4:sts=4:et