Make it easy to install ly on runit systems e.g. void (#431)

* Make it easy to install ly on runit systems e.g. void

* Tidy up runit section in readme

Co-authored-by: Daniel Haarhoff <daniel@rknt.de>

makefile

@@ -98,6 +98,11 @@ installopenrc:
 	@echo "installing openrc service"
 	@install -DZ $(RESD)/ly-openrc -m 755 -T ${DESTDIR}/etc/init.d/${NAME}
 
+installrunit:
+	@echo "installing runit service"
+	@install -dZ ${DESTDIR}/etc/sv/ly-runit-service
+	@install -DZ $(RESD)/ly-runit-service/* -t ${DESTDIR}/etc/sv/ly
+
 uninstall:
 	@echo "uninstalling"
 	@rm -rf ${DESTDIR}/etc/ly

readme.md

@@ -111,6 +111,26 @@ If you choose a tty that already has a login/getty running (has a basic login pr
 # rc-update del agetty.tty2
 ```
 
+### runit
+
+```
+$ make
+# make install installrunit
+# ln -s /etc/sv/ly /var/service/
+```
+
+Disable your existing display manager service if need be e.g.:
+
+```
+# rm /var/service/lxdm
+```
+
+If you are running on `tty2` (check your `/etc/ly/config.ini`) you can disable e.g. `agetty` running there:
+
+```
+# rm /var/service/agetty-tty2
+```
+
 ## Arch Linux Installation
 You can install ly from the [AUR](https://aur.archlinux.org/packages/ly), using yay for example:
 ``` 

res/ly-runit-service/conf

@@ -0,0 +1,14 @@
+if [ -x /sbin/agetty -o -x /bin/agetty ]; then
+	# util-linux specific settings
+	if [ "${tty}" = "tty1" ]; then
+		GETTY_ARGS="--noclear"
+	fi
+fi
+
+BAUD_RATE=38400
+TERM_NAME=linux
+
+StandardInput=tty
+TTYPath=/dev/tty2
+TTYReset=yes
+TTYVHangup=yes

res/ly-runit-service/finish

@@ -0,0 +1,3 @@
+#!/bin/sh
+tty=${PWD##*-}
+exec utmpset -w $tty

res/ly-runit-service/run

@@ -0,0 +1,15 @@
+#!/bin/sh
+
+tty=${PWD##*-}
+
+[ -r conf ] && . ./conf
+
+if [ -x /sbin/getty -o -x /bin/getty ]; then
+	# busybox
+	GETTY=getty
+elif [ -x /sbin/agetty -o -x /bin/agetty ]; then
+	# util-linux
+	GETTY=agetty
+fi
+
+exec setsid ${GETTY} ${GETTY_ARGS} -nl /usr/bin/ly tty2 "${BAUD_RATE}" "${TERM_NAME}"