rng-tools: add systemd service file

Add systemd service file for rng-tools.

(From OE-Core rev: d374897100ae756df72677d47c9c70c7fefca192)

Signed-off-by: Dengke Du <dengke.du@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-support/rng-tools/rng-tools/rngd.service

@@ -0,0 +1,9 @@
+[Unit]
+Description=Hardware RNG Entropy Gatherer Daemon
+
+[Service]
+ExecStart=@SBINDIR@/rngd -f -r /dev/urandom
+SuccessExitStatus=66
+
+[Install]
+WantedBy=multi-user.target

meta/recipes-support/rng-tools/rng-tools_5.bb

@@ -8,7 +8,9 @@ SRC_URI = "${SOURCEFORGE_MIRROR}/gkernel/${BP}.tar.gz \
            file://underquote.patch \
            file://rng-tools-5-fix-textrels-on-PIC-x86.patch \
            file://init \
-           file://default"
+           file://default \
+           file://rngd.service \
+"
 
 SRC_URI[md5sum] = "6726cdc6fae1f5122463f24ae980dd68"
 SRC_URI[sha256sum] = "60a102b6603bbcce2da341470cad42eeaa9564a16b4490e7867026ca11a3078e"
@@ -20,7 +22,7 @@ python () {
         d.setVar("INHIBIT_UPDATERCD_BBCLASS", "1")
 }
 
-inherit autotools update-rc.d
+inherit autotools update-rc.d systemd
 
 PACKAGECONFIG = "libgcrypt"
 PACKAGECONFIG_libc-musl = "libargp"
@@ -38,7 +40,15 @@ do_install_append() {
         install -d "${D}${sysconfdir}/default"
         install -m 0644 ${WORKDIR}/default ${D}${sysconfdir}/default/rng-tools
     fi
+
+    if ${@bb.utils.contains('DISTRO_FEATURES', 'systemd', 'true', 'false', d)}; then
+        install -d ${D}${systemd_unitdir}/system
+        install -m 644 ${WORKDIR}/rngd.service ${D}${systemd_unitdir}/system
+        sed -i -e 's,@SBINDIR@,${sbindir},g' ${D}${systemd_unitdir}/system/rngd.service
+    fi
 }
 
 INITSCRIPT_NAME = "rng-tools"
 INITSCRIPT_PARAMS = "start 30 2 3 4 5 . stop 30 0 6 1 ."
+
+SYSTEMD_SERVICE_${PN} = "rngd.service"