initscripts: add dmesg file to /var/log

We should create the /var/log/dmesg.log file as a default.
If we don't then a later kernel error can flush the dmesg
ring buffer, losing valuable debug information.

(From OE-Core rev: faa8cc6c2a582a32c695f3f2b0d45b6892c769fd)

Signed-off-by: Xin Ouyang <Xin.Ouyang@windriver.com>
Signed-off-by: Jackie Huang <jackie.huang@windriver.com>
Signed-off-by: Saul Wold <sgw@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-core/initscripts/initscripts-1.0/dmesg.sh

@@ -0,0 +1,17 @@
+#!/bin/sh
+### BEGIN INIT INFO
+# Provides:             dmesg
+# Required-Start:
+# Required-Stop:
+# Default-Start:        S
+# Default-Stop:
+### END INIT INFO
+
+if [ -f /var/log/dmesg ]; then
+	if [ -f /usr/sbin/logrotate ]; then
+		logrotate -f /etc/logrotate-dmesg.conf
+	else
+		mv -f /var/log/dmesg /var/log/dmesg.old
+	fi
+fi
+dmesg -s 131072 > /var/log/dmesg

meta/recipes-core/initscripts/initscripts-1.0/logrotate-dmesg.conf

@@ -0,0 +1,9 @@
+# see "man logrotate" for details
+# rotate dmesg, and keep 5 versions.
+
+/var/log/dmesg {
+	create
+	rotate 5
+	nodateext
+}
+