Busybox syslog uses a shmmem circular buffer [1][2] when launch with -C option
when systemd (is enabled) takes the control of syslog messages and then forward
the messages to busybox syslog daemon, systemd journald don't usage of shmmem
circular buffer.

If -C is specified busybox-syslog never be able to read the forwarded
messages from systemd journald and don't wrote it to /var/log/messages.

This file is only installed when systemd is enabled [3].

[1] https://git.busybox.net/busybox/tree/sysklogd/syslogd.c?h=1_24_stable#n464
[2] https://git.busybox.net/busybox/tree/sysklogd/logread.c?h=1_24_stable#n82
[3] http://git.yoctoproject.org/cgit/cgit.cgi/poky/tree/meta/recipes-core/busybox/busybox.inc#n295

Signed-off-by: Aníbal Limón <anibal.limon@linux.intel.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>

Add more comments to the systemd configuration file for busybox's
syslogd utility. The purpose is to easy the life of system administrators.

These comments are mostly derived from the comments in syslogd.c in
busybox.

[YOCTO #5722]

Signed-off-by: Chen Qi <Qi.Chen@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

The default command-line options for launching busybox's syslogd are
"-C" if using sysvinit; but because we use /etc/default/busybox-syslog
when using systemd which the sysvinit initscript doesn't use, and no
/etc/default/busybox-syslog is installed by default in OE-Core, the
default arguments with systemd were no arguments at all with OE-Core
alone. Effectively merge in the bbappend from meta-oe that adds a
default file in order to set the default options to "-C" for systemd as
well.

Signed-off-by: Paul Eggleton <paul.eggleton@linux.intel.com>
Signed-off-by: Saul Wold <sgw@linux.intel.com>