Change default behavior, allow kernel logs to console

A Linux system booted with the kernel command line option 'quiet' only
logs error (and above) severity messages to the console.  For embedded
systems, which is the primary target for Finit, this is what you want
to see.

Hence, and after careful consideration, this patch changes the default
behavior of Finit to allow kernel logs to the console.  A build-time
configure flags, --disable-kernel-logging, has been added to restore
legacy behavior.

Signed-off-by: Joachim Wiberg <troglobit@gmail.com>

configure.ac

@@ -71,6 +71,10 @@ AC_ARG_ENABLE(redirect,
         AS_HELP_STRING([--disable-redirect], [Disable redirection of service output to /dev/null]),,[
 	enable_redirect=yes])
 
+AC_ARG_ENABLE(kernel_logging,
+        AS_HELP_STRING([--disable-kernel-logging], [Disable kernel logging to console (use 'quiet' instead!]),,[
+	enable_kernel_logging=yes])
+
 AC_ARG_ENABLE(logrotate,
         AS_HELP_STRING([--disable-logrotate], [Disable built-in rotation of /var/log/wtmp]),,[
 	enable_logrotate=yes])
@@ -181,6 +185,9 @@ AS_IF([test "x$enable_auto_reload" = "xyes"], [
 AS_IF([test "x$enable_kernel_cmdline" = "xyes"], [
         AC_DEFINE(KERNEL_CMDLINE, 1, [Dumpster diving after init args from /proc/cmdline])])
 
+AS_IF([test "x$enable_kernel_logging" = "xyes"], [
+        AC_DEFINE(KERNEL_LOGGING, 1, [Keep kernel warn/err logs to console])])
+
 AS_IF([test "x$enable_fastboot" = "xyes"], [
 	AC_DEFINE(FAST_BOOT, 1, [Skip fsck check on filesystems listed in /etc/fstab])])
 
@@ -382,6 +389,8 @@ Optional features:
   Built-in sulogin......: $with_sulogin $sulogin
   Built-in watchdogd....: $with_watchdog $watchdog
   Built-in logrotate....: $enable_logrotate
+  Parse kernel cmdline..: $enable_kernel_cmdline
+  Keep kernel logging...: $enable_kernel_logging
   Skip fsck check.......: $enable_fastboot
   Run fsck fix mode.....: $enable_fsckfix
   Redirect output.......: $enable_redirect