Switch the default value (if no options DDB_ONPANIC is defined) for

ddb.onpanic to 1, change it back to 0 in sysctl.conf and make sure
postinstall installs this setting.
This avoids us trying to dump while booting from install CD, but keeps
the default the same once we are far enough through /etc/rc.d. Failing
earlier is unlikely to be recovered by an automatic reboot.
OK: core.

etc/sysctl.conf

@@ -1,9 +1,17 @@
 #!/sbin/sysctl -f
 #
-# $NetBSD: sysctl.conf,v 1.5 2003/11/03 15:12:06 briggs Exp $
+# $NetBSD: sysctl.conf,v 1.6 2009/03/11 23:22:57 martin Exp $
 #
 # sysctl(8) variables to set at boot time.
 
+# Default on panic: dump core and reboot. See savecore(8) for information.
+# Switch this to 1 if you want to enter the kernel debugger on crashes
+# instead. See ddb(4) for an introduction and also try the "help" command
+# at the db> prompt.
+# If you understand the implication and want to change the behaviour before
+# /etc/rc.d/sysctl is run, use the kernel option DDB_ONPANIC, see options(4).
+ddb.onpanic=0
+
 # Default core name template:
 #kern.defcorename=%n.core
 

sys/ddb/db_variables.c

@@ -1,4 +1,4 @@
-/*	$NetBSD: db_variables.c,v 1.41 2009/03/07 22:02:17 ad Exp $	*/
+/*	$NetBSD: db_variables.c,v 1.42 2009/03/11 23:22:57 martin Exp $	*/
 
 /*
  * Mach Operating System
@@ -27,7 +27,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: db_variables.c,v 1.41 2009/03/07 22:02:17 ad Exp $");
+__KERNEL_RCSID(0, "$NetBSD: db_variables.c,v 1.42 2009/03/11 23:22:57 martin Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_ddbparam.h"
@@ -46,7 +46,7 @@ __KERNEL_RCSID(0, "$NetBSD: db_variables.c,v 1.41 2009/03/07 22:02:17 ad Exp $")
  * panics.  Initialize it so that it's patchable.
  */
 #ifndef DDB_ONPANIC
-#define DDB_ONPANIC	0
+#define DDB_ONPANIC	1
 #endif
 int		db_onpanic = DDB_ONPANIC;
 

usr.sbin/postinstall/postinstall

@@ -1,6 +1,6 @@
 #!/bin/sh
 #
-# $NetBSD: postinstall,v 1.90 2009/02/26 10:32:43 apb Exp $
+# $NetBSD: postinstall,v 1.91 2009/03/11 23:22:57 martin Exp $
 #
 # Copyright (c) 2002-2008 The NetBSD Foundation, Inc.
 # All rights reserved.
@@ -662,6 +662,35 @@ do_bluetooth()
 	return ${failed}
 }
 
+#
+#	ddbonpanic
+#
+additem ddbonpanic "verify ddb.onpanic is configured in sysctl.conf"
+do_ddbonpanic()
+{
+	[ -n "$1" ] || err 3 "USAGE: do_ddbonpanic  fix|check"
+
+	if ${GREP} -E '^[[:space:]]*ddb\.onpanic[[:space:]]*=[[:space:]]*[[:digit:]]+' \
+		"${DEST_DIR}/etc/sysctl.conf" >/dev/null 2>&1
+	then
+		result=0
+	else
+		if [ "$1" = check ]; then
+			msg \
+    "The ddb.onpanic behaviour is not explicitly specified in /etc/sysctl.conf"
+			result=1
+		else
+			echo >> "${DEST_DIR}/etc/sysctl.conf"
+			sed < "${SRC_DIR}/etc/sysctl.conf" \
+			   -e '/^ddb\.onpanic/q' | \
+			       sed -e '1,/^$/d' >> \
+			    "${DEST_DIR}/etc/sysctl.conf"
+			result=$?
+		fi
+	fi
+	return ${result}
+}
+
 #
 #	defaults
 #