Add an option DDB_SAFE_CONSOLE that defaults db_console to 1.

In many cases, setting db_console in /etc/rc is too late.

1 files changed, 16 insertions, 1 deletions

diff --git a/sys/kern/subr_prf.c b/sys/kern/subr_prf.c
index 0ec990f67a9..5ab131ddc8d 100644
--- a/sys/kern/subr_prf.c
+++ b/sys/kern/subr_prf.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: subr_prf.c,v 1.27 2000/02/22 19:28:04 deraadt Exp $	*/
+/*	$OpenBSD: subr_prf.c,v 1.28 2000/03/02 10:50:29 art Exp $	*/
 /*	$NetBSD: subr_prf.c,v 1.45 1997/10/24 18:14:25 chuck Exp $	*/
 
 /*-
@@ -109,9 +109,24 @@ extern	int log_open;	/* subr_log: is /dev/klog open? */
 const	char *panicstr; /* arg to first call to panic (used as a flag
 			   to indicate that panic has already been called). */
 #ifdef DDB
+/*
+ * Enter ddb on panic.
+ */
 int	db_panic = 1;
+
+/*
+ * db_console controls if we can be able to enter ddb by a special key
+ * combination (machine dependent).
+ * If DDB_SAFE_CONSOLE is defined in the kernel configuration it allows
+ * to break into console during boot. It's _really_ useful when debugging
+ * some things in the kernel that can cause init(8) to crash.
+ */
+#ifdef DDB_SAFE_CONSOLE
+int	db_console = 1;
+#else
 int	db_console = 0;
 #endif
+#endif
 
 /*
  * v_putc: routine to putc on virtual console