From 909feda120d5690e8273b6180fc00925e80cbccf Mon Sep 17 00:00:00 2001
From: Attilio Rao <attilio@FreeBSD.org>
Date: Thu, 12 Nov 2009 01:30:17 +0000
Subject: [PATCH] Introduce a new option (BOOT_PROMPT_123) that lets enter the
 boot prompt only when typing the sequence "123" (opposite to the standard
 'push any button' approach). That results useful when using serial lines
 sending garbage and leading to unwilling boot prompt appearence.

Obtained from:	Sandvine Incorporated
Reviewed by:	emaste, jhb
Sponsored by:	Sandvine Incorporated
MFC:		1 week
---
 sys/boot/common/Makefile.inc |  4 ++++
 sys/boot/common/boot.c       | 18 ++++++++++++++++++
 2 files changed, 22 insertions(+)

diff --git a/sys/boot/common/Makefile.inc b/sys/boot/common/Makefile.inc
index 9ede3866fb3b..1f31aa9b601d 100644
--- a/sys/boot/common/Makefile.inc
+++ b/sys/boot/common/Makefile.inc
@@ -38,4 +38,8 @@ MAN+=	../forth/loader.conf.5
 MAN+=	../forth/loader.4th.8
 .endif
 
+.if defined(BOOT_PROMPT_123)
+CFLAGS+=	-DBOOT_PROMPT_123
+.endif
+
 MAN+=	loader.8
diff --git a/sys/boot/common/boot.c b/sys/boot/common/boot.c
index 315c039b4666..c6ab6812da72 100644
--- a/sys/boot/common/boot.c
+++ b/sys/boot/common/boot.c
@@ -162,6 +162,9 @@ autoboot(int timeout, char *prompt)
     int		c, yes;
     char	*argv[2], *cp, *ep;
     char	*kernelname;
+#ifdef BOOT_PROMPT_123
+    const char	*seq = "123", *p = seq;
+#endif
 
     autoboot_tried = 1;
 
@@ -192,14 +195,29 @@ autoboot(int timeout, char *prompt)
 
         yes = 0;
 
+#ifdef BOOT_PROMPT_123
+        printf("%s\n", (prompt == NULL) ? "Hit [Enter] to boot immediately, or "
+	    "1 2 3 sequence for command prompt." : prompt);
+#else
         printf("%s\n", (prompt == NULL) ? "Hit [Enter] to boot immediately, or any other key for command prompt." : prompt);
+#endif
 
         for (;;) {
 	    if (ischar()) {
 	        c = getchar();
+#ifdef BOOT_PROMPT_123
+		if ((c == '\r') || (c == '\n')) {
+			yes = 1;
+			break;
+		} else if (c != *p++)
+			p = seq;
+		if (*p == 0)
+			break;
+#else
 	        if ((c == '\r') || (c == '\n'))
 		    yes = 1;
 	        break;
+#endif
 	    }
 	    ntime = time(NULL);
 	    if (ntime >= when) {