From: Ben Gras <ben@minix3.org>
Date: Wed, 2 Jun 2010 13:23:15 +0000 (+0000)
Subject: boot monitor: introduce a 'reset' command that causes the cpu to
X-Git-Tag: v3.1.7~15
X-Git-Url: http://zhaoyanbai.com/repos/%22http:/www.isc.org/icons/zlib_tech.html?a=commitdiff_plain;h=495970a17ce4b2e3d7af3685ef950d1a7d112699;p=minix.git

boot monitor: introduce a 'reset' command that causes the cpu to
reset (triple fault).
---

diff --git a/boot/boot.c b/boot/boot.c
index c72838fc1..f73ae45b6 100644
--- a/boot/boot.c
+++ b/boot/boot.c
@@ -715,12 +715,12 @@ static void initialize(void)
 /* Reserved names: */
 enum resnames {
  	R_NULL, R_BOOT, R_CTTY, R_DELAY, R_ECHO, R_EXIT, R_HELP,
-	R_LS, R_MENU, R_OFF, R_SAVE, R_SET, R_TRAP, R_UNSET
+	R_LS, R_MENU, R_OFF, R_SAVE, R_SET, R_TRAP, R_UNSET, R_RESET
 };
 
 static char resnames[][6] = {
 	"", "boot", "ctty", "delay", "echo", "exit", "help",
-	"ls", "menu", "off", "save", "set", "trap", "unset",
+	"ls", "menu", "off", "save", "set", "trap", "unset", "reset",
 };
 
 /* Using this for all null strings saves a lot of memory. */
@@ -731,7 +731,7 @@ static enum resnames reserved(const char *s)
 {
 	enum resnames r;
 
-	for (r= R_BOOT; r <= R_UNSET; r++) {
+	for (r= R_BOOT; r <= R_RESET; r++) {
 		if (strcmp(s, resnames[r]) == 0) return r;
 	}
 	return R_NULL;
@@ -1877,6 +1877,7 @@ static void execute(void)
 		case R_EXIT:	exit(0);
 		case R_OFF:	off();		ok= 1;	break;
 		case R_CTTY:	ctty(nil);	ok= 1;	break;
+		case R_RESET:	reset();	ok= 1;  break;
 		}
 
 		/* Command to check bootparams: */
@@ -2029,6 +2030,9 @@ void main(int argc, char **argv)
 	}
 	exit(0);
 }
+
+reset() { }
+
 #endif /* UNIX */
 
 /*
diff --git a/boot/boothead.s b/boot/boothead.s
index f72777ff1..7fefb1ec3 100644
--- a/boot/boothead.s
+++ b/boot/boothead.s
@@ -1454,6 +1454,11 @@ _scan_keyboard:
 	outb	0x61
 	ret
 
+.define	_reset
+_reset:
+	lidt	idt_zero
+	int	0x3
+
 .data
 	.ascii	"(null)\0"	! Just in case someone follows a null pointer
 	.align	2
@@ -1461,6 +1466,8 @@ c60:	.data2	60		! Constants for MUL and DIV
 c1024:	.data2	1024
 c1080:	.data2	1080
 c19663:	.data2	19663
+idt_zero:
+.data4	0,0
 
 ! Global descriptor tables.
 	UNSET	= 0		! Must be computed