From 44496fb5f2dc87fc6ca3cbb949181e071d64918d Mon Sep 17 00:00:00 2001
From: John Baldwin <jhb@FreeBSD.org>
Date: Wed, 6 Dec 2006 17:45:35 +0000
Subject: [PATCH] Ignore any breakpoint instructions (int 3) we encounter in
 vm86 mode rather than treating them as a fatal exception and halting.  At
 least one storage BIOS (some newer mpt(4) parts) have a breakpoint
 instruction in their disk read routine.

MFC after:	3 days
---
 sys/boot/i386/btx/btx/btx.S | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/sys/boot/i386/btx/btx/btx.S b/sys/boot/i386/btx/btx/btx.S
index ce9962269cf..8838ca13aea 100644
--- a/sys/boot/i386/btx/btx/btx.S
+++ b/sys/boot/i386/btx/btx/btx.S
@@ -499,6 +499,8 @@ v86mon.4:	cmpb $0xfa,%al			# CLI?
 		je v86cli			# Yes
 		cmpb $0xfb,%al			# STI?
 		je v86sti			# Yes
+		cmpb $0xcc,%al			# INT3?
+		je v86mon.7			# Yes, ignore
 		movzwl 0x38(%ebp),%ebx		# Load V86 SS
 		shll $0x4,%ebx			# To offset
 		pushl %ebx			# Save