From 710c15a2e9078931f496424d8e10241f4930f940 Mon Sep 17 00:00:00 2001
From: bellard <bellard@c046a42c-6fe2-441c-8c8c-71466251a162>
Date: Fri, 4 Jun 2004 11:20:49 +0000
Subject: [PATCH] lmsw fix (aka dos4gw bug)

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@885 c046a42c-6fe2-441c-8c8c-71466251a162
---
 target-i386/op.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/target-i386/op.c b/target-i386/op.c
index 3f9afb17d3..8b28007078 100644
--- a/target-i386/op.c
+++ b/target-i386/op.c
@@ -980,8 +980,9 @@ void OPPROTO op_movl_drN_T0(void)
 
 void OPPROTO op_lmsw_T0(void)
 {
-    /* only 4 lower bits of CR0 are modified */
-    T0 = (env->cr[0] & ~0xf) | (T0 & 0xf);
+    /* only 4 lower bits of CR0 are modified. PE cannot be set to zero
+       if already set to one. */
+    T0 = (env->cr[0] & ~0xe) | (T0 & 0xf);
     helper_movl_crN_T0(0);
 }