From 52f503519030aa367935ec9a38c2c55bd5e152f0 Mon Sep 17 00:00:00 2001
From: John Baldwin <jhb@FreeBSD.org>
Date: Thu, 29 Jun 2000 01:25:31 +0000
Subject: [PATCH] Rework the detecting of the rdmsr and wrmsr instructions in
 the v86 monitor so that the codepath is cleaner and easier to maintain in the
 future.

---
 sys/boot/i386/btx/btx/btx.S | 14 +++++++-------
 sys/boot/i386/btx/btx/btx.s | 14 +++++++-------
 2 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/sys/boot/i386/btx/btx/btx.S b/sys/boot/i386/btx/btx/btx.S
index d957bfcebc4..e22fb2e389f 100644
--- a/sys/boot/i386/btx/btx/btx.S
+++ b/sys/boot/i386/btx/btx/btx.S
@@ -478,16 +478,16 @@ v86mon.2:	cmpb $0xf4,%al			# HLT?
 		cmpl $inthlt+0x1,%esi		# Is inthlt?
 		jne v86mon.7			# No (ignore)
 		jmp intrtn			# Return to user mode
-v86mon.3:	cmpb $0xf,%al			# Is
-		jne v86mon.3.1			#  this
-		cmpb $0x20,(%esi)		#  a
-		jne v86mon.3.1			#  MOV EAX,CR0
-		cmpb $0xc0,0x1(%esi)		#  instruction?
-		je v86mov			# Yes
-v86mon.3.1:	cmpb $0x30,(%esi)		# Is it a WRMSR?
+v86mon.3:	cmpb $0xf,%al			# Prefixed instruction?
+		jne v86mon.4			# No
+		cmpb $0x30,(%esi)		# Is it a WRMSR?
 		je v86wrmsr			# Yes
 		cmpb $0x32,(%esi)		# Is it a RDMSR?
 		je v86rdmsr			# Yes
+		cmpb $0x20,(%esi)		# Is this a
+		jne v86mon.4			#  MOV EAX,CR0
+		cmpb $0xc0,0x1(%esi)		#  instruction?
+		je v86mov			# Yes
 v86mon.4:	cmpb $0xfa,%al			# CLI?
 		je v86cli			# Yes
 		cmpb $0xfb,%al			# STI?
diff --git a/sys/boot/i386/btx/btx/btx.s b/sys/boot/i386/btx/btx/btx.s
index d957bfcebc4..e22fb2e389f 100644
--- a/sys/boot/i386/btx/btx/btx.s
+++ b/sys/boot/i386/btx/btx/btx.s
@@ -478,16 +478,16 @@ v86mon.2:	cmpb $0xf4,%al			# HLT?
 		cmpl $inthlt+0x1,%esi		# Is inthlt?
 		jne v86mon.7			# No (ignore)
 		jmp intrtn			# Return to user mode
-v86mon.3:	cmpb $0xf,%al			# Is
-		jne v86mon.3.1			#  this
-		cmpb $0x20,(%esi)		#  a
-		jne v86mon.3.1			#  MOV EAX,CR0
-		cmpb $0xc0,0x1(%esi)		#  instruction?
-		je v86mov			# Yes
-v86mon.3.1:	cmpb $0x30,(%esi)		# Is it a WRMSR?
+v86mon.3:	cmpb $0xf,%al			# Prefixed instruction?
+		jne v86mon.4			# No
+		cmpb $0x30,(%esi)		# Is it a WRMSR?
 		je v86wrmsr			# Yes
 		cmpb $0x32,(%esi)		# Is it a RDMSR?
 		je v86rdmsr			# Yes
+		cmpb $0x20,(%esi)		# Is this a
+		jne v86mon.4			#  MOV EAX,CR0
+		cmpb $0xc0,0x1(%esi)		#  instruction?
+		je v86mov			# Yes
 v86mon.4:	cmpb $0xfa,%al			# CLI?
 		je v86cli			# Yes
 		cmpb $0xfb,%al			# STI?