From ded957188a45de1222ddb45ebdfe2b1633904739 Mon Sep 17 00:00:00 2001
From: Peter Veenstra <qbix79@users.sourceforge.net>
Date: Fri, 27 Oct 2006 12:01:52 +0000
Subject: [PATCH] Add Beta1 patch: "Add very basic Clipper support." by wd.

Imported-from: https://svn.code.sf.net/p/dosbox/code-0/dosbox/trunk@2712
---
 src/cpu/core_normal.cpp           |  3 +++
 src/cpu/core_normal/prefix_none.h | 12 +++++++++++-
 src/cpu/core_simple.cpp           |  3 +++
 3 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/src/cpu/core_normal.cpp b/src/cpu/core_normal.cpp
index 14e65403..e74b9ee1 100644
--- a/src/cpu/core_normal.cpp
+++ b/src/cpu/core_normal.cpp
@@ -71,6 +71,7 @@ extern Bitu cycle_count;
 #define DO_PREFIX_SEG(_SEG)					\
 	BaseDS=SegBase(_SEG);					\
 	BaseSS=SegBase(_SEG);					\
+	core.base_val_ds=_SEG;					\
 	goto restart_opcode;
 
 #define DO_PREFIX_ADDR()								\
@@ -92,6 +93,7 @@ static struct {
 	Bitu opcode_index;
 	PhysPt cseip;
 	PhysPt base_ds,base_ss;
+	SegNames base_val_ds;
 	bool rep_zero;
 	Bitu prefixes;
 	GetEAHandler * ea_table;
@@ -142,6 +144,7 @@ Bits CPU_Core_Normal_Run(void) {
 		core.ea_table=&EATable[cpu.code.big*256];
 		BaseDS=SegBase(ds);
 		BaseSS=SegBase(ss);
+		core.base_val_ds=ds;
 #if C_DEBUG
 #if C_HEAVY_DEBUG
 		if (DEBUG_HeavyIsBreakpoint()) {
diff --git a/src/cpu/core_normal/prefix_none.h b/src/cpu/core_normal/prefix_none.h
index 97ea24d2..b7b4f174 100644
--- a/src/cpu/core_normal/prefix_none.h
+++ b/src/cpu/core_normal/prefix_none.h
@@ -431,7 +431,17 @@
 		{	
 			GetRMrb;
 			if (rm >= 0xc0 ) {GetEArb;*earb=*rmrb;}
-			else {GetEAa;SaveMb(eaa,*rmrb);}
+			else {
+				if (cpu.pmode) {
+					Descriptor desc;
+					cpu.gdt.GetDescriptor(SegValue(core.base_val_ds),desc);
+					if ((desc.Type()==DESC_CODE_R_NC_A) || (desc.Type()==DESC_CODE_R_NC_NA)) {
+						CPU_Exception(EXCEPTION_GP,SegValue(core.base_val_ds) & 0xfffc);
+						continue;
+					}
+				}
+				GetEAa;SaveMb(eaa,*rmrb);
+			}
 			break;
 		}
 	CASE_W(0x89)												/* MOV Ew,Gw */
diff --git a/src/cpu/core_simple.cpp b/src/cpu/core_simple.cpp
index c07aeba7..e79514ab 100644
--- a/src/cpu/core_simple.cpp
+++ b/src/cpu/core_simple.cpp
@@ -63,6 +63,7 @@ extern Bitu cycle_count;
 #define DO_PREFIX_SEG(_SEG)					\
 	BaseDS=SegBase(_SEG);					\
 	BaseSS=SegBase(_SEG);					\
+	core.base_val_ds=_SEG;					\
 	goto restart_opcode;
 
 #define DO_PREFIX_ADDR()								\
@@ -84,6 +85,7 @@ static struct {
 	Bitu opcode_index;
 	HostPt cseip;
 	PhysPt base_ds,base_ss;
+	SegNames base_val_ds;
 	bool rep_zero;
 	Bitu prefixes;
 	GetEAHandler * ea_table;
@@ -137,6 +139,7 @@ Bits CPU_Core_Simple_Run(void) {
 		core.ea_table=&EATable[cpu.code.big*256];
 		BaseDS=SegBase(ds);
 		BaseSS=SegBase(ss);
+		core.base_val_ds=ds;
 #if C_DEBUG
 #if C_HEAVY_DEBUG
 		if (DEBUG_HeavyIsBreakpoint()) {