From 8dc5a523de4e0d582e99c629d56fcb3622cbf8e1 Mon Sep 17 00:00:00 2001
From: Ulf Wohlers <finsterr@users.sourceforge.net>
Date: Mon, 4 Nov 2002 21:27:03 +0000
Subject: [PATCH] support for cpu trap flag

Imported-from: https://svn.code.sf.net/p/dosbox/code-0/dosbox/trunk@479
---
 src/cpu/core_16/main.h    | 11 ++++++++---
 src/cpu/core_16/support.h | 10 ++++++++--
 src/cpu/slow_16.cpp       | 14 +++++++++++++-
 3 files changed, 29 insertions(+), 6 deletions(-)

diff --git a/src/cpu/core_16/main.h b/src/cpu/core_16/main.h
index 1495e42b..2ba5b34a 100644
--- a/src/cpu/core_16/main.h
+++ b/src/cpu/core_16/main.h
@@ -856,10 +856,15 @@ restart:
 			}
 			break;
 		case 0xcc:												/* INT3 */
+#if C_DEBUG	
+			SAVEIP;
+			if (DEBUG_Breakpoint()) {
+				LOADIP;
+				return 1;
+			}
+			LOADIP;
+#endif			
 			INTERRUPT(3);
-#if C_DEBUG 
-			return 1; 
-#endif
 			break;
 		case 0xcd:												/* INT Ib */	
 			{
diff --git a/src/cpu/core_16/support.h b/src/cpu/core_16/support.h
index ace3a10f..5201b75c 100644
--- a/src/cpu/core_16/support.h
+++ b/src/cpu/core_16/support.h
@@ -376,7 +376,10 @@ countzero:
 		PIC_runIRQs();												\
 		LOADIP;														\
 	}																\
-	if (flags.tf)	LOG_DEBUG("CPU:Trap Flag not supported");			\
+	if (flags.tf) {													\
+		cpudecoder=&CPU_Real_16_Slow_Decode_Trap;					\
+		count=0;													\
+	}																\
 }
 
 #else 
@@ -394,7 +397,10 @@ countzero:
 		PIC_runIRQs();												\
 		LOADIP;														\
 	}																\
-	if (flags.tf)	LOG_DEBUG("CPU:Trap Flag not supported");			\
+	if (flags.tf) {													\
+		cpudecoder=&CPU_Real_16_Slow_Decode_Trap;					\
+		count=0;													\
+	}																\
 }
 
 #endif
diff --git a/src/cpu/slow_16.cpp b/src/cpu/slow_16.cpp
index 0bf3d76d..5a1aa242 100644
--- a/src/cpu/slow_16.cpp
+++ b/src/cpu/slow_16.cpp
@@ -60,7 +60,8 @@ extern Bitu cycle_count;
 #endif
 
 #include "core_16/support.h"
-static Bitu CPU_Real_16_Slow_Decode_Special(Bitu count);
+static Bitu CPU_Real_16_Slow_Decode_Special(Bits count);
+static Bitu CPU_Real_16_Slow_Decode_Trap(Bits count);
 
 static Bitu CPU_Real_16_Slow_Decode(Bits count) {
 #include "core_16/start.h"		
@@ -78,6 +79,17 @@ static Bitu CPU_Real_16_Slow_Decode(Bits count) {
 	return CBRET_NONE;
 }
 
+static Bitu CPU_Real_16_Slow_Decode_Trap(Bits count) 
+{
+	CPU_Real_16_Slow_Decode(1);
+
+	LOG_DEBUG("TRAP: Trap Flag executed");
+	INTERRUPT(1);
+	cpudecoder=&CPU_Real_16_Slow_Decode;
+
+	return CBRET_NONE;
+};
+
 static Bitu CPU_Real_16_Slow_Decode_Special(Bits count) {
 	while (count>0) {
 		if (flags.tf) {