From d8f68648d13961cff3d805c9cbac9ea9fa7e2230 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Sebastian=20Strohh=C3=A4cker?=
 <c2woody@users.sourceforge.net>
Date: Sat, 14 Apr 2007 14:08:51 +0000
Subject: [PATCH] precise pagefault address for block starts; fix upper part of
 eip content for certain  instructions in real/v86 mode (dynamic core; fixes
 Inner Worlds)

Imported-from: https://svn.code.sf.net/p/dosbox/code-0/dosbox/trunk@2836
---
 src/cpu/core_dyn_x86.cpp       |  3 +--
 src/cpu/core_dyn_x86/decoder.h | 17 +++++++++++------
 2 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/src/cpu/core_dyn_x86.cpp b/src/cpu/core_dyn_x86.cpp
index fc342519..50d78e8d 100644
--- a/src/cpu/core_dyn_x86.cpp
+++ b/src/cpu/core_dyn_x86.cpp
@@ -258,12 +258,11 @@ Bits CPU_Core_Dyn_X86_Run(void) {
 	/* Determine the linear address of CS:EIP */
 restart_core:
 	PhysPt ip_point=SegPhys(cs)+reg_eip;
-	Bitu ip_page=ip_point>>12;
 	#if C_HEAVY_DEBUG
 		if (DEBUG_HeavyIsBreakpoint()) return debugCallback;
 	#endif
 	CodePageHandler * chandler=0;
-	if (GCC_UNLIKELY(MakeCodePage(ip_page,chandler))) {
+	if (GCC_UNLIKELY(MakeCodePage(ip_point,chandler))) {
 		CPU_Exception(cpu.exception.which,cpu.exception.error);
 		goto restart_core;
 	}
diff --git a/src/cpu/core_dyn_x86/decoder.h b/src/cpu/core_dyn_x86/decoder.h
index 9bdf8514..a18f3a17 100644
--- a/src/cpu/core_dyn_x86/decoder.h
+++ b/src/cpu/core_dyn_x86/decoder.h
@@ -50,10 +50,11 @@ static struct DynDecode {
 	DynReg * segprefix;
 } decode;
 
-static bool MakeCodePage(Bitu lin_page,CodePageHandler * &cph) {
+static bool MakeCodePage(Bitu lin_addr,CodePageHandler * &cph) {
 	Bit8u rdval;
 	//Ensure page contains memory:
-	if (GCC_UNLIKELY(mem_readb_checked_x86(lin_page << 12,&rdval))) return true;
+	if (GCC_UNLIKELY(mem_readb_checked_x86(lin_addr,&rdval))) return true;
+	Bitu lin_page=lin_addr >> 12;
 	PageHandler * handler=paging.tlb.handler[lin_page];
 	if (handler->flags & PFLAG_HASCODE) {
 		cph=( CodePageHandler *)handler;
@@ -99,8 +100,10 @@ static Bit8u decode_fetchb(void) {
         /* Advance to the next page */
 		decode.active_block->page.end=4095;
 		/* trigger possible page fault here */
-		mem_readb((++decode.page.first) << 12);
-		MakeCodePage(decode.page.first,decode.page.code);
+		decode.page.first++;
+		Bitu fetchaddr=decode.page.first << 12;
+		mem_readb(fetchaddr);
+		MakeCodePage(fetchaddr,decode.page.code);
 		CacheBlock * newblock=cache_getblock();
 		decode.active_block->crossblock=newblock;
 		newblock->crossblock=decode.active_block;
@@ -252,7 +255,8 @@ static INLINE void dyn_set_eip_end(void) {
 
 static INLINE void dyn_set_eip_end(DynReg * endreg) {
 	gen_protectflags();
-	gen_dop_word(DOP_MOV,cpu.code.big,DREG(TMPW),DREG(EIP));
+	if (cpu.code.big) gen_dop_word(DOP_MOV,true,DREG(TMPW),DREG(EIP));
+	else gen_extend_word(false,DREG(TMPW),DREG(EIP));
 	gen_dop_word_imm(DOP_ADD,cpu.code.big,DREG(TMPW),decode.code-decode.code_start);
 }
 
@@ -1810,7 +1814,8 @@ static void dyn_call_near_imm(void) {
 	dyn_set_eip_end(DREG(TMPW));
 	dyn_push(DREG(TMPW));
 	gen_dop_word_imm(DOP_ADD,decode.big_op,DREG(TMPW),imm);
-	gen_dop_word(DOP_MOV,decode.big_op,DREG(EIP),DREG(TMPW));
+	if (cpu.code.big) gen_dop_word(DOP_MOV,true,DREG(EIP),DREG(TMPW));
+	else gen_extend_word(false,DREG(EIP),DREG(TMPW));
 	dyn_reduce_cycles();
 	dyn_save_critical_regs();
 	gen_jmp_ptr(&decode.block->link[0].to,offsetof(CacheBlock,cache.start));