mirrors/Bochs
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

- add CMPXCHG8B patch from Michael Hohmuth <hohmuth@innocent.com>

Browse Source
This commit is contained in:
Bryce Denney 2001-11-15 16:53:24 +00:00
parent a617b4e739
commit 980643e0fb
1 changed files with 88 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

88
bochs/patches/patch.cmpxchg8b Normal file
View File

@ -0,0 +1,88 @@
Date: 15 Nov 2001 17:41:33 +0100
From: Michael Hohmuth <hohmuth@innocent.com>
To: bochs-developers@lists.sourceforge.net
Subject: [Bochs-developers] Patch: CMPXCHG8B
Parts/Attachments:
1 Shown 19 lines Text
2 OK 59 lines Text
----------------------------------------
Bochs developers,
attached below is a patch to add support for the CMPXCHG8B instruction
to Bochs. The patch is relative to the 20011008 snapshot release. I
have tested the modification, and it seems to work fine.
One question:
I mostly adapted the code from the implementation of CMPXCHG,
implemented in BX_CPU_C::CMPXCHG_EdGd(). Could someone please explain
what the line containing ``SET_FLAGS_OSZAPC_32'' does in that
function, and whether something similar is needed for CMPXCHG8B?
Cheers,
Michael
--
hohmuth@innocent.com, hohmuth@inf.tu-dresden.de
http://home.pages.de/~hohmuth/
Index: arith32.cc
===================================================================
RCS file: /home/hohmuth/local/var/cvs/bochs/cpu/arith32.cc,v
retrieving revision 1.1.1.1
retrieving revision 1.2
diff -u -p -r1.1.1.1 -r1.2
--- arith32.cc 2001/11/14 17:26:46 1.1.1.1
+++ arith32.cc 2001/11/15 16:10:09 1.2
@@ -1,5 +1,5 @@
/////////////////////////////////////////////////////////////////////////
-// $Id: patch.cmpxchg8b,v 1.1 2001-11-15 16:53:24 bdenney Exp $
+// $Id: patch.cmpxchg8b,v 1.1 2001-11-15 16:53:24 bdenney Exp $
/////////////////////////////////////////////////////////////////////////
//
// Copyright (C) 2001 MandrakeSoft S.A.
@@ -856,11 +856,38 @@ BX_CPU_C::CMPXCHG_EdGd(BxInstruction_t *
BX_CPU_C::CMPXCHG8B(BxInstruction_t *i)
{
#if (BX_CPU_LEVEL >= 5) || (BX_CPU_LEVEL_HACKED >= 5)
- if (i->mod != 0xc0) {
- BX_INFO(("CMPXCHG8B: dest is reg: #UD"));
- UndefinedOpcode(i);
- }
- BX_PANIC(("CMPXCHG8B: not implemented yet"));
+
+ Bit32u op1_64_lo, op1_64_hi, diff;
+
+ if (i->mod == 0xc0) {
+ BX_INFO(("CMPXCHG8B: dest is reg: #UD"));
+ UndefinedOpcode(i);
+ }
+
+ /* pointer, segment address pair */
+ read_virtual_dword(i->seg, i->rm_addr, &op1_64_lo);
+ read_RMW_virtual_dword(i->seg, i->rm_addr + 4, &op1_64_hi);
+
+ diff = EAX - op1_64_lo;
+ diff |= EDX - op1_64_hi;
+
+// SET_FLAGS_OSZAPC_32(EAX, op1_32, diff_32, BX_INSTR_CMP32);
+
+ if (diff == 0) { // if accumulator == dest
+ // ZF = 1
+ set_ZF(1);
+ // dest <-- src
+ write_RMW_virtual_dword(ECX);
+ write_virtual_dword(i->seg, i->rm_addr, &EBX);
+ }
+ else {
+ // ZF = 0
+ set_ZF(0);
+ // accumulator <-- dest
+ EAX = op1_64_lo;
+ EDX = op1_64_hi;
+ }
+
#else
BX_INFO(("CMPXCHG8B: not implemented yet"));
UndefinedOpcode(i);