From 5a3cc5df3cf7fc617d11d4c2be68da63bc186f97 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Herm=C3=A8s=20B=C3=A9lusca-Ma=C3=AFto?=
 <hermes.belusca-maito@reactos.org>
Date: Fri, 21 Feb 2014 19:27:27 +0000
Subject: [PATCH] [NTVDM] Start to implement EmulatorSimulate /
 EmulatorUnsimulate (used by VDDSimulate16 and VDDUnsimualte16). This piece of
 code can be better written, but it works for what I'm going to commit next.

svn path=/branches/ntvdm/; revision=62282
---
 subsystems/ntvdm/clock.c    |  1 -
 subsystems/ntvdm/emulator.c | 10 ++++++++--
 subsystems/ntvdm/emulator.h |  2 ++
 subsystems/ntvdm/ntvdm.c    |  4 ++--
 4 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/subsystems/ntvdm/clock.c b/subsystems/ntvdm/clock.c
index 0bb3e0c21c8..a6d43f5c591 100644
--- a/subsystems/ntvdm/clock.c
+++ b/subsystems/ntvdm/clock.c
@@ -127,7 +127,6 @@ VOID ClockUpdate(VOID)
     VgaHorizontalRetrace();
 
     /* Continue CPU emulation */
-    // EmulatorSimulate();
     for (i = 0; (i < STEPS_PER_CYCLE) && VdmRunning; i++)
     {
         EmulatorStep();
diff --git a/subsystems/ntvdm/emulator.c b/subsystems/ntvdm/emulator.c
index 826ff3937ac..0e5cba83bab 100644
--- a/subsystems/ntvdm/emulator.c
+++ b/subsystems/ntvdm/emulator.c
@@ -177,12 +177,18 @@ VOID EmulatorStep(VOID)
 
 VOID EmulatorSimulate(VOID)
 {
-    UNIMPLEMENTED;
+    // FIXME: Do not mix VdmRunning (i.e. ntvdm running) and CpuSimulate!!
+    while (VdmRunning) ClockUpdate();
+
+    /* This takes into account for reentrance */
+    VdmRunning = TRUE;
 }
 
 VOID EmulatorUnsimulate(VOID)
 {
-    UNIMPLEMENTED;
+    /* Stop simulation */
+    // FIXME: Do not mix VdmRunning (i.e. ntvdm running) and CpuSimulate!!
+    VdmRunning = FALSE;
 }
 
 VOID EmulatorInterrupt(BYTE Number)
diff --git a/subsystems/ntvdm/emulator.h b/subsystems/ntvdm/emulator.h
index 49aff1e43ed..51e9dceb249 100644
--- a/subsystems/ntvdm/emulator.h
+++ b/subsystems/ntvdm/emulator.h
@@ -118,6 +118,8 @@ VOID EmulatorExecute(WORD Segment, WORD Offset);
 VOID EmulatorInterrupt(BYTE Number);
 VOID EmulatorInterruptSignal(VOID);
 VOID EmulatorStep(VOID);
+VOID EmulatorSimulate(VOID);
+VOID EmulatorUnsimulate(VOID);
 VOID EmulatorCleanup(VOID);
 VOID EmulatorSetA20(BOOLEAN Enabled);
 
diff --git a/subsystems/ntvdm/ntvdm.c b/subsystems/ntvdm/ntvdm.c
index 6dfe67a9d81..ab185ac8eeb 100644
--- a/subsystems/ntvdm/ntvdm.c
+++ b/subsystems/ntvdm/ntvdm.c
@@ -420,8 +420,8 @@ INT wmain(INT argc, WCHAR *argv[])
         goto Cleanup;
     }
 
-    /* Main loop */
-    while (VdmRunning) ClockUpdate();
+    /* Start simulation */
+    EmulatorSimulate();
 
     /* Perform another screen refresh */
     VgaRefreshDisplay();