[FAST486][NTVDM]

Get rid of Fast486Interrupt, since it's not used anywhere. Also we can now remove
workarounds for all of the bugs that it caused.
Implement the "single-instruction interrupt delay" for instructions that load the
stack segment only.


svn path=/trunk/; revision=65061

reactos/include/reactos/libs/fast486/fast486.h

@@ -169,14 +169,6 @@ typedef enum _FAST486_EXCEPTIONS
     FAST486_EXCEPTION_MC = 0x12
 } FAST486_EXCEPTIONS, *PFAST486_EXCEPTIONS;
 
-typedef enum _FAST486_INT_STATUS
-{
-    FAST486_INT_NONE = 0,
-    FAST486_INT_EXECUTE = 1,
-    FAST486_INT_SIGNAL = 2,
-    FAST486_INT_DELAYED = 3
-} FAST486_INT_STATUS, *PFAST486_INT_STATUS;
-
 typedef
 VOID
 (NTAPI *FAST486_MEM_READ_PROC)
@@ -495,8 +487,8 @@ struct _FAST486_STATE
     ULONG PrefixFlags;
     FAST486_SEG_REGS SegmentOverride;
     BOOLEAN Halted;
-    FAST486_INT_STATUS IntStatus;
-    UCHAR PendingIntNum;
+    BOOLEAN IntSignaled;
+    BOOLEAN DoNotInterrupt;
     PULONG Tlb;
 #ifndef FAST486_NO_PREFETCH
     BOOLEAN PrefetchValid;
@@ -548,10 +540,6 @@ VOID
 NTAPI
 Fast486DumpState(PFAST486_STATE State);
 
-VOID
-NTAPI
-Fast486Interrupt(PFAST486_STATE State, UCHAR Number);
-
 VOID
 NTAPI
 Fast486InterruptSignal(PFAST486_STATE State);

reactos/lib/fast486/fast486.c

@@ -85,7 +85,12 @@ NextInst:
          * Check if there is an interrupt to execute, or a hardware interrupt signal
          * while interrupts are enabled.
          */
-        if (State->Flags.Tf && !State->Halted)
+        if (State->DoNotInterrupt)
+        {
+            /* Clear the interrupt delay flag */
+            State->DoNotInterrupt = FALSE;
+        }
+        else if (State->Flags.Tf && !State->Halted)
         {
             /* Perform the interrupt */
             Fast486PerformInterrupt(State, 0x01);
@@ -99,29 +104,16 @@ NextInst:
              */
             State->Flags.Tf = FALSE;
         }
-        else if (State->IntStatus == FAST486_INT_EXECUTE)
+        else if (State->Flags.If && State->IntSignaled)
         {
             /* No longer halted */
             State->Halted = FALSE;
 
-            /* Perform the interrupt */
-            Fast486PerformInterrupt(State, State->PendingIntNum);
+            /* Acknowledge the interrupt and perform it */
+            Fast486PerformInterrupt(State, State->IntAckCallback(State));
 
             /* Clear the interrupt status */
-            State->IntStatus = FAST486_INT_NONE;
-        }
-        else if (State->Flags.If && (State->IntStatus == FAST486_INT_SIGNAL))
-        {
-            /* Acknowledge the interrupt to get the number */
-            State->PendingIntNum = State->IntAckCallback(State);
-
-            /* Set the interrupt status to execute on the next instruction */
-            State->IntStatus = FAST486_INT_EXECUTE;
-        }
-        else if (State->IntStatus == FAST486_INT_DELAYED)
-        {
-            /* Restore the old state */
-            State->IntStatus = FAST486_INT_EXECUTE;
+            State->IntSignaled = FALSE;
         }
     }
     while ((Command == FAST486_CONTINUE) ||
@@ -284,21 +276,11 @@ Fast486Reset(PFAST486_STATE State)
     State->Tlb              = Tlb;
 }
 
-VOID
-NTAPI
-Fast486Interrupt(PFAST486_STATE State, UCHAR Number)
-{
-    /* Set the interrupt status and the number */
-    State->IntStatus = FAST486_INT_EXECUTE;
-    State->PendingIntNum = Number;
-}
-
 VOID
 NTAPI
 Fast486InterruptSignal(PFAST486_STATE State)
 {
-    /* Set the interrupt status */
-    State->IntStatus = FAST486_INT_SIGNAL;
+    State->IntSignaled = TRUE;
 }
 
 VOID

reactos/lib/fast486/opcodes.c

@@ -2635,7 +2635,11 @@ FAST486_OPCODE_HANDLER(Fast486OpcodePopSs)
     }
 
     /* Call the internal API */
-    Fast486LoadSegment(State, FAST486_REG_SS, LOWORD(NewSelector));
+    if (Fast486LoadSegment(State, FAST486_REG_SS, LOWORD(NewSelector)))
+    {
+        /* Inhibit all interrupts until the next instruction */
+        State->DoNotInterrupt = TRUE;
+    }
 }
 
 FAST486_OPCODE_HANDLER(Fast486OpcodeSbbByteModrm)
@@ -3953,7 +3957,11 @@ FAST486_OPCODE_HANDLER(Fast486OpcodeMovLoadSeg)
             return;
         }
 
-        Fast486LoadSegment(State, ModRegRm.Register, LOWORD(Selector));
+        if (!Fast486LoadSegment(State, ModRegRm.Register, LOWORD(Selector)))
+        {
+            /* Exception occurred */
+            return;
+        }
     }
     else
     {
@@ -3965,7 +3973,17 @@ FAST486_OPCODE_HANDLER(Fast486OpcodeMovLoadSeg)
             return;
         }
 
-        Fast486LoadSegment(State, ModRegRm.Register, Selector);
+        if (Fast486LoadSegment(State, ModRegRm.Register, Selector))
+        {
+            /* Exception occurred */
+            return;
+        }
+    }
+
+    if ((INT)ModRegRm.Register == FAST486_REG_SS)
+    {
+        /* Inhibit all interrupts until the next instruction */
+        State->DoNotInterrupt = TRUE;
     }
 }
 
@@ -4261,10 +4279,7 @@ FAST486_OPCODE_HANDLER(Fast486OpcodeLdsLes)
              * changes the CS:IP, the interrupt handler won't execute and the
              * stack pointer will never be restored.
              */
-            if (State->IntStatus == FAST486_INT_EXECUTE)
-            {
-                State->IntStatus = FAST486_INT_DELAYED;
-            }
+            State->DoNotInterrupt = TRUE;
 
             return;
         }

reactos/subsystems/ntvdm/emulator.c

@@ -250,12 +250,6 @@ VOID EmulatorTerminate(VOID)
     VdmRunning = FALSE;
 }
 
-VOID EmulatorInterrupt(BYTE Number)
-{
-    /* Call the Fast486 API */
-    Fast486Interrupt(&EmulatorContext, Number);
-}
-
 VOID EmulatorInterruptSignal(VOID)
 {
     /* Call the Fast486 API */

reactos/subsystems/ntvdm/emulator.h

@@ -96,7 +96,6 @@ VOID EmulatorException(BYTE ExceptionNumber, LPWORD Stack);
 
 VOID EmulatorTerminate(VOID);
 
-VOID EmulatorInterrupt(BYTE Number);
 VOID EmulatorInterruptSignal(VOID);
 VOID EmulatorSetA20(BOOLEAN Enabled);
 

reactos/subsystems/ntvdm/ntvdm.c

@@ -204,9 +204,9 @@ ConsoleCtrlHandler(DWORD ControlType)
         case CTRL_C_EVENT:
         case CTRL_BREAK_EVENT:
         {
-            /* Call INT 23h */
-            DPRINT1("Ctrl-C/Break: Call INT 23h\n");
-            EmulatorInterrupt(0x23);
+            /* HACK: Stop the VDM */
+            EmulatorTerminate();
+
             break;
         }
         case CTRL_LAST_CLOSE_EVENT: