[aandrejevic] 68014: [FAST486] - Interrupts always clear TF. - Let at least one instruction happen between #DB's (when TF is set).

Author: aandrejevic
Date: Thu Jun  4 14:48:07 2015
New Revision: 68014

URL: http://svn.reactos.org/svn/reactos?rev=68014&view=rev
Log:
[FAST486]
- Interrupts always clear TF.
- Let at least one instruction happen between #DB's (when TF is set).

Modified:
    trunk/reactos/lib/fast486/common.c
    trunk/reactos/lib/fast486/fast486.c

Modified: trunk/reactos/lib/fast486/common.c
URL: http://svn.reactos.org/svn/reactos/trunk/reactos/lib/fast486/common.c?rev=68...
==============================================================================
--- trunk/reactos/lib/fast486/common.c	[iso-8859-1] (original)
+++ trunk/reactos/lib/fast486/common.c	[iso-8859-1] Thu Jun  4 14:48:07 2015
@@ -430,8 +430,8 @@
             State->InstPtr.LowWord = IdtEntry->Offset;
         }

-        /* Clear TF and NT */
-        State->Flags.Tf = State->Flags.Nt = FALSE;
+        /* Clear NT */
+       State->Flags.Nt = FALSE;

if (OldVm)
         {
@@ -512,6 +512,9 @@
         /* Disable interrupts after a jump to an interrupt gate handler */
         State->Flags.If = FALSE;
     }
+
+    /* Clear TF */
+    State->Flags.Tf = FALSE;

return TRUE;
 }

Modified: trunk/reactos/lib/fast486/fast486.c
URL: http://svn.reactos.org/svn/reactos/trunk/reactos/lib/fast486/fast486.c?rev=6...
==============================================================================
--- trunk/reactos/lib/fast486/fast486.c	[iso-8859-1] (original)
+++ trunk/reactos/lib/fast486/fast486.c	[iso-8859-1] Thu Jun  4 14:48:07 2015
@@ -50,10 +50,13 @@
     UCHAR Opcode;
     FAST486_OPCODE_HANDLER_PROC CurrentHandler;
     INT ProcedureCallCount = 0;
+    BOOLEAN Trap;

/* Main execution loop */
     do
     {
+        Trap = State->Flags.Tf;
+
         if (!State->Halted)
         {
 NextInst:
@@ -90,19 +93,10 @@
             /* Clear the interrupt delay flag */
             State->DoNotInterrupt = FALSE;
         }
-        else if (State->Flags.Tf && !State->Halted)
+        else if (Trap && !State->Halted)
         {
             /* Perform the interrupt */
-            Fast486PerformInterrupt(State, 0x01);
-
-            /*
-             * Flags and TF are pushed on stack so we can reset TF now,
-             * to not break into the INT 0x01 handler.
-             * After the INT 0x01 handler returns, the flags and therefore
-             * TF are popped back off the stack and restored, so TF will be
-             * automatically reset to its previous state.
-             */
-            State->Flags.Tf = FALSE;
+            Fast486PerformInterrupt(State, FAST486_EXCEPTION_DB);
         }
         else if (State->Flags.If && State->IntSignaled)
         {