[hbelusca] 60917: [NTVDM] Instead of reassembling each time the very same common stub code for each interrupt, do it once, and then assemble just a little part for each interrupt and jump to the co...

Author: hbelusca
Date: Sun Nov 10 16:22:33 2013
New Revision: 60917

URL: http://svn.reactos.org/svn/reactos?rev=60917&view=rev
Log:
[NTVDM]
Instead of reassembling each time the very same common stub code for each interrupt, do it once, and then assemble just a little part for each interrupt and jump to the common stub.
Now the 4DOS Ctrl-C exception bug changes, but I have an idea what's happening in there...

Modified:
    branches/ntvdm/subsystems/ntvdm/int32.c

Modified: branches/ntvdm/subsystems/ntvdm/int32.c
URL: http://svn.reactos.org/svn/reactos/branches/ntvdm/subsystems/ntvdm/int32.c?r...
==============================================================================
--- branches/ntvdm/subsystems/ntvdm/int32.c	[iso-8859-1] (original)
+++ branches/ntvdm/subsystems/ntvdm/int32.c	[iso-8859-1] Sun Nov 10 16:22:33 2013
@@ -128,25 +128,16 @@

VOID WINAPI InitializeInt32(WORD BiosSegment)
 {
+    LPDWORD IntVecTable = (LPDWORD)BaseAddress;
+    LPBYTE  BiosCode    = (LPBYTE)SEG_OFF_TO_PTR(BiosSegment, 0);
+
     USHORT i;
-    WORD Offset = 0;
+    WORD CommonStub, BopSeqOffset, Offset;

-    LPDWORD IntVecTable = (LPDWORD)BaseAddress;
-    LPBYTE BiosCode = (LPBYTE)SEG_OFF_TO_PTR(BiosSegment, 0);
+    CommonStub = Offset = 0x00;

-    /* Generate ISR stubs and fill the IVT */
-    for (i = 0x00; i <= 0xFF; i++)
+    /* Write the common stub code */
     {
-        IntVecTable[i] = MAKELONG(Offset, BiosSegment);
-
-        BiosCode[Offset++] = 0xFA; // cli
-
-        BiosCode[Offset++] = 0x6A; // push i
-        BiosCode[Offset++] = (UCHAR)i;
-
-        BiosCode[Offset++] = 0x6A; // push 0
-        BiosCode[Offset++] = 0x00;
-
 // BOP_SEQ:
         BiosCode[Offset++] = 0xF8; // clc

@@ -173,6 +164,27 @@

BiosCode[Offset++] = 0xCF; // iret
     }
+
+    /* Generate ISR stubs and fill the IVT */
+    for (i = 0x00; i <= 0xFF; i++)
+    {
+        IntVecTable[i] = MAKELONG(Offset, BiosSegment);
+
+        BiosCode[Offset++] = 0xFA; // cli
+
+        BiosCode[Offset++] = 0x6A; // push i
+        BiosCode[Offset++] = (UCHAR)i;
+
+        BiosCode[Offset++] = 0x6A; // push 0
+        BiosCode[Offset++] = 0x00;
+
+        BopSeqOffset = CommonStub - Offset - 3;
+
+        BiosCode[Offset+0] = 0xE9; // jmp near BOP_SEQ
+        BiosCode[Offset+1] = LOBYTE(BopSeqOffset);
+        BiosCode[Offset+2] = HIBYTE(BopSeqOffset);
+        Offset+=3;
+    }
 }

VOID WINAPI RegisterInt32(BYTE IntNumber, EMULATOR_INT32_PROC IntHandler)