subsystems/ntvdm/int32.c

   1 /*
   2  * COPYRIGHT:       GPL - See COPYING in the top level directory
   3  * PROJECT:         ReactOS Virtual DOS Machine
   4  * FILE:            int32.c
   5  * PURPOSE:         32-bit Interrupt Handlers
   6  * PROGRAMMERS:     Aleksandar Andrejevic <theflash AT sdf DOT lonestar DOT org>
   7  *                  Hermes Belusca-Maito (hermes.belusca@sfr.fr)
   8  */
   9
  10 /* INCLUDES *******************************************************************/
  11
  12 // #define NDEBUG
  13
  14 #include "emulator.h"
  15 #include "int32.h"
  16
  17 #include "bop.h"
  18
  19 /* PRIVATE VARIABLES **********************************************************/
  20
  21 /*
  22  * This is the list of registered 32-bit Interrupt handlers.
  23  */
  24 EMULATOR_INT32_PROC Int32Proc[EMULATOR_MAX_INT32_NUM] = { NULL };
  25
  26 /* BOP Identifiers */
  27 #define BOP_CONTROL             0xFF    // Control BOP Handler
  28     #define BOP_CONTROL_DEFFUNC 0x00    // Default Control BOP Function
  29
  30 /* 32-bit Interrupt dispatcher function code for the Control BOP Handler */
  31 #define BOP_CONTROL_INT32       0xFF
  32
  33 /* PUBLIC FUNCTIONS ***********************************************************/
  34
  35 VOID WINAPI Int32Dispatch(LPWORD Stack)
  36 {
  37     /* Get the interrupt number */
  38     BYTE IntNum = LOBYTE(Stack[STACK_INT_NUM]);
  39
  40     /* Call the 32-bit Interrupt handler */
  41     if (Int32Proc[IntNum] != NULL)
  42         Int32Proc[IntNum](Stack);
  43     else
  44         DPRINT("Unhandled 32-bit interrupt: 0x%02X, AX = 0x%04X\n", IntNum, getAX());
  45 }
  46
  47 VOID WINAPI ControlBop(LPWORD Stack)
  48 {
  49     /* Get the Function Number and skip it */
  50     BYTE FuncNum = *(PBYTE)SEG_OFF_TO_PTR(getCS(), getIP());
  51     setIP(getIP() + 1);
  52
  53     if (FuncNum == BOP_CONTROL_INT32)
  54         Int32Dispatch(Stack);
  55     else
  56         DPRINT("Unassigned Control BOP Function: 0x%02X\n", FuncNum);
  57 }
  58
  59 VOID InitializeInt32(WORD BiosSegment)
  60 {
  61     LPDWORD IntVecTable = (LPDWORD)BaseAddress;
  62     LPBYTE  BiosCode    = (LPBYTE)SEG_OFF_TO_PTR(BiosSegment, 0);
  63     USHORT i;
  64     WORD BopSeqOffset, Offset = 0;
  65
  66     /* Generate ISR stubs and fill the IVT */
  67     for (i = 0x00; i <= 0xFF; i++)
  68     {
  69         Offset = INT_HANDLER_OFFSET + (i << 4);
  70         IntVecTable[i] = MAKELONG(Offset, BiosSegment);
  71
  72         BiosCode[Offset++] = 0xFA; // cli
  73
  74         BiosCode[Offset++] = 0x6A; // push i
  75         BiosCode[Offset++] = (UCHAR)i;
  76
  77         BiosCode[Offset++] = 0x6A; // push 0
  78         BiosCode[Offset++] = 0x00;
  79
  80         BopSeqOffset = COMMON_STUB_OFFSET - (Offset + 3);
  81
  82         BiosCode[Offset++] = 0xE9; // jmp near BOP_SEQ
  83         BiosCode[Offset++] = LOBYTE(BopSeqOffset);
  84         BiosCode[Offset++] = HIBYTE(BopSeqOffset);
  85     }
  86
  87     /* Write the common stub code */
  88     Offset = COMMON_STUB_OFFSET;
  89
  90 // BOP_SEQ:
  91     BiosCode[Offset++] = 0xF8; // clc
  92
  93     BiosCode[Offset++] = LOBYTE(EMULATOR_BOP);  // BOP sequence
  94     BiosCode[Offset++] = HIBYTE(EMULATOR_BOP);
  95     BiosCode[Offset++] = BOP_CONTROL;           // Control BOP
  96     BiosCode[Offset++] = BOP_CONTROL_INT32;     // 32-bit Interrupt dispatcher
  97
  98     BiosCode[Offset++] = 0x73; // jnc EXIT (offset +4)
  99     BiosCode[Offset++] = 0x04;
 100
 101     BiosCode[Offset++] = 0xFB; // sti
 102
 103     // HACK: The following instruction should be HLT!
 104     BiosCode[Offset++] = 0x90; // nop
 105
 106     BiosCode[Offset++] = 0xEB; // jmp BOP_SEQ (offset -11)
 107     BiosCode[Offset++] = 0xF5;
 108
 109 // EXIT:
 110     BiosCode[Offset++] = 0x83; // add sp, 4
 111     BiosCode[Offset++] = 0xC4;
 112     BiosCode[Offset++] = 0x04;
 113
 114     BiosCode[Offset++] = 0xCF; // iret
 115
 116     /* Register the Control BOP */
 117     RegisterBop(BOP_CONTROL, ControlBop);
 118 }
 119
 120 VOID RegisterInt32(BYTE IntNumber, EMULATOR_INT32_PROC IntHandler)
 121 {
 122     Int32Proc[IntNumber] = IntHandler;
 123 }
 124
 125 /* EOF */