reactos/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     //
  62     // WARNING WARNING!!
  63     //
  64     // If you modify the code stubs here, think also
  65     // about updating them in callback.c too!!
  66     //
  67
  68     LPDWORD IntVecTable = (LPDWORD)BaseAddress;
  69     LPBYTE  BiosCode    = (LPBYTE)SEG_OFF_TO_PTR(BiosSegment, 0);
  70     USHORT i;
  71     WORD BopSeqOffset, Offset = 0;
  72
  73     /* Generate ISR stubs and fill the IVT */
  74     for (i = 0x00; i <= 0xFF; i++)
  75     {
  76         Offset = INT_HANDLER_OFFSET + (i << 4);
  77         IntVecTable[i] = MAKELONG(Offset, BiosSegment);
  78
  79         BiosCode[Offset++] = 0xFA; // cli
  80
  81         BiosCode[Offset++] = 0x6A; // push i
  82         BiosCode[Offset++] = (UCHAR)i;
  83
  84         BopSeqOffset = COMMON_STUB_OFFSET - (Offset + 3);
  85
  86         BiosCode[Offset++] = 0xE9; // jmp near BOP_SEQ
  87         BiosCode[Offset++] = LOBYTE(BopSeqOffset);
  88         BiosCode[Offset++] = HIBYTE(BopSeqOffset);
  89     }
  90
  91     /* Write the common stub code */
  92     Offset = COMMON_STUB_OFFSET;
  93
  94 // BOP_SEQ:
  95     BiosCode[Offset++] = 0xF8; // clc
  96
  97     BiosCode[Offset++] = LOBYTE(EMULATOR_BOP);  // BOP sequence
  98     BiosCode[Offset++] = HIBYTE(EMULATOR_BOP);
  99     BiosCode[Offset++] = BOP_CONTROL;           // Control BOP
 100     BiosCode[Offset++] = BOP_CONTROL_INT32;     // 32-bit Interrupt dispatcher
 101
 102     BiosCode[Offset++] = 0x73; // jnc EXIT (offset +4)
 103     BiosCode[Offset++] = 0x04;
 104
 105     BiosCode[Offset++] = 0xFB; // sti
 106
 107     // HACK: The following instruction should be HLT!
 108     BiosCode[Offset++] = 0x90; // nop
 109
 110     BiosCode[Offset++] = 0xEB; // jmp BOP_SEQ (offset -11)
 111     BiosCode[Offset++] = 0xF5;
 112
 113 // EXIT:
 114     BiosCode[Offset++] = 0x44; // inc sp
 115     BiosCode[Offset++] = 0x44; // inc sp
 116
 117     BiosCode[Offset++] = 0xCF; // iret
 118
 119     /* Register the Control BOP */
 120     RegisterBop(BOP_CONTROL, ControlBop);
 121 }
 122
 123 VOID RegisterInt32(BYTE IntNumber, EMULATOR_INT32_PROC IntHandler)
 124 {
 125     Int32Proc[IntNumber] = IntHandler;
 126 }
 127
 128 /* EOF */