reactos/subsystems/mvdm/ntvdm/int32.c

   1 /*
   2  * COPYRIGHT:       GPL - See COPYING in the top level directory
   3  * PROJECT:         ReactOS Virtual DOS Machine
   4  * FILE:            subsystems/mvdm/ntvdm/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 "ntvdm.h"
  15 #include "emulator.h"
  16 #include "int32.h"
  17
  18 #include "cpu/bop.h"
  19 #include <isvbop.h>
  20
  21 /* PRIVATE VARIABLES **********************************************************/
  22
  23 /*
  24  * This is the list of registered 32-bit Interrupt handlers.
  25  */
  26 static EMULATOR_INT32_PROC Int32Proc[EMULATOR_MAX_INT32_NUM] = { NULL };
  27
  28 /* BOP Identifiers */
  29 #define BOP_CONTROL             0xFF    // Control BOP Handler
  30     #define BOP_CONTROL_DEFFUNC 0x00    // Default Control BOP Function
  31     #define BOP_CONTROL_INT32   0xFF    // 32-bit Interrupt dispatcher
  32
  33 #define INT16_TRAMPOLINE_SIZE   sizeof(ULONGLONG) // == TRAMPOLINE_SIZE
  34
  35 /* 16-bit generic interrupt code for calling a 32-bit interrupt handler */
  36 static BYTE Int16To32[] =
  37 {
  38     0xFA,               // cli
  39
  40     /* Push the value of the interrupt to be called */
  41     0x6A, 0xFF,         // push i (patchable to 0x6A, 0xIntNum)
  42
  43     0xF8,               // clc
  44
  45     /* The BOP Sequence */
  46 // BOP_SEQ:
  47     BOP(BOP_CONTROL),   // Control BOP
  48     BOP_CONTROL_INT32,  // 32-bit Interrupt dispatcher
  49
  50     0x73, 0x04,         // jnc EXIT (offset +4)
  51
  52     0xFB,               // sti
  53
  54     0xF4,               // hlt
  55
  56     0xEB, 0xF6,         // jmp BOP_SEQ (offset -10)
  57
  58 // EXIT:
  59     0x44, 0x44,         // inc sp, inc sp
  60     0xCF,               // iret
  61 };
  62 C_ASSERT(sizeof(Int16To32) == Int16To32StubSize);
  63
  64 /* PUBLIC FUNCTIONS ***********************************************************/
  65
  66 static VOID WINAPI Int32Dispatch(LPWORD Stack)
  67 {
  68     /* Get the interrupt number */
  69     BYTE IntNum = LOBYTE(Stack[STACK_INT_NUM]);
  70
  71     /* Call the 32-bit Interrupt handler */
  72     if (Int32Proc[IntNum] != NULL)
  73         Int32Proc[IntNum](Stack);
  74     else
  75         DPRINT1("Unhandled 32-bit interrupt: 0x%02X, AX = 0x%04X\n", IntNum, getAX());
  76 }
  77
  78 static VOID WINAPI ControlBop(LPWORD Stack)
  79 {
  80     /* Get the Function Number and skip it */
  81     BYTE FuncNum = *(PBYTE)SEG_OFF_TO_PTR(getCS(), getIP());
  82     setIP(getIP() + 1);
  83
  84     switch (FuncNum)
  85     {
  86         case BOP_CONTROL_INT32:
  87             Int32Dispatch(Stack);
  88             break;
  89
  90         default:
  91             // DPRINT1("Unassigned Control BOP Function: 0x%02X\n", FuncNum);
  92             DisplayMessage(L"Unassigned Control BOP Function: 0x%02X", FuncNum);
  93             break;
  94     }
  95 }
  96
  97 ULONG
  98 RegisterInt16(IN  ULONG   FarPtr,
  99               IN  BYTE    IntNumber,
 100               IN  LPBYTE  CallbackCode,
 101               IN  SIZE_T  CallbackSize,
 102               OUT PSIZE_T CodeSize OPTIONAL)
 103 {
 104     /* Get a pointer to the IVT and set the corresponding entry (far pointer) */
 105     LPDWORD IntVecTable = (LPDWORD)SEG_OFF_TO_PTR(0x0000, 0x0000);
 106     IntVecTable[IntNumber] = FarPtr;
 107
 108     /* Register the 16-bit callback */
 109     return RegisterCallback16(FarPtr,
 110                               CallbackCode,
 111                               CallbackSize,
 112                               CodeSize);
 113 }
 114
 115 ULONG
 116 RegisterInt32(IN  ULONG   FarPtr,
 117               IN  BYTE    IntNumber,
 118               IN  EMULATOR_INT32_PROC IntHandler,
 119               OUT PSIZE_T CodeSize OPTIONAL)
 120 {
 121     /* Array for holding our copy of the 16-bit interrupt callback */
 122     BYTE IntCallback[sizeof(Int16To32)/sizeof(BYTE)];
 123
 124     /* Check whether the 32-bit interrupt was already registered */
 125 #if 0
 126     if (Int32Proc[IntNumber] != NULL)
 127     {
 128         DPRINT1("RegisterInt32: Interrupt 0x%02X already registered!\n", IntNumber);
 129         return 0;
 130     }
 131 #endif
 132
 133     /* Register the 32-bit interrupt handler */
 134     Int32Proc[IntNumber] = IntHandler;
 135
 136     /* Copy the generic 16-bit interrupt callback and patch it */
 137     RtlCopyMemory(IntCallback, Int16To32, sizeof(Int16To32));
 138     IntCallback[2] = IntNumber;
 139
 140     /* Register the 16-bit interrupt callback */
 141     return RegisterInt16(FarPtr,
 142                          IntNumber,
 143                          IntCallback,
 144                          sizeof(IntCallback),
 145                          CodeSize);
 146 }
 147
 148 VOID
 149 Int32Call(IN PCALLBACK16 Context,
 150           IN BYTE IntNumber)
 151 {
 152     /*
 153      * TODO: This function has almost the same code as RunCallback16.
 154      * Something that may be nice is to have a common interface to
 155      * build the trampoline...
 156      */
 157
 158     PUCHAR TrampolineBase = (PUCHAR)FAR_POINTER(Context->TrampolineFarPtr);
 159     PUCHAR Trampoline     = TrampolineBase;
 160     UCHAR  OldTrampoline[INT16_TRAMPOLINE_SIZE];
 161
 162     DPRINT("Int32Call(0x%02X)\n", IntNumber);
 163
 164     ASSERT(Context->TrampolineSize == INT16_TRAMPOLINE_SIZE);
 165
 166     /* Save the old trampoline */
 167     ((PULONGLONG)&OldTrampoline)[0] = ((PULONGLONG)TrampolineBase)[0];
 168
 169     /* Build the generic entry-point for 16-bit calls */
 170     if (IntNumber == 0x03)
 171     {
 172         /* We are redefining for INT 03h */
 173         *Trampoline++ = 0xCC; // Call INT 03h
 174         /** *Trampoline++ = 0x90; // nop **/
 175     }
 176     else
 177     {
 178         /* Normal interrupt */
 179         *Trampoline++ = 0xCD; // Call INT XXh
 180         *Trampoline++ = IntNumber;
 181     }
 182     UnSimulate16(Trampoline);
 183
 184     /* Perform the call */
 185     Call16(HIWORD(Context->TrampolineFarPtr),
 186            LOWORD(Context->TrampolineFarPtr));
 187
 188     /* Restore the old trampoline */
 189     ((PULONGLONG)TrampolineBase)[0] = ((PULONGLONG)&OldTrampoline)[0];
 190 }
 191
 192 VOID InitializeInt32(VOID)
 193 {
 194     /* Register the Control BOP */
 195     RegisterBop(BOP_CONTROL, ControlBop);
 196 }
 197
 198 /* EOF */