reactos/subsystems/ntvdm/callback.c

   1 /*
   2  * COPYRIGHT:       GPL - See COPYING in the top level directory
   3  * PROJECT:         ReactOS Virtual DOS Machine
   4  * FILE:            callback.c
   5  * PURPOSE:         16 and 32-bit Callbacks Support
   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 "callback.h"
  16
  17 #include "bop.h"
  18 #include <isvbop.h>
  19
  20 /* PRIVATE VARIABLES **********************************************************/
  21
  22 /*
  23  * This is the list of registered 32-bit Interrupt handlers.
  24  */
  25 EMULATOR_INT32_PROC Int32Proc[EMULATOR_MAX_INT32_NUM] = { NULL };
  26
  27 /* BOP Identifiers */
  28 #define BOP_CONTROL             0xFF    // Control BOP Handler
  29     #define BOP_CONTROL_DEFFUNC 0x00    // Default Control BOP Function
  30     #define BOP_CONTROL_INT32   0xFF    // 32-bit Interrupt dispatcher
  31                                         // function code for the Control BOP Handler
  32
  33 #define BOP(num)            LOBYTE(EMULATOR_BOP), HIBYTE(EMULATOR_BOP), (num)
  34 #define UnSimulate16(trap)           \
  35 do {                                 \
  36     *(PUSHORT)(trap) = EMULATOR_BOP; \
  37     (trap) += sizeof(USHORT);        \
  38     *(trap) = BOP_UNSIMULATE;        \
  39 } while(0)
  40 // #define UnSimulate16        MAKELONG(EMULATOR_BOP, BOP_UNSIMULATE) // BOP(BOP_UNSIMULATE)
  41
  42 #define CALL16_TRAMPOLINE_SIZE  (1 * sizeof(ULONGLONG))
  43 #define  INT16_TRAMPOLINE_SIZE  (1 * sizeof(ULONGLONG))
  44
  45 //
  46 // WARNING WARNING!!
  47 //
  48 // If you modify the code stubs here, think also
  49 // about updating them in int32.c too!!
  50 //
  51
  52 /* 16-bit generic interrupt code for calling a 32-bit interrupt handler */
  53 BYTE Int16To32[] =
  54 {
  55     0xFA,               // cli
  56
  57     /* Push the value of the interrupt to be called */
  58     0x6A, 0xFF,         // push i (patchable to 0x6A, 0xIntNum)
  59
  60     /* The BOP Sequence */
  61 // BOP_SEQ:
  62     0xF8,               // clc
  63     BOP(BOP_CONTROL),   // Control BOP
  64     BOP_CONTROL_INT32,  // 32-bit Interrupt dispatcher
  65
  66     0x73, 0x04,         // jnc EXIT (offset +4)
  67
  68     0xFB,               // sti
  69
  70     // HACK: The following instruction should be HLT!
  71     0x90,               // nop
  72
  73     0xEB, 0xF5,         // jmp BOP_SEQ (offset -11)
  74
  75 // EXIT:
  76     0x44, 0x44,         // inc sp, inc sp
  77     0xCF,               // iret
  78 };
  79
  80 /* PUBLIC FUNCTIONS ***********************************************************/
  81
  82 VOID
  83 InitializeContext(IN PCALLBACK16 Context,
  84                   IN USHORT      Segment,
  85                   IN USHORT      Offset)
  86 {
  87     Context->TrampolineFarPtr = MAKELONG(Offset, Segment);
  88     Context->Segment          = Segment;
  89     Context->NextOffset       = Offset + max(CALL16_TRAMPOLINE_SIZE,
  90                                               INT16_TRAMPOLINE_SIZE);
  91 }
  92
  93 VOID
  94 Call16(IN USHORT Segment,
  95        IN USHORT Offset)
  96 {
  97     /* Save CS:IP */
  98     USHORT OrgCS = getCS();
  99     USHORT OrgIP = getIP();
 100
 101     /* Set the new CS:IP */
 102     setCS(Segment);
 103     setIP(Offset);
 104
 105     DPRINT("Call16(%04X:%04X)\n", Segment, Offset);
 106
 107     /* Start CPU simulation */
 108     EmulatorSimulate();
 109
 110     /* Restore CS:IP */
 111     setCS(OrgCS);
 112     setIP(OrgIP);
 113 }
 114
 115
 116
 117 ULONG
 118 RegisterCallback16(IN  ULONG   FarPtr,
 119                    IN  LPBYTE  CallbackCode,
 120                    IN  SIZE_T  CallbackSize,
 121                    OUT PSIZE_T CodeSize OPTIONAL)
 122 {
 123     LPBYTE CodeStart = (LPBYTE)FAR_POINTER(FarPtr);
 124     LPBYTE Code      = CodeStart;
 125
 126     SIZE_T OurCodeSize = CallbackSize;
 127
 128     if (CallbackCode == NULL) CallbackSize = 0;
 129
 130     if (CallbackCode)
 131     {
 132         /* 16-bit interrupt code */
 133         RtlCopyMemory(Code, CallbackCode, CallbackSize);
 134         Code += CallbackSize;
 135     }
 136
 137     /* Return the real size of the code if needed */
 138     if (CodeSize) *CodeSize = OurCodeSize; // == (ULONG_PTR)Code - (ULONG_PTR)CodeStart;
 139
 140     // /* Return the entry-point address for 32-bit calls */
 141     // return (ULONG_PTR)(CodeStart + CallbackSize);
 142     return OurCodeSize;
 143 }
 144
 145 VOID
 146 RunCallback16(IN PCALLBACK16 Context,
 147               IN ULONG       FarPtr)
 148 {
 149     PUCHAR TrampolineBase = (PUCHAR)FAR_POINTER(Context->TrampolineFarPtr);
 150     PUCHAR Trampoline     = TrampolineBase;
 151     UCHAR  OldTrampoline[CALL16_TRAMPOLINE_SIZE];
 152
 153     /* Save the old trampoline */
 154     ((PULONGLONG)&OldTrampoline)[0] = ((PULONGLONG)TrampolineBase)[0];
 155
 156     DPRINT1("RunCallback16(0x%p)\n", FarPtr);
 157
 158     /* Build the generic entry-point for 16-bit far calls */
 159     *Trampoline++ = 0x9A; // Call far seg:off
 160     *(PULONG)Trampoline = FarPtr;
 161     Trampoline += sizeof(ULONG);
 162     UnSimulate16(Trampoline);
 163
 164     /* Perform the call */
 165     Call16(HIWORD(Context->TrampolineFarPtr),
 166            LOWORD(Context->TrampolineFarPtr));
 167
 168     /* Restore the old trampoline */
 169     ((PULONGLONG)TrampolineBase)[0] = ((PULONGLONG)&OldTrampoline)[0];
 170 }
 171
 172
 173
 174 ULONG
 175 RegisterInt16(IN  ULONG   FarPtr,
 176               IN  BYTE    IntNumber,
 177               IN  LPBYTE  CallbackCode,
 178               IN  SIZE_T  CallbackSize,
 179               OUT PSIZE_T CodeSize OPTIONAL)
 180 {
 181     /* Get a pointer to the IVT and set the corresponding entry (far pointer) */
 182     LPDWORD IntVecTable = (LPDWORD)SEG_OFF_TO_PTR(0x0000, 0x0000);
 183     IntVecTable[IntNumber] = FarPtr;
 184
 185     /* Register the 16-bit callback */
 186     return RegisterCallback16(FarPtr,
 187                               CallbackCode,
 188                               CallbackSize,
 189                               CodeSize);
 190 }
 191
 192 ULONG
 193 RegisterInt32(IN  ULONG   FarPtr,
 194               IN  BYTE    IntNumber,
 195               IN  EMULATOR_INT32_PROC IntHandler,
 196               OUT PSIZE_T CodeSize OPTIONAL)
 197 {
 198     /* Array for holding our copy of the 16-bit interrupt callback */
 199     BYTE IntCallback[sizeof(Int16To32)/sizeof(BYTE)];
 200
 201     /* Check whether the 32-bit interrupt was already registered */
 202 #if 0
 203     if (Int32Proc[IntNumber] != NULL)
 204     {
 205         DPRINT1("RegisterInt32: Interrupt 0x%X already registered!\n", IntNumber);
 206         return 0;
 207     }
 208 #endif
 209
 210     /* Register the 32-bit interrupt handler */
 211     Int32Proc[IntNumber] = IntHandler;
 212
 213     /* Copy the generic 16-bit interrupt callback and patch it */
 214     RtlCopyMemory(IntCallback, Int16To32, sizeof(Int16To32));
 215     IntCallback[2] = IntNumber;
 216
 217     /* Register the 16-bit interrupt callback */
 218     return RegisterInt16(FarPtr,
 219                          IntNumber,
 220                          IntCallback,
 221                          sizeof(IntCallback),
 222                          CodeSize);
 223 }
 224
 225 VOID
 226 Int32Call(IN PCALLBACK16 Context,
 227           IN BYTE IntNumber)
 228 {
 229     PUCHAR TrampolineBase = (PUCHAR)FAR_POINTER(Context->TrampolineFarPtr);
 230     PUCHAR Trampoline     = TrampolineBase;
 231     UCHAR  OldTrampoline[INT16_TRAMPOLINE_SIZE];
 232
 233     DPRINT("Int32Call(0x%X)\n", IntNumber);
 234
 235     /* Save the old trampoline */
 236     ((PULONGLONG)&OldTrampoline)[0] = ((PULONGLONG)TrampolineBase)[0];
 237
 238     /* Build the generic entry-point for 16-bit calls */
 239     if (IntNumber == 0x03)
 240     {
 241         /* We are redefining for INT 03h */
 242         *Trampoline++ = 0xCC; // Call INT 03h
 243         /** *Trampoline++ = 0x90; // nop **/
 244     }
 245     else
 246     {
 247         /* Normal interrupt */
 248         *Trampoline++ = 0xCD; // Call INT XXh
 249         *Trampoline++ = IntNumber;
 250     }
 251     UnSimulate16(Trampoline);
 252
 253     /* Perform the call */
 254     Call16(HIWORD(Context->TrampolineFarPtr),
 255            LOWORD(Context->TrampolineFarPtr));
 256
 257     /* Restore the old trampoline */
 258     ((PULONGLONG)TrampolineBase)[0] = ((PULONGLONG)&OldTrampoline)[0];
 259 }
 260
 261
 262
 263 VOID WINAPI Int32Dispatch(LPWORD Stack)
 264 {
 265     /* Get the interrupt number */
 266     BYTE IntNum = LOBYTE(Stack[STACK_INT_NUM]);
 267
 268     /* Call the 32-bit Interrupt handler */
 269     if (Int32Proc[IntNum] != NULL)
 270         Int32Proc[IntNum](Stack);
 271     else
 272         DPRINT1("Unhandled 32-bit interrupt: 0x%02X, AX = 0x%04X\n", IntNum, getAX());
 273 }
 274
 275 static VOID WINAPI ControlBop(LPWORD Stack)
 276 {
 277     /* Get the Function Number and skip it */
 278     BYTE FuncNum = *(PBYTE)SEG_OFF_TO_PTR(getCS(), getIP());
 279     setIP(getIP() + 1);
 280
 281     switch (FuncNum)
 282     {
 283         case BOP_CONTROL_INT32:
 284             Int32Dispatch(Stack);
 285             break;
 286
 287         default:
 288             // DPRINT1("Unassigned Control BOP Function: 0x%02X\n", FuncNum);
 289             DisplayMessage(L"Unassigned Control BOP Function: 0x%02X", FuncNum);
 290             break;
 291     }
 292 }
 293
 294 VOID InitializeCallbacks(VOID)
 295 {
 296     /* Register the Control BOP */
 297     RegisterBop(BOP_CONTROL, ControlBop);
 298 }
 299
 300 /* EOF */