subsystems/ntvdm/emulator.h

   1 /*
   2  * COPYRIGHT:       GPL - See COPYING in the top level directory
   3  * PROJECT:         ReactOS Virtual DOS Machine
   4  * FILE:            emulator.h
   5  * PURPOSE:         Minimal x86 machine emulator for the VDM (header file)
   6  * PROGRAMMERS:     Aleksandar Andrejevic <theflash AT sdf DOT lonestar DOT org>
   7  */
   8
   9 #ifndef _EMULATOR_H_
  10 #define _EMULATOR_H_
  11
  12 /* INCLUDES *******************************************************************/
  13
  14 #include "ntvdm.h"
  15
  16 #ifndef NEW_EMULATOR
  17 #include <softx86/softx86.h>
  18 #include <softx86/softx87.h>
  19 #endif
  20
  21 /* DEFINES ********************************************************************/
  22
  23 /* FLAGS */
  24 #define EMULATOR_FLAG_CF (1 << 0)
  25 #define EMULATOR_FLAG_PF (1 << 2)
  26 #define EMULATOR_FLAG_AF (1 << 4)
  27 #define EMULATOR_FLAG_ZF (1 << 6)
  28 #define EMULATOR_FLAG_SF (1 << 7)
  29 #define EMULATOR_FLAG_TF (1 << 8)
  30 #define EMULATOR_FLAG_IF (1 << 9)
  31 #define EMULATOR_FLAG_DF (1 << 10)
  32 #define EMULATOR_FLAG_OF (1 << 11)
  33 #define EMULATOR_FLAG_NT (1 << 14)
  34 #define EMULATOR_FLAG_RF (1 << 16)
  35 #define EMULATOR_FLAG_VM (1 << 17)
  36 #define EMULATOR_FLAG_AC (1 << 18)
  37 #define EMULATOR_FLAG_VIF (1 << 19)
  38 #define EMULATOR_FLAG_VIP (1 << 20)
  39 #define EMULATOR_FLAG_ID (1 << 21)
  40
  41 /* CR0 */
  42 #define EMULATOR_CR0_PE (1 << 0)
  43 #define EMULATOR_CR0_MP (1 << 1)
  44 #define EMULATOR_CR0_EM (1 << 2)
  45 #define EMULATOR_CR0_TS (1 << 3)
  46 #define EMULATOR_CR0_ET (1 << 4)
  47 #define EMULATOR_CR0_NE (1 << 5)
  48 #define EMULATOR_CR0_WP (1 << 16)
  49 #define EMULATOR_CR0_AM (1 << 18)
  50 #define EMULATOR_CR0_NW (1 << 29)
  51 #define EMULATOR_CR0_CD (1 << 30)
  52 #define EMULATOR_CR0_PG (1 << 31)
  53
  54 /* GDT Access byte */
  55 #define GDT_SEG_ACCESSED (1 << 0)
  56 #define GDT_DATA_WRITEABLE (1 << 1)
  57 #define GDT_CODE_READABLE (1 << 1)
  58 #define GDT_CONFORMING (1 << 2)
  59 #define GDT_DIRECTION (1 << 2)
  60 #define GDT_CODE_SEGMENT (1 << 3)
  61 #define GDT_PRESENT (1 << 7)
  62
  63 /* GDT flags */
  64 #define GDT_32BIT_SEGMENT (1 << 2)
  65 #define GDT_PAGE_GRANULARITY (1 << 3)
  66
  67 /* Common definitions */
  68 #define EMULATOR_NUM_GENERAL_REGS 8
  69 #define EMULATOR_NUM_SEGMENT_REGS 6
  70 #define EMULATOR_NUM_CONTROL_REGS 8
  71 #define EMULATOR_NUM_DEBUG_REGS 8
  72 #define MAX_GDT_ENTRIES 8192
  73 #define EMULATOR_BOP 0xC4C4
  74 #define EMULATOR_INT_BOP 0xBEEF
  75 #define STACK_INT_NUM 0
  76 #define STACK_IP 1
  77 #define STACK_CS 2
  78 #define STACK_FLAGS 3
  79
  80 enum
  81 {
  82     EMULATOR_EXCEPTION_DIVISION_BY_ZERO,
  83     EMULATOR_EXCEPTION_DEBUG,
  84     EMULATOR_EXCEPTION_NMI,
  85     EMULATOR_EXCEPTION_BREAKPOINT,
  86     EMULATOR_EXCEPTION_OVERFLOW,
  87     EMULATOR_EXCEPTION_BOUND,
  88     EMULATOR_EXCEPTION_INVALID_OPCODE,
  89     EMULATOR_EXCEPTION_NO_FPU,
  90     EMULATOR_EXCEPTION_DOUBLE_FAULT,
  91     EMULATOR_EXCEPTION_FPU_SEGMENT,
  92     EMULATOR_EXCEPTION_INVALID_TSS,
  93     EMULATOR_EXCEPTION_NO_SEGMENT,
  94     EMULATOR_EXCEPTION_STACK_SEGMENT,
  95     EMULATOR_EXCEPTION_GPF,
  96     EMULATOR_EXCEPTION_PAGE_FAULT
  97 };
  98
  99 enum
 100 {
 101     EMULATOR_REG_AX,
 102     EMULATOR_REG_CX,
 103     EMULATOR_REG_DX,
 104     EMULATOR_REG_BX,
 105     EMULATOR_REG_SP,
 106     EMULATOR_REG_BP,
 107     EMULATOR_REG_SI,
 108     EMULATOR_REG_DI,
 109     EMULATOR_REG_ES,
 110     EMULATOR_REG_CS,
 111     EMULATOR_REG_SS,
 112     EMULATOR_REG_DS,
 113     EMULATOR_REG_FS,
 114     EMULATOR_REG_GS
 115 };
 116
 117 typedef union
 118 {
 119     struct
 120     {
 121         BYTE LowByte;
 122         BYTE HighByte;
 123     };
 124     WORD LowWord;
 125     DWORD Long;
 126 } EMULATOR_REGISTER, *PEMULATOR_REGISTER;
 127
 128 typedef struct
 129 {
 130     ULONG Limit : 16;
 131     ULONG Base : 24;
 132     ULONG AccessByte : 8;
 133     ULONG LimitHigh : 4;
 134     ULONG Flags : 4;
 135     ULONG BaseHigh : 8;
 136 } EMULATOR_GDT_ENTRY;
 137
 138 typedef struct
 139 {
 140     ULONG Offset : 16;
 141     ULONG Selector : 16;
 142     ULONG Zero : 8;
 143     ULONG TypeAndAttributes : 8;
 144     ULONG OffsetHigh : 16;
 145 } EMULATOR_IDT_ENTRY;
 146
 147 typedef struct
 148 {
 149     WORD Size;
 150     DWORD Address;
 151 } EMULATOR_TABLE_REGISTER;
 152
 153 typedef struct
 154 {
 155     EMULATOR_REGISTER Registers[EMULATOR_NUM_GENERAL_REGS
 156                                 + EMULATOR_NUM_SEGMENT_REGS];
 157     EMULATOR_REGISTER Flags;
 158     EMULATOR_REGISTER InstructionPointer;
 159     EMULATOR_REGISTER ControlRegisters[EMULATOR_NUM_CONTROL_REGS];
 160     EMULATOR_REGISTER DebugRegisters[EMULATOR_NUM_DEBUG_REGS];
 161     ULONGLONG TimeStampCounter;
 162     BOOLEAN OperandSizeOverload;
 163     BOOLEAN AddressSizeOverload;
 164     EMULATOR_TABLE_REGISTER Gdtr, Idtr;
 165     EMULATOR_GDT_ENTRY CachedDescriptors[EMULATOR_NUM_SEGMENT_REGS];
 166     UINT ExceptionCount;
 167 } EMULATOR_CONTEXT, *PEMULATOR_CONTEXT;
 168
 169 typedef VOID (*EMULATOR_OPCODE_HANDLER)(PEMULATOR_CONTEXT Context, BYTE Opcode);
 170
 171 /* FUNCTIONS ******************************************************************/
 172
 173 BOOLEAN EmulatorInitialize();
 174 VOID EmulatorSetStack(WORD Segment, WORD Offset);
 175 VOID EmulatorExecute(WORD Segment, WORD Offset);
 176 VOID EmulatorInterrupt(BYTE Number);
 177 VOID EmulatorExternalInterrupt(BYTE Number);
 178 ULONG EmulatorGetRegister(ULONG Register);
 179 VOID EmulatorSetRegister(ULONG Register, ULONG Value);
 180 BOOLEAN EmulatorGetFlag(ULONG Flag);
 181 VOID EmulatorSetFlag(ULONG Flag);
 182 VOID EmulatorClearFlag(ULONG Flag);
 183 VOID EmulatorStep();
 184 VOID EmulatorCleanup();
 185 VOID EmulatorSetA20(BOOLEAN Enabled);
 186
 187 #endif // _EMULATOR_H_
 188
 189 /* EOF */