lib/soft386/soft386.c

   1 /*
   2  * Soft386 386/486 CPU Emulation Library
   3  * soft386.c
   4  *
   5  * Copyright (C) 2013 Aleksandar Andrejevic <theflash AT sdf DOT lonestar DOT org>
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License
   9  * as published by the Free Software Foundation; either version 2
  10  * of the License, or (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  20  */
  21
  22 /* INCLUDES *******************************************************************/
  23
  24 // #define WIN32_NO_STATUS
  25 // #define _INC_WINDOWS
  26 #include <windef.h>
  27
  28 // #define NDEBUG
  29 #include <debug.h>
  30
  31 #include <soft386.h>
  32 #include "common.h"
  33 #include "opcodes.h"
  34
  35 /* DEFINES ********************************************************************/
  36
  37 typedef enum
  38 {
  39     SOFT386_STEP_INTO,
  40     SOFT386_STEP_OVER,
  41     SOFT386_STEP_OUT,
  42     SOFT386_CONTINUE
  43 } SOFT386_EXEC_CMD;
  44
  45 /* PRIVATE FUNCTIONS **********************************************************/
  46
  47 static
  48 inline
  49 VOID
  50 NTAPI
  51 Soft386ExecutionControl(PSOFT386_STATE State, INT Command)
  52 {
  53     UCHAR Opcode;
  54     INT ProcedureCallCount = 0;
  55
  56     /* Main execution loop */
  57     do
  58     {
  59         /* If this is a new instruction, save the IP */
  60         if (State->PrefixFlags == 0) State->SavedInstPtr = State->InstPtr;
  61
  62         /* Perform an instruction fetch */
  63         if (!Soft386FetchByte(State, &Opcode)) continue;
  64
  65         // TODO: Check for CALL/RET to update ProcedureCallCount.
  66
  67         if (Soft386OpcodeHandlers[Opcode] != NULL)
  68         {
  69             /* Call the opcode handler */
  70             Soft386OpcodeHandlers[Opcode](State, Opcode);
  71         }
  72         else
  73         {
  74             /* This is not a valid opcode */
  75             Soft386Exception(State, SOFT386_EXCEPTION_UD);
  76         }
  77
  78         if (Soft386OpcodeHandlers[Opcode] != Soft386OpcodePrefix)
  79         {
  80             /* A non-prefix opcode has been executed, reset the prefix flags */
  81             State->PrefixFlags = 0;
  82         }
  83         else
  84         {
  85             /* This is a prefix, go to the next instruction immediately */
  86             continue;
  87         }
  88
  89         /* Increment the time stamp counter */
  90         State->TimeStampCounter++;
  91     }
  92     while ((Command == SOFT386_CONTINUE)
  93            || (Command == SOFT386_STEP_OVER && ProcedureCallCount > 0)
  94            || (Command == SOFT386_STEP_OUT && ProcedureCallCount >= 0)
  95            || (Soft386OpcodeHandlers[Opcode] == Soft386OpcodePrefix));
  96 }
  97
  98 /* PUBLIC FUNCTIONS ***********************************************************/
  99
 100 VOID
 101 NTAPI
 102 Soft386Continue(PSOFT386_STATE State)
 103 {
 104     /* Call the internal function */
 105     Soft386ExecutionControl(State, SOFT386_CONTINUE);
 106 }
 107
 108 VOID
 109 NTAPI
 110 Soft386StepInto(PSOFT386_STATE State)
 111 {
 112     /* Call the internal function */
 113     Soft386ExecutionControl(State, SOFT386_STEP_INTO);
 114 }
 115
 116 VOID
 117 NTAPI
 118 Soft386StepOver(PSOFT386_STATE State)
 119 {
 120     /* Call the internal function */
 121     Soft386ExecutionControl(State, SOFT386_STEP_OVER);
 122 }
 123
 124 VOID
 125 NTAPI
 126 Soft386StepOut(PSOFT386_STATE State)
 127 {
 128     /* Call the internal function */
 129     Soft386ExecutionControl(State, SOFT386_STEP_OUT);
 130 }
 131
 132 VOID
 133 NTAPI
 134 Soft386DumpState(PSOFT386_STATE State)
 135 {
 136     DPRINT1("\nCPU currently executing in %s mode at %04X:%08X\n"
 137             "Time Stamp Counter = %016X\n",
 138             (State->ControlRegisters[0] & SOFT386_CR0_PE) ? "protected" : "real",
 139             State->SegmentRegs[SOFT386_REG_CS].Selector,
 140             State->InstPtr.Long,
 141             State->TimeStampCounter);
 142     DPRINT1("\nGeneral purpose registers:\n"
 143             "EAX = %08X\tECX = %08X\tEDX = %08X\tEBX = %08X\n"
 144             "ESP = %08X\tEBP = %08X\tESI = %08X\tEDI = %08X\n",
 145             State->GeneralRegs[SOFT386_REG_EAX].Long,
 146             State->GeneralRegs[SOFT386_REG_ECX].Long,
 147             State->GeneralRegs[SOFT386_REG_EDX].Long,
 148             State->GeneralRegs[SOFT386_REG_EBX].Long,
 149             State->GeneralRegs[SOFT386_REG_ESP].Long,
 150             State->GeneralRegs[SOFT386_REG_EBP].Long,
 151             State->GeneralRegs[SOFT386_REG_ESI].Long,
 152             State->GeneralRegs[SOFT386_REG_EDI].Long);
 153     DPRINT1("\nSegment registers:\n"
 154             "ES = %04X (Base: %08X, Limit: %08X, Dpl: %u)\n"
 155             "CS = %04X (Base: %08X, Limit: %08X, Dpl: %u)\n"
 156             "SS = %04X (Base: %08X, Limit: %08X, Dpl: %u)\n"
 157             "DS = %04X (Base: %08X, Limit: %08X, Dpl: %u)\n"
 158             "FS = %04X (Base: %08X, Limit: %08X, Dpl: %u)\n"
 159             "GS = %04X (Base: %08X, Limit: %08X, Dpl: %u)\n",
 160             State->SegmentRegs[SOFT386_REG_ES].Selector,
 161             State->SegmentRegs[SOFT386_REG_ES].Base,
 162             State->SegmentRegs[SOFT386_REG_ES].Limit,
 163             State->SegmentRegs[SOFT386_REG_ES].Dpl,
 164             State->SegmentRegs[SOFT386_REG_CS].Selector,
 165             State->SegmentRegs[SOFT386_REG_CS].Base,
 166             State->SegmentRegs[SOFT386_REG_CS].Limit,
 167             State->SegmentRegs[SOFT386_REG_CS].Dpl,
 168             State->SegmentRegs[SOFT386_REG_SS].Selector,
 169             State->SegmentRegs[SOFT386_REG_SS].Base,
 170             State->SegmentRegs[SOFT386_REG_SS].Limit,
 171             State->SegmentRegs[SOFT386_REG_SS].Dpl,
 172             State->SegmentRegs[SOFT386_REG_DS].Selector,
 173             State->SegmentRegs[SOFT386_REG_DS].Base,
 174             State->SegmentRegs[SOFT386_REG_DS].Limit,
 175             State->SegmentRegs[SOFT386_REG_DS].Dpl,
 176             State->SegmentRegs[SOFT386_REG_FS].Selector,
 177             State->SegmentRegs[SOFT386_REG_FS].Base,
 178             State->SegmentRegs[SOFT386_REG_FS].Limit,
 179             State->SegmentRegs[SOFT386_REG_FS].Dpl,
 180             State->SegmentRegs[SOFT386_REG_GS].Selector,
 181             State->SegmentRegs[SOFT386_REG_GS].Base,
 182             State->SegmentRegs[SOFT386_REG_GS].Limit,
 183             State->SegmentRegs[SOFT386_REG_GS].Dpl);
 184     DPRINT1("\nFlags: %08X (%s %s %s %s %s %s %s %s %s %s %s %s %s %s %s) Iopl: %u\n",
 185             State->Flags.Long,
 186             State->Flags.Cf ? "CF" : "cf",
 187             State->Flags.Pf ? "PF" : "pf",
 188             State->Flags.Af ? "AF" : "af",
 189             State->Flags.Zf ? "ZF" : "zf",
 190             State->Flags.Sf ? "SF" : "sf",
 191             State->Flags.Tf ? "TF" : "tf",
 192             State->Flags.If ? "IF" : "if",
 193             State->Flags.Df ? "DF" : "df",
 194             State->Flags.Of ? "OF" : "of",
 195             State->Flags.Nt ? "NT" : "nt",
 196             State->Flags.Rf ? "RF" : "rf",
 197             State->Flags.Vm ? "VM" : "vm",
 198             State->Flags.Ac ? "AC" : "ac",
 199             State->Flags.Vif ? "VIF" : "vif",
 200             State->Flags.Vip ? "VIP" : "vip",
 201             State->Flags.Iopl);
 202     DPRINT1("\nControl Registers:\n"
 203             "CR0 = %08X\tCR1 = %08X\tCR2 = %08X\tCR3 = %08X\n"
 204             "CR4 = %08X\tCR5 = %08X\tCR6 = %08X\tCR7 = %08X\n",
 205             State->ControlRegisters[SOFT386_REG_CR0],
 206             State->ControlRegisters[SOFT386_REG_CR1],
 207             State->ControlRegisters[SOFT386_REG_CR2],
 208             State->ControlRegisters[SOFT386_REG_CR3],
 209             State->ControlRegisters[SOFT386_REG_CR4],
 210             State->ControlRegisters[SOFT386_REG_CR5],
 211             State->ControlRegisters[SOFT386_REG_CR6],
 212             State->ControlRegisters[SOFT386_REG_CR7]);
 213     DPRINT1("\nDebug Registers:\n"
 214             "DR0 = %08X\tDR1 = %08X\tDR2 = %08X\tDR3 = %08X\n"
 215             "DR4 = %08X\tDR5 = %08X\tDR6 = %08X\tDR7 = %08X\n",
 216             State->DebugRegisters[SOFT386_REG_DR0],
 217             State->DebugRegisters[SOFT386_REG_DR1],
 218             State->DebugRegisters[SOFT386_REG_DR2],
 219             State->DebugRegisters[SOFT386_REG_DR3],
 220             State->DebugRegisters[SOFT386_REG_DR4],
 221             State->DebugRegisters[SOFT386_REG_DR5],
 222             State->DebugRegisters[SOFT386_REG_DR6],
 223             State->DebugRegisters[SOFT386_REG_DR7]);
 224 }
 225
 226 VOID
 227 NTAPI
 228 Soft386Reset(PSOFT386_STATE State)
 229 {
 230     INT i;
 231     SOFT386_MEM_READ_PROC MemReadCallback = State->MemReadCallback;
 232     SOFT386_MEM_WRITE_PROC MemWriteCallback = State->MemWriteCallback;
 233     SOFT386_IO_READ_PROC IoReadCallback = State->IoReadCallback;
 234     SOFT386_IO_WRITE_PROC IoWriteCallback = State->IoWriteCallback;
 235     SOFT386_IDLE_PROC IdleCallback = State->IdleCallback;
 236     SOFT386_BOP_PROC BopCallback = State->BopCallback;
 237
 238     /* Clear the entire structure */
 239     RtlZeroMemory(State, sizeof(*State));
 240
 241     /* Initialize the registers */
 242     State->Flags.AlwaysSet = 1;
 243     State->InstPtr.LowWord = 0xFFF0;
 244
 245     /* Initialize segments */
 246     for (i = 0; i < SOFT386_NUM_SEG_REGS; i++)
 247     {
 248         /* Set the selector, base and limit, other values don't apply in real mode */
 249         State->SegmentRegs[i].Selector = 0;
 250         State->SegmentRegs[i].Base = 0;
 251         State->SegmentRegs[i].Limit = 0xFFFF;
 252     }
 253
 254     /* Initialize the code segment */
 255     State->SegmentRegs[SOFT386_REG_CS].Selector = 0xF000;
 256     State->SegmentRegs[SOFT386_REG_CS].Base = 0xFFFF0000;
 257
 258     /* Initialize the IDT */
 259     State->Idtr.Size = 0x3FF;
 260     State->Idtr.Address = 0;
 261
 262     /* Initialize CR0 */
 263     State->ControlRegisters[SOFT386_REG_CR0] |= SOFT386_CR0_ET;
 264
 265     /* Restore the callbacks */
 266     State->MemReadCallback = MemReadCallback;
 267     State->MemWriteCallback = MemWriteCallback;
 268     State->IoReadCallback = IoReadCallback;
 269     State->IoWriteCallback = IoWriteCallback;
 270     State->IdleCallback = IdleCallback;
 271     State->BopCallback = BopCallback;
 272 }
 273
 274 VOID
 275 NTAPI
 276 Soft386Interrupt(PSOFT386_STATE State, UCHAR Number, BOOLEAN Hardware)
 277 {
 278     SOFT386_IDT_ENTRY IdtEntry;
 279
 280     if (Hardware)
 281     {
 282         /* Set the hardware interrupt flag */
 283         State->HardwareInt = TRUE;
 284     }
 285
 286     if (!Soft386GetIntVector(State, Number, &IdtEntry))
 287     {
 288         /* An exception occurred, let the handler execute */
 289         return;
 290     }
 291
 292     /* Perform the interrupt */
 293     Soft386InterruptInternal(State,
 294                              IdtEntry.Selector,
 295                              MAKELONG(IdtEntry.Offset, IdtEntry.OffsetHigh),
 296                              IdtEntry.Type);
 297 }
 298
 299 VOID
 300 NTAPI
 301 Soft386ExecuteAt(PSOFT386_STATE State, USHORT Segment, ULONG Offset)
 302 {
 303     /* Load the new CS */
 304     if (!Soft386LoadSegment(State, SOFT386_REG_CS, Segment))
 305     {
 306         /* An exception occurred, let the handler execute instead */
 307         return;
 308     }
 309
 310     /* Set the new IP */
 311     State->InstPtr.Long = Offset;
 312 }
 313
 314 VOID
 315 NTAPI
 316 Soft386SetStack(PSOFT386_STATE State, USHORT Segment, ULONG Offset)
 317 {
 318     /* Load the new SS */
 319     if (!Soft386LoadSegment(State, SOFT386_REG_SS, Segment))
 320     {
 321         /* An exception occurred, let the handler execute instead */
 322         return;
 323     }
 324
 325     /* Set the new SP */
 326     State->GeneralRegs[SOFT386_REG_ESP].Long = Offset;
 327 }
 328
 329 VOID
 330 NTAPI
 331 Soft386SetSegment(PSOFT386_STATE State,
 332                   SOFT386_SEG_REGS Segment,
 333                   USHORT Selector)
 334 {
 335     /* Call the internal function */
 336     Soft386LoadSegment(State, Segment, Selector);
 337 }
 338
 339 /* EOF */