* Fast486 386/486 CPU Emulation Library
* fast486.c
*
- * Copyright (C) 2013 Aleksandar Andrejevic <theflash AT sdf DOT lonestar DOT org>
+ * Copyright (C) 2014 Aleksandar Andrejevic <theflash AT sdf DOT lonestar DOT org>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
/* INCLUDES *******************************************************************/
-// #define WIN32_NO_STATUS
-// #define _INC_WINDOWS
#include <windef.h>
// #define NDEBUG
#include <fast486.h>
#include "common.h"
#include "opcodes.h"
+#include "fpu.h"
/* DEFINES ********************************************************************/
/* PRIVATE FUNCTIONS **********************************************************/
-static
-inline
VOID
NTAPI
-Fast486ExecutionControl(PFAST486_STATE State, INT Command)
+Fast486ExecutionControl(PFAST486_STATE State, FAST486_EXEC_CMD Command)
{
UCHAR Opcode;
+ FAST486_OPCODE_HANDLER_PROC CurrentHandler;
INT ProcedureCallCount = 0;
/* Main execution loop */
do
{
- /* Check if this is a new instruction */
- if (State->PrefixFlags == 0)
+ if (!State->Halted)
{
- State->SavedInstPtr = State->InstPtr;
+NextInst:
+ /* Check if this is a new instruction */
+ if (State->PrefixFlags == 0) State->SavedInstPtr = State->InstPtr;
- /* Check if interrupts are enabled and there is an interrupt pending */
- if (State->Flags.If && State->HardwareInt)
+ /* Perform an instruction fetch */
+ if (!Fast486FetchByte(State, &Opcode))
{
- FAST486_IDT_ENTRY IdtEntry;
-
- /* Get the interrupt vector */
- if (Fast486GetIntVector(State, State->PendingIntNum, &IdtEntry))
- {
- /* Perform the interrupt */
- Fast486InterruptInternal(State,
- IdtEntry.Selector,
- MAKELONG(IdtEntry.Offset, IdtEntry.OffsetHigh),
- IdtEntry.Type);
- }
-
- /* Clear the interrupt pending flag */
- State->HardwareInt = FALSE;
+ /* Exception occurred */
+ State->PrefixFlags = 0;
+ continue;
}
- }
-
- /* Perform an instruction fetch */
- if (!Fast486FetchByte(State, &Opcode)) continue;
- // TODO: Check for CALL/RET to update ProcedureCallCount.
+ // TODO: Check for CALL/RET to update ProcedureCallCount.
- if (Fast486OpcodeHandlers[Opcode] != NULL)
- {
/* Call the opcode handler */
- Fast486OpcodeHandlers[Opcode](State, Opcode);
+ CurrentHandler = Fast486OpcodeHandlers[Opcode];
+ CurrentHandler(State, Opcode);
+
+ /* If this is a prefix, go to the next instruction immediately */
+ if (CurrentHandler == Fast486OpcodePrefix) goto NextInst;
+
+ /* A non-prefix opcode has been executed, reset the prefix flags */
+ State->PrefixFlags = 0;
}
- else
+
+ /*
+ * Check if there is an interrupt to execute, or a hardware interrupt signal
+ * while interrupts are enabled.
+ */
+ if (State->Flags.Tf && !State->Halted)
{
- /* This is not a valid opcode */
- Fast486Exception(State, FAST486_EXCEPTION_UD);
+ /* Perform the interrupt */
+ Fast486PerformInterrupt(State, 0x01);
+
+ /*
+ * Flags and TF are pushed on stack so we can reset TF now,
+ * to not break into the INT 0x01 handler.
+ * After the INT 0x01 handler returns, the flags and therefore
+ * TF are popped back off the stack and restored, so TF will be
+ * automatically reset to its previous state.
+ */
+ State->Flags.Tf = FALSE;
}
+ else if (State->IntStatus == FAST486_INT_EXECUTE)
+ {
+ /* No longer halted */
+ State->Halted = FALSE;
- if (Fast486OpcodeHandlers[Opcode] != Fast486OpcodePrefix)
+ /* Perform the interrupt */
+ Fast486PerformInterrupt(State, State->PendingIntNum);
+
+ /* Clear the interrupt status */
+ State->IntStatus = FAST486_INT_NONE;
+ }
+ else if (State->Flags.If && (State->IntStatus == FAST486_INT_SIGNAL))
{
- /* A non-prefix opcode has been executed, reset the prefix flags */
- State->PrefixFlags = 0;
+ /* Acknowledge the interrupt to get the number */
+ State->PendingIntNum = State->IntAckCallback(State);
+
+ /* Set the interrupt status to execute on the next instruction */
+ State->IntStatus = FAST486_INT_EXECUTE;
}
- else
+ else if (State->IntStatus == FAST486_INT_DELAYED)
{
- /* This is a prefix, go to the next instruction immediately */
- continue;
+ /* Restore the old state */
+ State->IntStatus = FAST486_INT_EXECUTE;
}
}
- while ((Command == FAST486_CONTINUE)
- || (Command == FAST486_STEP_OVER && ProcedureCallCount > 0)
- || (Command == FAST486_STEP_OUT && ProcedureCallCount >= 0)
- || (Fast486OpcodeHandlers[Opcode] == Fast486OpcodePrefix));
+ while ((Command == FAST486_CONTINUE) ||
+ (Command == FAST486_STEP_OVER && ProcedureCallCount > 0) ||
+ (Command == FAST486_STEP_OUT && ProcedureCallCount >= 0));
}
-/* PUBLIC FUNCTIONS ***********************************************************/
+/* DEFAULT CALLBACKS **********************************************************/
-VOID
+static VOID
NTAPI
-Fast486Continue(PFAST486_STATE State)
+Fast486MemReadCallback(PFAST486_STATE State, ULONG Address, PVOID Buffer, ULONG Size)
{
- /* Call the internal function */
- Fast486ExecutionControl(State, FAST486_CONTINUE);
+ UNREFERENCED_PARAMETER(State);
+ RtlMoveMemory(Buffer, (PVOID)Address, Size);
}
-VOID
+static VOID
NTAPI
-Fast486StepInto(PFAST486_STATE State)
+Fast486MemWriteCallback(PFAST486_STATE State, ULONG Address, PVOID Buffer, ULONG Size)
{
- /* Call the internal function */
- Fast486ExecutionControl(State, FAST486_STEP_INTO);
+ UNREFERENCED_PARAMETER(State);
+ RtlMoveMemory((PVOID)Address, Buffer, Size);
}
-VOID
+static VOID
NTAPI
-Fast486StepOver(PFAST486_STATE State)
+Fast486IoReadCallback(PFAST486_STATE State, USHORT Port, PVOID Buffer, ULONG DataCount, UCHAR DataSize)
{
- /* Call the internal function */
- Fast486ExecutionControl(State, FAST486_STEP_OVER);
+ UNREFERENCED_PARAMETER(State);
+ UNREFERENCED_PARAMETER(Port);
+ UNREFERENCED_PARAMETER(Buffer);
+ UNREFERENCED_PARAMETER(DataCount);
+ UNREFERENCED_PARAMETER(DataSize);
}
-VOID
+static VOID
NTAPI
-Fast486StepOut(PFAST486_STATE State)
+Fast486IoWriteCallback(PFAST486_STATE State, USHORT Port, PVOID Buffer, ULONG DataCount, UCHAR DataSize)
{
- /* Call the internal function */
- Fast486ExecutionControl(State, FAST486_STEP_OUT);
+ UNREFERENCED_PARAMETER(State);
+ UNREFERENCED_PARAMETER(Port);
+ UNREFERENCED_PARAMETER(Buffer);
+ UNREFERENCED_PARAMETER(DataCount);
+ UNREFERENCED_PARAMETER(DataSize);
+}
+
+static VOID
+NTAPI
+Fast486BopCallback(PFAST486_STATE State, UCHAR BopCode)
+{
+ UNREFERENCED_PARAMETER(State);
+ UNREFERENCED_PARAMETER(BopCode);
+}
+
+static UCHAR
+NTAPI
+Fast486IntAckCallback(PFAST486_STATE State)
+{
+ UNREFERENCED_PARAMETER(State);
+
+ /* Return something... defaulted to single-step interrupt */
+ return 0x01;
}
+/* PUBLIC FUNCTIONS ***********************************************************/
+
VOID
NTAPI
-Fast486DumpState(PFAST486_STATE State)
+Fast486Initialize(PFAST486_STATE State,
+ FAST486_MEM_READ_PROC MemReadCallback,
+ FAST486_MEM_WRITE_PROC MemWriteCallback,
+ FAST486_IO_READ_PROC IoReadCallback,
+ FAST486_IO_WRITE_PROC IoWriteCallback,
+ FAST486_BOP_PROC BopCallback,
+ FAST486_INT_ACK_PROC IntAckCallback,
+ PULONG Tlb)
{
- DPRINT1("\nCPU currently executing in %s mode at %04X:%08X\n",
- (State->ControlRegisters[0] & FAST486_CR0_PE) ? "protected" : "real",
- State->SegmentRegs[FAST486_REG_CS].Selector,
- State->InstPtr.Long);
- DPRINT1("\nGeneral purpose registers:\n"
- "EAX = %08X\tECX = %08X\tEDX = %08X\tEBX = %08X\n"
- "ESP = %08X\tEBP = %08X\tESI = %08X\tEDI = %08X\n",
- State->GeneralRegs[FAST486_REG_EAX].Long,
- State->GeneralRegs[FAST486_REG_ECX].Long,
- State->GeneralRegs[FAST486_REG_EDX].Long,
- State->GeneralRegs[FAST486_REG_EBX].Long,
- State->GeneralRegs[FAST486_REG_ESP].Long,
- State->GeneralRegs[FAST486_REG_EBP].Long,
- State->GeneralRegs[FAST486_REG_ESI].Long,
- State->GeneralRegs[FAST486_REG_EDI].Long);
- DPRINT1("\nSegment registers:\n"
- "ES = %04X (Base: %08X, Limit: %08X, Dpl: %u)\n"
- "CS = %04X (Base: %08X, Limit: %08X, Dpl: %u)\n"
- "SS = %04X (Base: %08X, Limit: %08X, Dpl: %u)\n"
- "DS = %04X (Base: %08X, Limit: %08X, Dpl: %u)\n"
- "FS = %04X (Base: %08X, Limit: %08X, Dpl: %u)\n"
- "GS = %04X (Base: %08X, Limit: %08X, Dpl: %u)\n",
- State->SegmentRegs[FAST486_REG_ES].Selector,
- State->SegmentRegs[FAST486_REG_ES].Base,
- State->SegmentRegs[FAST486_REG_ES].Limit,
- State->SegmentRegs[FAST486_REG_ES].Dpl,
- State->SegmentRegs[FAST486_REG_CS].Selector,
- State->SegmentRegs[FAST486_REG_CS].Base,
- State->SegmentRegs[FAST486_REG_CS].Limit,
- State->SegmentRegs[FAST486_REG_CS].Dpl,
- State->SegmentRegs[FAST486_REG_SS].Selector,
- State->SegmentRegs[FAST486_REG_SS].Base,
- State->SegmentRegs[FAST486_REG_SS].Limit,
- State->SegmentRegs[FAST486_REG_SS].Dpl,
- State->SegmentRegs[FAST486_REG_DS].Selector,
- State->SegmentRegs[FAST486_REG_DS].Base,
- State->SegmentRegs[FAST486_REG_DS].Limit,
- State->SegmentRegs[FAST486_REG_DS].Dpl,
- State->SegmentRegs[FAST486_REG_FS].Selector,
- State->SegmentRegs[FAST486_REG_FS].Base,
- State->SegmentRegs[FAST486_REG_FS].Limit,
- State->SegmentRegs[FAST486_REG_FS].Dpl,
- State->SegmentRegs[FAST486_REG_GS].Selector,
- State->SegmentRegs[FAST486_REG_GS].Base,
- State->SegmentRegs[FAST486_REG_GS].Limit,
- State->SegmentRegs[FAST486_REG_GS].Dpl);
- DPRINT1("\nFlags: %08X (%s %s %s %s %s %s %s %s %s %s %s %s %s %s %s) Iopl: %u\n",
- State->Flags.Long,
- State->Flags.Cf ? "CF" : "cf",
- State->Flags.Pf ? "PF" : "pf",
- State->Flags.Af ? "AF" : "af",
- State->Flags.Zf ? "ZF" : "zf",
- State->Flags.Sf ? "SF" : "sf",
- State->Flags.Tf ? "TF" : "tf",
- State->Flags.If ? "IF" : "if",
- State->Flags.Df ? "DF" : "df",
- State->Flags.Of ? "OF" : "of",
- State->Flags.Nt ? "NT" : "nt",
- State->Flags.Rf ? "RF" : "rf",
- State->Flags.Vm ? "VM" : "vm",
- State->Flags.Ac ? "AC" : "ac",
- State->Flags.Vif ? "VIF" : "vif",
- State->Flags.Vip ? "VIP" : "vip",
- State->Flags.Iopl);
- DPRINT1("\nControl Registers:\n"
- "CR0 = %08X\tCR1 = %08X\tCR2 = %08X\tCR3 = %08X\n"
- "CR4 = %08X\tCR5 = %08X\tCR6 = %08X\tCR7 = %08X\n",
- State->ControlRegisters[FAST486_REG_CR0],
- State->ControlRegisters[FAST486_REG_CR1],
- State->ControlRegisters[FAST486_REG_CR2],
- State->ControlRegisters[FAST486_REG_CR3],
- State->ControlRegisters[FAST486_REG_CR4],
- State->ControlRegisters[FAST486_REG_CR5],
- State->ControlRegisters[FAST486_REG_CR6],
- State->ControlRegisters[FAST486_REG_CR7]);
- DPRINT1("\nDebug Registers:\n"
- "DR0 = %08X\tDR1 = %08X\tDR2 = %08X\tDR3 = %08X\n"
- "DR4 = %08X\tDR5 = %08X\tDR6 = %08X\tDR7 = %08X\n",
- State->DebugRegisters[FAST486_REG_DR0],
- State->DebugRegisters[FAST486_REG_DR1],
- State->DebugRegisters[FAST486_REG_DR2],
- State->DebugRegisters[FAST486_REG_DR3],
- State->DebugRegisters[FAST486_REG_DR4],
- State->DebugRegisters[FAST486_REG_DR5],
- State->DebugRegisters[FAST486_REG_DR6],
- State->DebugRegisters[FAST486_REG_DR7]);
+ /* Set the callbacks (or use default ones if some are NULL) */
+ State->MemReadCallback = (MemReadCallback ? MemReadCallback : Fast486MemReadCallback );
+ State->MemWriteCallback = (MemWriteCallback ? MemWriteCallback : Fast486MemWriteCallback);
+ State->IoReadCallback = (IoReadCallback ? IoReadCallback : Fast486IoReadCallback );
+ State->IoWriteCallback = (IoWriteCallback ? IoWriteCallback : Fast486IoWriteCallback );
+ State->BopCallback = (BopCallback ? BopCallback : Fast486BopCallback );
+ State->IntAckCallback = (IntAckCallback ? IntAckCallback : Fast486IntAckCallback );
+
+ /* Set the TLB (if given) */
+ State->Tlb = Tlb;
+
+ /* Reset the CPU */
+ Fast486Reset(State);
}
VOID
NTAPI
Fast486Reset(PFAST486_STATE State)
{
- INT i;
- FAST486_MEM_READ_PROC MemReadCallback = State->MemReadCallback;
+ FAST486_SEG_REGS i;
+
+ /* Save the callbacks and TLB */
+ FAST486_MEM_READ_PROC MemReadCallback = State->MemReadCallback;
FAST486_MEM_WRITE_PROC MemWriteCallback = State->MemWriteCallback;
- FAST486_IO_READ_PROC IoReadCallback = State->IoReadCallback;
- FAST486_IO_WRITE_PROC IoWriteCallback = State->IoWriteCallback;
- FAST486_IDLE_PROC IdleCallback = State->IdleCallback;
- FAST486_BOP_PROC BopCallback = State->BopCallback;
+ FAST486_IO_READ_PROC IoReadCallback = State->IoReadCallback;
+ FAST486_IO_WRITE_PROC IoWriteCallback = State->IoWriteCallback;
+ FAST486_BOP_PROC BopCallback = State->BopCallback;
+ FAST486_INT_ACK_PROC IntAckCallback = State->IntAckCallback;
+ PULONG Tlb = State->Tlb;
/* Clear the entire structure */
RtlZeroMemory(State, sizeof(*State));
State->Flags.AlwaysSet = 1;
State->InstPtr.LowWord = 0xFFF0;
+ /* Set the CPL to 0 */
+ State->Cpl = 0;
+
/* Initialize segments */
for (i = 0; i < FAST486_NUM_SEG_REGS; i++)
{
- /* Set the selector, base and limit, other values don't apply in real mode */
State->SegmentRegs[i].Selector = 0;
State->SegmentRegs[i].Base = 0;
State->SegmentRegs[i].Limit = 0xFFFF;
+ State->SegmentRegs[i].Present = TRUE;
+ State->SegmentRegs[i].ReadWrite = TRUE;
+ State->SegmentRegs[i].Executable = FALSE;
+ State->SegmentRegs[i].DirConf = FALSE;
+ State->SegmentRegs[i].SystemType = 1; // Segment descriptor
+ State->SegmentRegs[i].Dpl = 0;
+ State->SegmentRegs[i].Size = FALSE; // 16-bit
}
/* Initialize the code segment */
+ State->SegmentRegs[FAST486_REG_CS].Executable = TRUE;
State->SegmentRegs[FAST486_REG_CS].Selector = 0xF000;
State->SegmentRegs[FAST486_REG_CS].Base = 0xFFFF0000;
State->Idtr.Size = 0x3FF;
State->Idtr.Address = 0;
+#ifndef FAST486_NO_FPU
/* Initialize CR0 */
State->ControlRegisters[FAST486_REG_CR0] |= FAST486_CR0_ET;
- /* Restore the callbacks */
- State->MemReadCallback = MemReadCallback;
+ /* Initialize the FPU control and tag registers */
+ State->FpuControl.Value = FAST486_FPU_DEFAULT_CONTROL;
+ State->FpuStatus.Value = 0;
+ State->FpuTag = 0xFFFF;
+#endif
+
+ /* Restore the callbacks and TLB */
+ State->MemReadCallback = MemReadCallback;
State->MemWriteCallback = MemWriteCallback;
- State->IoReadCallback = IoReadCallback;
- State->IoWriteCallback = IoWriteCallback;
- State->IdleCallback = IdleCallback;
- State->BopCallback = BopCallback;
+ State->IoReadCallback = IoReadCallback;
+ State->IoWriteCallback = IoWriteCallback;
+ State->BopCallback = BopCallback;
+ State->IntAckCallback = IntAckCallback;
+ State->Tlb = Tlb;
}
VOID
NTAPI
Fast486Interrupt(PFAST486_STATE State, UCHAR Number)
{
- /* Set the hardware interrupt flag */
- State->HardwareInt = TRUE;
+ /* Set the interrupt status and the number */
+ State->IntStatus = FAST486_INT_EXECUTE;
State->PendingIntNum = Number;
}
+VOID
+NTAPI
+Fast486InterruptSignal(PFAST486_STATE State)
+{
+ /* Set the interrupt status */
+ State->IntStatus = FAST486_INT_SIGNAL;
+}
+
VOID
NTAPI
Fast486ExecuteAt(PFAST486_STATE State, USHORT Segment, ULONG Offset)
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