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43ee57f2f7
The behavior of the I/O port bus depends on the data width. In the case of 16-bit/32-bit access, two/four adjacent ports will be accessed. svn path=/branches/ntvdm/; revision=60891
410 lines
10 KiB
C
410 lines
10 KiB
C
/*
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* COPYRIGHT: GPL - See COPYING in the top level directory
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* PROJECT: ReactOS Virtual DOS Machine
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* FILE: emulator.c
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* PURPOSE: Minimal x86 machine emulator for the VDM
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* PROGRAMMERS: Aleksandar Andrejevic <theflash AT sdf DOT lonestar DOT org>
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*/
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/* INCLUDES *******************************************************************/
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#define NDEBUG
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#include "emulator.h"
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#include "bios.h"
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#include "bop.h"
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#include "dos.h"
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#include "speaker.h"
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#include "vga.h"
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#include "pic.h"
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#include "ps2.h"
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#include "timer.h"
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#include "cmos.h"
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/* PRIVATE VARIABLES **********************************************************/
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FAST486_STATE EmulatorContext;
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static BOOLEAN A20Line = FALSE;
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/* PRIVATE FUNCTIONS **********************************************************/
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static VOID WINAPI EmulatorReadMemory(PFAST486_STATE State, ULONG Address, PVOID Buffer, ULONG Size)
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{
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UNREFERENCED_PARAMETER(State);
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/* If the A20 line is disabled, mask bit 20 */
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if (!A20Line) Address &= ~(1 << 20);
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/* Make sure the requested address is valid */
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if ((Address + Size) >= MAX_ADDRESS) return;
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/* Read the data from the virtual address space and store it in the buffer */
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RtlCopyMemory(Buffer, (LPVOID)((ULONG_PTR)BaseAddress + Address), Size);
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/* Check if we modified the console video memory */
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if (((Address + Size) >= VgaGetVideoBaseAddress())
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&& (Address < VgaGetVideoLimitAddress()))
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{
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DWORD VgaAddress = max(Address, VgaGetVideoBaseAddress());
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LPBYTE VgaBuffer = (LPBYTE)((ULONG_PTR)Buffer + VgaAddress - Address);
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/* Read from the VGA memory */
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VgaReadMemory(VgaAddress, VgaBuffer, Size);
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}
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}
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static VOID WINAPI EmulatorWriteMemory(PFAST486_STATE State, ULONG Address, PVOID Buffer, ULONG Size)
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{
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UNREFERENCED_PARAMETER(State);
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/* If the A20 line is disabled, mask bit 20 */
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if (!A20Line) Address &= ~(1 << 20);
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/* Make sure the requested address is valid */
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if ((Address + Size) >= MAX_ADDRESS) return;
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/* Make sure we don't write to the ROM area */
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if ((Address + Size) >= ROM_AREA_START && (Address < ROM_AREA_END)) return;
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/* Read the data from the buffer and store it in the virtual address space */
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RtlCopyMemory((LPVOID)((ULONG_PTR)BaseAddress + Address), Buffer, Size);
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/* Check if we modified the console video memory */
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if (((Address + Size) >= VgaGetVideoBaseAddress())
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&& (Address < VgaGetVideoLimitAddress()))
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{
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DWORD VgaAddress = max(Address, VgaGetVideoBaseAddress());
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LPBYTE VgaBuffer = (LPBYTE)((ULONG_PTR)Buffer + VgaAddress - Address);
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/* Write to the VGA memory */
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VgaWriteMemory(VgaAddress, VgaBuffer, Size);
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}
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}
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static VOID WINAPI EmulatorReadIo(PFAST486_STATE State, ULONG Port, PVOID Buffer, ULONG Size, UCHAR Width)
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{
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INT i, j;
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LPBYTE Address = (LPBYTE)Buffer;
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UNREFERENCED_PARAMETER(State);
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for (i = 0; i < Size; i++) for (j = 0; j < Width; j++)
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{
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ULONG CurrentPort = Port + j;
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switch (CurrentPort)
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{
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case PIC_MASTER_CMD:
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case PIC_SLAVE_CMD:
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{
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*(Address++) = PicReadCommand(CurrentPort);
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break;
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}
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case PIC_MASTER_DATA:
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case PIC_SLAVE_DATA:
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{
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*(Address++) = PicReadData(CurrentPort);
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break;
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}
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case PIT_DATA_PORT(0):
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case PIT_DATA_PORT(1):
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case PIT_DATA_PORT(2):
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{
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*(Address++) = PitReadData(CurrentPort - PIT_DATA_PORT(0));
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break;
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}
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case PS2_CONTROL_PORT:
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{
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*(Address++) = KeyboardReadStatus();
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break;
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}
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case PS2_DATA_PORT:
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{
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*(Address++) = KeyboardReadData();
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break;
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}
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case CMOS_DATA_PORT:
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{
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*(Address++) = CmosReadData();
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break;
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}
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case SPEAKER_CONTROL_PORT:
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{
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*(Address++) = SpeakerReadStatus();
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break;
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}
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case VGA_AC_WRITE:
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case VGA_AC_READ:
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case VGA_SEQ_INDEX:
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case VGA_SEQ_DATA:
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case VGA_DAC_READ_INDEX:
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case VGA_DAC_WRITE_INDEX:
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case VGA_DAC_DATA:
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case VGA_MISC_READ:
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case VGA_MISC_WRITE:
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case VGA_CRTC_INDEX:
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case VGA_CRTC_DATA:
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case VGA_GC_INDEX:
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case VGA_GC_DATA:
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case VGA_STAT_MONO:
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case VGA_STAT_COLOR:
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{
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*(Address++) = VgaReadPort(CurrentPort);
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break;
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}
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default:
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{
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DPRINT1("Read from unknown port: 0x%X\n", CurrentPort);
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}
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}
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}
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}
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static VOID WINAPI EmulatorWriteIo(PFAST486_STATE State, ULONG Port, PVOID Buffer, ULONG Size, UCHAR Width)
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{
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INT i, j;
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LPBYTE Address = (LPBYTE)Buffer;
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UNREFERENCED_PARAMETER(State);
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for (i = 0; i < Size; i++) for (j = 0; j < Width; j++)
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{
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ULONG CurrentPort = Port + j;
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switch (CurrentPort)
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{
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case PIT_COMMAND_PORT:
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{
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PitWriteCommand(*(Address++));
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break;
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}
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case PIT_DATA_PORT(0):
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case PIT_DATA_PORT(1):
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case PIT_DATA_PORT(2):
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{
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PitWriteData(CurrentPort - PIT_DATA_PORT(0), *(Address++));
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break;
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}
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case PIC_MASTER_CMD:
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case PIC_SLAVE_CMD:
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{
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PicWriteCommand(CurrentPort, *(Address++));
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break;
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}
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case PIC_MASTER_DATA:
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case PIC_SLAVE_DATA:
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{
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PicWriteData(CurrentPort, *(Address++));
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break;
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}
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case PS2_CONTROL_PORT:
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{
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KeyboardWriteCommand(*(Address++));
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break;
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}
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case PS2_DATA_PORT:
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{
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KeyboardWriteData(*(Address++));
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break;
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}
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case CMOS_ADDRESS_PORT:
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{
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CmosWriteAddress(*(Address++));
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break;
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}
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case CMOS_DATA_PORT:
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{
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CmosWriteData(*(Address++));
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break;
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}
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case SPEAKER_CONTROL_PORT:
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{
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SpeakerWriteCommand(*(Address++));
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break;
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}
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case VGA_AC_WRITE:
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case VGA_AC_READ:
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case VGA_SEQ_INDEX:
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case VGA_SEQ_DATA:
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case VGA_DAC_READ_INDEX:
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case VGA_DAC_WRITE_INDEX:
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case VGA_DAC_DATA:
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case VGA_MISC_READ:
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case VGA_MISC_WRITE:
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case VGA_CRTC_INDEX:
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case VGA_CRTC_DATA:
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case VGA_GC_INDEX:
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case VGA_GC_DATA:
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case VGA_STAT_MONO:
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case VGA_STAT_COLOR:
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{
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VgaWritePort(CurrentPort, *(Address++));
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break;
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}
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default:
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{
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DPRINT1("Write to unknown port: 0x%X\n", CurrentPort);
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}
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}
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}
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}
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static VOID WINAPI EmulatorBiosOperation(PFAST486_STATE State, UCHAR BopCode)
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{
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WORD StackSegment, StackPointer;
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LPWORD Stack;
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/* Get the SS:SP */
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StackSegment = State->SegmentRegs[FAST486_REG_SS].Selector;
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StackPointer = State->GeneralRegs[FAST486_REG_ESP].LowWord;
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/* Get the stack */
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Stack = (LPWORD)SEG_OFF_TO_PTR(StackSegment, StackPointer);
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if (BopProc[BopCode] != NULL)
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BopProc[BopCode](Stack);
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else
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DPRINT1("Invalid BOP code %u\n", BopCode);
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}
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static UCHAR WINAPI EmulatorIntAcknowledge(PFAST486_STATE State)
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{
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UNREFERENCED_PARAMETER(State);
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/* Get the interrupt number from the PIC */
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return PicGetInterrupt();
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}
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/* PUBLIC FUNCTIONS ***********************************************************/
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BOOLEAN EmulatorInitialize(VOID)
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{
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/* Allocate memory for the 16-bit address space */
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BaseAddress = HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, MAX_ADDRESS);
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if (BaseAddress == NULL) return FALSE;
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/* Initialize the CPU */
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Fast486Initialize(&EmulatorContext,
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EmulatorReadMemory,
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EmulatorWriteMemory,
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EmulatorReadIo,
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EmulatorWriteIo,
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NULL,
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EmulatorBiosOperation,
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EmulatorIntAcknowledge);
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/* Enable interrupts */
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EmulatorSetFlag(EMULATOR_FLAG_IF);
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return TRUE;
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}
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VOID EmulatorCleanup(VOID)
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{
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/* Free the memory allocated for the 16-bit address space */
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if (BaseAddress != NULL) HeapFree(GetProcessHeap(), 0, BaseAddress);
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}
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VOID EmulatorSetStack(WORD Segment, DWORD Offset)
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{
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Fast486SetStack(&EmulatorContext, Segment, Offset);
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}
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// FIXME: This function assumes 16-bit mode!!!
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VOID EmulatorExecute(WORD Segment, WORD Offset)
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{
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/* Tell Fast486 to move the instruction pointer */
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Fast486ExecuteAt(&EmulatorContext, Segment, Offset);
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}
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VOID EmulatorInterrupt(BYTE Number)
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{
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/* Call the Fast486 API */
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Fast486Interrupt(&EmulatorContext, Number);
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}
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VOID EmulatorInterruptSignal(VOID)
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{
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/* Call the Fast486 API */
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Fast486InterruptSignal(&EmulatorContext);
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}
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ULONG EmulatorGetRegister(ULONG Register)
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{
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if (Register < EMULATOR_REG_ES)
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{
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return EmulatorContext.GeneralRegs[Register].Long;
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}
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else
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{
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return EmulatorContext.SegmentRegs[Register - EMULATOR_REG_ES].Selector;
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}
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}
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VOID EmulatorSetRegister(ULONG Register, ULONG Value)
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{
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if (Register < EMULATOR_REG_ES)
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{
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EmulatorContext.GeneralRegs[Register].Long = Value;
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}
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else
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{
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Fast486SetSegment(&EmulatorContext, Register - EMULATOR_REG_ES, (USHORT)Value);
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}
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}
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ULONG EmulatorGetProgramCounter(VOID)
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{
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return EmulatorContext.InstPtr.Long;
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}
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BOOLEAN EmulatorGetFlag(ULONG Flag)
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{
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return (EmulatorContext.Flags.Long & Flag) ? TRUE : FALSE;
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}
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VOID EmulatorSetFlag(ULONG Flag)
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{
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EmulatorContext.Flags.Long |= Flag;
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}
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VOID EmulatorClearFlag(ULONG Flag)
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{
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EmulatorContext.Flags.Long &= ~Flag;
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}
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VOID EmulatorStep(VOID)
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{
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/* Dump the state for debugging purposes */
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// Fast486DumpState(&EmulatorContext);
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/* Execute the next instruction */
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Fast486StepInto(&EmulatorContext);
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}
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VOID EmulatorSetA20(BOOLEAN Enabled)
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{
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A20Line = Enabled;
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}
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/* EOF */
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