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/*
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Copyright (c) 2019-2021 Andreas T Jonsson
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This software is provided 'as-is', without any express or implied
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warranty. In no event will the authors be held liable for any damages
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arising from the use of this software.
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Permission is granted to anyone to use this software for any purpose,
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including commercial applications, and to alter it and redistribute it
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freely, subject to the following restrictions:
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1. The origin of this software must not be misrepresented; you must not
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claim that you wrote the original software. If you use this software
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in a product, an acknowledgment in the product documentation would be
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appreciated but is not required.
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2. Altered source versions must be plainly marked as such, and must not be
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misrepresented as being the original software.
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3. This notice may not be removed or altered from any source distribution.
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*/
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package cpu
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import (
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"log"
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"runtime"
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"time"
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"github.com/andreas-jonsson/virtualxt/emulator/memory"
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"github.com/andreas-jonsson/virtualxt/emulator/processor"
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"github.com/andreas-jonsson/virtualxt/emulator/processor/validator"
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)
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var zero16 uint16
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type instructionState struct {
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opcode, modRegRM,
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repeatMode byte
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isWide, rmToReg,
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halted bool
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decodeAt uint16
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segOverride *uint16
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cycleCount int
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}
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func (p *CPU) getReg() byte {
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return (p.modRegRM >> 3) & 7
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}
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func (p *CPU) regLocation() dataLocation {
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return dataLocation(p.getReg()) | registerLocation
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}
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func (p *CPU) segLocation() dataLocation {
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return dataLocation(p.getReg()) | segmentLocation
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}
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func (p *CPU) rmLocation() dataLocation {
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idx := p.modRegRM & 0xC7
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f := modRMLookup[idx]
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return f(p)
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}
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func (p *CPU) peakOpcodeStream() byte {
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return p.ReadByte(memory.NewPointer(p.CS, p.IP))
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}
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func (p *CPU) readOpcodeStream() byte {
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v := p.peakOpcodeStream()
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p.IP++
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return v
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}
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func (p *CPU) readOpcodeImm16() uint16 {
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v := p.ReadWord(memory.NewPointer(p.CS, p.IP))
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p.IP += 2
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return v
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}
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func (p *CPU) readModRegRM() {
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p.modRegRM = p.readOpcodeStream()
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}
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func (p *CPU) parseOperands() (dataLocation, dataLocation) {
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p.readModRegRM()
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reg, rm := p.regLocation(), p.rmLocation()
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if p.rmToReg {
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return reg, rm
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}
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return rm, reg
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}
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func (p *CPU) parseOpcode() {
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p.segOverride = nil
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p.repeatMode = 0
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p.decodeAt = p.IP
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var op byte
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loop:
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for {
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switch op = p.readOpcodeStream(); op {
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case 0x26: // ES:
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p.segOverride = &p.ES
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case 0x2E: // CS:
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p.segOverride = &p.CS
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case 0x36: // SS:
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p.segOverride = &p.SS
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case 0x3E: // DS:
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p.segOverride = &p.DS
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case 0xF0: // LOCK
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// NOP...
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case 0xF1:
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//log.Printf("Unsupported instruction prefix: 0x%X", op)
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//p.invalidOpcode()
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//break loop
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case 0xF2, 0xF3: // REPNE/REPNZ,REP/REPE/REPZ
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p.repeatMode = op
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default:
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break loop
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}
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}
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p.opcode = op
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p.isWide = op&1 != 0
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p.rmToReg = op&2 != 0
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}
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func (p *CPU) packFlags8() byte {
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var flags byte = 0x2
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if p.CF {
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flags |= 0x001
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}
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if p.PF {
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flags |= 0x004
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}
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if p.AF {
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flags |= 0x010
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}
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if p.ZF {
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flags |= 0x040
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}
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if p.SF {
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flags |= 0x080
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}
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return flags
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}
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func (p *CPU) packFlags16() uint16 {
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flags := uint16(p.packFlags8())
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if p.TF {
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flags |= 0x100
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}
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if p.IF {
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flags |= 0x200
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}
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if p.DF {
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flags |= 0x400
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}
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if p.OF {
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flags |= 0x800
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}
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return flags
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}
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func (p *CPU) unpackFlags8(flags byte) {
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p.CF = flags&0x001 != 0
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p.PF = flags&0x004 != 0
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p.AF = flags&0x010 != 0
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p.ZF = flags&0x040 != 0
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p.SF = flags&0x080 != 0
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}
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func (p *CPU) unpackFlags16(flags uint16) {
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p.unpackFlags8(byte(flags & 0xFF))
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p.TF = flags&0x100 != 0
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p.IF = flags&0x200 != 0
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p.DF = flags&0x400 != 0
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p.OF = flags&0x800 != 0
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}
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func signExtend16(v byte) uint16 {
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if v&0x80 != 0 {
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return uint16(v) | 0xFF00
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}
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return uint16(v)
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}
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func signExtend32(v uint16) uint32 {
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if v&0x8000 != 0 {
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return uint32(v) | 0xFFFF0000
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}
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return uint32(v)
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}
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func (p *CPU) stackTop() memory.Pointer {
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return memory.NewPointer(p.SS, p.SP)
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}
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func (p *CPU) push16(v uint16) {
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p.SP -= 2
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p.WriteWord(p.stackTop(), v)
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}
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func (p *CPU) pop16() uint16 {
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v := p.ReadWord(p.stackTop())
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p.SP += 2
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return v
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}
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func (p *CPU) updateFlagsSZP8(res byte) {
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p.SF = res&0x80 != 0
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p.ZF = res == 0
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p.PF = parityLookup[res]
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}
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func (p *CPU) updateFlagsSZP16(res uint16) {
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p.SF = res&0x8000 != 0
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p.ZF = res == 0
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p.PF = parityLookup[res&0xFF]
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}
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func (p *CPU) getFlagsMask() (uint32, uint32) {
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maskC := uint32(0xFF00)
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maskO := uint32(0x0080)
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if p.isWide {
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maskC = 0xFFFF0000
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maskO = 0x00008000
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}
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return maskC, maskO
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}
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func (p *CPU) clearFlagsOC() {
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p.CF = false
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p.OF = false
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}
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func (p *CPU) updateFlagsOSZPCLog8(res byte) {
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p.updateFlagsSZP8(res)
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p.clearFlagsOC()
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}
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func (p *CPU) updateFlagsOSZPCLog16(res uint16) {
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p.updateFlagsSZP16(res)
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p.clearFlagsOC()
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}
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func (p *CPU) updateFlagsOACAdd(res, a, b uint32) {
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maskC, maskO := p.getFlagsMask()
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p.CF = res&maskC != 0
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p.AF = ((a ^ b ^ res) & 0x10) == 0x10
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p.OF = ((res ^ a) & (res ^ b) & maskO) == maskO
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}
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254
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255
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func (p *CPU) updateFlagsOACSub(res, a, b uint32) {
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maskC, maskO := p.getFlagsMask()
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p.CF = res&maskC != 0
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p.AF = ((a ^ b ^ res) & 0x10) != 0
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p.OF = ((res ^ a) & (a ^ b) & maskO) != 0
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}
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261
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262
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func (p *CPU) updateFlagsOACSubCarry(res, a, b uint32) {
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263
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b += b2ui32(p.CF)
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264
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p.updateFlagsOACSub(res, a, b)
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}
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266
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267
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func b2ui16(b bool) uint16 {
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268
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if b {
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269
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return 1
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270
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}
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271
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6
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return 0
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272
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}
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273
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274
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func b2ui32(b bool) uint32 {
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275
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6
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return uint32(b2ui16(b))
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276
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}
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277
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278
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func opXCHG(a, b *uint16) {
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279
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tmp := *a
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280
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*a = *b
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281
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6
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*b = tmp
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282
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}
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283
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284
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func (p *CPU) getSeg(seg uint16) uint16 {
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285
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6
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if p.segOverride != nil {
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286
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6
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return *p.segOverride
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287
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}
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288
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6
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return seg
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289
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}
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290
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291
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func (p *CPU) divisionByZero() {
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292
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6
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p.IP = p.decodeAt
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293
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6
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p.doInterrupt(0)
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294
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}
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295
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296
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func (p *CPU) doInterrupt(n int) {
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297
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6
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p.stats.NumInterrupts++
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298
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6
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validator.Discard()
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299
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300
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6
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p.halted = false
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301
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302
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6
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if handler := p.interceptors[n]; handler != nil {
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303
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0
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if err := handler.HandleInterrupt(n); err == nil {
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304
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0
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p.TF, p.IF = false, false
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305
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0
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return
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306
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0
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} else if err != processor.ErrInterruptNotHandled {
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307
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0
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log.Panic(err)
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308
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}
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309
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}
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310
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311
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6
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p.push16(p.packFlags16())
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6
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p.push16(p.CS)
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313
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6
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p.push16(p.IP)
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314
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315
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6
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offset := n * 4
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316
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6
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p.CS = p.ReadWord(memory.Pointer(offset + 2))
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317
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6
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p.IP = p.ReadWord(memory.Pointer(offset))
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318
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6
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p.TF, p.IF = false, false
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319
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}
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320
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321
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func (p *CPU) Step() (int, error) {
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322
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// Reset cycle counter.
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323
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6
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p.cycleCount = 0
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324
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325
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6
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if p.trap {
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326
|
0
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p.doInterrupt(1)
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|
327
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}
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328
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6
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p.trap = p.TF
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329
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330
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6
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if !p.trap && p.IF {
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331
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6
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if n, err := p.pic.GetInterrupt(); err == nil {
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332
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0
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p.doInterrupt(n)
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|
333
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}
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|
334
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|
}
|
|
335
|
|
|
|
336
|
6
|
if p.halted {
|
|
337
|
6
|
return 0, processor.ErrCPUHalt
|
|
338
|
|
}
|
|
339
|
|
|
|
340
|
6
|
p.parseOpcode()
|
|
341
|
6
|
if p.repeatMode != 0 {
|
|
342
|
6
|
err := p.doRepeat()
|
|
343
|
6
|
return p.cycleCount, err
|
|
344
|
|
}
|
|
345
|
|
|
|
346
|
6
|
validator.Begin(p.opcode, p.Registers)
|
|
347
|
6
|
if err := p.execute(); err != nil {
|
|
348
|
0
|
return p.cycleCount, err
|
|
349
|
|
}
|
|
350
|
6
|
validator.End(p.Registers)
|
|
351
|
|
|
|
352
|
|
for _, d := range p.peripherals {
|
|
353
|
6
|
if err := d.Step(p.cycleCount); err != nil {
|
|
354
|
0
|
return p.cycleCount, err
|
|
355
|
|
}
|
|
356
|
|
}
|
|
357
|
6
|
return p.cycleCount, nil
|
|
358
|
|
}
|
|
359
|
|
|
|
360
|
|
func (p *CPU) execute() error {
|
|
361
|
|
// All instructions are 1 cycle right now.
|
|
362
|
6
|
p.cycleCount++
|
|
363
|
|
|
|
364
|
6
|
op := p.opcode
|
|
365
|
6
|
carry := op > 0x0F && p.CF
|
|
366
|
6
|
carryOp := b2ui32(carry)
|
|
367
|
|
|
|
368
|
6
|
switch op {
|
|
369
|
6
|
case 0x00, 0x02, 0x10, 0x12: // ADD/ADC r/m8,r8
|
|
370
|
6
|
dest, src := p.parseOperands()
|
|
371
|
6
|
a, b := uint32(dest.readByte(p)), uint32(src.readByte(p))
|
|
372
|
6
|
res := a + b + carryOp
|
|
373
|
6
|
dest.writeByte(p, byte(res))
|
|
374
|
6
|
p.updateFlagsSZP8(byte(res))
|
|
375
|
6
|
p.updateFlagsOACAdd(res, a, b)
|
|
376
|
6
|
case 0x01, 0x03, 0x11, 0x13: // ADD/ADC r/m16,r16
|
|
377
|
6
|
dest, src := p.parseOperands()
|
|
378
|
6
|
a, b := uint32(dest.readWord(p)), uint32(src.readWord(p))
|
|
379
|
6
|
res := a + b + carryOp
|
|
380
|
6
|
dest.writeWord(p, uint16(res))
|
|
381
|
6
|
p.updateFlagsSZP16(uint16(res))
|
|
382
|
6
|
p.updateFlagsOACAdd(res, a, b)
|
|
383
|
6
|
case 0x04, 0x14: // ADD/ADC AL,d8
|
|
384
|
6
|
a, b := uint32(p.AL()), uint32(p.readOpcodeStream())
|
|
385
|
6
|
res := a + b + carryOp
|
|
386
|
6
|
p.SetAL(byte(res))
|
|
387
|
6
|
p.updateFlagsSZP8(byte(res))
|
|
388
|
6
|
p.updateFlagsOACAdd(res, a, b)
|
|
389
|
6
|
case 0x05, 0x15: // ADD/ADC AX,d16
|
|
390
|
6
|
a, b := uint32(p.AX), uint32(p.readOpcodeImm16())
|
|
391
|
6
|
res := a + b + carryOp
|
|
392
|
6
|
p.AX = uint16(res)
|
|
393
|
6
|
p.updateFlagsSZP16(uint16(res))
|
|
394
|
6
|
p.updateFlagsOACAdd(res, a, b)
|
|
395
|
6
|
case 0x06: // PUSH ES
|
|
396
|
6
|
p.push16(p.ES)
|
|
397
|
6
|
case 0x07: // POP ES
|
|
398
|
6
|
p.ES = p.pop16()
|
|
399
|
6
|
case 0x08, 0x0A: // OR r/m8,r8
|
|
400
|
6
|
dest, src := p.parseOperands()
|
|
401
|
6
|
a, b := dest.readByte(p), src.readByte(p)
|
|
402
|
6
|
res := a | b
|
|
403
|
6
|
dest.writeByte(p, res)
|
|
404
|
6
|
p.updateFlagsOSZPCLog8(res)
|
|
405
|
6
|
case 0x09, 0x0B: // OR r/m16,r16
|
|
406
|
6
|
dest, src := p.parseOperands()
|
|
407
|
6
|
a, b := dest.readWord(p), src.readWord(p)
|
|
408
|
6
|
res := a | b
|
|
409
|
6
|
dest.writeWord(p, res)
|
|
410
|
6
|
p.updateFlagsOSZPCLog16(res)
|
|
411
|
6
|
case 0x0C: // OR AL,d8
|
|
412
|
6
|
a, b := p.AL(), p.readOpcodeStream()
|
|
413
|
6
|
res := a | b
|
|
414
|
6
|
p.SetAL(res)
|
|
415
|
6
|
p.updateFlagsOSZPCLog8(res)
|
|
416
|
6
|
case 0x0D: // OR AX,d16
|
|
417
|
6
|
p.AX = p.AX | p.readOpcodeImm16()
|
|
418
|
6
|
p.updateFlagsOSZPCLog16(p.AX)
|
|
419
|
0
|
case 0x0E: // PUSH CS
|
|
420
|
0
|
p.push16(p.CS)
|
|
421
|
0
|
case 0x0F: // *POP CS
|
|
422
|
0
|
if !p.isV20 {
|
|
423
|
0
|
p.CS = p.pop16()
|
|
424
|
|
}
|
|
425
|
|
|
|
426
|
|
// 0x1x
|
|
427
|
|
|
|
428
|
0
|
case 0x16: // PUSH SS
|
|
429
|
0
|
p.push16(p.SS)
|
|
430
|
0
|
case 0x17: // POP SS
|
|
431
|
0
|
p.SS = p.pop16()
|
|
432
|
6
|
case 0x18, 0x1A: // SBB r/m8,r8
|
|
433
|
6
|
dest, src := p.parseOperands()
|
|
434
|
6
|
a, b := uint32(dest.readByte(p)), uint32(src.readByte(p))
|
|
435
|
6
|
res := a - (b + carryOp)
|
|
436
|
6
|
dest.writeByte(p, byte(res))
|
|
437
|
6
|
p.updateFlagsSZP8(byte(res))
|
|
438
|
6
|
p.updateFlagsOACSubCarry(res, a, b)
|
|
439
|
6
|
case 0x19, 0x1B: // SBB r/m16,r16
|
|
440
|
6
|
dest, src := p.parseOperands()
|
|
441
|
6
|
a, b := uint32(dest.readWord(p)), uint32(src.readWord(p))
|
|
442
|
6
|
res := a - (b + carryOp)
|
|
443
|
6
|
dest.writeWord(p, uint16(res))
|
|
444
|
6
|
p.updateFlagsSZP16(uint16(res))
|
|
445
|
6
|
p.updateFlagsOACSubCarry(res, a, b)
|
|
446
|
6
|
case 0x1C: // SBB AL,d8
|
|
447
|
6
|
a, b := uint32(p.AL()), uint32(p.readOpcodeStream())
|
|
448
|
6
|
res := a - (b + carryOp)
|
|
449
|
6
|
p.SetAL(byte(res))
|
|
450
|
6
|
p.updateFlagsSZP8(byte(res))
|
|
451
|
6
|
p.updateFlagsOACSubCarry(res, a, b)
|
|
452
|
0
|
case 0x1D: // SBB AX,d16
|
|
453
|
0
|
a, b := uint32(p.AX), uint32(p.readOpcodeImm16())
|
|
454
|
0
|
res := a - (b + carryOp)
|
|
455
|
0
|
p.updateFlagsSZP16(uint16(res))
|
|
456
|
0
|
p.updateFlagsOACSubCarry(res, a, b)
|
|
457
|
0
|
case 0x1E: // PUSH DS
|
|
458
|
0
|
p.push16(p.DS)
|
|
459
|
0
|
case 0x1F: // POP DS
|
|
460
|
0
|
p.DS = p.pop16()
|
|
461
|
|
|
|
462
|
|
// 0x2x
|
|
463
|
|
|
|
464
|
6
|
case 0x20, 0x22: // AND r/m8,r8
|
|
465
|
6
|
dest, src := p.parseOperands()
|
|
466
|
6
|
a, b := dest.readByte(p), src.readByte(p)
|
|
467
|
6
|
res := uint16(a) & uint16(b)
|
|
468
|
6
|
dest.writeByte(p, byte(res))
|
|
469
|
6
|
p.updateFlagsOSZPCLog8(byte(res))
|
|
470
|
6
|
case 0x21, 0x23: // AND r/m16,r16
|
|
471
|
6
|
dest, src := p.parseOperands()
|
|
472
|
6
|
a, b := dest.readWord(p), src.readWord(p)
|
|
473
|
6
|
res := uint32(a) & uint32(b)
|
|
474
|
6
|
dest.writeWord(p, uint16(res))
|
|
475
|
6
|
p.updateFlagsOSZPCLog16(uint16(res))
|
|
476
|
6
|
case 0x24: // AND AL,d8
|
|
477
|
6
|
a, b := p.AL(), p.readOpcodeStream()
|
|
478
|
6
|
res := uint16(a) & uint16(b)
|
|
479
|
6
|
p.SetAL(byte(res))
|
|
480
|
6
|
p.updateFlagsOSZPCLog8(byte(res))
|
|
481
|
6
|
case 0x25: // AND AX,d16
|
|
482
|
6
|
b := p.readOpcodeImm16()
|
|
483
|
6
|
res := uint32(p.AX) & uint32(b)
|
|
484
|
6
|
p.AX = uint16(res)
|
|
485
|
6
|
p.updateFlagsOSZPCLog16(uint16(res))
|
|
486
|
6
|
case 0x27: // DAA
|
|
487
|
6
|
if al := p.AL(); ((al & 0xF) > 9) || p.AF {
|
|
488
|
6
|
v := uint16(al) + 6
|
|
489
|
6
|
p.SetAL(byte(v & 0xFF))
|
|
490
|
6
|
p.CF = (v & 0xFF00) != 0
|
|
491
|
6
|
p.AF = true
|
|
492
|
6
|
} else {
|
|
493
|
6
|
p.AF = false
|
|
494
|
|
}
|
|
495
|
|
|
|
496
|
6
|
if al := p.AL(); ((al & 0xF0) > 0x90) || p.CF {
|
|
497
|
6
|
p.SetAL(al + 0x60)
|
|
498
|
6
|
p.CF = true
|
|
499
|
6
|
} else {
|
|
500
|
6
|
p.CF = false
|
|
501
|
|
}
|
|
502
|
|
|
|
503
|
6
|
al := p.AL()
|
|
504
|
6
|
p.SetAL(al)
|
|
505
|
6
|
p.updateFlagsSZP8(al)
|
|
506
|
6
|
case 0x28, 0x2A: // SUB r/m8,r8
|
|
507
|
6
|
dest, src := p.parseOperands()
|
|
508
|
6
|
a, b := uint32(dest.readByte(p)), uint32(src.readByte(p))
|
|
509
|
6
|
res := a - b
|
|
510
|
6
|
dest.writeByte(p, byte(res))
|
|
511
|
6
|
p.updateFlagsSZP8(byte(res))
|
|
512
|
6
|
p.updateFlagsOACSub(res, a, b)
|
|
513
|
6
|
case 0x29, 0x2B: // SUB r/m16,r16
|
|
514
|
6
|
dest, src := p.parseOperands()
|
|
515
|
6
|
a, b := uint32(dest.readWord(p)), uint32(src.readWord(p))
|
|
516
|
6
|
res := a - b
|
|
517
|
6
|
dest.writeWord(p, uint16(res))
|
|
518
|
6
|
p.updateFlagsSZP16(uint16(res))
|
|
519
|
6
|
p.updateFlagsOACSub(res, a, b)
|
|
520
|
6
|
case 0x2C: // SUB AL,d8
|
|
521
|
6
|
a, b := uint32(p.AL()), uint32(p.readOpcodeStream())
|
|
522
|
6
|
res := a - b
|
|
523
|
6
|
p.SetAL(byte(res))
|
|
524
|
6
|
p.updateFlagsSZP8(byte(res))
|
|
525
|
6
|
p.updateFlagsOACSub(res, a, b)
|
|
526
|
0
|
case 0x2D: // SUB AX,d16
|
|
527
|
0
|
a, b := uint32(p.AX), uint32(p.readOpcodeImm16())
|
|
528
|
0
|
res := a - b
|
|
529
|
0
|
p.AX = uint16(res)
|
|
530
|
0
|
p.updateFlagsSZP16(uint16(res))
|
|
531
|
0
|
p.updateFlagsOACSub(res, a, b)
|
|
532
|
6
|
case 0x2F: // DAS
|
|
533
|
6
|
if al := p.AL(); ((al & 15) > 9) || p.AF {
|
|
534
|
6
|
v := uint16(al) - 6
|
|
535
|
6
|
p.SetAL(byte(v & 0xFF))
|
|
536
|
6
|
p.CF = (v & 0xFF00) != 0
|
|
537
|
6
|
p.AF = true
|
|
538
|
6
|
} else {
|
|
539
|
6
|
p.AF = false
|
|
540
|
|
}
|
|
541
|
|
|
|
542
|
6
|
if al := p.AL(); ((al & 0xF0) > 0x90) || p.CF {
|
|
543
|
6
|
p.SetAL(al - 0x60)
|
|
544
|
6
|
p.CF = true
|
|
545
|
6
|
} else {
|
|
546
|
6
|
p.CF = false
|
|
547
|
|
}
|
|
548
|
6
|
p.updateFlagsSZP8(p.AL())
|
|
549
|
|
|
|
550
|
|
// 0x3x
|
|
551
|
|
|
|
552
|
6
|
case 0x30, 0x32: // XOR r/m8,r8
|
|
553
|
6
|
dest, src := p.parseOperands()
|
|
554
|
6
|
a, b := dest.readByte(p), src.readByte(p)
|
|
555
|
6
|
res := uint16(a) ^ uint16(b)
|
|
556
|
6
|
dest.writeByte(p, byte(res))
|
|
557
|
6
|
p.updateFlagsOSZPCLog8(byte(res))
|
|
558
|
6
|
case 0x31, 0x33: // XOR r/m16,r16
|
|
559
|
6
|
dest, src := p.parseOperands()
|
|
560
|
6
|
a, b := dest.readWord(p), src.readWord(p)
|
|
561
|
6
|
res := uint32(a) ^ uint32(b)
|
|
562
|
6
|
dest.writeWord(p, uint16(res))
|
|
563
|
6
|
p.updateFlagsOSZPCLog16(uint16(res))
|
|
564
|
6
|
case 0x34: // XOR AL,d8
|
|
565
|
6
|
a, b := p.AL(), p.readOpcodeStream()
|
|
566
|
6
|
res := uint16(a) ^ uint16(b)
|
|
567
|
6
|
p.SetAL(byte(res))
|
|
568
|
6
|
p.updateFlagsOSZPCLog8(byte(res))
|
|
569
|
6
|
case 0x35: // XOR AX,d16
|
|
570
|
6
|
b := p.readOpcodeImm16()
|
|
571
|
6
|
res := uint32(p.AX) ^ uint32(b)
|
|
572
|
6
|
p.AX = uint16(res)
|
|
573
|
6
|
p.updateFlagsOSZPCLog16(uint16(res))
|
|
574
|
6
|
case 0x37: // AAA
|
|
575
|
6
|
if al := p.AL(); ((al & 0xF) > 9) || p.AF {
|
|
576
|
6
|
p.SetAL(al + 6)
|
|
577
|
6
|
p.SetAH(p.AH() + 1)
|
|
578
|
6
|
p.AF, p.CF = true, true
|
|
579
|
6
|
} else {
|
|
580
|
6
|
p.AF, p.CF = false, false
|
|
581
|
|
}
|
|
582
|
6
|
al := p.AL() & 0xF
|
|
583
|
6
|
p.SetAL(al)
|
|
584
|
6
|
p.updateFlagsSZP8(al)
|
|
585
|
6
|
case 0x38, 0x3A: // CMP r/m8,r8
|
|
586
|
6
|
dest, src := p.parseOperands()
|
|
587
|
6
|
a, b := uint32(dest.readByte(p)), uint32(src.readByte(p))
|
|
588
|
6
|
res := a - b
|
|
589
|
6
|
p.updateFlagsOACSub(res, a, b)
|
|
590
|
6
|
p.updateFlagsSZP8(byte(res))
|
|
591
|
6
|
case 0x39, 0x3B: // CMP r/m16,r16
|
|
592
|
6
|
dest, src := p.parseOperands()
|
|
593
|
6
|
a, b := uint32(dest.readWord(p)), uint32(src.readWord(p))
|
|
594
|
6
|
res := a - b
|
|
595
|
6
|
p.updateFlagsOACSub(res, a, b)
|
|
596
|
6
|
p.updateFlagsSZP16(uint16(res))
|
|
597
|
6
|
case 0x3C: // CMP AL,d8
|
|
598
|
6
|
a, b := uint32(p.AL()), uint32(p.readOpcodeStream())
|
|
599
|
6
|
res := a - b
|
|
600
|
6
|
p.updateFlagsOACSub(res, a, b)
|
|
601
|
6
|
p.updateFlagsSZP8(byte(res))
|
|
602
|
0
|
case 0x3D: // CMP AX,d16
|
|
603
|
0
|
a, b := uint32(p.AX), uint32(p.readOpcodeImm16())
|
|
604
|
0
|
res := a - b
|
|
605
|
0
|
p.updateFlagsOACSub(res, a, b)
|
|
606
|
0
|
p.updateFlagsSZP16(uint16(res))
|
|
607
|
6
|
case 0x3F: // AAS
|
|
608
|
6
|
if al := p.AL(); ((al & 0xF) > 9) || p.AF {
|
|
609
|
6
|
p.SetAL(al - 6)
|
|
610
|
6
|
p.SetAH(p.AH() - 1)
|
|
611
|
6
|
p.AF, p.CF = true, true
|
|
612
|
6
|
} else {
|
|
613
|
6
|
p.AF, p.CF = false, false
|
|
614
|
|
}
|
|
615
|
6
|
al := p.AL() & 0xF
|
|
616
|
6
|
p.SetAL(al)
|
|
617
|
6
|
p.updateFlagsSZP8(al)
|
|
618
|
|
|
|
619
|
|
// 0x4x
|
|
620
|
|
|
|
621
|
6
|
case 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47: // INC AX/CX/DX/BX/SP/BP/SI/DI
|
|
622
|
6
|
reg := dataLocation(op-0x40) | registerLocation
|
|
623
|
6
|
a := reg.readWord(p)
|
|
624
|
6
|
res := a + 1
|
|
625
|
6
|
reg.writeWord(p, res)
|
|
626
|
|
|
|
627
|
6
|
cf := p.CF
|
|
628
|
6
|
p.updateFlagsOACAdd(uint32(res), uint32(a), 1)
|
|
629
|
6
|
p.updateFlagsSZP16(res)
|
|
630
|
6
|
p.CF = cf
|
|
631
|
6
|
case 0x48, 0x49, 0x4A, 0x4B, 0x4C, 0x4D, 0x4E, 0x4F: // DEC AX/CX/DX/BX/SP/BP/SI/DI
|
|
632
|
6
|
reg := dataLocation(op-0x40) | registerLocation
|
|
633
|
6
|
a := reg.readWord(p)
|
|
634
|
6
|
res := a - 1
|
|
635
|
6
|
reg.writeWord(p, res)
|
|
636
|
|
|
|
637
|
6
|
cf := p.CF
|
|
638
|
6
|
p.updateFlagsOACSub(uint32(res), uint32(a), 1)
|
|
639
|
6
|
p.updateFlagsSZP16(res)
|
|
640
|
6
|
p.CF = cf
|
|
641
|
|
|
|
642
|
|
// 0x5x
|
|
643
|
|
|
|
644
|
6
|
case 0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57: // PUSH AX/CX/DX/BX/SP/BP/SI/DI
|
|
645
|
6
|
p.push16((dataLocation(op-0x50) | registerLocation).readWord(p))
|
|
646
|
6
|
case 0x58, 0x59, 0x5A, 0x5B, 0x5C, 0x5D, 0x5E, 0x5F: // POP AX/CX/DX/BX/SP/BP/SI/DI
|
|
647
|
6
|
(dataLocation(op-0x58) | registerLocation).writeWord(p, p.pop16())
|
|
648
|
|
|
|
649
|
|
// 0x6x
|
|
650
|
|
|
|
651
|
0
|
case 0x60: // PUSHA (80186)
|
|
652
|
0
|
if p.isV20 {
|
|
653
|
0
|
sp := p.SP
|
|
654
|
0
|
p.push16(p.AX)
|
|
655
|
0
|
p.push16(p.CX)
|
|
656
|
0
|
p.push16(p.DX)
|
|
657
|
0
|
p.push16(p.BX)
|
|
658
|
0
|
p.push16(sp)
|
|
659
|
0
|
p.push16(p.BP)
|
|
660
|
0
|
p.push16(p.SI)
|
|
661
|
0
|
p.push16(p.DI)
|
|
662
|
0
|
} else {
|
|
663
|
0
|
p.invalidOpcode()
|
|
664
|
|
}
|
|
665
|
0
|
case 0x61: // POPA (80186)
|
|
666
|
0
|
if p.isV20 {
|
|
667
|
0
|
p.DI = p.pop16()
|
|
668
|
0
|
p.SI = p.pop16()
|
|
669
|
0
|
p.BP = p.pop16()
|
|
670
|
0
|
p.pop16()
|
|
671
|
0
|
p.BX = p.pop16()
|
|
672
|
0
|
p.DX = p.pop16()
|
|
673
|
0
|
p.CX = p.pop16()
|
|
674
|
0
|
p.AX = p.pop16()
|
|
675
|
0
|
} else {
|
|
676
|
0
|
p.invalidOpcode()
|
|
677
|
|
}
|
|
678
|
0
|
case 0x62: // BOUND (80186)
|
|
679
|
0
|
if p.isV20 {
|
|
680
|
0
|
p.readModRegRM()
|
|
681
|
0
|
idx := signExtend32(p.regLocation().readWord(p))
|
|
682
|
0
|
addr := p.rmLocation().getAddress()
|
|
683
|
|
|
|
684
|
0
|
if idx < signExtend32(p.ReadWord(addr.Pointer())) || idx > signExtend32(p.ReadWord(addr.AddInt(2).Pointer())) {
|
|
685
|
0
|
p.IP = p.decodeAt
|
|
686
|
0
|
p.doInterrupt(5)
|
|
687
|
|
}
|
|
688
|
0
|
} else {
|
|
689
|
0
|
p.invalidOpcode()
|
|
690
|
|
}
|
|
691
|
0
|
case 0x69, 0x6B: // IMUL r/m16,d8/d16 (80186)
|
|
692
|
0
|
if p.isV20 {
|
|
693
|
0
|
p.readModRegRM()
|
|
694
|
0
|
dest := p.rmLocation()
|
|
695
|
0
|
a := signExtend32(dest.readWord(p))
|
|
696
|
|
|
|
697
|
0
|
var res uint32
|
|
698
|
0
|
if op == 69 {
|
|
699
|
0
|
res = a * signExtend32(signExtend16(p.readOpcodeStream()))
|
|
700
|
0
|
} else {
|
|
701
|
0
|
res = a * signExtend32(p.readOpcodeImm16())
|
|
702
|
|
}
|
|
703
|
0
|
res16 := uint16(res & 0xFFFF)
|
|
704
|
0
|
upper := uint16(res >> 16)
|
|
705
|
|
|
|
706
|
0
|
dest.writeWord(p, res16)
|
|
707
|
0
|
p.updateFlagsSZP16(res16)
|
|
708
|
|
|
|
709
|
0
|
if res16&0x8000 == 0x8000 {
|
|
710
|
0
|
p.CF = upper != 0xFFFF
|
|
711
|
0
|
} else {
|
|
712
|
0
|
p.CF = upper != 0x0
|
|
713
|
|
}
|
|
714
|
0
|
p.OF = p.CF
|
|
715
|
0
|
} else {
|
|
716
|
0
|
p.invalidOpcode()
|
|
717
|
|
}
|
|
718
|
0
|
case 0x68, 0x6A, 0x6C, 0x6D, 0x6E, 0x6F:
|
|
719
|
0
|
if p.isV20 {
|
|
720
|
0
|
log.Printf("opcode not implemented: 0x%X", op)
|
|
721
|
0
|
p.Break()
|
|
722
|
0
|
} else {
|
|
723
|
0
|
p.invalidOpcode()
|
|
724
|
|
}
|
|
725
|
|
|
|
726
|
|
// 0x7x
|
|
727
|
|
|
|
728
|
6
|
case 0x70: // JO rel8
|
|
729
|
6
|
p.jmpRel8Cond(p.OF)
|
|
730
|
6
|
case 0x71: // JNO rel8
|
|
731
|
6
|
p.jmpRel8Cond(!p.OF)
|
|
732
|
6
|
case 0x72: // JB/JNAE rel8
|
|
733
|
6
|
p.jmpRel8Cond(p.CF)
|
|
734
|
6
|
case 0x73: // JNB/JAE rel8
|
|
735
|
6
|
p.jmpRel8Cond(!p.CF)
|
|
736
|
6
|
case 0x74: // JE/JZ rel8
|
|
737
|
6
|
p.jmpRel8Cond(p.ZF)
|
|
738
|
6
|
case 0x75: // JNE/JNZ rel8
|
|
739
|
6
|
p.jmpRel8Cond(!p.ZF)
|
|
740
|
6
|
case 0x76: // JBE/JNA rel8
|
|
741
|
6
|
p.jmpRel8Cond(p.CF || p.ZF)
|
|
742
|
6
|
case 0x77: // JNBE/JA rel8
|
|
743
|
6
|
p.jmpRel8Cond(!p.CF && !p.ZF)
|
|
744
|
6
|
case 0x78: // JS rel8
|
|
745
|
6
|
p.jmpRel8Cond(p.SF)
|
|
746
|
6
|
case 0x79: // JNS rel8
|
|
747
|
6
|
p.jmpRel8Cond(!p.SF)
|
|
748
|
6
|
case 0x7A: // JP/JPE rel8
|
|
749
|
6
|
p.jmpRel8Cond(p.PF)
|
|
750
|
6
|
case 0x7B: // JNP/JPO rel8
|
|
751
|
6
|
p.jmpRel8Cond(!p.PF)
|
|
752
|
6
|
case 0x7C: // JL/JNGE rel8
|
|
753
|
6
|
p.jmpRel8Cond(p.SF != p.OF)
|
|
754
|
6
|
case 0x7D: // JNL/JGE rel8
|
|
755
|
6
|
p.jmpRel8Cond(p.SF == p.OF)
|
|
756
|
6
|
case 0x7E: // JLE/JNG rel8
|
|
757
|
6
|
p.jmpRel8Cond(p.SF != p.OF || p.ZF)
|
|
758
|
6
|
case 0x7F: // JNLE/JG rel8
|
|
759
|
6
|
p.jmpRel8Cond(!p.ZF && p.SF == p.OF)
|
|
760
|
|
|
|
761
|
|
// 0x8x
|
|
762
|
|
|
|
763
|
6
|
case 0x80, 0x82: // _ALU1 r/m8,d8
|
|
764
|
6
|
p.grp1()
|
|
765
|
6
|
case 0x81, 0x83: // _ALU1 r/m16,d16
|
|
766
|
6
|
p.grp1w()
|
|
767
|
6
|
case 0x84: // TEST r/m8,r8
|
|
768
|
6
|
p.readModRegRM()
|
|
769
|
6
|
a, b := p.rmLocation().readByte(p), p.regLocation().readByte(p)
|
|
770
|
6
|
p.updateFlagsOSZPCLog8(a & b)
|
|
771
|
6
|
case 0x85: // TEST r/m16,r16
|
|
772
|
6
|
p.readModRegRM()
|
|
773
|
6
|
a, b := p.rmLocation().readWord(p), p.regLocation().readWord(p)
|
|
774
|
6
|
p.updateFlagsOSZPCLog16(a & b)
|
|
775
|
6
|
case 0x86: // XCHG r8,r/m8
|
|
776
|
6
|
p.readModRegRM()
|
|
777
|
6
|
dst, src := p.regLocation(), p.rmLocation()
|
|
778
|
6
|
d, s := dst.readByte(p), src.readByte(p)
|
|
779
|
6
|
dst.writeByte(p, s)
|
|
780
|
6
|
src.writeByte(p, d)
|
|
781
|
6
|
case 0x87: // XCHG r16,r/m16
|
|
782
|
6
|
p.readModRegRM()
|
|
783
|
6
|
dst, src := p.regLocation(), p.rmLocation()
|
|
784
|
6
|
d, s := dst.readWord(p), src.readWord(p)
|
|
785
|
6
|
dst.writeWord(p, s)
|
|
786
|
6
|
src.writeWord(p, d)
|
|
787
|
6
|
case 0x88, 0x8A: // MOV r/m8,r8
|
|
788
|
6
|
dest, src := p.parseOperands()
|
|
789
|
6
|
dest.writeByte(p, src.readByte(p))
|
|
790
|
6
|
case 0x89, 0x8B: // MOV r/m16,r16
|
|
791
|
6
|
dest, src := p.parseOperands()
|
|
792
|
6
|
dest.writeWord(p, src.readWord(p))
|
|
793
|
6
|
case 0x8C: // _MOV r/m16,sr
|
|
794
|
6
|
p.readModRegRM()
|
|
795
|
6
|
p.rmLocation().writeWord(p, p.segLocation().readWord(p))
|
|
796
|
6
|
case 0x8D: // LEA r16,r/m16
|
|
797
|
6
|
p.readModRegRM()
|
|
798
|
6
|
p.segOverride = &zero16
|
|
799
|
6
|
addr := p.rmLocation().getPointer()
|
|
800
|
6
|
p.regLocation().writeWord(p, uint16(addr))
|
|
801
|
6
|
case 0x8E: // _MOV sr,r/m16
|
|
802
|
6
|
p.readModRegRM()
|
|
803
|
6
|
p.segLocation().writeWord(p, p.rmLocation().readWord(p))
|
|
804
|
6
|
case 0x8F: // _POP r/m16
|
|
805
|
6
|
p.readModRegRM()
|
|
806
|
6
|
p.rmLocation().writeWord(p, p.pop16())
|
|
807
|
|
|
|
808
|
|
// 0x9x
|
|
809
|
|
|
|
810
|
6
|
case 0x90: // NOP
|
|
811
|
6
|
p.stats.NOP++
|
|
812
|
0
|
case 0x91: // XCHG AX,CX
|
|
813
|
0
|
opXCHG(&p.AX, &p.CX)
|
|
814
|
0
|
case 0x92: // XCHG AX,DX
|
|
815
|
0
|
opXCHG(&p.AX, &p.DX)
|
|
816
|
6
|
case 0x93: // XCHG AX,BX
|
|
817
|
6
|
opXCHG(&p.AX, &p.BX)
|
|
818
|
0
|
case 0x94: // XCHG AX,SP
|
|
819
|
0
|
opXCHG(&p.AX, &p.SP)
|
|
820
|
0
|
case 0x95: // XCHG AX,BP
|
|
821
|
0
|
opXCHG(&p.AX, &p.BP)
|
|
822
|
0
|
case 0x96: // XCHG AX,SI
|
|
823
|
0
|
opXCHG(&p.AX, &p.SI)
|
|
824
|
0
|
case 0x97: // XCHG AX,DI
|
|
825
|
0
|
opXCHG(&p.AX, &p.DI)
|
|
826
|
6
|
case 0x98: // CBW
|
|
827
|
6
|
p.AX = signExtend16(p.AL())
|
|
828
|
6
|
case 0x99: // CWD
|
|
829
|
6
|
if p.AX&0x8000 != 0 {
|
|
830
|
6
|
p.DX = 0xFFFF
|
|
831
|
6
|
} else {
|
|
832
|
6
|
p.DX = 0
|
|
833
|
|
}
|
|
834
|
6
|
case 0x9A: // CALL seg:a16
|
|
835
|
6
|
ip := p.readOpcodeImm16()
|
|
836
|
6
|
cs := p.readOpcodeImm16()
|
|
837
|
6
|
p.push16(p.CS)
|
|
838
|
6
|
p.push16(p.IP)
|
|
839
|
6
|
p.IP, p.CS = ip, cs
|
|
840
|
0
|
case 0x9B: // WAIT
|
|
841
|
6
|
case 0x9C: // PUSHF
|
|
842
|
6
|
p.push16(p.packFlags16())
|
|
843
|
6
|
case 0x9D: // POPF
|
|
844
|
6
|
p.unpackFlags16(p.pop16())
|
|
845
|
6
|
case 0x9E: // SAHF
|
|
846
|
6
|
p.unpackFlags8(p.AH())
|
|
847
|
6
|
case 0x9F: // LAHF
|
|
848
|
6
|
p.SetAH(p.packFlags8())
|
|
849
|
|
|
|
850
|
|
// 0xAx
|
|
851
|
|
|
|
852
|
0
|
case 0xA0: // MOV AL,[addr]
|
|
853
|
0
|
p.SetAL(p.ReadByte(memory.NewPointer(p.getSeg(p.DS), p.readOpcodeImm16())))
|
|
854
|
6
|
case 0xA1: // MOV AX,[addr]
|
|
855
|
6
|
p.AX = p.ReadWord(memory.NewPointer(p.getSeg(p.DS), p.readOpcodeImm16()))
|
|
856
|
6
|
case 0xA2: // MOV [addr],AL
|
|
857
|
6
|
p.WriteByte(memory.NewPointer(p.getSeg(p.DS), p.readOpcodeImm16()), p.AL())
|
|
858
|
6
|
case 0xA3: // MOV [addr],AX
|
|
859
|
6
|
p.WriteWord(memory.NewPointer(p.getSeg(p.DS), p.readOpcodeImm16()), p.AX)
|
|
860
|
6
|
case 0xA4: // MOVSB
|
|
861
|
6
|
p.WriteByte(memory.NewPointer(p.ES, p.DI), p.ReadByte(memory.NewPointer(p.getSeg(p.DS), p.SI)))
|
|
862
|
6
|
p.updateDISI()
|
|
863
|
6
|
case 0xA5: // MOVSW
|
|
864
|
6
|
p.WriteWord(memory.NewPointer(p.ES, p.DI), p.ReadWord(memory.NewPointer(p.getSeg(p.DS), p.SI)))
|
|
865
|
6
|
p.updateDISI()
|
|
866
|
6
|
case 0xA6: // CMPSB
|
|
867
|
6
|
a, b := uint32(p.ReadByte(memory.NewPointer(p.getSeg(p.DS), p.SI))), uint32(p.ReadByte(memory.NewPointer(p.ES, p.DI)))
|
|
868
|
6
|
res := a - b
|
|
869
|
6
|
p.updateFlagsOACSub(res, a, b)
|
|
870
|
6
|
p.updateFlagsSZP8(byte(res))
|
|
871
|
6
|
p.updateDISI()
|
|
872
|
6
|
case 0xA7: // CMPSW
|
|
873
|
6
|
a, b := uint32(p.ReadWord(memory.NewPointer(p.getSeg(p.DS), p.SI))), uint32(p.ReadWord(memory.NewPointer(p.ES, p.DI)))
|
|
874
|
6
|
res := a - b
|
|
875
|
6
|
p.updateFlagsOACSub(res, a, b)
|
|
876
|
6
|
p.updateFlagsSZP16(uint16(res))
|
|
877
|
6
|
p.updateDISI()
|
|
878
|
6
|
case 0xA8: // TEST AL,d8
|
|
879
|
6
|
p.updateFlagsSZP8(p.AL() & p.readOpcodeStream())
|
|
880
|
6
|
case 0xA9: // TEST AX,d16
|
|
881
|
6
|
p.updateFlagsSZP16(p.AX & p.readOpcodeImm16())
|
|
882
|
6
|
case 0xAA: // STOSB
|
|
883
|
6
|
p.WriteByte(memory.NewPointer(p.ES, p.DI), p.AL())
|
|
884
|
6
|
p.updateDI()
|
|
885
|
6
|
case 0xAB: // STOSW
|
|
886
|
6
|
p.WriteWord(memory.NewPointer(p.ES, p.DI), p.AX)
|
|
887
|
6
|
p.updateDI()
|
|
888
|
6
|
case 0xAC: // LODSB
|
|
889
|
6
|
p.SetAL(p.ReadByte(memory.NewPointer(p.getSeg(p.DS), p.SI)))
|
|
890
|
6
|
p.updateSI()
|
|
891
|
6
|
case 0xAD: // LODSW
|
|
892
|
6
|
p.AX = p.ReadWord(memory.NewPointer(p.getSeg(p.DS), p.SI))
|
|
893
|
6
|
p.updateSI()
|
|
894
|
6
|
case 0xAE: // SCASB
|
|
895
|
6
|
a, b := uint32(p.AL()), uint32(p.ReadByte(memory.NewPointer(p.ES, p.DI)))
|
|
896
|
6
|
res := a - b
|
|
897
|
6
|
p.updateFlagsOACSub(res, a, b)
|
|
898
|
6
|
p.updateFlagsSZP8(byte(res))
|
|
899
|
6
|
p.updateDI()
|
|
900
|
6
|
case 0xAF: // SCASW
|
|
901
|
6
|
a, b := uint32(p.AX), uint32(p.ReadWord(memory.NewPointer(p.ES, p.DI)))
|
|
902
|
6
|
res := a - b
|
|
903
|
6
|
p.updateFlagsOACSub(res, a, b)
|
|
904
|
6
|
p.updateFlagsSZP16(uint16(res))
|
|
905
|
6
|
p.updateDI()
|
|
906
|
|
|
|
907
|
|
// 0xBx
|
|
908
|
|
|
|
909
|
6
|
case 0xB0, 0xB1, 0xB2, 0xB3, 0xB4, 0xB5, 0xB6, 0xB7: // MOV AL/CL/DL/BL/AH/CH/DH/BH,d8
|
|
910
|
6
|
(dataLocation(op-0xB0) | registerLocation).writeByte(p, p.readOpcodeStream())
|
|
911
|
6
|
case 0xB8, 0xB9, 0xBA, 0xBB, 0xBC, 0xBD, 0xBE, 0xBF: // MOV AX/CX/DX/BX/SP/BP/SI/DI,d16
|
|
912
|
6
|
(dataLocation(op-0xB8) | registerLocation).writeWord(p, p.readOpcodeImm16())
|
|
913
|
|
|
|
914
|
|
// 0xCx
|
|
915
|
|
|
|
916
|
0
|
case 0xC0: // SHL r/m8,d8 (80186)
|
|
917
|
0
|
if p.isV20 {
|
|
918
|
0
|
p.readModRegRM()
|
|
919
|
0
|
dest := p.rmLocation()
|
|
920
|
0
|
dest.writeByte(p, p.shiftOrRotate8(p.getReg(), dest.readByte(p), p.readOpcodeStream()))
|
|
921
|
0
|
} else {
|
|
922
|
0
|
p.invalidOpcode()
|
|
923
|
|
}
|
|
924
|
0
|
case 0xC1: // SHL r/m16,d16 (80186)
|
|
925
|
0
|
if p.isV20 {
|
|
926
|
0
|
p.readModRegRM()
|
|
927
|
0
|
dest := p.rmLocation()
|
|
928
|
0
|
dest.writeWord(p, p.shiftOrRotate16(p.getReg(), dest.readWord(p), p.readOpcodeStream()))
|
|
929
|
0
|
} else {
|
|
930
|
0
|
p.invalidOpcode()
|
|
931
|
|
}
|
|
932
|
6
|
case 0xC2: // RET d16
|
|
933
|
6
|
ip := p.pop16()
|
|
934
|
6
|
p.SP += p.readOpcodeImm16()
|
|
935
|
6
|
p.IP = ip
|
|
936
|
6
|
case 0xC3: // RET
|
|
937
|
6
|
p.IP = p.pop16()
|
|
938
|
6
|
case 0xC4: // LES r16,m32
|
|
939
|
6
|
p.readModRegRM()
|
|
940
|
6
|
addr := p.rmLocation().getAddress()
|
|
941
|
6
|
p.regLocation().writeWord(p, p.ReadWord(addr.Pointer()))
|
|
942
|
6
|
p.ES = p.ReadWord(addr.AddInt(2).Pointer())
|
|
943
|
6
|
case 0xC5: // LDS r16,m32
|
|
944
|
6
|
p.readModRegRM()
|
|
945
|
6
|
addr := p.rmLocation().getAddress()
|
|
946
|
6
|
p.regLocation().writeWord(p, p.ReadWord(addr.Pointer()))
|
|
947
|
6
|
p.DS = p.ReadWord(addr.AddInt(2).Pointer())
|
|
948
|
6
|
case 0xC6: // _MOV r/m8,d8
|
|
949
|
6
|
p.readModRegRM()
|
|
950
|
6
|
p.rmLocation().writeByte(p, p.readOpcodeStream())
|
|
951
|
6
|
case 0xC7: // _MOV r/m16,d16
|
|
952
|
6
|
p.readModRegRM()
|
|
953
|
6
|
p.rmLocation().writeWord(p, p.readOpcodeImm16())
|
|
954
|
0
|
case 0xC8: // ENTER (80186)
|
|
955
|
0
|
p.invalidOpcode()
|
|
956
|
0
|
case 0xC9: // LEAVE (80186)
|
|
957
|
0
|
p.invalidOpcode()
|
|
958
|
6
|
case 0xCA: // RETF d16
|
|
959
|
6
|
sp := p.readOpcodeImm16()
|
|
960
|
6
|
p.IP = p.pop16()
|
|
961
|
6
|
p.CS = p.pop16()
|
|
962
|
6
|
p.SP += sp
|
|
963
|
6
|
case 0xCB: // RETF
|
|
964
|
6
|
p.IP = p.pop16()
|
|
965
|
6
|
p.CS = p.pop16()
|
|
966
|
0
|
case 0xCC: // INT 3
|
|
967
|
0
|
p.doInterrupt(3)
|
|
968
|
6
|
case 0xCD: // INT d8
|
|
969
|
6
|
p.doInterrupt(int(p.readOpcodeStream()))
|
|
970
|
6
|
case 0xCE: // INTO
|
|
971
|
6
|
if p.OF {
|
|
972
|
6
|
p.doInterrupt(4)
|
|
973
|
|
}
|
|
974
|
6
|
case 0xCF: // IRET
|
|
975
|
6
|
p.IP = p.pop16()
|
|
976
|
6
|
p.CS = p.pop16()
|
|
977
|
6
|
p.unpackFlags16(p.pop16())
|
|
978
|
|
|
|
979
|
|
// 0xDx
|
|
980
|
|
|
|
981
|
6
|
case 0xD0: // _ROT r/m8,1
|
|
982
|
6
|
p.readModRegRM()
|
|
983
|
6
|
dest := p.rmLocation()
|
|
984
|
6
|
dest.writeByte(p, p.shiftOrRotate8(p.getReg(), dest.readByte(p), 1))
|
|
985
|
6
|
case 0xD1: // _ROT r/m16,1
|
|
986
|
6
|
p.readModRegRM()
|
|
987
|
6
|
dest := p.rmLocation()
|
|
988
|
6
|
dest.writeWord(p, p.shiftOrRotate16(p.getReg(), dest.readWord(p), 1))
|
|
989
|
6
|
case 0xD2: // _ROT r/m8,CL
|
|
990
|
6
|
p.readModRegRM()
|
|
991
|
6
|
dest := p.rmLocation()
|
|
992
|
6
|
dest.writeByte(p, p.shiftOrRotate8(p.getReg(), dest.readByte(p), p.CL()))
|
|
993
|
6
|
case 0xD3: // _ROT r/m16,CL
|
|
994
|
6
|
p.readModRegRM()
|
|
995
|
6
|
dest := p.rmLocation()
|
|
996
|
6
|
dest.writeWord(p, p.shiftOrRotate16(p.getReg(), dest.readWord(p), p.CL()))
|
|
997
|
6
|
case 0xD4: // AAM *d8
|
|
998
|
6
|
if a, b := p.AL(), p.readOpcodeStream(); b == 0 {
|
|
999
|
6
|
p.divisionByZero()
|
|
1000
|
6
|
} else {
|
|
1001
|
6
|
p.SetAH(a / b)
|
|
1002
|
6
|
p.SetAL(a % b)
|
|
1003
|
6
|
p.updateFlagsSZP16(p.AX)
|
|
1004
|
|
}
|
|
1005
|
6
|
case 0xD5: // AAD *d8
|
|
1006
|
6
|
p.AX = (uint16(p.AL()) + uint16(p.AH())*uint16(p.readOpcodeStream())) & 0xFF
|
|
1007
|
6
|
p.updateFlagsSZP16(p.AX)
|
|
1008
|
0
|
case 0xD6: // *SALC
|
|
1009
|
|
// This is XLAT on V20.
|
|
1010
|
0
|
if !p.isV20 {
|
|
1011
|
0
|
if p.CF {
|
|
1012
|
0
|
p.SetAL(0xFF)
|
|
1013
|
0
|
} else {
|
|
1014
|
0
|
p.SetAL(0)
|
|
1015
|
|
}
|
|
1016
|
0
|
break
|
|
1017
|
|
}
|
|
1018
|
0
|
fallthrough
|
|
1019
|
6
|
case 0xD7: // XLAT
|
|
1020
|
6
|
p.SetAL(p.ReadByte(memory.NewPointer(p.getSeg(p.DS), p.BX+uint16(p.AL()))))
|
|
1021
|
0
|
case 0xD8, 0xD9, 0xDA, 0xDB, 0xDC, 0xDD, 0xDE, 0xDF: // ESC
|
|
1022
|
0
|
p.readModRegRM()
|
|
1023
|
0
|
_, src := p.parseOperands()
|
|
1024
|
0
|
src.readByte(p)
|
|
1025
|
|
|
|
1026
|
|
// 0xEx
|
|
1027
|
|
|
|
1028
|
6
|
case 0xE0: // LOOPNZ/NE rel8
|
|
1029
|
6
|
p.CX--
|
|
1030
|
6
|
p.jmpRel8Cond(p.CX != 0 && !p.ZF)
|
|
1031
|
6
|
case 0xE1: // LOOPZ/E rel8
|
|
1032
|
6
|
p.CX--
|
|
1033
|
6
|
p.jmpRel8Cond(p.CX != 0 && p.ZF)
|
|
1034
|
6
|
case 0xE2: // LOOP rel8
|
|
1035
|
6
|
p.CX--
|
|
1036
|
6
|
p.jmpRel8Cond(p.CX != 0)
|
|
1037
|
6
|
case 0xE3: // JCXZ rel8
|
|
1038
|
6
|
p.jmpRel8Cond(p.CX == 0)
|
|
1039
|
0
|
case 0xE4: // IN AL,[d8]
|
|
1040
|
0
|
p.SetAL(p.InByte(uint16(p.readOpcodeStream())))
|
|
1041
|
0
|
case 0xE5: // IN AX,[d8]
|
|
1042
|
0
|
p.AX = p.InWord(uint16(p.readOpcodeStream()))
|
|
1043
|
0
|
case 0xE6: // OUT [d8],AL
|
|
1044
|
0
|
p.OutByte(uint16(p.readOpcodeStream()), p.AL())
|
|
1045
|
0
|
case 0xE7: // OUT [d8],AX
|
|
1046
|
0
|
p.OutWord(uint16(p.readOpcodeStream()), p.AX)
|
|
1047
|
6
|
case 0xE8: // CALL rel16
|
|
1048
|
6
|
p.push16(p.jmpRel16())
|
|
1049
|
6
|
case 0xE9: // JMP rel16
|
|
1050
|
6
|
p.jmpRel16()
|
|
1051
|
6
|
case 0xEA: // JMP seg:a16
|
|
1052
|
6
|
ip := p.readOpcodeImm16()
|
|
1053
|
6
|
p.CS = p.readOpcodeImm16()
|
|
1054
|
6
|
p.IP = ip
|
|
1055
|
6
|
case 0xEB: // JMP rel8
|
|
1056
|
6
|
p.jmpRel8()
|
|
1057
|
0
|
case 0xEC: // IN AL,[DX]
|
|
1058
|
0
|
p.SetAL(p.InByte(p.DX))
|
|
1059
|
0
|
case 0xED: // IN AX,[DX]
|
|
1060
|
0
|
p.AX = p.InWord(p.DX)
|
|
1061
|
0
|
case 0xEE: // OUT [DX],AL
|
|
1062
|
0
|
p.OutByte(p.DX, p.AL())
|
|
1063
|
6
|
case 0xEF: // OUT [DX],AX
|
|
1064
|
6
|
p.OutWord(p.DX, p.AX)
|
|
1065
|
|
|
|
1066
|
|
// 0xFx
|
|
1067
|
|
|
|
1068
|
6
|
case 0xF4: // HLT
|
|
1069
|
6
|
p.halted = true
|
|
1070
|
6
|
case 0xF5: // CMC
|
|
1071
|
6
|
p.CF = !p.CF
|
|
1072
|
6
|
case 0xF6: // _ALU2 r/m8,d8
|
|
1073
|
6
|
p.grp3a()
|
|
1074
|
6
|
case 0xF7: // _ALU2 r/m16,d16
|
|
1075
|
6
|
p.grp3b()
|
|
1076
|
6
|
case 0xF8: // CLC
|
|
1077
|
6
|
p.CF = false
|
|
1078
|
6
|
case 0xF9: // STC
|
|
1079
|
6
|
p.CF = true
|
|
1080
|
6
|
case 0xFA: // CLI
|
|
1081
|
6
|
p.IF = false
|
|
1082
|
6
|
case 0xFB: // STI
|
|
1083
|
6
|
p.IF = true
|
|
1084
|
6
|
case 0xFC: // CLD
|
|
1085
|
6
|
p.DF = false
|
|
1086
|
6
|
case 0xFD: // STD
|
|
1087
|
6
|
p.DF = true
|
|
1088
|
6
|
case 0xFE: // _MISC r/m8
|
|
1089
|
6
|
p.grp4()
|
|
1090
|
6
|
case 0xFF: // _MISC r/m16
|
|
1091
|
6
|
p.grp5()
|
|
1092
|
0
|
default:
|
|
1093
|
0
|
p.invalidOpcode()
|
|
1094
|
|
}
|
|
1095
|
|
|
|
1096
|
6
|
p.stats.NumInstructions++
|
|
1097
|
6
|
return nil
|
|
1098
|
|
}
|
|
1099
|
|
|
|
1100
|
|
func (p *CPU) grp1() {
|
|
1101
|
6
|
p.readModRegRM()
|
|
1102
|
6
|
dest := p.rmLocation()
|
|
1103
|
6
|
a, b := uint32(dest.readByte(p)), uint32(p.readOpcodeStream())
|
|
1104
|
|
|
|
1105
|
6
|
var res uint32
|
|
1106
|
6
|
switch op := p.getReg(); op {
|
|
1107
|
6
|
case 0:
|
|
1108
|
6
|
res = a + b
|
|
1109
|
6
|
p.updateFlagsOACAdd(res, a, b)
|
|
1110
|
6
|
case 1:
|
|
1111
|
6
|
res = a | b
|
|
1112
|
6
|
p.clearFlagsOC()
|
|
1113
|
6
|
case 2:
|
|
1114
|
6
|
res = a + b + b2ui32(p.CF)
|
|
1115
|
6
|
p.updateFlagsOACAdd(res, a, b)
|
|
1116
|
6
|
case 3:
|
|
1117
|
6
|
res = a - (b + b2ui32(p.CF))
|
|
1118
|
6
|
p.updateFlagsOACSubCarry(res, a, b)
|
|
1119
|
6
|
case 4:
|
|
1120
|
6
|
res = a & b
|
|
1121
|
6
|
p.clearFlagsOC()
|
|
1122
|
6
|
case 5:
|
|
1123
|
6
|
res = a - b
|
|
1124
|
6
|
p.updateFlagsOACSub(res, a, b)
|
|
1125
|
6
|
case 6:
|
|
1126
|
6
|
res = a ^ b
|
|
1127
|
6
|
p.clearFlagsOC()
|
|
1128
|
6
|
case 7:
|
|
1129
|
6
|
res = a - b
|
|
1130
|
6
|
p.updateFlagsOACSub(res, a, b)
|
|
1131
|
6
|
p.updateFlagsSZP8(byte(res))
|
|
1132
|
6
|
return
|
|
1133
|
0
|
default:
|
|
1134
|
0
|
log.Panicf("invalid opcode: grp1(0x%X)", op)
|
|
1135
|
|
}
|
|
1136
|
|
|
|
1137
|
6
|
dest.writeByte(p, byte(res))
|
|
1138
|
6
|
p.updateFlagsSZP8(byte(res))
|
|
1139
|
|
}
|
|
1140
|
|
|
|
1141
|
|
func (p *CPU) grp1w() {
|
|
1142
|
6
|
p.readModRegRM()
|
|
1143
|
6
|
dest := p.rmLocation()
|
|
1144
|
6
|
a := uint32(dest.readWord(p))
|
|
1145
|
|
|
|
1146
|
|
// Not super nice. :(
|
|
1147
|
6
|
var b uint32
|
|
1148
|
6
|
if p.opcode == 0x83 {
|
|
1149
|
6
|
b = uint32(signExtend16(p.readOpcodeStream()))
|
|
1150
|
6
|
} else {
|
|
1151
|
6
|
b = uint32(p.readOpcodeImm16())
|
|
1152
|
|
}
|
|
1153
|
|
|
|
1154
|
6
|
var res uint32
|
|
1155
|
6
|
switch op := p.getReg(); op {
|
|
1156
|
6
|
case 0:
|
|
1157
|
6
|
res = a + b
|
|
1158
|
6
|
p.updateFlagsOACAdd(res, a, b)
|
|
1159
|
6
|
case 1:
|
|
1160
|
6
|
res = a | b
|
|
1161
|
6
|
p.clearFlagsOC()
|
|
1162
|
6
|
case 2:
|
|
1163
|
6
|
res = a + b + b2ui32(p.CF)
|
|
1164
|
6
|
p.updateFlagsOACAdd(res, a, b)
|
|
1165
|
6
|
case 3:
|
|
1166
|
6
|
res = a - (b + b2ui32(p.CF))
|
|
1167
|
6
|
p.updateFlagsOACSubCarry(res, a, b)
|
|
1168
|
6
|
case 4:
|
|
1169
|
6
|
res = a & b
|
|
1170
|
6
|
p.clearFlagsOC()
|
|
1171
|
6
|
case 5:
|
|
1172
|
6
|
res = a - b
|
|
1173
|
6
|
p.updateFlagsOACSub(res, a, b)
|
|
1174
|
6
|
case 6:
|
|
1175
|
6
|
res = a ^ b
|
|
1176
|
6
|
p.clearFlagsOC()
|
|
1177
|
6
|
case 7:
|
|
1178
|
6
|
res = a - b
|
|
1179
|
6
|
p.updateFlagsOACSub(res, a, b)
|
|
1180
|
6
|
p.updateFlagsSZP16(uint16(res))
|
|
1181
|
6
|
return
|
|
1182
|
0
|
default:
|
|
1183
|
0
|
log.Panicf("invalid opcode: grp1w(0x%X)", op)
|
|
1184
|
|
}
|
|
1185
|
|
|
|
1186
|
6
|
dest.writeWord(p, uint16(res))
|
|
1187
|
6
|
p.updateFlagsSZP16(uint16(res))
|
|
1188
|
|
}
|
|
1189
|
|
|
|
1190
|
|
func (p *CPU) opDIV8(a uint16, b byte) {
|
|
1191
|
6
|
if b == 0 {
|
|
1192
|
0
|
p.divisionByZero()
|
|
1193
|
0
|
return
|
|
1194
|
|
}
|
|
1195
|
|
|
|
1196
|
6
|
if res := a / uint16(b); res > 0xFF {
|
|
1197
|
6
|
p.divisionByZero()
|
|
1198
|
6
|
} else {
|
|
1199
|
6
|
p.SetAL(byte(res))
|
|
1200
|
6
|
p.SetAH(byte(a % uint16(b)))
|
|
1201
|
|
}
|
|
1202
|
|
}
|
|
1203
|
|
|
|
1204
|
|
func (p *CPU) opIDIV8(a uint16, b byte) {
|
|
1205
|
|
// Reference: fake86's - cpu.c
|
|
1206
|
|
|
|
1207
|
6
|
if b == 0 {
|
|
1208
|
0
|
p.divisionByZero()
|
|
1209
|
0
|
return
|
|
1210
|
|
}
|
|
1211
|
|
|
|
1212
|
6
|
d := signExtend16(b)
|
|
1213
|
6
|
sign := ((a ^ d) & 0x8000) != 0
|
|
1214
|
|
|
|
1215
|
6
|
if a >= 0x8000 {
|
|
1216
|
6
|
a = (^a + 1) & 0xFFFF
|
|
1217
|
|
}
|
|
1218
|
6
|
if d >= 0x8000 {
|
|
1219
|
6
|
d = (^d + 1) & 0xFFFF
|
|
1220
|
|
}
|
|
1221
|
|
|
|
1222
|
6
|
res1, res2 := a/d, a%d
|
|
1223
|
6
|
if res1&0xFF00 != 0 {
|
|
1224
|
6
|
p.divisionByZero()
|
|
1225
|
6
|
return
|
|
1226
|
|
}
|
|
1227
|
|
|
|
1228
|
6
|
if sign {
|
|
1229
|
6
|
res1 = (^res1 + 1) & 0xFF
|
|
1230
|
6
|
res2 = (^res2 + 1) & 0xFF
|
|
1231
|
|
}
|
|
1232
|
|
|
|
1233
|
6
|
p.SetAL(byte(res1))
|
|
1234
|
6
|
p.SetAH(byte(res2))
|
|
1235
|
|
}
|
|
1236
|
|
|
|
1237
|
|
func (p *CPU) opDIV16(a uint32, b uint16) {
|
|
1238
|
6
|
if b == 0 {
|
|
1239
|
6
|
p.divisionByZero()
|
|
1240
|
6
|
return
|
|
1241
|
|
}
|
|
1242
|
|
|
|
1243
|
6
|
if res := a / uint32(b); res > 0xFFFF {
|
|
1244
|
6
|
p.divisionByZero()
|
|
1245
|
6
|
} else {
|
|
1246
|
6
|
p.AX, p.DX = uint16(res), uint16(a%uint32(b))
|
|
1247
|
|
}
|
|
1248
|
|
}
|
|
1249
|
|
|
|
1250
|
|
func (p *CPU) opIDIV16(a uint32, b uint16) {
|
|
1251
|
|
// Reference: fake86's - cpu.c
|
|
1252
|
|
|
|
1253
|
6
|
if b == 0 {
|
|
1254
|
0
|
p.divisionByZero()
|
|
1255
|
0
|
return
|
|
1256
|
|
}
|
|
1257
|
|
|
|
1258
|
6
|
d := signExtend32(b)
|
|
1259
|
6
|
sign := ((a ^ d) & 0x80000000) != 0
|
|
1260
|
|
|
|
1261
|
6
|
if a >= 0x80000000 {
|
|
1262
|
6
|
a = (^a + 1) & 0xFFFFFFFF
|
|
1263
|
|
}
|
|
1264
|
6
|
if d >= 0x80000000 {
|
|
1265
|
6
|
d = (^d + 1) & 0xFFFFFFFF
|
|
1266
|
|
}
|
|
1267
|
|
|
|
1268
|
6
|
res1, res2 := a/d, a%d
|
|
1269
|
6
|
if res1&0xFFFF0000 != 0 {
|
|
1270
|
6
|
p.divisionByZero()
|
|
1271
|
6
|
return
|
|
1272
|
|
}
|
|
1273
|
|
|
|
1274
|
6
|
if sign {
|
|
1275
|
6
|
res1 = (^res1 + 1) & 0xFFFF
|
|
1276
|
6
|
res2 = (^res2 + 1) & 0xFFFF
|
|
1277
|
|
}
|
|
1278
|
6
|
p.AX, p.DX = uint16(res1), uint16(res2)
|
|
1279
|
|
}
|
|
1280
|
|
|
|
1281
|
|
func (p *CPU) grp3a() {
|
|
1282
|
6
|
p.readModRegRM()
|
|
1283
|
6
|
operand := p.rmLocation()
|
|
1284
|
|
|
|
1285
|
6
|
switch op := p.getReg(); op {
|
|
1286
|
6
|
case 0, 1:
|
|
1287
|
6
|
a, b := operand.readByte(p), p.readOpcodeStream()
|
|
1288
|
6
|
p.updateFlagsSZP8(a & b)
|
|
1289
|
6
|
p.clearFlagsOC()
|
|
1290
|
6
|
case 2:
|
|
1291
|
6
|
operand.writeByte(p, ^operand.readByte(p))
|
|
1292
|
6
|
case 3:
|
|
1293
|
6
|
a, b := uint32(0), uint32(operand.readByte(p))
|
|
1294
|
6
|
res := a - b
|
|
1295
|
6
|
operand.writeByte(p, byte(res))
|
|
1296
|
6
|
p.updateFlagsOACSub(res, a, b)
|
|
1297
|
6
|
p.updateFlagsSZP8(byte(res))
|
|
1298
|
6
|
p.CF = b != 0
|
|
1299
|
6
|
case 4:
|
|
1300
|
6
|
a, b := uint32(p.AL()), uint32(operand.readByte(p))
|
|
1301
|
6
|
res := a * b
|
|
1302
|
6
|
p.AX = uint16(res & 0xFFFF)
|
|
1303
|
6
|
p.updateFlagsSZP8(uint8(res))
|
|
1304
|
6
|
p.CF = p.AH() != 0
|
|
1305
|
6
|
p.OF = p.CF
|
|
1306
|
6
|
if !p.isV20 {
|
|
1307
|
0
|
p.ZF = false
|
|
1308
|
|
}
|
|
1309
|
6
|
case 5:
|
|
1310
|
6
|
p.AX = signExtend16(p.AL()) * signExtend16(operand.readByte(p))
|
|
1311
|
6
|
p.updateFlagsSZP8(byte(p.AX))
|
|
1312
|
6
|
if p.AL()&0x80 == 0x80 {
|
|
1313
|
6
|
p.CF = p.AH() != 0xFF
|
|
1314
|
6
|
} else {
|
|
1315
|
6
|
p.CF = p.AH() != 0x0
|
|
1316
|
|
}
|
|
1317
|
6
|
p.OF = p.CF
|
|
1318
|
6
|
if !p.isV20 {
|
|
1319
|
0
|
p.ZF = false
|
|
1320
|
|
}
|
|
1321
|
6
|
case 6:
|
|
1322
|
6
|
p.opDIV8(p.AX, operand.readByte(p))
|
|
1323
|
6
|
case 7:
|
|
1324
|
6
|
p.opIDIV8(p.AX, operand.readByte(p))
|
|
1325
|
0
|
default:
|
|
1326
|
0
|
log.Panicf("invalid opcode: grp3a(0x%X)", op)
|
|
1327
|
|
}
|
|
1328
|
|
}
|
|
1329
|
|
|
|
1330
|
|
func (p *CPU) grp3b() {
|
|
1331
|
6
|
p.readModRegRM()
|
|
1332
|
6
|
operand := p.rmLocation()
|
|
1333
|
|
|
|
1334
|
6
|
switch op := p.getReg(); op {
|
|
1335
|
6
|
case 0, 1:
|
|
1336
|
6
|
a, b := operand.readWord(p), p.readOpcodeImm16()
|
|
1337
|
6
|
p.updateFlagsSZP16(a & b)
|
|
1338
|
6
|
p.clearFlagsOC()
|
|
1339
|
6
|
case 2:
|
|
1340
|
6
|
operand.writeWord(p, ^operand.readWord(p))
|
|
1341
|
6
|
case 3:
|
|
1342
|
6
|
a, b := uint32(0), uint32(operand.readWord(p))
|
|
1343
|
6
|
res := a - b
|
|
1344
|
6
|
operand.writeWord(p, uint16(res))
|
|
1345
|
6
|
p.updateFlagsOACSub(res, a, b)
|
|
1346
|
6
|
p.updateFlagsSZP16(uint16(res))
|
|
1347
|
6
|
p.CF = b != 0
|
|
1348
|
6
|
case 4:
|
|
1349
|
6
|
a, b := uint32(p.AX), uint32(operand.readWord(p))
|
|
1350
|
6
|
res := a * b
|
|
1351
|
6
|
p.DX, p.AX = uint16(res>>16), uint16(res&0xFFFF)
|
|
1352
|
6
|
p.updateFlagsSZP16(uint16(res))
|
|
1353
|
6
|
p.CF = p.DX != 0
|
|
1354
|
6
|
p.OF = p.CF
|
|
1355
|
6
|
if !p.isV20 {
|
|
1356
|
0
|
p.ZF = false
|
|
1357
|
|
}
|
|
1358
|
6
|
case 5:
|
|
1359
|
6
|
res := signExtend32(p.AX) * signExtend32(operand.readWord(p))
|
|
1360
|
6
|
p.DX, p.AX = uint16(res>>16), uint16(res&0xFFFF)
|
|
1361
|
6
|
p.updateFlagsSZP16(uint16(res))
|
|
1362
|
6
|
if p.AX&0x8000 == 0x8000 {
|
|
1363
|
6
|
p.CF = p.DX != 0xFFFF
|
|
1364
|
6
|
} else {
|
|
1365
|
6
|
p.CF = p.DX != 0x0
|
|
1366
|
|
}
|
|
1367
|
6
|
p.OF = p.CF
|
|
1368
|
6
|
if !p.isV20 {
|
|
1369
|
0
|
p.ZF = false
|
|
1370
|
|
}
|
|
1371
|
6
|
case 6:
|
|
1372
|
6
|
p.opDIV16((uint32(p.DX)<<16)|uint32(p.AX), operand.readWord(p))
|
|
1373
|
6
|
case 7:
|
|
1374
|
6
|
p.opIDIV16((uint32(p.DX)<<16)|uint32(p.AX), operand.readWord(p))
|
|
1375
|
0
|
default:
|
|
1376
|
0
|
log.Panicf("invalid opcode: grp3b(0x%X)", op)
|
|
1377
|
|
}
|
|
1378
|
|
}
|
|
1379
|
|
|
|
1380
|
|
func (p *CPU) grp4() {
|
|
1381
|
6
|
p.readModRegRM()
|
|
1382
|
6
|
dest := p.rmLocation()
|
|
1383
|
6
|
v := uint32(dest.readByte(p))
|
|
1384
|
6
|
cf := p.CF
|
|
1385
|
|
|
|
1386
|
6
|
var res uint32
|
|
1387
|
6
|
switch op := p.getReg(); op {
|
|
1388
|
6
|
case 0:
|
|
1389
|
6
|
res = v + 1
|
|
1390
|
6
|
p.updateFlagsOACAdd(res, v, 1)
|
|
1391
|
6
|
case 1:
|
|
1392
|
6
|
res = v - 1
|
|
1393
|
6
|
p.updateFlagsOACSub(res, v, 1)
|
|
1394
|
0
|
default:
|
|
1395
|
0
|
p.invalidOpcode()
|
|
1396
|
0
|
return
|
|
1397
|
|
}
|
|
1398
|
|
|
|
1399
|
6
|
dest.writeByte(p, byte(res))
|
|
1400
|
6
|
p.updateFlagsSZP8(byte(res))
|
|
1401
|
6
|
p.CF = cf
|
|
1402
|
|
}
|
|
1403
|
|
|
|
1404
|
|
func (p *CPU) grp5() {
|
|
1405
|
6
|
p.readModRegRM()
|
|
1406
|
6
|
dest := p.rmLocation()
|
|
1407
|
6
|
v := uint32(dest.readWord(p))
|
|
1408
|
6
|
cf := p.CF
|
|
1409
|
|
|
|
1410
|
6
|
var res uint32
|
|
1411
|
6
|
switch op := p.getReg(); op {
|
|
1412
|
6
|
case 0:
|
|
1413
|
6
|
res = v + 1
|
|
1414
|
6
|
p.updateFlagsOACAdd(res, v, 1)
|
|
1415
|
6
|
case 1:
|
|
1416
|
6
|
res = v - 1
|
|
1417
|
6
|
p.updateFlagsOACSub(res, v, 1)
|
|
1418
|
6
|
case 2:
|
|
1419
|
6
|
p.push16(p.IP)
|
|
1420
|
6
|
p.IP = uint16(v)
|
|
1421
|
6
|
return
|
|
1422
|
6
|
case 3:
|
|
1423
|
6
|
p.push16(p.CS)
|
|
1424
|
6
|
p.push16(p.IP)
|
|
1425
|
6
|
p.IP = uint16(v)
|
|
1426
|
6
|
p.CS = p.ReadWord(dest.getAddress().AddInt(2).Pointer())
|
|
1427
|
6
|
return
|
|
1428
|
6
|
case 4:
|
|
1429
|
6
|
p.IP = uint16(v)
|
|
1430
|
6
|
return
|
|
1431
|
6
|
case 5:
|
|
1432
|
6
|
p.IP = uint16(v)
|
|
1433
|
6
|
p.CS = p.ReadWord(dest.getAddress().AddInt(2).Pointer())
|
|
1434
|
6
|
return
|
|
1435
|
6
|
case 6:
|
|
1436
|
6
|
p.push16(uint16(v))
|
|
1437
|
6
|
return
|
|
1438
|
0
|
default:
|
|
1439
|
0
|
p.invalidOpcode()
|
|
1440
|
0
|
return
|
|
1441
|
|
}
|
|
1442
|
|
|
|
1443
|
6
|
dest.writeWord(p, uint16(res))
|
|
1444
|
6
|
p.updateFlagsSZP16(uint16(res))
|
|
1445
|
6
|
p.CF = cf
|
|
1446
|
|
}
|
|
1447
|
|
|
|
1448
|
|
func (p *CPU) jmpRel8() uint16 {
|
|
1449
|
6
|
diff := uint16(int8(p.readOpcodeStream()))
|
|
1450
|
6
|
ip := p.IP
|
|
1451
|
6
|
p.IP += diff
|
|
1452
|
6
|
return ip
|
|
1453
|
|
}
|
|
1454
|
|
|
|
1455
|
|
func (p *CPU) jmpRel16() uint16 {
|
|
1456
|
6
|
diff := p.readOpcodeImm16()
|
|
1457
|
6
|
ip := p.IP
|
|
1458
|
6
|
p.IP += diff
|
|
1459
|
6
|
return ip
|
|
1460
|
|
}
|
|
1461
|
|
|
|
1462
|
|
func (p *CPU) jmpRel8Cond(cond bool) {
|
|
1463
|
6
|
if cond {
|
|
1464
|
6
|
p.jmpRel8()
|
|
1465
|
6
|
} else {
|
|
1466
|
6
|
p.readOpcodeStream()
|
|
1467
|
|
}
|
|
1468
|
|
}
|
|
1469
|
|
|
|
1470
|
|
func (p *CPU) invalidOpcode() {
|
|
1471
|
0
|
log.Printf("invalid opcode: 0x%X", p.opcode)
|
|
1472
|
0
|
if p.isV20 {
|
|
1473
|
0
|
p.IP = p.decodeAt
|
|
1474
|
0
|
p.doInterrupt(6)
|
|
1475
|
0
|
} else {
|
|
1476
|
0
|
p.Break()
|
|
1477
|
|
}
|
|
1478
|
|
}
|
|
1479
|
|
|
|
1480
|
|
func (p *CPU) isValidRepeat() (bool, bool) {
|
|
1481
|
6
|
switch p.opcode {
|
|
1482
|
0
|
case 0x6C, 0x6D, 0x6E, 0x6F:
|
|
1483
|
0
|
if p.isV20 {
|
|
1484
|
0
|
return false, false
|
|
1485
|
|
}
|
|
1486
|
0
|
fallthrough
|
|
1487
|
6
|
case 0xA4, 0xA5, 0xAC, 0xAD, 0xAA, 0xAB:
|
|
1488
|
6
|
return true, false
|
|
1489
|
6
|
case 0xA6, 0xA7, 0xAE, 0xAF:
|
|
1490
|
6
|
return true, true
|
|
1491
|
|
}
|
|
1492
|
6
|
return false, false
|
|
1493
|
|
}
|
|
1494
|
|
|
|
1495
|
|
func (p *CPU) doRepeat() error {
|
|
1496
|
6
|
if valid, primitive := p.isValidRepeat(); valid {
|
|
1497
|
6
|
ip := p.IP
|
|
1498
|
|
for p.CX > 0 {
|
|
1499
|
6
|
p.IP = ip
|
|
1500
|
6
|
if err := p.execute(); err != nil {
|
|
1501
|
0
|
return err
|
|
1502
|
|
}
|
|
1503
|
6
|
p.CX--
|
|
1504
|
|
|
|
1505
|
6
|
if primitive && ((p.repeatMode == 0xF2 && p.ZF) || (p.repeatMode == 0xF3 && !p.ZF)) {
|
|
1506
|
6
|
break
|
|
1507
|
|
}
|
|
1508
|
|
|
|
1509
|
|
// This is to prevent the JS backend from deadlocking.
|
|
1510
|
6
|
if runtime.GOOS == "js" && p.CX%1000 == 0 {
|
|
1511
|
0
|
time.Sleep(time.Nanosecond)
|
|
1512
|
|
}
|
|
1513
|
|
}
|
|
1514
|
6
|
} else {
|
|
1515
|
6
|
p.repeatMode = 0
|
|
1516
|
6
|
if err := p.execute(); err != nil {
|
|
1517
|
0
|
return err
|
|
1518
|
|
}
|
|
1519
|
|
}
|
|
1520
|
6
|
return nil
|
|
1521
|
|
}
|
|
1522
|
|
|
|
1523
|
|
func (p *CPU) updateDI() {
|
|
1524
|
6
|
var n uint16 = 1
|
|
1525
|
6
|
if p.isWide {
|
|
1526
|
6
|
n = 2
|
|
1527
|
|
}
|
|
1528
|
6
|
if p.DF {
|
|
1529
|
6
|
p.DI -= n
|
|
1530
|
6
|
} else {
|
|
1531
|
6
|
p.DI += n
|
|
1532
|
|
}
|
|
1533
|
|
}
|
|
1534
|
|
|
|
1535
|
|
func (p *CPU) updateSI() {
|
|
1536
|
6
|
var n uint16 = 1
|
|
1537
|
6
|
if p.isWide {
|
|
1538
|
6
|
n = 2
|
|
1539
|
|
}
|
|
1540
|
6
|
if p.DF {
|
|
1541
|
6
|
p.SI -= n
|
|
1542
|
6
|
} else {
|
|
1543
|
6
|
p.SI += n
|
|
1544
|
|
}
|
|
1545
|
|
}
|
|
1546
|
|
|
|
1547
|
|
func (p *CPU) updateDISI() {
|
|
1548
|
6
|
p.updateDI()
|
|
1549
|
6
|
p.updateSI()
|
|
1550
|
|
}
|
andreas-jonsson