mirror of
https://github.com/transistorfet/moa.git
synced 2024-05-29 04:41:29 +00:00
408 lines
14 KiB
Rust
408 lines
14 KiB
Rust
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use crate::error::Error;
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use crate::memory::{Address, AddressSpace};
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use super::decode::{Instruction, Target, Size, Direction, ControlRegister, RegisterType};
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pub trait Processor {
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fn reset();
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fn step();
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}
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#[derive(Copy, Clone, Debug, PartialEq)]
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pub enum State {
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Init,
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Running,
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Halted,
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}
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pub struct MC68010 {
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pub state: State,
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pub pc: u32,
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pub sr: u16,
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pub d_reg: [u32; 8],
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pub a_reg: [u32; 7],
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pub msp: u32,
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pub usp: u32,
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pub vbr: u32,
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}
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const FLAGS_ON_RESET: u16 = 0x2700;
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pub const FLAGS_SUPERVISOR: u16 = 0x2000;
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pub const ERR_BUS_ERROR: u32 = 2;
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pub const ERR_ADDRESS_ERROR: u32 = 3;
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pub const ERR_ILLEGAL_INSTRUCTION: u32 = 4;
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impl MC68010 {
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pub fn new() -> MC68010 {
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MC68010 {
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state: State::Init,
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pc: 0,
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sr: FLAGS_ON_RESET,
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d_reg: [0; 8],
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a_reg: [0; 7],
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msp: 0,
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usp: 0,
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vbr: 0,
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}
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}
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pub fn reset(&mut self) {
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self.state = State::Init;
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self.pc = 0;
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self.sr = FLAGS_ON_RESET;
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self.d_reg = [0; 8];
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self.a_reg = [0; 7];
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self.msp = 0;
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self.usp = 0;
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self.vbr = 0;
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}
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pub fn is_running(&self) -> bool {
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self.state != State::Halted
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}
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pub fn init(&mut self, space: &mut AddressSpace) -> Result<(), Error> {
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println!("Initializing CPU");
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self.msp = space.read_beu32(0)?;
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self.pc = space.read_beu32(4)?;
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self.state = State::Running;
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Ok(())
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}
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pub fn step(&mut self, space: &mut AddressSpace) -> Result<(), Error> {
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match self.state {
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State::Init => self.init(space),
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State::Halted => Err(Error::new("CPU halted")),
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State::Running => self.execute_one(space),
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}
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}
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fn is_supervisor(&self) -> bool {
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self.sr & FLAGS_SUPERVISOR != 0
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}
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fn push_long(&mut self, space: &mut AddressSpace, value: u32) -> Result<(), Error> {
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let reg = if self.is_supervisor() { &mut self.msp } else { &mut self.usp };
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*reg -= 4;
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space.write_beu32(*reg as Address, value)
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}
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fn execute_one(&mut self, space: &mut AddressSpace) -> Result<(), Error> {
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let addr = self.pc;
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let ins = self.decode_one(space)?;
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println!("{:08x}: {:?}", addr, ins);
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match ins {
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//Instruction::ADD(Target, Target, Size) => {
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//},
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//Instruction::AND(Target, Target, Size) => {
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//},
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//Instruction::ANDtoCCR(u8) => {
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//},
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//Instruction::ANDtoSR(u16) => {
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//},
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//Instruction::ASd(Target, Target, Size, ShiftDirection) => {
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//},
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//Instruction::Bcc(Condition, u16) => {
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//},
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Instruction::BRA(offset) => {
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self.pc = self.pc.wrapping_add(offset as u32) - 2;
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},
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Instruction::BSR(offset) => {
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self.push_long(space, self.pc)?;
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self.pc = self.pc.wrapping_add(offset as u32) - 2;
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},
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//Instruction::BTST(Target, Target, Size) => {
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//},
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//Instruction::BCHG(Target, Target, Size) => {
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//},
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//Instruction::BCLR(Target, Target, Size) => {
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//},
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//Instruction::BSET(Target, Target, Size) => {
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//},
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Instruction::CLR(target, size) => {
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self.set_target_value(space, target, 0, size)?;
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},
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//Instruction::CMP(Target, Target, Size) => {
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//},
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//Instruction::DBcc(Condition, u16) => {
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//},
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//Instruction::DIV(Target, Target, Size, Sign) => {
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//},
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//Instruction::EOR(Target, Target, Size) => {
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//},
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//Instruction::EORtoCCR(u8) => {
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//},
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//Instruction::EORtoSR(u16) => {
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//},
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//Instruction::EXG(Target, Target) => {
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//},
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//Instruction::EXT(u8, Size) => {
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//},
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//Instruction::ILLEGAL => {
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//},
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Instruction::JMP(target) => {
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self.pc = self.get_target_address(target)?;
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},
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Instruction::JSR(target) => {
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self.push_long(space, self.pc)?;
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self.pc = self.get_target_address(target)?;
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},
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Instruction::LEA(target, reg) => {
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let value = self.get_target_address(target)?;
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let addr = self.get_a_reg(reg);
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*addr = value;
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},
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//Instruction::LINK(u8, u16) => {
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//},
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//Instruction::LSd(Target, Target, Size, ShiftDirection) => {
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//},
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Instruction::MOVE(src, dest, size) => {
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let value = self.get_target_value(space, src, size)?;
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self.set_target_value(space, dest, value, size)?;
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},
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Instruction::MOVEfromSR(target) => {
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self.set_target_value(space, target, self.sr as u32, Size::Word)?;
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},
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Instruction::MOVEtoSR(target) => {
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self.sr = self.get_target_value(space, target, Size::Word)? as u16;
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},
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//Instruction::MOVEtoCCR(Target) => {
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//},
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Instruction::MOVEC(target, control_reg, dir) => {
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match dir {
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Direction::FromTarget => {
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let value = self.get_target_value(space, target, Size::Long)?;
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let addr = self.get_control_reg_mut(control_reg);
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*addr = value;
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},
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Direction::ToTarget => {
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let addr = self.get_control_reg_mut(control_reg);
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let value = *addr;
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self.set_target_value(space, target, value, Size::Long)?;
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},
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}
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},
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//Instruction::MOVEUSP(Target, Direction) => {
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//},
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//Instruction::MOVEM(Target, Size, Direction, u16) => {
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//},
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//Instruction::MOVEQ(u8, u8) => {
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//},
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//Instruction::MUL(Target, Target, Size, Sign) => {
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//},
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//Instruction::NBCD(Target) => {
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//},
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//Instruction::NEG(Target, Size) => {
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//},
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//Instruction::NEGX(Target, Size) => {
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//},
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Instruction::NOP => { },
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//Instruction::NOT(Target, Size) => {
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//},
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//Instruction::OR(Target, Target, Size) => {
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//},
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//Instruction::ORtoCCR(u8) => {
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//},
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Instruction::ORtoSR(value) => {
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self.sr = self.sr | value;
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},
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//Instruction::PEA(Target) => {
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//},
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//Instruction::RESET => {
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//},
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//Instruction::ROd(Target, Target, Size, ShiftDirection) => {
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//},
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//Instruction::ROXd(Target, Target, Size, ShiftDirection) => {
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//},
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//Instruction::RTE => {
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//},
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//Instruction::RTR => {
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//},
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//Instruction::RTS => {
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//},
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//Instruction::STOP(u16) => {
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//},
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//Instruction::SUB(Target, Target, Size) => {
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//},
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//Instruction::SWAP(u8) => {
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//},
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//Instruction::TAS(Target) => {
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//},
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//Instruction::TST(Target, Size) => {
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//},
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//Instruction::TRAP(u8) => {
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//},
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//Instruction::TRAPV => {
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//},
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//Instruction::UNLK(u8) => {
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//},
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_ => { panic!(""); },
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}
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Ok(())
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}
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fn get_target_value(&mut self, space: &mut AddressSpace, target: Target, size: Size) -> Result<u32, Error> {
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match target {
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Target::Immediate(value) => Ok(value),
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Target::DirectDReg(reg) => Ok(get_value_sized(self.d_reg[reg as usize], size)),
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Target::DirectAReg(reg) => Ok(get_value_sized(*self.get_a_reg(reg), size)),
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Target::IndirectAReg(reg) => get_address_sized(space, *self.get_a_reg(reg) as Address, size),
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Target::IndirectARegInc(reg) => {
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let addr = self.get_a_reg(reg);
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let value = get_address_sized(space, *addr as Address, size);
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*addr += size.in_bytes();
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value
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},
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Target::IndirectARegDec(reg) => {
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let addr = self.get_a_reg(reg);
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*addr -= size.in_bytes();
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get_address_sized(space, *addr as Address, size)
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},
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Target::IndirectARegOffset(reg, offset) => {
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let addr = self.get_a_reg(reg);
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get_address_sized(space, (*addr).wrapping_add(offset as u32) as Address, size)
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},
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Target::IndirectARegXRegOffset(reg, rtype, xreg, offset, target_size) => {
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let reg_offset = get_value_sized(self.get_x_reg_value(rtype, xreg), target_size);
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let addr = self.get_a_reg(reg);
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get_address_sized(space, (*addr).wrapping_add(reg_offset).wrapping_add(offset as u32) as Address, size)
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},
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Target::IndirectMemory(addr) => {
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get_address_sized(space, addr as Address, size)
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},
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Target::IndirectPCOffset(offset) => {
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get_address_sized(space, self.pc.wrapping_add(offset as u32) as Address, size)
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},
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Target::IndirectPCXRegOffset(rtype, xreg, offset, target_size) => {
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let reg_offset = get_value_sized(self.get_x_reg_value(rtype, xreg), target_size);
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get_address_sized(space, self.pc.wrapping_add(reg_offset).wrapping_add(offset as u32) as Address, size)
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},
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_ => Err(Error::new(&format!("Unimplemented addressing target: {:?}", target))),
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}
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}
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fn set_target_value(&mut self, space: &mut AddressSpace, target: Target, value: u32, size: Size) -> Result<(), Error> {
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match target {
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Target::DirectDReg(reg) => {
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set_value_sized(&mut self.d_reg[reg as usize], value, size);
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},
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Target::DirectAReg(reg) => {
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set_value_sized(self.get_a_reg(reg), value, size);
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},
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Target::IndirectAReg(reg) => {
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set_address_sized(space, *self.get_a_reg(reg) as Address, value, size)?;
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},
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_ => return Err(Error::new(&format!("Unimplemented addressing target: {:?}", target))),
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}
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Ok(())
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}
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fn get_target_address(&mut self, target: Target) -> Result<u32, Error> {
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let addr = match target {
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Target::IndirectAReg(reg) => *self.get_a_reg(reg),
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Target::IndirectARegOffset(reg, offset) => {
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let addr = self.get_a_reg(reg);
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(*addr).wrapping_add(offset as u32)
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},
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Target::IndirectARegXRegOffset(reg, rtype, xreg, offset, target_size) => {
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let reg_offset = get_value_sized(self.get_x_reg_value(rtype, xreg), target_size);
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let addr = self.get_a_reg(reg);
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(*addr).wrapping_add(reg_offset).wrapping_add(offset as u32)
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},
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Target::IndirectMemory(addr) => {
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addr
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},
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Target::IndirectPCOffset(offset) => {
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self.pc.wrapping_add(offset as u32)
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},
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Target::IndirectPCXRegOffset(rtype, xreg, offset, target_size) => {
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let reg_offset = get_value_sized(self.get_x_reg_value(rtype, xreg), target_size);
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self.pc.wrapping_add(reg_offset).wrapping_add(offset as u32)
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},
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_ => return Err(Error::new(&format!("Unimplemented addressing target: {:?}", target))),
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};
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Ok(addr)
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}
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fn get_control_reg_mut(&mut self, control_reg: ControlRegister) -> &mut u32 {
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match control_reg {
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ControlRegister::VBR => &mut self.vbr,
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}
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}
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#[inline(always)]
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fn get_stack_pointer(&mut self) -> &mut u32 {
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if self.is_supervisor() { &mut self.msp } else { &mut self.usp }
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}
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#[inline(always)]
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fn get_a_reg(&mut self, reg: u8) -> &mut u32 {
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if reg == 7 {
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if self.is_supervisor() { &mut self.msp } else { &mut self.usp }
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} else {
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&mut self.a_reg[reg as usize]
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}
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}
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fn get_x_reg_value(&self, rtype: RegisterType, reg: u8) -> u32 {
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match rtype {
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RegisterType::Data => self.d_reg[reg as usize],
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RegisterType::Address => self.d_reg[reg as usize],
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}
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}
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}
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fn get_value_sized(value: u32, size: Size) -> u32 {
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match size {
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Size::Byte => { 0x000000FF & value },
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Size::Word => { 0x0000FFFF & value },
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Size::Long => { value },
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}
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}
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fn get_address_sized(space: &mut AddressSpace, addr: Address, size: Size) -> Result<u32, Error> {
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match size {
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Size::Byte => space.read_u8(addr).map(|value| value as u32),
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Size::Word => space.read_beu16(addr).map(|value| value as u32),
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Size::Long => space.read_beu32(addr),
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}
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}
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fn set_value_sized(addr: &mut u32, value: u32, size: Size) {
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match size {
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Size::Byte => { *addr = (*addr & 0xFFFFFF00) | (0x000000FF & value); }
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Size::Word => { *addr = (*addr & 0xFFFF0000) | (0x0000FFFF & value); }
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Size::Long => { *addr = value; }
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}
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}
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fn set_address_sized(space: &mut AddressSpace, addr: Address, value: u32, size: Size) -> Result<(), Error> {
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match size {
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Size::Byte => space.write_u8(addr, value as u8),
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Size::Word => space.write_beu16(addr, value as u16),
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Size::Long => space.write_beu32(addr, value),
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}
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}
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/*
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impl Processor for MC68010 {
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}
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*/
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