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feat: reimplement cycles newtype

This commit is contained in:
Rekai Nyangadzayi Musuka 2021-01-18 22:54:38 -06:00
parent 2fc7ac3833
commit 9b4c95ce4c
8 changed files with 273 additions and 143 deletions
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8
src/bus.rs
View File

@ -1,3 +1,5 @@
use crate::instruction::Cycles;
use super::cartridge::Cartridge;
use super::high_ram::HighRAM;
use super::interrupt::Interrupt;
@ -50,6 +52,12 @@ impl Bus {
pub fn load_cartridge(&mut self, path: &str) {
self.cartridge = Some(Cartridge::new(path).unwrap());
}
pub fn step(&mut self, cycles: Cycles) {
let _ = self.timer.step(cycles);
let _ = self.sound.step(cycles);
let _ = self.ppu.step(cycles);
}
}
impl Bus {

15
src/cpu.rs
View File

@ -68,6 +68,21 @@ impl Cpu {
pub fn execute(&mut self, instruction: Instruction) -> Cycles {
Instruction::execute(self, instruction)
}
pub fn step(&mut self) -> Cycles {
let opcode = self.fetch();
let instr = self.decode(opcode);
let cycles = self.execute(instr);
println!(
"Addr: {:#06X} | Opcode: {:#04X} | Instr: {:X?}",
self.reg.pc, opcode, instr
);
self.bus.step(cycles);
cycles
}
}
impl Cpu {

2
src/high_ram.rs
View File

@ -6,7 +6,7 @@ pub struct HighRAM {
impl Default for HighRAM {
fn default() -> Self {
Self {
buf: vec![0u8; 127].into_boxed_slice(),
buf: vec![0u8; 128].into_boxed_slice(),
}
}
}

325
src/instruction.rs
View File

@ -118,18 +118,18 @@ pub enum JumpCondition {
#[derive(Debug, Copy, Clone)]
struct Table;
#[derive(Debug, Copy, Clone)]
pub struct Cycles(u8);
#[derive(Debug, Copy, Clone, PartialEq, Eq, PartialOrd, Ord)]
pub struct Cycles(u32);
impl Instruction {
pub fn execute(cpu: &mut Cpu, instruction: Self) -> Cycles {
match instruction {
Instruction::NOP => Cycles(4),
Instruction::NOP => Cycles::new(4),
Instruction::LD(lhs, rhs) => match (lhs, rhs) {
(LDTarget::ByteAtAddress(nn), LDTarget::RegisterPair(RegisterPair::SP)) => {
// LD (nn), SP | Put Stack Pointer at address nn
cpu.write_word(nn, cpu.register_pair(RegisterPair::SP));
Cycles(20)
Cycles::new(20)
}
(LDTarget::RegisterPair(pair), LDTarget::ImmediateWord(nn)) => {
// LD rp[p], nn | Put value nn into register pair
@ -140,7 +140,7 @@ impl Instruction {
| RegisterPair::SP => cpu.set_register_pair(pair, nn),
_ => unreachable!(),
}
Cycles(12)
Cycles::new(12)
}
(LDTarget::IndirectRegister(pair), LDTarget::Register(InstrRegister::A)) => {
let a = cpu.register(Register::A);
@ -167,7 +167,7 @@ impl Instruction {
}
_ => unreachable!(),
}
Cycles(8)
Cycles::new(8)
}
(LDTarget::Register(InstrRegister::A), LDTarget::IndirectRegister(pair)) => {
match pair {
@ -196,7 +196,7 @@ impl Instruction {
}
_ => unreachable!(),
}
Cycles(8)
Cycles::new(8)
}
(LDTarget::Register(reg), LDTarget::ImmediateByte(n)) => {
// LD r[y], n | Store n in Register
@ -204,7 +204,7 @@ impl Instruction {
InstrRegister::IndirectHL => {
let addr = cpu.register_pair(RegisterPair::HL);
cpu.write_byte(addr, n);
Cycles(12)
Cycles::new(12)
}
InstrRegister::A
| InstrRegister::B
@ -214,7 +214,7 @@ impl Instruction {
| InstrRegister::H
| InstrRegister::L => {
cpu.set_register(Register::try_from(reg).unwrap(), n);
Cycles(8)
Cycles::new(8)
}
}
}
@ -222,13 +222,13 @@ impl Instruction {
// LD (0xFF00 + C), A | Store value of register A at address 0xFF00 + C
let addr = 0xFF00 + cpu.register(Register::C) as u16;
cpu.write_byte(addr, cpu.register(Register::A));
Cycles(8)
Cycles::new(8)
}
(LDTarget::Register(InstrRegister::A), LDTarget::IndirectC) => {
let addr = 0xFF00 + cpu.register(Register::C) as u16;
let byte = cpu.read_byte(addr);
cpu.set_register(Register::A, byte);
Cycles(8)
Cycles::new(8)
}
(LDTarget::Register(lhs), LDTarget::Register(rhs)) => {
// LD r[y], r[z] | Store value of RHS Register in LHS Register
@ -258,25 +258,25 @@ impl Instruction {
| InstrRegister::L
| InstrRegister::A => {
cpu.set_register(Register::try_from(lhs).unwrap(), rhs_value);
Cycles(4)
Cycles::new(4)
}
InstrRegister::IndirectHL => {
let addr = cpu.register_pair(RegisterPair::HL);
cpu.write_byte(addr, rhs_value);
Cycles(8)
Cycles::new(8)
}
}
}
(LDTarget::ByteAtAddressWithOffset(n), LDTarget::Register(InstrRegister::A)) => {
// LD (0xFF00 + n), A | Store register A at address (0xFF00 + n)
cpu.write_byte(0xFF00 + (n as u16), cpu.register(Register::A));
Cycles(12)
Cycles::new(12)
}
(LDTarget::Register(InstrRegister::A), LDTarget::ByteAtAddressWithOffset(n)) => {
// LD A, (0xFF00 + n) | Store value at address (0xFF00 + n) in register A
let byte = cpu.read_byte(0xFF00 + (n as u16));
cpu.set_register(Register::A, byte);
Cycles(12)
Cycles::new(12)
}
(
LDTarget::RegisterPair(RegisterPair::SP),
@ -284,20 +284,20 @@ impl Instruction {
) => {
// LD SP, HL | Load Register HL into Register SP
cpu.set_register_pair(RegisterPair::SP, cpu.register_pair(RegisterPair::HL));
Cycles(8)
Cycles::new(8)
}
(LDTarget::ByteAtAddress(nn), LDTarget::Register(InstrRegister::A)) => {
cpu.write_byte(nn, cpu.register(Register::A));
Cycles(16)
Cycles::new(16)
}
(LDTarget::Register(InstrRegister::A), LDTarget::ByteAtAddress(nn)) => {
let byte = cpu.read_byte(nn);
cpu.set_register(Register::A, byte);
Cycles(16)
Cycles::new(16)
}
_ => unreachable!(),
},
Instruction::STOP => Cycles(4),
Instruction::STOP => Cycles::new(4),
Instruction::JR(cond, offset) => {
// JR cc[y - 4], d | If condition is true, then add d to current address and jump
// JR d | Add d to current address and jump
@ -308,36 +308,36 @@ impl Instruction {
match cond {
JumpCondition::Always => {
cpu.set_register_pair(RegisterPair::PC, new_addr);
Cycles(12)
Cycles::new(12)
}
JumpCondition::NotZero => {
if !flags.z {
cpu.set_register_pair(RegisterPair::PC, new_addr);
return Cycles(12);
return Cycles::new(12);
}
Cycles(8)
Cycles::new(8)
}
JumpCondition::Zero => {
if flags.z {
cpu.set_register_pair(RegisterPair::PC, new_addr);
return Cycles(12);
return Cycles::new(12);
}
Cycles(8)
Cycles::new(8)
}
JumpCondition::NotCarry => {
if !flags.c {
cpu.set_register_pair(RegisterPair::PC, new_addr);
return Cycles(12);
return Cycles::new(12);
}
Cycles(8)
Cycles::new(8)
}
JumpCondition::Carry => {
if flags.c {
cpu.set_register_pair(RegisterPair::PC, new_addr);
return Cycles(12);
return Cycles::new(12);
}
Cycles(8)
Cycles::new(8)
}
}
}
@ -360,7 +360,7 @@ impl Instruction {
_ => unreachable!(),
}
cpu.set_register(Register::Flag, flags.into());
Cycles(8)
Cycles::new(8)
}
(MATHTarget::Register(InstrRegister::A), MATHTarget::Register(reg)) => {
// ADD A, r[z] | Add (A + r[z]) to register A
@ -378,12 +378,12 @@ impl Instruction {
| InstrRegister::A => {
let value = cpu.register(Register::try_from(reg).unwrap());
sum = Self::add_u8s(a_value, value, &mut flags);
cycles = Cycles(8);
cycles = Cycles::new(8);
}
InstrRegister::IndirectHL => {
let value = cpu.read_byte(cpu.register_pair(RegisterPair::HL));
sum = Self::add_u8s(a_value, value, &mut flags);
cycles = Cycles(4);
cycles = Cycles::new(4);
}
}
@ -397,7 +397,7 @@ impl Instruction {
let d = d as i8;
let sum = Self::add_u16_i8(cpu.register_pair(RegisterPair::SP), d, &mut flags);
cpu.set_register_pair(RegisterPair::SP, sum);
Cycles(16)
Cycles::new(16)
}
(MATHTarget::Register(InstrRegister::A), MATHTarget::ImmediateByte(n)) => {
// ADD A, n | Add n to register A
@ -406,7 +406,7 @@ impl Instruction {
cpu.set_register(Register::A, sum);
cpu.set_register(Register::Flag, flags.into());
Cycles(8)
Cycles::new(8)
}
_ => unreachable!(),
},
@ -429,13 +429,13 @@ impl Instruction {
let value = cpu.register(reg);
cpu.set_register(reg, Self::inc_register(value, &mut flags));
cycles = Cycles(4)
cycles = Cycles::new(4)
}
InstrRegister::IndirectHL => {
let addr = cpu.register_pair(RegisterPair::HL);
let byte = Self::inc_register(cpu.read_byte(addr), &mut flags);
cpu.write_byte(addr, byte);
cycles = Cycles(12)
cycles = Cycles::new(12)
}
}
cpu.set_register(Register::Flag, flags.into());
@ -453,7 +453,7 @@ impl Instruction {
}
_ => unreachable!(),
}
Cycles(8)
Cycles::new(8)
}
}
}
@ -466,7 +466,7 @@ impl Instruction {
}
_ => unreachable!(),
}
Cycles(8)
Cycles::new(8)
}
Instruction::DEC(Registers::Byte(reg)) => {
// DEC r[y] | Decrement Register
@ -485,13 +485,13 @@ impl Instruction {
let value = cpu.register(reg);
cpu.set_register(reg, Self::dec_register(value, &mut flags));
cycles = Cycles(4);
cycles = Cycles::new(4);
}
InstrRegister::IndirectHL => {
let addr = cpu.register_pair(RegisterPair::HL);
let byte = cpu.read_byte(addr);
cpu.write_byte(addr, Self::dec_register(byte, &mut flags));
cycles = Cycles(12);
cycles = Cycles::new(12);
}
}
cpu.set_register(Register::Flag, flags.into());
@ -508,7 +508,7 @@ impl Instruction {
flags.update(false, false, false, msb == 0x01);
cpu.set_register(Register::Flag, flags.into());
cpu.set_register(Register::A, rot_a);
Cycles(4)
Cycles::new(4)
}
Instruction::RRCA => {
// Rotate Register A right
@ -521,7 +521,7 @@ impl Instruction {
flags.update(false, false, false, lsb == 0x01);
cpu.set_register(Register::Flag, flags.into());
cpu.set_register(Register::A, rot_a);
Cycles(4)
Cycles::new(4)
}
Instruction::RLA => {
// Rotate register A left through carry
@ -533,7 +533,7 @@ impl Instruction {
flags.update(false, false, false, carry);
cpu.set_register(Register::Flag, flags.into());
cpu.set_register(Register::A, rot_a);
Cycles(4)
Cycles::new(4)
}
Instruction::RRA => {
// Rotate register A right through carry
@ -545,7 +545,7 @@ impl Instruction {
flags.update(false, false, false, carry);
cpu.set_register(Register::Flag, flags.into());
cpu.set_register(Register::A, rot_a);
Cycles(4)
Cycles::new(4)
}
Instruction::DAA => unimplemented!(),
Instruction::CPL => {
@ -558,7 +558,7 @@ impl Instruction {
cpu.set_register(Register::Flag, flags.into());
cpu.set_register(Register::A, !a); // Bitwise not is ! instead of ~
Cycles(4)
Cycles::new(4)
}
Instruction::SCF => {
// Set Carry Flag
@ -569,7 +569,7 @@ impl Instruction {
flags.c = true;
cpu.set_register(Register::Flag, flags.into());
Cycles(4)
Cycles::new(4)
}
Instruction::CCF => {
// Compliment Carry Flag (inverse)
@ -580,7 +580,7 @@ impl Instruction {
flags.c = !flags.c;
cpu.set_register(Register::Flag, flags.into());
Cycles(4)
Cycles::new(4)
}
Instruction::HALT => unimplemented!(),
Instruction::ADC(target) => match target {
@ -603,12 +603,12 @@ impl Instruction {
let value =
cpu.register(Register::try_from(reg).unwrap()) + (flags.c as u8);
sum = Self::add_u8s(a_value, value, &mut flags);
cycles = Cycles(4);
cycles = Cycles::new(4);
}
InstrRegister::IndirectHL => {
let value = cpu.read_byte(cpu.register_pair(RegisterPair::HL));
sum = Self::add_u8s(a_value, value, &mut flags);
cycles = Cycles(8);
cycles = Cycles::new(8);
}
}
cpu.set_register(Register::Flag, flags.into());
@ -623,7 +623,7 @@ impl Instruction {
cpu.set_register(Register::Flag, flags.into());
cpu.set_register(Register::A, sum);
Cycles(8)
Cycles::new(8)
}
_ => unreachable!(),
},
@ -645,12 +645,12 @@ impl Instruction {
| InstrRegister::A => {
let value = cpu.register(Register::try_from(reg).unwrap());
diff = Self::sub_u8s(a_value, value, &mut flags);
cycles = Cycles(4);
cycles = Cycles::new(4);
}
InstrRegister::IndirectHL => {
let value = cpu.read_byte(cpu.register_pair(RegisterPair::HL));
diff = Self::sub_u8s(a_value, value, &mut flags);
cycles = Cycles(8);
cycles = Cycles::new(8);
}
}
@ -665,7 +665,7 @@ impl Instruction {
cpu.set_register(Register::Flag, flags.into());
cpu.set_register(Register::A, diff);
Cycles(8)
Cycles::new(8)
}
_ => unreachable!(),
},
@ -689,12 +689,12 @@ impl Instruction {
let value =
cpu.register(Register::try_from(reg).unwrap()) + (flags.c as u8);
diff = Self::sub_u8s(a_value, value, &mut flags);
cycles = Cycles(4);
cycles = Cycles::new(4);
}
InstrRegister::IndirectHL => {
let value = cpu.read_byte(cpu.register_pair(RegisterPair::HL));
diff = Self::sub_u8s(a_value, value, &mut flags);
cycles = Cycles(8);
cycles = Cycles::new(8);
}
}
@ -711,7 +711,7 @@ impl Instruction {
cpu.set_register(Register::Flag, flags.into());
cpu.set_register(Register::A, diff);
Cycles(8)
Cycles::new(8)
}
_ => unreachable!(),
},
@ -733,12 +733,12 @@ impl Instruction {
| InstrRegister::A => {
let value = cpu.register(Register::try_from(reg).unwrap());
result = a_value & value;
cycles = Cycles(4);
cycles = Cycles::new(4);
}
InstrRegister::IndirectHL => {
let value = cpu.read_byte(cpu.register_pair(RegisterPair::HL));
result = a_value & value;
cycles = Cycles(8);
cycles = Cycles::new(8);
}
}
@ -755,7 +755,7 @@ impl Instruction {
flags.update(result == 0, false, true, false);
cpu.set_register(Register::Flag, flags.into());
cpu.set_register(Register::A, result);
Cycles(8)
Cycles::new(8)
}
_ => unreachable!(),
},
@ -777,12 +777,12 @@ impl Instruction {
| InstrRegister::A => {
let value = cpu.register(Register::try_from(reg).unwrap());
result = a_value ^ value;
cycles = Cycles(4);
cycles = Cycles::new(4);
}
InstrRegister::IndirectHL => {
let value = cpu.read_byte(cpu.register_pair(RegisterPair::HL));
result = a_value ^ value;
cycles = Cycles(8);
cycles = Cycles::new(8);
}
}
@ -799,7 +799,7 @@ impl Instruction {
flags.update(result == 0, false, false, false);
cpu.set_register(Register::Flag, flags.into());
cpu.set_register(Register::A, result);
Cycles(8)
Cycles::new(8)
}
_ => unreachable!(),
},
@ -821,12 +821,12 @@ impl Instruction {
| InstrRegister::A => {
let value = cpu.register(Register::try_from(reg).unwrap());
result = a_value | value;
cycles = Cycles(4);
cycles = Cycles::new(4);
}
InstrRegister::IndirectHL => {
let value = cpu.read_byte(cpu.register_pair(RegisterPair::HL));
result = a_value | value;
cycles = Cycles(8);
cycles = Cycles::new(8);
}
}
@ -843,7 +843,7 @@ impl Instruction {
flags.update(result == 0, false, false, false);
cpu.set_register(Register::Flag, flags.into());
cpu.set_register(Register::A, result);
Cycles(8)
Cycles::new(8)
}
_ => unreachable!(),
},
@ -864,12 +864,12 @@ impl Instruction {
| InstrRegister::A => {
let value = cpu.register(Register::try_from(reg).unwrap());
let _ = Self::sub_u8s(a_value, value, &mut flags);
cycles = Cycles(4);
cycles = Cycles::new(4);
}
InstrRegister::IndirectHL => {
let value = cpu.read_byte(cpu.register_pair(RegisterPair::HL));
let _ = Self::sub_u8s(a_value, value, &mut flags);
cycles = Cycles(8);
cycles = Cycles::new(8);
}
}
@ -882,7 +882,7 @@ impl Instruction {
let _ = Self::sub_u8s(cpu.register(Register::A), n, &mut flags);
cpu.set_register(Register::Flag, flags.into());
Cycles(8)
Cycles::new(8)
}
_ => unreachable!(),
},
@ -896,38 +896,38 @@ impl Instruction {
if !flags.z {
let addr = Self::pop(cpu);
cpu.set_register_pair(RegisterPair::PC, addr);
return Cycles(20);
return Cycles::new(20);
}
Cycles(8)
Cycles::new(8)
}
JumpCondition::Zero => {
if flags.z {
let addr = Self::pop(cpu);
cpu.set_register_pair(RegisterPair::PC, addr);
return Cycles(20);
return Cycles::new(20);
}
Cycles(8)
Cycles::new(8)
}
JumpCondition::NotCarry => {
if !flags.c {
let addr = Self::pop(cpu);
cpu.set_register_pair(RegisterPair::PC, addr);
return Cycles(20);
return Cycles::new(20);
}
Cycles(8)
Cycles::new(8)
}
JumpCondition::Carry => {
if flags.c {
let addr = Self::pop(cpu);
cpu.set_register_pair(RegisterPair::PC, addr);
return Cycles(20);
return Cycles::new(20);
}
Cycles(8)
Cycles::new(8)
}
JumpCondition::Always => {
let addr = Self::pop(cpu);
cpu.set_register_pair(RegisterPair::PC, addr);
Cycles(16)
Cycles::new(16)
}
}
}
@ -937,7 +937,7 @@ impl Instruction {
let mut flags: Flags = cpu.register(Register::Flag).into();
let sum = Self::add_u16_i8(cpu.register_pair(RegisterPair::SP), d, &mut flags);
cpu.set_register_pair(RegisterPair::HL, sum);
Cycles(12)
Cycles::new(12)
}
Instruction::POP(pair) => {
// POP rp2[p] | Pop from stack into register pair rp[2]
@ -949,20 +949,20 @@ impl Instruction {
}
_ => unreachable!(),
}
Cycles(12)
Cycles::new(12)
}
Instruction::RETI => {
// Same as RET, after which interrupts are enabled.
let addr = Self::pop(cpu);
cpu.set_register_pair(RegisterPair::PC, addr);
cpu.set_ime(true);
Cycles(16)
Cycles::new(16)
}
Instruction::JP(cond, target) => match target {
JPTarget::RegisterPair(RegisterPair::HL) => {
// JP HL | Load register pair HL into program counter
cpu.set_register_pair(RegisterPair::PC, cpu.register_pair(RegisterPair::HL));
Cycles(4)
Cycles::new(4)
}
JPTarget::ImmediateWord(nn) => {
// JP cc[y], nn | Store Immediate Word in the Program Counter if cond is met
@ -973,34 +973,34 @@ impl Instruction {
JumpCondition::NotZero => {
if !flags.z {
cpu.set_register_pair(RegisterPair::PC, nn);
return Cycles(16);
return Cycles::new(16);
}
Cycles(12)
Cycles::new(12)
}
JumpCondition::Zero => {
if flags.z {
cpu.set_register_pair(RegisterPair::PC, nn);
return Cycles(16);
return Cycles::new(16);
}
Cycles(12)
Cycles::new(12)
}
JumpCondition::NotCarry => {
if !flags.c {
cpu.set_register_pair(RegisterPair::PC, nn);
return Cycles(16);
return Cycles::new(16);
}
Cycles(12)
Cycles::new(12)
}
JumpCondition::Carry => {
if flags.c {
cpu.set_register_pair(RegisterPair::PC, nn);
return Cycles(16);
return Cycles::new(16);
}
Cycles(12)
Cycles::new(12)
}
JumpCondition::Always => {
cpu.set_register_pair(RegisterPair::PC, nn);
Cycles(16)
Cycles::new(16)
}
}
}
@ -1009,13 +1009,13 @@ impl Instruction {
Instruction::DI => {
// Disable IME
cpu.set_ime(false);
Cycles(4)
Cycles::new(4)
}
Instruction::EI => {
// Enable IME (After the next instruction)
// FIXME: IME is set after the next instruction, this currently is not represented in this emulator.
cpu.set_ime(true);
Cycles(4)
Cycles::new(4)
}
Instruction::CALL(cond, nn) => {
// CALL cc[y], nn | Store nn on the stack, then store nn in the program coutner if cond is met
@ -1028,38 +1028,38 @@ impl Instruction {
if !flags.z {
Self::push(cpu, pc);
cpu.set_register_pair(RegisterPair::PC, nn);
return Cycles(24);
return Cycles::new(24);
}
Cycles(12)
Cycles::new(12)
}
JumpCondition::Zero => {
if flags.z {
Self::push(cpu, pc);
cpu.set_register_pair(RegisterPair::PC, nn);
return Cycles(24);
return Cycles::new(24);
}
Cycles(12)
Cycles::new(12)
}
JumpCondition::NotCarry => {
if !flags.c {
Self::push(cpu, pc);
cpu.set_register_pair(RegisterPair::PC, nn);
return Cycles(24);
return Cycles::new(24);
}
Cycles(12)
Cycles::new(12)
}
JumpCondition::Carry => {
if flags.c {
Self::push(cpu, pc);
cpu.set_register_pair(RegisterPair::PC, nn);
return Cycles(24);
return Cycles::new(24);
}
Cycles(12)
Cycles::new(12)
}
JumpCondition::Always => {
Self::push(cpu, pc);
cpu.set_register_pair(RegisterPair::PC, nn);
Cycles(24)
Cycles::new(24)
}
}
}
@ -1072,14 +1072,14 @@ impl Instruction {
}
_ => unreachable!(),
}
Cycles(16)
Cycles::new(16)
}
Instruction::RST(n) => {
// RST n | Push current address onto the stack, jump to 0x0000 + n
let addr = cpu.register_pair(RegisterPair::PC);
Self::push(cpu, addr);
cpu.set_register_pair(RegisterPair::PC, n as u16);
Cycles(16)
Cycles::new(16)
}
Instruction::RLC(reg) => {
// RLC r[z] | Rotate register r[z] left
@ -1103,7 +1103,7 @@ impl Instruction {
rot_reg = value.rotate_left(1);
cpu.set_register(register, rot_reg);
cycles = Cycles(8);
cycles = Cycles::new(8);
}
InstrRegister::IndirectHL => {
let addr = cpu.register_pair(RegisterPair::HL);
@ -1113,7 +1113,7 @@ impl Instruction {
rot_reg = value.rotate_left(1);
cpu.write_byte(addr, rot_reg);
cycles = Cycles(16);
cycles = Cycles::new(16);
}
}
@ -1143,7 +1143,7 @@ impl Instruction {
rot_reg = value.rotate_right(1);
cpu.set_register(register, rot_reg);
cycles = Cycles(8);
cycles = Cycles::new(8);
}
InstrRegister::IndirectHL => {
let addr = cpu.register_pair(RegisterPair::HL);
@ -1153,7 +1153,7 @@ impl Instruction {
rot_reg = value.rotate_right(1);
cpu.write_byte(addr, rot_reg);
cycles = Cycles(16);
cycles = Cycles::new(16);
}
}
@ -1184,7 +1184,7 @@ impl Instruction {
carry = new_carry;
cpu.set_register(register, rot_reg);
cycles = Cycles(8);
cycles = Cycles::new(8);
}
InstrRegister::IndirectHL => {
let addr = cpu.register_pair(RegisterPair::HL);
@ -1195,7 +1195,7 @@ impl Instruction {
carry = new_carry;
cpu.write_byte(addr, rot_reg);
cycles = Cycles(16);
cycles = Cycles::new(16);
}
}
@ -1227,7 +1227,7 @@ impl Instruction {
carry = new_carry;
cpu.set_register(register, rot_reg);
cycles = Cycles(8);
cycles = Cycles::new(8);
}
InstrRegister::IndirectHL => {
let addr = cpu.register_pair(RegisterPair::HL);
@ -1238,7 +1238,7 @@ impl Instruction {
carry = new_carry;
cpu.write_byte(addr, rot_reg);
cycles = Cycles(16);
cycles = Cycles::new(16);
}
}
@ -1269,7 +1269,7 @@ impl Instruction {
shift_reg = value << 1;
cpu.set_register(register, shift_reg);
cycles = Cycles(8);
cycles = Cycles::new(8);
}
InstrRegister::IndirectHL => {
let addr = cpu.register_pair(RegisterPair::HL);
@ -1279,7 +1279,7 @@ impl Instruction {
shift_reg = value << 1;
cpu.write_byte(addr, value);
cycles = Cycles(16);
cycles = Cycles::new(16);
}
}
@ -1311,7 +1311,7 @@ impl Instruction {
shift_reg = (value >> 1) | (msb << 7); // msb is duplicated in this op
cpu.set_register(register, shift_reg);
cycles = Cycles(8);
cycles = Cycles::new(8);
}
InstrRegister::IndirectHL => {
let addr = cpu.register_pair(RegisterPair::HL);
@ -1322,7 +1322,7 @@ impl Instruction {
shift_reg = (value >> 1) | (msb << 7); // msb is duplicated in this op
cpu.write_byte(addr, value);
cycles = Cycles(16);
cycles = Cycles::new(16);
}
}
@ -1351,7 +1351,7 @@ impl Instruction {
swap_reg = Self::swap_bits(value);
cpu.set_register(register, swap_reg);
cycles = Cycles(8);
cycles = Cycles::new(8);
}
InstrRegister::IndirectHL => {
@ -1361,7 +1361,7 @@ impl Instruction {
swap_reg = Self::swap_bits(value);
cpu.write_byte(addr, swap_reg);
cycles = Cycles(16)
cycles = Cycles::new(16)
}
}
@ -1392,7 +1392,7 @@ impl Instruction {
shift_reg = value >> 1;
cpu.set_register(register, shift_reg);
cycles = Cycles(8);
cycles = Cycles::new(8);
}
InstrRegister::IndirectHL => {
let addr = cpu.register_pair(RegisterPair::HL);
@ -1402,7 +1402,7 @@ impl Instruction {
shift_reg = value >> 1;
cpu.write_byte(addr, shift_reg);
cycles = Cycles(16);
cycles = Cycles::new(16);
}
}
@ -1428,14 +1428,14 @@ impl Instruction {
let value = cpu.register(register);
is_bit_set = ((value >> y) & 0x01) == 0x01;
cycles = Cycles(8);
cycles = Cycles::new(8);
}
InstrRegister::IndirectHL => {
let addr = cpu.register_pair(RegisterPair::HL);
let value = cpu.read_byte(addr);
is_bit_set = ((value >> y) & 0x01) == 0x01;
cycles = Cycles(12);
cycles = Cycles::new(12);
}
}
@ -1462,14 +1462,14 @@ impl Instruction {
let value = cpu.register(register);
cpu.set_register(register, value & !(1u8 << y));
Cycles(8)
Cycles::new(8)
}
InstrRegister::IndirectHL => {
let addr = cpu.register_pair(RegisterPair::HL);
let value = cpu.read_byte(addr);
cpu.write_byte(addr, value & !(1u8 << y));
Cycles(16)
Cycles::new(16)
}
}
}
@ -1490,14 +1490,14 @@ impl Instruction {
let value = cpu.register(register);
cpu.set_register(register, value | (1u8 << y));
Cycles(8)
Cycles::new(8)
}
InstrRegister::IndirectHL => {
let addr = cpu.register_pair(RegisterPair::HL);
let value = cpu.read_byte(addr);
cpu.write_byte(addr, value | (1u8 << y));
Cycles(16)
Cycles::new(16)
}
}
}
@ -2085,3 +2085,80 @@ impl std::fmt::Debug for Registers {
}
}
}
impl Cycles {
pub fn new(num: u32) -> Self {
Self(num)
}
}
impl std::ops::Add for Cycles {
type Output = Self;
fn add(self, rhs: Self) -> Self::Output {
Self(self.0 + rhs.0)
}
}
impl std::ops::Add<u32> for Cycles {
type Output = Self;
fn add(self, rhs: u32) -> Self::Output {
Self(self.0 + rhs)
}
}
impl std::ops::AddAssign for Cycles {
fn add_assign(&mut self, rhs: Self) {
*self = Self(self.0 + rhs.0);
}
}
impl std::ops::AddAssign<u32> for Cycles {
fn add_assign(&mut self, rhs: u32) {
*self = Self(self.0 + rhs);
}
}
impl std::ops::Rem for Cycles {
type Output = Self;
fn rem(self, rhs: Self) -> Self::Output {
Self(self.0 % rhs.0)
}
}
impl std::ops::Rem<u32> for Cycles {
type Output = Self;
fn rem(self, rhs: u32) -> Self::Output {
Self(self.0 % rhs)
}
}
impl From<u32> for Cycles {
fn from(num: u32) -> Self {
Self(num)
}
}
#[cfg(test)]
mod tests {
use super::Cycles;
#[test]
fn cycle_add_works() {
let lhs: Cycles = Cycles::new(0);
let rhs: Cycles = Cycles::new(0);
assert_eq!(Cycles::new(9), rhs + lhs);
}
#[test]
fn cycle_add_assign_works() {
let mut cycles: Cycles = Cycles::new(0);
cycles += 5;
assert_eq!(Cycles::new(10), cycles);
}
}

19
src/main.rs
View File

@ -1,7 +1,6 @@
use anyhow::{anyhow, Result};
use gb::cpu::Cpu as LR35902;
use pixels::{Pixels, SurfaceTexture};
use std::io::Write;
use winit::{
dpi::LogicalSize,
event::{Event, VirtualKeyCode},
@ -20,9 +19,6 @@ fn main() -> Result<()> {
let mut input = WinitInputHelper::new();
let window = create_window(&event_loop)?;
let mut pixels = create_pixels(&window)?;
let out = Box::leak(Box::new(std::io::stdout()));
let mut out_handle = out.lock();
let mut game_boy = LR35902::new();
game_boy.load_cartridge("bin/cpu_instrs.gb");
@ -54,19 +50,8 @@ fn main() -> Result<()> {
}
// Emulation
let addr = game_boy.register_pair(gb::cpu::RegisterPair::PC);
let opcode = game_boy.fetch();
let instruction = game_boy.decode(opcode);
let _cycles = game_boy.execute(instruction);
window.request_redraw();
write!(
out_handle,
"Addr: {:#06X} | Opcode: {:#04X} | Instr: {:X?}\n",
addr, opcode, instruction
)
.unwrap();
let _cycles = game_boy.step();
// window.request_redraw();
}
});

31
src/ppu.rs
View File

@ -1,14 +1,32 @@
use crate::instruction::Cycles;
#[derive(Debug, Clone)]
pub struct PPU {
pub lcd_control: LCDControl,
pub monochrome: Monochrome,
pub pos: ScreenPosition,
pub vram: Box<[u8]>,
pub oam: Box<[u8]>,
pub stat: LCDStatus,
cycles: Cycles,
mode: PPUMode,
}
impl PPU {
pub fn step(&mut self) {}
pub fn step(&mut self, cycles: Cycles) {
self.cycles += cycles;
match self.mode {
PPUMode::OAMScan => {
if self.cycles >= 80.into() {
self.cycles = cycles % 80;
}
}
PPUMode::Draw => {}
PPUMode::HBlank => {}
PPUMode::VBlank => {}
}
}
pub fn draw(&self, frame: &mut [u8]) {
for (_i, pixel) in frame.chunks_exact_mut(4).enumerate() {
@ -26,10 +44,21 @@ impl Default for PPU {
pos: Default::default(),
stat: Default::default(),
vram: vec![0; 8192].into_boxed_slice(),
oam: vec![0; 160].into_boxed_slice(),
cycles: 0.into(),
mode: PPUMode::OAMScan,
}
}
}
#[derive(Debug, Clone, Copy)]
enum PPUMode {
OAMScan,
Draw,
HBlank,
VBlank,
}
#[derive(Debug, Clone, Copy, Default)]
pub struct LCDStatus {
lyc_eq_ly: bool,

8
src/sound.rs
View File

@ -1,9 +1,17 @@
use crate::instruction::Cycles;
#[derive(Debug, Clone, Copy, Default)]
pub struct Sound {
pub control: SoundControl,
pub ch1: Channel1,
}
impl Sound {
pub fn step(&mut self, _cycles: Cycles) {
//
}
}
#[derive(Debug, Clone, Copy, Default)]
pub struct SoundControl {
pub channel: ChannelControl,

8
src/timer.rs
View File

@ -1,8 +1,16 @@
use crate::instruction::Cycles;
#[derive(Debug, Clone, Copy)]
pub struct Timer {
pub control: TimerControl,
}
impl Timer {
pub fn step(&mut self, _cycles: Cycles) {
//
}
}
impl Default for Timer {
fn default() -> Self {
Self {