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Daniel Bulant 2023-01-18 22:00:00 +01:00
commit 953cc4aac6
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target

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# Default ignored files
/shelf/
/workspace.xml
# Editor-based HTTP Client requests
/httpRequests/
# Datasource local storage ignored files
/dataSources/
/dataSources.local.xml

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<?xml version="1.0" encoding="UTF-8"?>
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<orderEntry type="inheritedJdk" />
<orderEntry type="sourceFolder" forTests="false" />
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# This file is automatically @generated by Cargo.
# It is not intended for manual editing.
version = 3
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version = "1.0.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
[[package]]
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version = "0.1.0"
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"rand_core",
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Cargo.toml Normal file
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[package]
name = "chip8"
version = "0.1.0"
edition = "2021"
# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
[dependencies]
rand = "0.8.5"

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use std::env::args;
use std::fs::File;
use std::io::Read;
use std::time::{Duration, Instant};
use rand::prelude::*;
mod opcodes;
fn main() {
let file_path = args().nth(1);
match file_path {
None => panic!("No file path"),
Some(file_path) => {
let mut file = File::open(file_path).unwrap();
let mut data = Vec::new();
let len = file.read_to_end(&mut data).unwrap();
let mut chip8 = Chip8::new();
chip8.load_rom(data);
loop {
chip8.run_next();
}
}
}
}
/// 12 bit address pointer
type Address = u16;
#[derive(Debug)]
struct Chip8 {
/// 4K memory
memory: [u8; 4096],
/// registers
v: [u8; 16],
/// current address
i: Address,
/// program counter
pc: Address,
/// stack (return addresses)
stack: Vec<Address>,
/// delay timer (60Hz, when non-zero, decremented at 60Hz)
delay_timer: u8,
/// sound timer (when non-zero, beeps, and decrements at 60Hz)
sound_timer: u8,
/// graphics (64x32 black and white)
display: [bool; 64 * 32],
start_time: Instant,
last_processed_timers: Instant
}
const WIDTH: usize = 32;
const HEIGHT: usize = 64;
impl Chip8 {
fn new() -> Chip8 {
let mut c = Chip8 {
memory: [0; 4096],
v: [0; 16],
i: 0,
pc: 0x100,
stack: Vec::new(),
delay_timer: 0,
sound_timer: 0,
display: [false; 64 * 32],
start_time: Instant::now(),
last_processed_timers: Instant::now()
};
// initialize font
c.memory[0..80].clone_from_slice(&[
0xF0, 0x90, 0x90, 0x90, 0xF0, // 0
0x20, 0x60, 0x20, 0x20, 0x70, // 1
0xF0, 0x10, 0xF0, 0x80, 0xF0, // 2
0xF0, 0x10, 0xF0, 0x10, 0xF0, // 3
0x90, 0x90, 0xF0, 0x10, 0x10, // 4
0xF0, 0x80, 0xF0, 0x10, 0xF0, // 5
0xF0, 0x80, 0xF0, 0x90, 0xF0, // 6
0xF0, 0x10, 0x20, 0x40, 0x40, // 7
0xF0, 0x90, 0xF0, 0x90, 0xF0, // 8
0xF0, 0x90, 0xF0, 0x10, 0xF0, // 9
0xF0, 0x90, 0xF0, 0x90, 0x90, // A
0xE0, 0x90, 0xE0, 0x90, 0xE0, // B
0xF0, 0x80, 0x80, 0x80, 0xF0, // C
0xE0, 0x90, 0x90, 0x90, 0xE0, // D
0xF0, 0x80, 0xF0, 0x80, 0xF0, // E
0xF0, 0x80, 0xF0, 0x80, 0x80 // F
]);
c
}
fn load_rom(&mut self, rom: Vec<u8>) {
self.memory[0x200..0x200+rom.len()].clone_from_slice(&*rom);
}
fn run_next(&mut self) {
let current = (self.memory[self.pc as usize * 2] as u16) << 8 | (self.memory[self.pc as usize * 2 + 1] as u16);
let first = ((current & 0xF000) as u16 >> 12) as u8;
let first_raw = (current & 0xF000) as u16;
let second = ((current & 0x0F00 as u16) >> 8 as u16) as u8;
let second_raw = (current & 0x0F00) as u16;
let third = ((current & 0x00F0) as u16 >> 4) as u8;
let third_raw = (current & 0x00F0) as u16;
let fourth = (current & 0x000F) as u8;
let fourth_raw = (current & 0x000F) as u16;
let last_two = (third_raw|fourth_raw) as u8;
let after_first = current ^ (first_raw as Address);
print!("{:#x}", self.pc);
if current == 0 {
dbg!(&self);
panic!("Null call {}", self.pc);
}
// println!("{current:#04x} -> F{first_raw:#x} S{second_raw:#x} T{third_raw:#x} F{fourth_raw:#x} - !F={after_first:#x} {last_two:#x}");
if first == 0 {
// syscalls
if current == 0x00e0 {
println!("CLS");
self.display = [false; 64 * 32];
} else if current == 0x00ee {
if self.stack.is_empty() {
panic!("Stack underflow");
}
self.pc = self.stack.pop().unwrap();
return;
} else {
println!("SYS {}", after_first);
}
} else if first == 1 {
// jump
println!("JP {after_first:#x} ({after_first})");
if after_first / 2 == self.pc {
panic!("HALT! Jump to self (direct infinite loop)");
}
self.pc = after_first / 2;
return;
} else if first == 2 {
// call
println!("CALL {}", after_first);
self.stack.push(self.pc);
self.pc = after_first;
} else if first == 3 {
// if eq
println!("SE IF V{second} == {}", last_two);
if self.v[second as usize] != last_two {
self.pc += 1;
}
} else if first == 4 {
// if not eq
println!("SNE IF V{second} != {}", last_two);
if self.v[second as usize] == last_two {
self.pc += 1;
}
} else if first == 5 {
// if Vx == Vy
if self.v[second as usize] != self.v[third as usize] {
self.pc += 1;
}
} else if first == 6 {
// LOAD; Vx = NN
println!("LD V{second} = {last_two:#x} ({last_two})");
self.v[second as usize] = last_two;
} else if first == 7 {
// ADD; Vx += NN
println!("ADD V{second} += {last_two:#x} ({last_two})");
self.v[second as usize] += last_two;
} else if first == 8 {
println!("eights");
if fourth == 0 {
self.v[second as usize] = self.v[third as usize];
} else if fourth == 1 {
self.v[second as usize] |= self.v[third as usize];
} else if fourth == 2 {
self.v[second as usize] &= self.v[third as usize];
} else if fourth == 3 {
self.v[second as usize] ^= self.v[third as usize];
} else if fourth == 4 {
self.v[second as usize] += self.v[third as usize];
// TODO! Carry implementation
} else if fourth == 5 {
self.v[second as usize] -= self.v[third as usize];
// TODO! Borrow implementation
} else if fourth == 6 {
self.v[0xF] = self.v[second as usize] & 1;
self.v[second as usize] >>= 1;
} else if fourth == 7 {
self.v[second as usize] = self.v[third as usize] - self.v[second as usize];
} else if fourth == 0xE {
self.v[0xF] = if (self.v[second as usize] & 0b10000000) != 0 { 1 } else { 0};
self.v[second as usize] <<= 1;
}
} else if first == 9 {
// if Vx != Vy
println!("IF V{second} != V{third}");
if self.v[second as usize] == self.v[third as usize] {
self.pc += 1;
}
} else if first == 0xA {
// I=NNN
println!("I={after_first:#x} ({after_first})");
self.i = after_first;
} else if first == 0xB {
println!("JP+ {} {after_first:#x} ({after_first})", self.v[0]);
self.pc = (self.v[0] as Address) + after_first;
return;
} else if first == 0xC {
// I=rand() & NN
println!("RND V{second} = random & {last_two:#x} ({last_two} {last_two:#b})");
let random: u8 = random();
self.v[second as usize] = random & last_two;
} else if first == 0xD {
// draw(Vx, Vy, N)
// draws at Vx, Vy, width 8, height N
// sprite (bit coded XOR (set bits flip the bit value)) from I
// VF set to 1 if any bit is set to 0
println!("DRW X=V{second} Y=V{third} W=16 H={fourth}");
let x = self.v[second as usize] % (WIDTH as u8);
let y = self.v[third as usize] % (HEIGHT as u8);
let sprite_height = fourth as usize;
self.v[0xF] = 0;
for sprite_y in 1..sprite_height+1 {
let sprite_y = (sprite_height - sprite_y + y as usize) % (HEIGHT);
let sprite_row = self.memory[self.i as usize + sprite_y];
println!("\n{:#b} ({:#x})", sprite_row, sprite_row);
for b in 0..8 {
let mut pos: usize = (sprite_y as usize * WIDTH) + ((b as usize) + (x as usize) % WIDTH as usize);
if (x as i16) + (b as i16) < 0 { pos += WIDTH - 1 }
// let orig = self.display[pos];
self.display[pos] ^= (sprite_row & (1 << (7-b))) > 0;
// println!("pos{} x{} y{}", pos, pos % WIDTH, pos / WIDTH);
// println!("x{x} + y{y}*16 + {b} = {pos} .. {:#010b} = {:#010b}", 1 << (7-b), (memory & (1 << (7-b))));
// print!("{}", if (sprite_row & (1 << (7-b))) > 0 { "█" } else { " " });
// println!("");
if self.v[0xF] == 0 {
self.v[0xF] = if self.display[pos] && (sprite_row & (1 << (7-b))) > 0 { 1 } else { 0 };
}
}
}
for x in 0..WIDTH {
for y in 0..HEIGHT {
print!("{}", if self.display[y*WIDTH + x] { "█" } else { " " });
}
println!();
}
} else if first == 0xE {
// Keyboard operations
// TODO! implement keyboard
if last_two == 0x9E {
// if key() == Vx
println!("key() == V{last_two}");
} else if last_two == 0xA1 {
// if key() != Vx
println!("key() != V{last_two}");
}
} else if first == 0xF {
if last_two == 0x07 {
// Vx = get_delay()
println!("V{second} = delay()");
self.v[second as usize] = self.delay_timer;
} else if last_two == 0x0A {
// Vx = get_key()
println!("V{second} = key()");
self.v[second as usize] = 0; // TODO! implement keyboard
} else if last_two == 0x15 {
println!("delay(V{second})");
self.delay_timer = self.v[second as usize];
} else if last_two == 0x18 {
println!("sound({second})");
self.sound_timer = self.v[second as usize];
} else if last_two == 0x1E {
println!("I += V{second}");
self.i += self.v[second as usize] as u16;
} else if last_two == 0x29 {
// I = sprite_addr[Vx]
// Characters 0x0-0xF are represented by a 4x5 font
println!("I=sprite_addr[V{second}]");
self.i = (4 * 5 * second) as Address;
} else if last_two == 0x33 {
// Stores binary-coded decimal representation of Vx, hundreds digit at I, tens digit at I+1 and ones digit at I+2
let num = self.v[second as usize];
self.memory[self.i as usize] = num / 100;
self.memory[self.i as usize + 1] = num / 10 % 100;
self.memory[self.i as usize + 2] = num % 10;
println!("encoded I = V{second}");
} else if last_two == 0x55 {
// reg_dump(Vx, &I)
println!("reg_dump(V{second}, I)");
if (self.i+second as u16) as usize >= self.memory.len() {
panic!("overflow with reg_dump");
}
self.memory[self.i as usize..second as usize].clone_from_slice(&self.v[0..second as usize])
} else if last_two == 0x65 {
// reg_load(Vx, &I)
println!("reg_load(V{second}, I)");
if (self.i+second as u16) as usize >= self.memory.len() {
panic!("overflow with reg_load");
}
self.v[0..second as usize].clone_from_slice(&self.memory[self.i as usize..second as usize]);
}
}
self.pc += 1;
if self.pc as usize > self.memory.len() {
panic!("Halted (Program counter over ROM length)");
}
let now = Instant::now();
if now - self.last_processed_timers > Duration::from_millis(16) {
if self.sound_timer > 0 {
print!("\x07");
self.sound_timer -= 1;
}
if self.delay_timer > 0 {
self.delay_timer -= 1;
}
}
}
}

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pub enum Opcode {
DisplayClear
}