101 lines
2.1 KiB
Rust
101 lines
2.1 KiB
Rust
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#![feature(exclusive_range_pattern)]
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use clap::Parser;
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use std::fs;
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/// Simple program to greet a person
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#[derive(Parser, Debug)]
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#[command(author, version, about, long_about = None)]
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struct Args {
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/// ROM path
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#[arg(short, long)]
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rom: String,
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}
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type Register = u16;
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type ROM = Vec<u8>;
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type Operation = u8;
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struct Memory {
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rom: ROM,
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}
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impl Memory {
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fn get(&mut self, address: u16) -> u8 {
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match address {
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0x0..0x8000 => {
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// rom access
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// todo - switchable rom banks
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return self.rom[address as usize];
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}
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0x8000..0xA000 => {
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panic!("vram");
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}
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0xA000..0xC000 => {
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panic!("switchable ram bank");
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}
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0xC000..0xE000 => {
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panic!("ram")
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}
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0xE000..0xFE00 => {
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panic!("ram mirror")
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}
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0xFE00..0xFEA0 => {
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panic!("sprite attrib memory");
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}
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0xFEA0..0xFF00 => {
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panic!("empty")
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}
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0xFF00..0xFF4C => {
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panic!("I/O");
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}
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0xFF4C..0xFF80 => {
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panic!("empty");
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}
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0xFF80..0xFFFF => {
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panic!("internal ram");
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}
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0xFFFF => {
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panic!("interrupt enable register");
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}
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}
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}
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}
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#[derive(Debug)]
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struct State {
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af: Register,
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bc: Register,
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de: Register,
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hl: Register,
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sp: Register,
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pc: Register,
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}
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impl Default for State {
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fn default() -> Self {
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Self {
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af: 0x01B0,
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bc: 0x0013,
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de: 0x00D8,
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hl: 0x014D,
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sp: 0xFFFE,
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pc: 0x0100,
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}
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}
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}
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fn main() {
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let args = Args::parse();
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let rom: ROM = fs::read(args.rom).expect("Could not load ROM");
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let state = State::default();
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loop {
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let op = fetch_op(&rom, state.pc);
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}
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}
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fn fetch_op(rom: &ROM, pc: Register) -> Operation {
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rom[pc as usize]
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}
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