gb-emu/src/processor/memory/rom.rs

use crate::processor::memory::Address;
use std::str::from_utf8_unchecked;

#[derive(Debug)]
enum MBC {
    ROM,
    MBC1,
}

pub struct ROM {
    title: String,
    data: Vec<u8>,
    mbc: MBC,
}

impl ROM {
    pub fn load(data: Vec<u8>) -> Self {
        let mut title_length = 0x143;
        for i in 0x134..0x143 {
            title_length = i;
            if data[i] == 0x0 {
                break;
            }
        }
        let title = unsafe { from_utf8_unchecked(&data[0x134..title_length]).to_string() };
        let _gbc_flag = data[0x143];
        let _sgb_flag = data[0x146];
        let _rom_size = data[0x148];
        let _ram_size = data[0x149];
        let mbc = match data[0x147] {
            0x00 => MBC::ROM,
            0x01 => MBC::MBC1,
            _ => panic!("unimplemented mbc: {:#X}", data[0x147]),
        };
        Self { title, data, mbc }
    }

    pub fn get_title(&self) -> &String {
        &self.title
    }

    pub(super) fn get(&self, address: Address) -> u8 {
        self.data[address as usize]
    }
}