Playing around with reading gameboy roms, and maybe emulation

header should be there i think

Changed files
+348 -28
src
+1
.gitignore
···
/target
/LegallyObtainedRom.gb
.idea/
···
/target
/LegallyObtainedRom.gb
+
/OtherLegallyObtainedRom.gb
.idea/
+189
src/enums.rs
···
···
+
pub enum CartridgeHeaderAddress {
+
// Whole Header
+
CartridgeHeaderStart = 0x0100,
+
CartridgeHeaderEnd = 0x014F,
+
// 0100-0103 — Entry point
+
EntryPointEnd = 0x0103,
+
// 0104-0133 — Nintendo logo
+
NintendoLogoStart = 0x0104,
+
NintendoLogoEnd = 0x00133,
+
// 0134-0143 — Title
+
TitleStart = 0x0134,
+
TitleEnd = 0x0143,
+
// 013F-0142 — Manufacturer code
+
ManufacturerCodeStart = 0x013F,
+
ManufacturerCodeEnd = 0x0142,
+
// 0144–0145 — New licensee code
+
NewLicenseStart = 0x0144,
+
NewLicenseEnd = 0x0145,
+
// 0146 — SGB flag
+
SgbFlag = 0x0146,
+
// 0147 — Cartridge type
+
CartType = 0x0147,
+
// 0148 — ROM size
+
RomSize = 0x0148,
+
// 0149 - RAM Size,
+
RamSize = 0x0149,
+
// 014A — Destination code
+
DestinationCode = 0x014A,
+
// 014B — Old licensee code
+
OldLicenseeCode = 0x014b,
+
// 014C — Mask ROM version number,
+
MaskRomVersion = 0x014C,
+
// 014D — Header checksum
+
HeaderChecksum = 0x014D,
+
// 014E-014F — Global checksum
+
GlobalChecksumStart = 0x014E,
+
//End is the end of cartheader
+
}
+
+
pub enum Error {
+
CartridgeReadError,
+
//Nintendo logos do not match
+
NotAValidRom,
+
}
+
+
pub enum DestinationCode {
+
Japan = 0x00,
+
NotJapan = 0x01,
+
}
+
+
impl DestinationCode {
+
pub fn from_byte(byte: u8) -> Self {
+
match byte {
+
0x00 => Self::Japan,
+
0x01 | _ => Self::NotJapan,
+
}
+
}
+
}
+
+
#[derive(Debug)]
+
pub enum RamSize {
+
NoRAM = 0x000,
+
Unused = 0x001,
+
Ram8KiB = 0x002,
+
Ram32KiB = 0x003,
+
Ram128KiB = 0x004,
+
Ram64KiB = 0x005,
+
}
+
+
impl RamSize {
+
pub fn from_byte(byte: u8) -> Self {
+
match byte {
+
0x001 => Self::Unused,
+
0x002 => Self::Ram8KiB,
+
0x003 => Self::Ram32KiB,
+
0x004 => Self::Ram128KiB,
+
0x005 => Self::Ram64KiB,
+
_ => Self::NoRAM,
+
}
+
}
+
}
+
#[derive(Debug)]
+
pub enum CartridgeType {
+
RomOnly = 0x000,
+
MBC1 = 0x001,
+
Mbc1Ram = 0x002,
+
Mbc1RamBattery = 0x003,
+
MBC2 = 0x005,
+
Mbc2Battery = 0x006,
+
RomRam9 = 0x008,
+
RomRamBattery9 = 0x009,
+
MMM01 = 0x00B,
+
Mmm01Ram = 0x00C,
+
Mmm01RamBattery = 0x00D,
+
Mbc3TimerBattery = 0x00F,
+
Mbc3TimerRamBattery10 = 0x010,
+
MBC3 = 0x011,
+
Mbc3Ram10 = 0x012,
+
Mbc3RaBattery10 = 0x013,
+
MBC5 = 0x019,
+
Mbc5Ram = 0x01A,
+
Mbc5RamBattery = 0x01B,
+
Mbc5Rumble = 0x01C,
+
Mbc5RumbleRam = 0x01D,
+
Mbc5RumbleRamBattery = 0x01E,
+
MBC6 = 0x020,
+
Mbc7SensorRumbleRamBattery = 0x022,
+
PocketCamera = 0x0FC,
+
BandaiTama5 = 0x0FD,
+
HuC3 = 0x0FE,
+
HuC1RamBattery = 0x0FF,
+
}
+
+
impl CartridgeType {
+
pub fn from_byte(byte: u8) -> Self {
+
match byte {
+
0x001 => Self::MBC1,
+
0x002 => Self::Mbc1Ram,
+
0x003 => Self::Mbc1RamBattery,
+
0x005 => Self::MBC2,
+
0x006 => Self::Mbc2Battery,
+
0x008 => Self::RomRam9,
+
0x009 => Self::RomRamBattery9,
+
0x00B => Self::MMM01,
+
0x00C => Self::Mmm01Ram,
+
0x00D => Self::Mmm01RamBattery,
+
0x00F => Self::Mbc3TimerBattery,
+
0x010 => Self::Mbc3TimerRamBattery10,
+
0x011 => Self::MBC3,
+
0x012 => Self::Mbc3Ram10,
+
0x013 => Self::Mbc3RaBattery10,
+
0x019 => Self::MBC5,
+
0x01A => Self::Mbc5Ram,
+
0x01B => Self::Mbc5RamBattery,
+
0x01C => Self::Mbc5Rumble,
+
0x01D => Self::Mbc5RumbleRam,
+
0x01E => Self::Mbc5RumbleRamBattery,
+
0x020 => Self::MBC6,
+
0x022 => Self::Mbc7SensorRumbleRamBattery,
+
0x0FC => Self::PocketCamera,
+
0x0FD => Self::BandaiTama5,
+
0x0FE => Self::HuC3,
+
0x0FF => Self::HuC1RamBattery,
+
0x000 | _ => Self::RomOnly,
+
}
+
}
+
}
+
+
#[derive(Debug)]
+
pub enum RomSize {
+
Rom32KiB = 0x000,
+
Rom64KiB = 0x001,
+
Rom128KiB = 0x002,
+
Rom256KiB = 0x003,
+
Rom512KiB = 0x004,
+
Rom1MiB = 0x005,
+
Rom2MiB = 0x006,
+
Rom4MiB = 0x007,
+
Rom8MiB = 0x008,
+
Rom1_1MiB = 0x052,
+
Rom1_2MiB = 0x053,
+
Rom1_5MiB = 0x054,
+
}
+
+
impl RomSize {
+
pub fn from_byte(byte: u8) -> Self {
+
match byte {
+
0x001 => Self::Rom64KiB,
+
0x002 => Self::Rom128KiB,
+
0x003 => Self::Rom256KiB,
+
0x004 => Self::Rom512KiB,
+
0x005 => Self::Rom1MiB,
+
0x006 => Self::Rom2MiB,
+
0x007 => Self::Rom4MiB,
+
0x008 => Self::Rom8MiB,
+
0x052 => Self::Rom1_1MiB,
+
0x053 => Self::Rom1_2MiB,
+
0x054 => Self::Rom1_5MiB,
+
0x000 | _ => Self::Rom32KiB,
+
}
+
}
+
}
+
+
#[derive(Debug)]
+
pub enum CGBFlag {
+
SupportsColorBackwardCompatiable,
+
ColorOnly,
+
NotSet,
+
}
+158 -28
src/main.rs
···
use std::fs::File;
-
use std::io::{Read, Seek, SeekFrom, Write};
const ROM_NAME: &str = "LegallyObtainedRom.gb";
-
-
pub enum Error {
-
CartridgeReadError,
-
}
struct CartridgeHeader {
//Should be 80 bytes (0x014F(335) - 0x0100(256)) + 1 to include the last address
buffer: [u8; 80],
}
-
impl CartridgeHeader {
-
fn new(rom_bytes: &[u8] ) -> Result<Self, Error> {
-
let start = CartridgeHeaderAddress::CartridgeHeaderStart as usize;
-
//We know the header is only 80 chars
-
let end = start + 80;
Ok(Self {
-
buffer: rom_bytes[start..end].try_into().map_err(|_| Error::CartridgeReadError)?
})
}
···
}
}
-
-
pub enum CartridgeHeaderAddress {
-
CartridgeHeaderStart = 0x0100,
-
CartridgeHeaderEnd = 0x014F
-
}
-
-
fn main() -> std::io::Result<()> {
let mut rom_file = File::open(ROM_NAME)?;
let mut rom_buffer: Vec<u8> = Vec::new();
rom_file.read_to_end(&mut rom_buffer)?;
-
let cart_header = CartridgeHeader::new(&*rom_buffer).map_err(|err| std::io::Error::new(std::io::ErrorKind::Other, "Rom failed to parse"))?;
-
cart_header.print_test();
-
Ok(())
-
}
-
fn buffer_from_file(path: &str) -> Vec<u8> {
-
let mut file = std::fs::File::open(path).expect("File not there");
-
let mut buffer = Vec::new();
-
file.read_to_end(&mut buffer).expect("Could not read file");
-
buffer
-
}
···
+
mod enums;
+
+
use crate::enums::CartridgeHeaderAddress::OldLicenseeCode;
+
use crate::enums::{
+
CGBFlag, CartridgeHeaderAddress, CartridgeType, DestinationCode, Error, RamSize, RomSize,
+
};
use std::fs::File;
+
use std::io::Read;
+
// https://github.com/ISSOtm/gb-bootroms/blob/2dce25910043ce2ad1d1d3691436f2c7aabbda00/src/dmg.asm#L259-L269
+
// Each tile is encoded using 2 (!) bytes
+
// The tiles are represented below
+
// XX.. .XX. XX.. .... .... .... .... .... .... ...X X... ....
+
// XXX. .XX. XX.. .... ..XX .... .... .... .... ...X X... ....
+
// XXX. .XX. .... .... .XXX X... .... .... .... ...X X... ....
+
// XX.X .XX. XX.X X.XX ..XX ..XX XX.. XX.X X... XXXX X..X XXX.
+
// XX.X .XX. XX.X XX.X X.XX .XX. .XX. XXX. XX.X X..X X.XX ..XX
+
// XX.. XXX. XX.X X..X X.XX .XXX XXX. XX.. XX.X X..X X.XX ..XX
+
// XX.. XXX. XX.X X..X X.XX .XX. .... XX.. XX.X X..X X.XX ..XX
+
// XX.. .XX. XX.X X..X X.XX ..XX XXX. XX.. XX.. XXXX X..X XXX.
+
const NINTENDO_LOGO: [u8; 48] = [
+
0x0CE, 0x0ED, 0x066, 0x066, 0x0CC, 0x00D, 0x000, 0x00B, 0x003, 0x073, 0x000, 0x083, 0x000,
+
0x00C, 0x000, 0x00D, 0x000, 0x008, 0x011, 0x01F, 0x088, 0x089, 0x000, 0x00E, 0x0DC, 0x0CC,
+
0x06E, 0x0E6, 0x0DD, 0x0DD, 0x0D9, 0x099, 0x0BB, 0x0BB, 0x067, 0x063, 0x06E, 0x00E, 0x0EC,
+
0x0CC, 0x0DD, 0x0DC, 0x099, 0x09F, 0x0BB, 0x0B9, 0x033, 0x03E,
+
];
+
// const ROM_NAME: &str = "OtherLegallyObtainedRom.gb";
const ROM_NAME: &str = "LegallyObtainedRom.gb";
struct CartridgeHeader {
//Should be 80 bytes (0x014F(335) - 0x0100(256)) + 1 to include the last address
buffer: [u8; 80],
+
title: [char; 16],
+
manufacturer_code: [char; 4],
+
cgb_flag: CGBFlag,
+
// https://gbdev.io/pandocs/The_Cartridge_Header.html#01440145--new-licensee-code
+
license_code: [char; 2],
+
support_gb: bool,
+
cart_type: CartridgeType,
+
rom_size: RomSize,
+
ram_size: RamSize,
+
old_licensee_code: Option<u8>,
+
destination_code: DestinationCode,
+
version: u8,
+
header_checksum: u8,
+
global_checksum: u16,
}
+
impl CartridgeHeader {
+
fn bytes_to_chars<const N: usize>(bytes: &[u8], break_on_null: bool) -> [char; N] {
+
let mut chars = [0x000 as char; N];
+
for (i, byte) in bytes.iter().enumerate() {
+
if break_on_null && *byte == 0x00 {
+
break;
+
}
+
chars[i] = *byte as char;
+
}
+
chars
+
}
+
fn parse(rom_bytes: &[u8]) -> Result<Self, Error> {
+
let start = CartridgeHeaderAddress::CartridgeHeaderStart as usize;
+
let end = start + 80;
+
let header_buffer: &[u8] = rom_bytes[start..end]
+
.try_into()
+
.map_err(|_| Error::CartridgeReadError)?;
+
//Checks if the Nintendo logo matches the device's version. Early anti piracy feature. Neat to take note of
+
let nintendo_logo_from_rom = &rom_bytes[CartridgeHeaderAddress::NintendoLogoStart as usize
+
..CartridgeHeaderAddress::NintendoLogoEnd as usize + 1];
+
for (i, true_logo_byte) in NINTENDO_LOGO.iter().enumerate() {
+
let rom_byte = nintendo_logo_from_rom[i];
+
if rom_byte != *true_logo_byte {
+
return Err(Error::CartridgeReadError);
+
}
+
}
+
let title = &rom_bytes[CartridgeHeaderAddress::TitleStart as usize
+
..CartridgeHeaderAddress::TitleEnd as usize + 1];
+
let title_chars = Self::bytes_to_chars::<16>(title, true);
+
let manufacturer_code = &rom_bytes[CartridgeHeaderAddress::ManufacturerCodeStart as usize
+
..CartridgeHeaderAddress::ManufacturerCodeEnd as usize + 1];
+
let man_code_chars = Self::bytes_to_chars::<4>(manufacturer_code, false);
+
let cgb_flag_byte = rom_bytes[0x0143];
+
let cgb_flag = match cgb_flag_byte {
+
0x80 => CGBFlag::SupportsColorBackwardCompatiable,
+
0xC0 => CGBFlag::ColorOnly,
+
_ => CGBFlag::NotSet,
+
};
+
+
let license_code = &rom_bytes[CartridgeHeaderAddress::NewLicenseStart as usize
+
..CartridgeHeaderAddress::NewLicenseEnd as usize + 1];
+
let license_code_chars = Self::bytes_to_chars::<2>(license_code, false);
+
+
// https://gbdev.io/pandocs/The_Cartridge_Header.html#0146--sgb-flag
+
let sgb_flag = rom_bytes[CartridgeHeaderAddress::SgbFlag as usize] == 0x03;
+
+
let cart_type =
+
CartridgeType::from_byte(rom_bytes[CartridgeHeaderAddress::CartType as usize]);
+
+
let rom_size = RomSize::from_byte(rom_bytes[CartridgeHeaderAddress::RomSize as usize]);
+
let ram_size = RamSize::from_byte(rom_bytes[CartridgeHeaderAddress::RamSize as usize]);
+
+
let mut old_licensee_code = None;
+
if !sgb_flag {
+
old_licensee_code = Some(rom_bytes[CartridgeHeaderAddress::OldLicenseeCode as usize])
+
}
+
+
let destination_code =
+
DestinationCode::from_byte(rom_bytes[CartridgeHeaderAddress::DestinationCode as usize]);
+
+
let version = rom_bytes[CartridgeHeaderAddress::MaskRomVersion as usize];
+
let header_checksum = rom_bytes[CartridgeHeaderAddress::HeaderChecksum as usize];
+
let global_checksum = u16::from_le_bytes([
+
rom_bytes[CartridgeHeaderAddress::GlobalChecksumStart as usize],
+
rom_bytes[CartridgeHeaderAddress::CartridgeHeaderEnd as usize],
+
]);
Ok(Self {
+
buffer: header_buffer
+
.try_into()
+
.map_err(|_| Error::CartridgeReadError)?,
+
title: title_chars,
+
manufacturer_code: man_code_chars,
+
cgb_flag,
+
license_code: license_code_chars,
+
support_gb: sgb_flag,
+
cart_type,
+
rom_size,
+
ram_size,
+
old_licensee_code,
+
destination_code,
+
version,
+
header_checksum,
+
global_checksum,
})
}
···
}
}
fn main() -> std::io::Result<()> {
let mut rom_file = File::open(ROM_NAME)?;
let mut rom_buffer: Vec<u8> = Vec::new();
rom_file.read_to_end(&mut rom_buffer)?;
+
let cart_header = match CartridgeHeader::parse(&*rom_buffer) {
+
Ok(header) => header,
+
Err(err) => {
+
return Err(std::io::Error::new(
+
std::io::ErrorKind::Other,
+
"Rom failed to parse",
+
));
+
}
+
};
+
// cart_header.print_test();
+
let title: String = String::from_iter(cart_header.title);
+
println!("Title: {}", title);
+
let manufacturer_code = String::from_iter(cart_header.manufacturer_code);
+
println!("Manufacturer Code: {}", manufacturer_code);
+
match cart_header.old_licensee_code {
+
Some(code) => println!("Uses Old Licensee Code: {:#X}", code),
+
None => println!(
+
"Uses New Licensee Code: {}",
+
String::from_iter(cart_header.license_code)
+
),
+
}
+
+
println!("CGB Flag: {:?}", cart_header.cgb_flag);
+
println!("Supports SGB: {:?}", cart_header.support_gb);
+
println!("Cartridge Type: {:?}", cart_header.cart_type);
+
println!("ROM Size: {:?}", cart_header.rom_size);
+
println!("RAM Size: {:?}", cart_header.ram_size);
+
match cart_header.destination_code {
+
DestinationCode::Japan => println!("Destination Code: Japan"),
+
DestinationCode::NotJapan => println!("Destination Code: Not Japan"),
+
}
+
println!("Version: {:?}", cart_header.version);
+
println!("Header Checksum: {:#X}", cart_header.header_checksum);
+
println!("Global Checksum: {:#X}", cart_header.global_checksum);
+
+
Ok(())
+
}