baileytownsend.dev
+124
src/cartridge_header.rs
+124
src/cartridge_header.rs
···
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use crate::NINTENDO_LOGO;
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use crate::enums::{
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CGBFlag, CartridgeHeaderAddress, CartridgeType, DestinationCode, Error, RamSize, RomSize,
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};
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pub struct CartridgeHeader {
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//Should be 80 bytes (0x014F(335) - 0x0100(256)) + 1 to include the last address
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pub buffer: [u8; 80],
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pub title: [char; 16],
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pub manufacturer_code: [char; 4],
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pub cgb_flag: CGBFlag,
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// https://gbdev.io/pandocs/The_Cartridge_Header.html#01440145--new-licensee-code
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pub license_code: [char; 2],
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pub support_gb: bool,
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pub cart_type: CartridgeType,
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pub rom_size: RomSize,
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pub ram_size: RamSize,
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// If None uses new license code which is just license_code
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// https://gbdev.io/pandocs/The_Cartridge_Header.html#014b--old-licensee-code
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pub old_licensee_code: Option<u8>,
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pub destination_code: DestinationCode,
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pub version: u8,
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pub header_checksum: u8,
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pub global_checksum: u16,
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}
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+
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impl CartridgeHeader {
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fn bytes_to_chars<const N: usize>(bytes: &[u8], break_on_null: bool) -> [char; N] {
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let mut chars = [0x000 as char; N];
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for (i, byte) in bytes.iter().enumerate() {
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if break_on_null && *byte == 0x00 {
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break;
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}
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chars[i] = *byte as char;
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}
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chars
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}
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pub fn parse(rom_bytes: &[u8]) -> Result<Self, Error> {
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let start = CartridgeHeaderAddress::CartridgeHeaderStart as usize;
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let end = start + 80;
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let header_buffer: &[u8] = rom_bytes[start..end]
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.try_into()
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.map_err(|_| Error::CartridgeReadError)?;
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+
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//Checks if the Nintendo logo matches the device's version. Early anti piracy feature. Neat to take note of
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let nintendo_logo_from_rom = &rom_bytes[CartridgeHeaderAddress::NintendoLogoStart as usize
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..CartridgeHeaderAddress::NintendoLogoEnd as usize + 1];
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for (i, true_logo_byte) in NINTENDO_LOGO.iter().enumerate() {
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let rom_byte = nintendo_logo_from_rom[i];
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if rom_byte != *true_logo_byte {
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return Err(Error::CartridgeReadError);
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}
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}
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let title = &rom_bytes[CartridgeHeaderAddress::TitleStart as usize
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..CartridgeHeaderAddress::TitleEnd as usize + 1];
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let title_chars = Self::bytes_to_chars::<16>(title, true);
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let manufacturer_code = &rom_bytes[CartridgeHeaderAddress::ManufacturerCodeStart as usize
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..CartridgeHeaderAddress::ManufacturerCodeEnd as usize + 1];
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let man_code_chars = Self::bytes_to_chars::<4>(manufacturer_code, false);
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let cgb_flag_byte = rom_bytes[0x0143];
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let cgb_flag = match cgb_flag_byte {
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0x80 => CGBFlag::SupportsColorBackwardCompatiable,
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0xC0 => CGBFlag::ColorOnly,
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_ => CGBFlag::NotSet,
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};
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let license_code = &rom_bytes[CartridgeHeaderAddress::NewLicenseStart as usize
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..CartridgeHeaderAddress::NewLicenseEnd as usize + 1];
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let license_code_chars = Self::bytes_to_chars::<2>(license_code, false);
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// https://gbdev.io/pandocs/The_Cartridge_Header.html#0146--sgb-flag
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let sgb_flag = rom_bytes[CartridgeHeaderAddress::SgbFlag as usize] == 0x03;
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let cart_type =
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CartridgeType::from_byte(rom_bytes[CartridgeHeaderAddress::CartType as usize]);
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let rom_size = RomSize::from_byte(rom_bytes[CartridgeHeaderAddress::RomSize as usize]);
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let ram_size = RamSize::from_byte(rom_bytes[CartridgeHeaderAddress::RamSize as usize]);
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let mut old_licensee_code = None;
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if !sgb_flag {
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old_licensee_code = Some(rom_bytes[CartridgeHeaderAddress::OldLicenseeCode as usize])
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}
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let destination_code =
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DestinationCode::from_byte(rom_bytes[CartridgeHeaderAddress::DestinationCode as usize]);
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let version = rom_bytes[CartridgeHeaderAddress::MaskRomVersion as usize];
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let header_checksum = rom_bytes[CartridgeHeaderAddress::HeaderChecksum as usize];
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let global_checksum = u16::from_le_bytes([
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rom_bytes[CartridgeHeaderAddress::GlobalChecksumStart as usize],
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rom_bytes[CartridgeHeaderAddress::CartridgeHeaderEnd as usize],
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]);
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Ok(Self {
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buffer: header_buffer
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.try_into()
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.map_err(|_| Error::CartridgeReadError)?,
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title: title_chars,
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manufacturer_code: man_code_chars,
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cgb_flag,
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license_code: license_code_chars,
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support_gb: sgb_flag,
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cart_type,
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rom_size,
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ram_size,
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old_licensee_code,
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destination_code,
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version,
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header_checksum,
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global_checksum,
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})
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}
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fn print_test(&self) {
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for byte in self.buffer.iter() {
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print!("{} ", *byte as char);
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}
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}
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}
+2
-118
src/main.rs
+2
-118
src/main.rs
···
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mod cartridge_header;
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mod enums;
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use crate::cartridge_header::CartridgeHeader;
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use crate::enums::CartridgeHeaderAddress::OldLicenseeCode;
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use crate::enums::{
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CGBFlag, CartridgeHeaderAddress, CartridgeType, DestinationCode, Error, RamSize, RomSize,
···
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// const ROM_NAME: &str = "OtherLegallyObtainedRom.gb";
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const ROM_NAME: &str = "LegallyObtainedRom.gb";
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struct CartridgeHeader {
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//Should be 80 bytes (0x014F(335) - 0x0100(256)) + 1 to include the last address
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buffer: [u8; 80],
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title: [char; 16],
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manufacturer_code: [char; 4],
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cgb_flag: CGBFlag,
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// https://gbdev.io/pandocs/The_Cartridge_Header.html#01440145--new-licensee-code
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license_code: [char; 2],
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support_gb: bool,
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cart_type: CartridgeType,
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rom_size: RomSize,
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ram_size: RamSize,
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old_licensee_code: Option<u8>,
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destination_code: DestinationCode,
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version: u8,
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header_checksum: u8,
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global_checksum: u16,
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}
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impl CartridgeHeader {
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fn bytes_to_chars<const N: usize>(bytes: &[u8], break_on_null: bool) -> [char; N] {
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let mut chars = [0x000 as char; N];
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for (i, byte) in bytes.iter().enumerate() {
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if break_on_null && *byte == 0x00 {
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break;
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}
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chars[i] = *byte as char;
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}
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chars
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}
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fn parse(rom_bytes: &[u8]) -> Result<Self, Error> {
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let start = CartridgeHeaderAddress::CartridgeHeaderStart as usize;
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let end = start + 80;
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let header_buffer: &[u8] = rom_bytes[start..end]
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.try_into()
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.map_err(|_| Error::CartridgeReadError)?;
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//Checks if the Nintendo logo matches the device's version. Early anti piracy feature. Neat to take note of
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let nintendo_logo_from_rom = &rom_bytes[CartridgeHeaderAddress::NintendoLogoStart as usize
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..CartridgeHeaderAddress::NintendoLogoEnd as usize + 1];
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for (i, true_logo_byte) in NINTENDO_LOGO.iter().enumerate() {
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let rom_byte = nintendo_logo_from_rom[i];
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if rom_byte != *true_logo_byte {
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return Err(Error::CartridgeReadError);
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}
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}
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let title = &rom_bytes[CartridgeHeaderAddress::TitleStart as usize
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..CartridgeHeaderAddress::TitleEnd as usize + 1];
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let title_chars = Self::bytes_to_chars::<16>(title, true);
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let manufacturer_code = &rom_bytes[CartridgeHeaderAddress::ManufacturerCodeStart as usize
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..CartridgeHeaderAddress::ManufacturerCodeEnd as usize + 1];
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let man_code_chars = Self::bytes_to_chars::<4>(manufacturer_code, false);
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let cgb_flag_byte = rom_bytes[0x0143];
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let cgb_flag = match cgb_flag_byte {
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0x80 => CGBFlag::SupportsColorBackwardCompatiable,
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0xC0 => CGBFlag::ColorOnly,
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_ => CGBFlag::NotSet,
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};
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let license_code = &rom_bytes[CartridgeHeaderAddress::NewLicenseStart as usize
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..CartridgeHeaderAddress::NewLicenseEnd as usize + 1];
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let license_code_chars = Self::bytes_to_chars::<2>(license_code, false);
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// https://gbdev.io/pandocs/The_Cartridge_Header.html#0146--sgb-flag
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let sgb_flag = rom_bytes[CartridgeHeaderAddress::SgbFlag as usize] == 0x03;
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let cart_type =
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CartridgeType::from_byte(rom_bytes[CartridgeHeaderAddress::CartType as usize]);
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let rom_size = RomSize::from_byte(rom_bytes[CartridgeHeaderAddress::RomSize as usize]);
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let ram_size = RamSize::from_byte(rom_bytes[CartridgeHeaderAddress::RamSize as usize]);
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let mut old_licensee_code = None;
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if !sgb_flag {
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old_licensee_code = Some(rom_bytes[CartridgeHeaderAddress::OldLicenseeCode as usize])
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}
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let destination_code =
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DestinationCode::from_byte(rom_bytes[CartridgeHeaderAddress::DestinationCode as usize]);
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let version = rom_bytes[CartridgeHeaderAddress::MaskRomVersion as usize];
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let header_checksum = rom_bytes[CartridgeHeaderAddress::HeaderChecksum as usize];
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let global_checksum = u16::from_le_bytes([
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rom_bytes[CartridgeHeaderAddress::GlobalChecksumStart as usize],
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rom_bytes[CartridgeHeaderAddress::CartridgeHeaderEnd as usize],
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]);
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Ok(Self {
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buffer: header_buffer
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.try_into()
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.map_err(|_| Error::CartridgeReadError)?,
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title: title_chars,
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manufacturer_code: man_code_chars,
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cgb_flag,
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license_code: license_code_chars,
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support_gb: sgb_flag,
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cart_type,
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rom_size,
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ram_size,
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old_licensee_code,
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destination_code,
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version,
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header_checksum,
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global_checksum,
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})
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}
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fn print_test(&self) {
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for byte in self.buffer.iter() {
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print!("{} ", *byte as char);
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}
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}
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}
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fn main() -> std::io::Result<()> {
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let mut rom_file = File::open(ROM_NAME)?;