From 17519464cdfd47b9767a89589aae87c5aa6ae41d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jo=C3=A3o=20Magalh=C3=A3es?= <joamag@gmail.com>
Date: Sat, 10 Jun 2023 13:20:23 +0100
Subject: [PATCH] chore: improved delegation of game genie
---
src/gb.rs | 7 +++-
src/genie.rs | 92 +++++++++++++++++++++++++++++++++++++++++
src/lib.rs | 1 +
src/rom.rs | 113 +++++++++++++++++++++++++--------------------------
4 files changed, 153 insertions(+), 60 deletions(-)
create mode 100644 src/genie.rs
diff --git a/src/gb.rs b/src/gb.rs
index d418355d..26675bbf 100644
--- a/src/gb.rs
+++ b/src/gb.rs
@@ -12,6 +12,7 @@ use crate::{
devices::{printer::PrinterDevice, stdout::StdoutDevice},
dma::Dma,
gen::{COMPILATION_DATE, COMPILATION_TIME, COMPILER, COMPILER_VERSION, VERSION},
+ genie::GameGenie,
mmu::Mmu,
pad::{Pad, PadKey},
ppu::{Ppu, PpuMode, Tile, DISPLAY_HEIGHT, DISPLAY_WIDTH, FRAME_BUFFER_SIZE},
@@ -970,8 +971,10 @@ impl GameBoy {
pub fn load_rom(&mut self, data: &[u8]) -> &Cartridge {
let mut rom = Cartridge::from_data(data);
- rom.add_genie_code("00A-17B-C49").unwrap(); // SML
- rom.add_genie_code("008-60A-E6E").unwrap(); // SML
+ let mut game_genie = GameGenie::default();
+ game_genie.add_code("00A-17B-C49").unwrap(); // SML
+ game_genie.add_code("008-60A-E6E").unwrap(); // SML
+ rom.attach_genie(game_genie);
self.mmu().set_rom(rom);
self.mmu().rom()
}
diff --git a/src/genie.rs b/src/genie.rs
new file mode 100644
index 00000000..c28178e0
--- /dev/null
+++ b/src/genie.rs
@@ -0,0 +1,92 @@
+use std::{
+ collections::HashMap,
+ fmt::{Display, Formatter, self},
+};
+
+#[derive(Clone)]
+pub struct GameGenie {
+ /// Hash map that contains the complete set of Game Genie
+ /// codes that have been registered for the current ROM.
+ /// These codes are going to apply a series of patches to
+ /// the ROM effectively allowing the user to cheat.
+ codes: HashMap<u16, GameGenieCode>,
+}
+
+impl GameGenie {
+ pub fn new() -> Self {
+ Self {
+ codes: HashMap::new(),
+ }
+ }
+
+ pub fn contains_addr(&self, addr: u16) -> bool {
+ self.codes.contains_key(&addr)
+ }
+
+ pub fn get_addr(&self, addr: u16) -> &GameGenieCode {
+ self.codes.get(&addr).unwrap()
+ }
+
+ pub fn add_code(&mut self, code: &str) -> Result<&GameGenieCode, &str> {
+ if code.len() != 11 {
+ return Err("Invalid Game Genie code length");
+ }
+
+ let code_u = code.to_uppercase();
+
+ let new_data_slice = &code_u[0..=1];
+ let new_data = u8::from_str_radix(new_data_slice, 16).unwrap();
+
+ let old_data_slice = format!("{}{}", &code_u[8..=8], &code_u[10..=10]);
+ let old_data: u8 = u8::from_str_radix(old_data_slice.as_str(), 16)
+ .unwrap()
+ .rotate_right(2)
+ ^ 0xba;
+
+ let addr_slice = format!("{}{}{}", &code_u[6..=6], &code_u[2..=2], &code_u[4..=5]);
+ let addr = u16::from_str_radix(addr_slice.as_str(), 16).unwrap() ^ 0xf000;
+
+ let genie_code = GameGenieCode {
+ code: code_u,
+ addr,
+ new_data,
+ old_data,
+ };
+
+ self.codes.insert(addr, genie_code);
+ Ok(self.codes.get(&addr).unwrap())
+ }
+}
+
+impl Default for GameGenie {
+ fn default() -> Self {
+ Self::new()
+ }
+}
+
+#[derive(Clone)]
+pub struct GameGenieCode {
+ pub code: String,
+ pub addr: u16,
+ pub new_data: u8,
+ pub old_data: u8,
+}
+
+impl GameGenieCode {
+ pub fn short_description(&self) -> String {
+ self.code.to_string()
+ }
+
+ pub fn description(&self) -> String {
+ format!(
+ "Code: {}, Address: 0x{:04x}, New Data: 0x{:04x}, Old Data: 0x{:04x}",
+ self.code, self.addr, self.new_data, self.old_data
+ )
+ }
+}
+
+impl Display for GameGenieCode {
+ fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
+ write!(f, "{}", self.short_description())
+ }
+}
diff --git a/src/lib.rs b/src/lib.rs
index 0f8c9a49..f03d7b48 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -7,6 +7,7 @@ pub mod devices;
pub mod dma;
pub mod gb;
pub mod gen;
+pub mod genie;
pub mod inst;
pub mod macros;
pub mod mmu;
diff --git a/src/rom.rs b/src/rom.rs
index 8e42666e..4a7724b7 100644
--- a/src/rom.rs
+++ b/src/rom.rs
@@ -1,11 +1,10 @@
use core::fmt;
use std::{
cmp::max,
- collections::HashMap,
fmt::{Display, Formatter},
};
-use crate::{debugln, gb::GameBoyMode, util::read_file, warnln};
+use crate::{debugln, gb::GameBoyMode, genie::GameGenie, util::read_file, warnln};
#[cfg(feature = "wasm")]
use wasm_bindgen::prelude::*;
@@ -255,6 +254,13 @@ pub struct Cartridge {
/// RAM and ROM access on the current cartridge.
mbc: &'static Mbc,
+ /// The current memory handler in charge of handling the
+ /// memory access for the current cartridge.
+ /// Typically this is the same as the MBC, but to allow
+ /// memory patching (ex: Game Genie) we may need another
+ /// level of indirection.
+ handler: &'static Mbc,
+
/// The number of ROM banks (of 8KB) that are available
/// to the current cartridge, this is a computed value
/// to allow improved performance.
@@ -277,16 +283,15 @@ pub struct Cartridge {
/// control of memory access to avoid corruption.
ram_enabled: bool,
- // The final offset of the last character of the title
- // that is considered to be non zero (0x0) so that a
- // proper safe conversion to UTF-8 string can be done.
+ /// The final offset of the last character of the title
+ /// that is considered to be non zero (0x0) so that a
+ /// proper safe conversion to UTF-8 string can be done.
title_offset: usize,
- /// Hash map that contains the complete set of Game Genie
- /// codes that have been registered for the current ROM.
- /// These codes are going to apply a series of patches to
- /// the ROM effectively allowing the user to cheat.
- genie_codes: HashMap<u16, GameGenieCode>,
+ /// Optional reference to the Game Genie instance that
+ /// would be used for the "cheating" by patching the
+ /// current ROM's cartridge data.
+ game_genie: Option<GameGenie>,
}
impl Cartridge {
@@ -295,13 +300,14 @@ impl Cartridge {
rom_data: vec![],
ram_data: vec![],
mbc: &NO_MBC,
+ handler: &NO_MBC,
rom_bank_count: 0,
ram_bank_count: 0,
rom_offset: 0x4000,
ram_offset: 0x0000,
ram_enabled: false,
title_offset: 0x0143,
- genie_codes: HashMap::new(),
+ game_genie: None,
}
}
@@ -317,24 +323,11 @@ impl Cartridge {
}
pub fn read(&self, addr: u16) -> u8 {
- if self.genie_codes.contains_key(&addr) {
- let genie_code = self.genie_codes.get(&addr).unwrap();
-
- // checks if the current data at the address is the same as the
- // one that is expected by the Game Genie code, if that's the case
- // applies the patch, otherwise returns the original strategy is
- // going to be used
- if genie_code.old_data == (self.mbc.read_rom)(self, addr) {
- debugln!("Applying Game Genie code: {}", game_genie_code);
- return genie_code.new_data;
- }
- }
-
match addr & 0xf000 {
0x0000 | 0x1000 | 0x2000 | 0x3000 | 0x4000 | 0x5000 | 0x6000 | 0x7000 => {
- (self.mbc.read_rom)(self, addr)
+ (self.handler.read_rom)(self, addr)
}
- 0xa000 | 0xb000 => (self.mbc.read_ram)(self, addr),
+ 0xa000 | 0xb000 => (self.handler.read_ram)(self, addr),
_ => {
debugln!("Reading from unknown Cartridge control 0x{:04x}", addr);
0x00
@@ -345,9 +338,9 @@ impl Cartridge {
pub fn write(&mut self, addr: u16, value: u8) {
match addr & 0xf000 {
0x0000 | 0x1000 | 0x2000 | 0x3000 | 0x4000 | 0x5000 | 0x6000 | 0x7000 => {
- (self.mbc.write_rom)(self, addr, value)
+ (self.handler.write_rom)(self, addr, value)
}
- 0xa000 | 0xb000 => (self.mbc.write_ram)(self, addr, value),
+ 0xa000 | 0xb000 => (self.handler.write_ram)(self, addr, value),
_ => debugln!("Writing to unknown Cartridge address 0x{:04x}", addr),
}
}
@@ -405,6 +398,7 @@ impl Cartridge {
fn set_mbc(&mut self) {
self.mbc = self.get_mbc();
+ self.handler = self.mbc;
}
fn set_computed(&mut self) {
@@ -437,36 +431,6 @@ impl Cartridge {
let ram_banks = max(self.ram_size().ram_banks(), 1);
self.ram_data = vec![0u8; ram_banks as usize * RAM_BANK_SIZE];
}
-
- pub fn add_genie_code(&mut self, code: &str) -> Result<&GameGenieCode, &str> {
- if code.len() != 11 {
- return Err("Invalid Game Genie code length");
- }
-
- let code_u = code.to_uppercase();
-
- let new_data_slice = &code_u[0..=1];
- let new_data = u8::from_str_radix(new_data_slice, 16).unwrap();
-
- let old_data_slice = format!("{}{}", &code_u[8..=8], &code_u[10..=10]);
- let old_data: u8 = u8::from_str_radix(old_data_slice.as_str(), 16)
- .unwrap()
- .rotate_right(2)
- ^ 0xba;
-
- let address_slice = format!("{}{}{}", &code_u[6..=6], &code_u[2..=2], &code_u[4..=5]);
- let address = u16::from_str_radix(address_slice.as_str(), 16).unwrap() ^ 0xf000;
-
- let genie_code = GameGenieCode {
- code: code_u,
- address,
- new_data,
- old_data,
- };
-
- self.genie_codes.insert(address, genie_code);
- Ok(self.genie_codes.get(&address).unwrap())
- }
}
#[cfg_attr(feature = "wasm", wasm_bindgen)]
@@ -600,6 +564,16 @@ impl Cartridge {
self.ram_data = ram_data;
}
+ pub fn attach_genie(&mut self, game_genie: GameGenie) {
+ self.game_genie = Some(game_genie);
+ self.handler = &GAME_GENIE;
+ }
+
+ pub fn detach_genie(&mut self) {
+ self.game_genie = None;
+ self.handler = self.mbc;
+ }
+
pub fn description(&self, column_length: usize) -> String {
let name_l = format!("{:width$}", "Name", width = column_length);
let type_l = format!("{:width$}", "Type", width = column_length);
@@ -829,3 +803,26 @@ pub static MBC5: Mbc = Mbc {
rom.ram_data[rom.ram_offset + (addr - 0xa000) as usize] = value;
},
};
+
+pub static GAME_GENIE: Mbc = Mbc {
+ name: "GameGenie",
+ read_rom: |rom: &Cartridge, addr: u16| -> u8 {
+ let game_genie = rom.game_genie.as_ref().unwrap();
+ if game_genie.contains_addr(addr) {
+ let genie_code = game_genie.get_addr(addr);
+
+ // checks if the current data at the address is the same as the
+ // one that is expected by the Game Genie code, if that's the case
+ // applies the patch, otherwise returns the original strategy is
+ // going to be used
+ if genie_code.old_data == (rom.mbc.read_rom)(rom, addr) {
+ debugln!("Applying Game Genie code: {}", game_genie_code);
+ return genie_code.new_data;
+ }
+ }
+ (rom.mbc.read_rom)(rom, addr)
+ },
+ write_rom: |rom: &mut Cartridge, addr: u16, value: u8| (rom.mbc.write_rom)(rom, addr, value),
+ read_ram: |rom: &Cartridge, addr: u16| -> u8 { (rom.mbc.read_ram)(rom, addr) },
+ write_ram: |rom: &mut Cartridge, addr: u16, value: u8| (rom.mbc.write_ram)(rom, addr, value),
+};
--
GitLab