Merge pull request #58 from Jujstme/sms

Added support for Sega Master System / Game Gear (SMS) emulators

Cargo.toml

@@ -38,4 +38,5 @@ gcn = ["flags"]
 genesis = ["flags", "signature"]
 ps1 = ["flags", "signature"]
 ps2 = ["flags", "signature"]
+sms = ["flags", "signature"]
 wii = ["flags"]

src/emulator/mod.rs

@@ -10,5 +10,7 @@ pub mod genesis;
 pub mod ps1;
 #[cfg(feature = "ps2")]
 pub mod ps2;
+#[cfg(feature = "sms")]
+pub mod sms;
 #[cfg(feature = "wii")]
 pub mod wii;

src/emulator/sms/blastem.rs

@@ -0,0 +1,33 @@
+use crate::{runtime::MemoryRangeFlags, signature::Signature, Address, Address32, Process};
+
+#[derive(Copy, Clone, Debug, PartialEq, Eq)]
+pub struct State;
+
+impl State {
+    pub fn find_ram(&self, game: &Process) -> Option<Address> {
+        const SIG: Signature<15> = Signature::new("66 81 E1 FF 1F 0F B7 C9 8A 89 ?? ?? ?? ?? C3");
+
+        let scanned_address = game
+            .memory_ranges()
+            .filter(|m| {
+                m.flags()
+                    .unwrap_or_default()
+                    .contains(MemoryRangeFlags::WRITE)
+                    && m.size().unwrap_or_default() == 0x101000
+            })
+            .find_map(|m| SIG.scan_process_range(game, m.range().ok()?))?
+            + 10;
+
+        let wram: Address = game.read::<Address32>(scanned_address).ok()?.into();
+
+        if wram.is_null() {
+            None
+        } else {
+            Some(wram)
+        }
+    }
+
+    pub const fn keep_alive(&self) -> bool {
+        true
+    }
+}

src/emulator/sms/fusion.rs

@@ -0,0 +1,37 @@
+use crate::{signature::Signature, Address, Address32, Process};
+
+#[derive(Copy, Clone, Debug, PartialEq, Eq)]
+pub struct State {
+    addr: Address,
+}
+
+impl State {
+    pub fn find_ram(&mut self, game: &Process) -> Option<Address> {
+        const SIG: Signature<4> = Signature::new("74 C8 83 3D");
+
+        let main_module = super::PROCESS_NAMES
+            .iter()
+            .filter(|(_, state)| matches!(state, super::State::Fusion(_)))
+            .find_map(|(name, _)| game.get_module_range(name).ok())?;
+
+        let ptr = SIG.scan_process_range(game, main_module)? + 4;
+        self.addr = game.read::<Address32>(ptr).ok()?.into();
+
+        Some(game.read::<Address32>(self.addr).ok()?.add(0xC000).into())
+    }
+
+    pub fn keep_alive(&self, game: &Process, wram_base: &mut Option<Address>) -> bool {
+        *wram_base = Some(match game.read::<Address32>(self.addr) {
+            Ok(Address32::NULL) => Address::NULL,
+            Ok(x) => x.add(0xC000).into(),
+            _ => return false,
+        });
+        true
+    }
+
+    pub const fn new() -> Self {
+        Self {
+            addr: Address::NULL,
+        }
+    }
+}

src/emulator/sms/mednafen.rs

@@ -0,0 +1,30 @@
+use crate::{file_format::pe, signature::Signature, Address, Address32, Process};
+
+#[derive(Copy, Clone, Debug, PartialEq, Eq)]
+pub struct State;
+
+impl State {
+    pub fn find_ram(&self, game: &Process) -> Option<Address> {
+        const SIG_32: Signature<8> = Signature::new("25 FF 1F 00 00 0F B6 80");
+        const SIG_64: Signature<7> = Signature::new("25 FF 1F 00 00 88 90");
+
+        let main_module_range = super::PROCESS_NAMES
+            .iter()
+            .filter(|(_, state)| matches!(state, super::State::Mednafen(_)))
+            .find_map(|(name, _)| game.get_module_range(name).ok())?;
+
+        let is_64_bit =
+            pe::MachineType::read(game, main_module_range.0) == Some(pe::MachineType::X86_64);
+
+        let ptr = match is_64_bit {
+            true => SIG_64.scan_process_range(game, main_module_range)? + 8,
+            false => SIG_32.scan_process_range(game, main_module_range)? + 7,
+        };
+
+        Some(game.read::<Address32>(ptr).ok()?.into())
+    }
+
+    pub const fn keep_alive(&self) -> bool {
+        true
+    }
+}

src/emulator/sms/mod.rs

@@ -0,0 +1,115 @@
+//! Support for attaching to SEGA Master System / SEGA GameGear emulators.
+
+use crate::{Address, Error, Process};
+use bytemuck::CheckedBitPattern;
+
+mod blastem;
+mod fusion;
+mod mednafen;
+mod retroarch;
+
+/// A SEGA Master System / GameGear emulator that the auto splitter is attached to.
+pub struct Emulator {
+    /// The attached emulator process
+    process: Process,
+    /// An enum stating which emulator is currently attached
+    state: State,
+    /// The memory address of the emulated RAM
+    ram_base: Option<Address>,
+}
+
+impl Emulator {
+    /// Attaches to the emulator process
+    ///
+    /// Returns `Option<T>` if successful, `None` otherwise.
+    ///
+    /// Supported emulators are:
+    /// - Retroarch, with one of the following cores: `genesis_plus_gx_libretro.dll`,
+    /// `genesis_plus_gx_wide_libretro.dll`, `picodrive_libretro.dll`, `smsplus_libretro.dll`, `gearsystem_libretro.dll`
+    /// - Fusion
+    /// - BlastEm
+    pub fn attach() -> Option<Self> {
+        let (&state, process) = PROCESS_NAMES
+            .iter()
+            .find_map(|(name, state)| Some((state, Process::attach(name)?)))?;
+
+        Some(Self {
+            process,
+            state,
+            ram_base: None,
+        })
+    }
+
+    /// Checks whether the emulator is still open. If it is not open anymore,
+    /// you should drop the emulator.
+    pub fn is_open(&self) -> bool {
+        self.process.is_open()
+    }
+
+    /// Calls the internal routines needed in order to find (and update, if
+    /// needed) the address of the emulated RAM.
+    ///
+    /// Returns true if successful, false otherwise.
+    pub fn update(&mut self) -> bool {
+        if self.ram_base.is_none() {
+            self.ram_base = match match &mut self.state {
+                State::Retroarch(x) => x.find_ram(&self.process),
+                State::Fusion(x) => x.find_ram(&self.process),
+                State::BlastEm(x) => x.find_ram(&self.process),
+                State::Mednafen(x) => x.find_ram(&self.process),
+            } {
+                None => return false,
+                something => something,
+            };
+        }
+
+        let success = match &self.state {
+            State::Retroarch(x) => x.keep_alive(&self.process),
+            State::Fusion(x) => x.keep_alive(&self.process, &mut self.ram_base),
+            State::BlastEm(x) => x.keep_alive(),
+            State::Mednafen(x) => x.keep_alive(),
+        };
+
+        if success {
+            true
+        } else {
+            self.ram_base = None;
+            false
+        }
+    }
+
+    /// Reads any value from the emulated RAM.
+    ///
+    /// The offset provided is meant to be the same used on the original hardware.
+    ///
+    /// The SEGA Master System has 8KB of RAM, mapped from address
+    /// `0xC000` to `0xDFFF`.
+    ///
+    /// Providing any offset outside this range will return `Err()`.
+    pub fn read<T: CheckedBitPattern>(&self, offset: u32) -> Result<T, Error> {
+        if (offset > 0x1FFF && offset < 0xC000) || offset > 0xDFFF {
+            return Err(Error {});
+        }
+
+        let wram = self.ram_base.ok_or(Error {})?;
+        let end_offset = offset.checked_sub(0xC000).unwrap_or(offset);
+
+        self.process.read(wram + end_offset)
+    }
+}
+
+#[doc(hidden)]
+#[derive(Copy, Clone, Debug, PartialEq, Eq)]
+pub enum State {
+    Retroarch(retroarch::State),
+    Fusion(fusion::State),
+    BlastEm(blastem::State),
+    Mednafen(mednafen::State),
+}
+
+static PROCESS_NAMES: &[(&str, State)] = &[
+    ("retroarch.exe", State::Retroarch(retroarch::State::new())),
+    ("Fusion.exe", State::Fusion(fusion::State::new())),
+    ("blastem.exe", State::BlastEm(blastem::State)),
+    ("mednafen.exe", State::Mednafen(mednafen::State)),
+];

src/emulator/sms/retroarch.rs

@@ -0,0 +1,133 @@
+use crate::{file_format::pe, signature::Signature, Address, Address32, Address64, Process};
+
+#[derive(Copy, Clone, Debug, PartialEq, Eq)]
+pub struct State {
+    core_base: Address,
+}
+
+impl State {
+    pub fn find_ram(&mut self, game: &Process) -> Option<Address> {
+        const SUPPORTED_CORES: &[&str] = &[
+            "genesis_plus_gx_libretro.dll",
+            "genesis_plus_gx_wide_libretro.dll",
+            "picodrive_libretro.dll",
+            "smsplus_libretro.dll",
+            "gearsystem_libretro.dll",
+        ];
+
+        let main_module_address = super::PROCESS_NAMES
+            .iter()
+            .filter(|(_, state)| matches!(state, super::State::Retroarch(_)))
+            .find_map(|(name, _)| game.get_module_address(name).ok())?;
+
+        let is_64_bit =
+            pe::MachineType::read(game, main_module_address) == Some(pe::MachineType::X86_64);
+
+        let (core_name, core_address) = SUPPORTED_CORES
+            .iter()
+            .find_map(|&m| Some((m, game.get_module_address(m).ok()?)))?;
+
+        self.core_base = core_address;
+
+        match core_name {
+            "genesis_plus_gx_libretro.dll" | "genesis_plus_gx_wide_libretro.dll" => {
+                self.genesis_plus(game, is_64_bit, core_name)
+            }
+            "picodrive_libretro.dll" => self.picodrive(game, is_64_bit, core_name),
+            "smsplus_libretro.dll" => self.sms_plus(game, is_64_bit, core_name),
+            "gearsystem_libretro.dll" => self.gearsystem(game, is_64_bit, core_name),
+            _ => None,
+        }
+    }
+
+    fn picodrive(&self, game: &Process, is_64_bit: bool, core_name: &str) -> Option<Address> {
+        let module_size = game.get_module_size(core_name).ok()?;
+
+        Some(
+            if is_64_bit {
+                const SIG: Signature<9> = Signature::new("48 8D 0D ?? ?? ?? ?? 41 B8");
+                let ptr = SIG.scan_process_range(game, (self.core_base, module_size))? + 3;
+                ptr + 0x4 + game.read::<i32>(ptr).ok()?
+            } else {
+                const SIG: Signature<8> = Signature::new("B9 ?? ?? ?? ?? C1 EF 10");
+                let ptr = SIG.scan_process_range(game, (self.core_base, module_size))? + 1;
+                game.read::<Address32>(ptr).ok()?.into()
+            } + 0x20000,
+        )
+    }
+
+    fn genesis_plus(&self, game: &Process, is_64_bit: bool, core_name: &str) -> Option<Address> {
+        let module_size = game.get_module_size(core_name).ok()?;
+
+        Some(if is_64_bit {
+            const SIG: Signature<10> = Signature::new("48 8D 0D ?? ?? ?? ?? 4C 8B 2D");
+            let ptr = SIG.scan_process_range(game, (self.core_base, module_size))? + 3;
+            ptr + 0x4 + game.read::<i32>(ptr).ok()?
+        } else {
+            const SIG: Signature<7> = Signature::new("A3 ?? ?? ?? ?? 29 F9");
+            let ptr = SIG.scan_process_range(game, (self.core_base, module_size))? + 1;
+            game.read::<Address32>(ptr).ok()?.into()
+        })
+    }
+
+    fn sms_plus(&self, game: &Process, is_64_bit: bool, core_name: &str) -> Option<Address> {
+        let module_size = game.get_module_size(core_name).ok()?;
+
+        Some(if is_64_bit {
+            const SIG: Signature<5> = Signature::new("31 F6 48 C7 05");
+            let ptr = SIG.scan_process_range(game, (self.core_base, module_size))? + 5;
+            ptr + 0x8 + game.read::<i32>(ptr).ok()?
+        } else {
+            const SIG: Signature<4> = Signature::new("83 FA 02 B8");
+            let ptr = SIG.scan_process_range(game, (self.core_base, module_size))? + 4;
+            game.read::<Address32>(ptr).ok()?.into()
+        })
+    }
+
+    fn gearsystem(&self, game: &Process, is_64_bit: bool, core_name: &str) -> Option<Address> {
+        let module_size = game.get_module_size(core_name).ok()?;
+
+        Some(if is_64_bit {
+            const SIG: Signature<13> = Signature::new("83 ?? 02 75 ?? 48 8B 0D ?? ?? ?? ?? E8");
+            let ptr = SIG.scan_process_range(game, (self.core_base, module_size))? + 8;
+            let offset = game
+                .read::<u8>(ptr + 13 + 0x4 + game.read::<i32>(ptr + 13).ok()? + 3)
+                .ok()?;
+            let addr = game
+                .read_pointer_path64::<Address64>(
+                    ptr + 0x4 + game.read::<i32>(ptr).ok()?,
+                    &[0x0, 0x0, offset as _],
+                )
+                .ok()?;
+            if addr.is_null() {
+                return None;
+            } else {
+                addr.add(0xC000).into()
+            }
+        } else {
+            const SIG: Signature<12> = Signature::new("83 ?? 02 75 ?? 8B ?? ?? ?? ?? ?? E8");
+            let ptr = SIG.scan_process_range(game, (self.core_base, module_size))? + 7;
+            let offset = game
+                .read::<u8>(ptr + 12 + 0x4 + game.read::<i32>(ptr + 12).ok()? + 2)
+                .ok()?;
+            let addr = game
+                .read_pointer_path32::<Address32>(ptr, &[0x0, 0x0, 0x0, offset as _])
+                .ok()?;
+            if addr.is_null() {
+                return None;
+            } else {
+                addr.add(0xC000).into()
+            }
+        })
+    }
+
+    pub fn keep_alive(&self, game: &Process) -> bool {
+        game.read::<u8>(self.core_base).is_ok()
+    }
+
+    pub const fn new() -> Self {
+        Self {
+            core_base: Address::NULL,
+        }
+    }
+}