From af5f3a547f9f4a55dde35b1ce207f3ae50c9b7b6 Mon Sep 17 00:00:00 2001
From: Jujstme <just.tribe@gmail.com>
Date: Fri, 1 Dec 2023 17:28:38 +0100
Subject: [PATCH] Added support for Mednafen (PS1 emu) (#57)

---
 src/emulator/ps1/mednafen.rs | 30 ++++++++++++++++++++++++++++++
 src/emulator/ps1/mod.rs      |  7 ++++++-
 2 files changed, 36 insertions(+), 1 deletion(-)
 create mode 100644 src/emulator/ps1/mednafen.rs

diff --git a/src/emulator/ps1/mednafen.rs b/src/emulator/ps1/mednafen.rs
new file mode 100644
index 0000000..9d351bb
--- /dev/null
+++ b/src/emulator/ps1/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<10> = Signature::new("89 01 0F B6 82 ?? ?? ?? ?? C3");
+        const SIG_64: Signature<5> = Signature::new("89 01 0F B6 82");
+
+        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)?,
+            false => SIG_32.scan_process_range(game, main_module_range)?,
+        } + 0x5;
+
+        Some(game.read::<Address32>(ptr).ok()?.into())
+    }
+
+    pub const fn keep_alive(&self) -> bool {
+        true
+    }
+}
diff --git a/src/emulator/ps1/mod.rs b/src/emulator/ps1/mod.rs
index 8a3f201..b63251d 100644
--- a/src/emulator/ps1/mod.rs
+++ b/src/emulator/ps1/mod.rs
@@ -5,6 +5,7 @@ use bytemuck::CheckedBitPattern;
 
 mod duckstation;
 mod epsxe;
+mod mednafen;
 mod pcsx_redux;
 mod psxfin;
 mod retroarch;
@@ -63,6 +64,7 @@ impl Emulator {
                 State::Retroarch(x) => x.find_ram(&self.process),
                 State::PcsxRedux(x) => x.find_ram(&self.process),
                 State::Xebra(x) => x.find_ram(&self.process),
+                State::Mednafen(x) => x.find_ram(&self.process),
             } {
                 None => return false,
                 something => something,
@@ -76,6 +78,7 @@ impl Emulator {
             State::Retroarch(x) => x.keep_alive(&self.process),
             State::PcsxRedux(x) => x.keep_alive(&self.process),
             State::Xebra(x) => x.keep_alive(),
+            State::Mednafen(x) => x.keep_alive(),
         };
 
         if success {
@@ -122,9 +125,10 @@ enum State {
     Retroarch(retroarch::State),
     PcsxRedux(pcsx_redux::State),
     Xebra(xebra::State),
+    Mednafen(mednafen::State),
 }
 
-const PROCESS_NAMES: [(&str, State); 7] = [
+const PROCESS_NAMES: [(&str, State); 8] = [
     ("ePSXe.exe", State::Epsxe(epsxe::State)),
     ("psxfin.exe", State::PsxFin(psxfin::State)),
     (
@@ -141,4 +145,5 @@ const PROCESS_NAMES: [(&str, State); 7] = [
         State::PcsxRedux(pcsx_redux::State::new()),
     ),
     ("XEBRA.EXE", State::Xebra(xebra::State)),
+    ("mednafen.exe", State::Mednafen(mednafen::State)),
 ];