chore: Release lemur version 0.9.0

Reviewed-on: #7

Cargo.toml

@@ -4,7 +4,7 @@ description = "An emulator for the Virtual Boy."
 repository = "https://git.virtual-boy.com/PVB/lemur"
 publish = false
 license = "MIT"
-version = "0.5.0"
+version = "0.9.0"
 edition = "2024"
 
 [dependencies]
@@ -16,34 +16,40 @@ bytemuck = { version = "1", features = ["derive"] }
 clap = { version = "4", features = ["derive"] }
 cpal = { git = "https://github.com/sidit77/cpal.git", rev = "66ed6be" }
 directories = "6"
-egui = { version = "0.30", features = ["serde"] }
+egui = { version = "0.32", features = ["serde"] }
-egui_extras = { version = "0.30", features = ["image"] }
+egui_extras = { version = "0.32", features = ["image"] }
-egui-toast = { git = "https://github.com/urholaukkarinen/egui-toast.git", rev = "d0bcf97" }
+egui-notify = "0.20"
-egui-winit = "0.30"
+egui-winit = "0.32"
-egui-wgpu = { version = "0.30", features = ["winit"] }
+egui-wgpu = { version = "0.32", features = ["winit"] }
+fxprof-processed-profile = "0.8"
 fixed = { version = "1.28", features = ["num-traits"] }
 gilrs = { version = "0.11", features = ["serde-serialize"] }
+gimli = "0.32"
 hex = "0.4"
 image = { version = "0.25", default-features = false, features = ["png"] }
 itertools = "0.14"
+normpath = "1"
 num-derive = "0.4"
 num-traits = "0.2"
+object = "0.37"
 oneshot = "0.1"
 pollster = "0.4"
+rand = "0.9"
 rfd = { version = "0.15", default-features = false, features = ["xdg-portal", "async-std"]}
 rtrb = "0.3"
 rubato = "0.16"
 serde = { version = "1", features = ["derive"] }
 serde_json = "1"
-thread-priority = "1"
+thread-priority = "2"
 tokio = { version = "1", features = ["io-util", "macros", "net", "rt", "sync", "time"] }
 tracing = { version = "0.1", features = ["release_max_level_info"] }
 tracing-subscriber = { version = "0.3", features = ["env-filter"] }
-wgpu = "23"
+wgpu = "25"
+wholesym = "0.8"
 winit = { version = "0.30", features = ["serde"] }
 
 [target.'cfg(windows)'.dependencies]
-windows = { version = "0.59", features = ["Win32_System_Threading"] }
+windows = { version = "0.61", features = ["Win32_System_Threading"] }
 
 [build-dependencies]
 cc = "1"

build.Dockerfile

@@ -1,24 +1,39 @@
 # This Dockerfile produces a base image for builds.
 # It includes all dependencies necessary to cross-compile for Windows/MacOS/Linux.
 
-FROM crazymax/osxcross:latest-ubuntu AS osxcross
+FROM debian:bookworm AS osxcross
+ADD --chmod=644 "https://apt.llvm.org/llvm-snapshot.gpg.key" /etc/apt/trusted.gpg.d/apt.llvm.org.asc
+WORKDIR /build/osxcross
+ADD "https://github.com/tpoechtrager/osxcross.git#47936a512273bb3b414b5a2e83043c92eabc7ae7" .
+ADD "https://github.com/joseluisq/macosx-sdks/releases/download/14.5/MacOSX14.5.sdk.tar.xz" ./tarballs/MacOSX14.5.sdk.tar.xz
+RUN apt-get update && \
+    apt-get install -y ca-certificates
+COPY llvm.sources /etc/apt/sources.list.d/llvm.sources
+RUN apt-get update && \
+    apt-get install -y bash bzip2 clang-20 git lld-20 llvm-20 make patch xz-utils && \
+    ln -s $(which clang-20) /usr/bin/clang && \
+    ln -s $(which clang++-20) /usr/bin/clang++ && \
+    ln -s $(which ld64.lld-20) /usr/bin/ld64.lld && \
+    SDK_VERSION=14.5 UNATTENDED=1 ENABLE_COMPILER_RT_INSTALL=1 TARGET_DIR=/osxcross ./build.sh
 
-FROM rust:latest
+FROM rust:1.89-bookworm
+ADD --chmod=644 "https://apt.llvm.org/llvm-snapshot.gpg.key" /etc/apt/trusted.gpg.d/apt.llvm.org.asc
+COPY llvm.sources /etc/apt/sources.list.d/llvm.sources
 RUN rustup target add x86_64-pc-windows-msvc && \
     rustup target add x86_64-apple-darwin && \
     rustup target add aarch64-apple-darwin && \
     apt-get update && \
-    apt-get install -y clang-19 lld-19 libc6-dev libasound2-dev libudev-dev genisoimage mingw-w64 && \
+    apt-get install -y clang-20 lld-20 libc6-dev libasound2-dev libudev-dev genisoimage mingw-w64 && \
     cargo install cargo-bundle xwin && \
     xwin --accept-license splat --output xwin && \
     rm -rf .xwin-cache && \
-    ln -s $(which clang-19) /usr/bin/clang && \
+    ln -s $(which clang-20) /usr/bin/clang && \
-    ln -s $(which clang++-19) /usr/bin/clang++
+    ln -s $(which clang++-20) /usr/bin/clang++
 COPY --from=osxcross /osxcross /osxcross
 
 ENV PATH="/osxcross/bin:$PATH" \
     LD_LIBRARY_PATH="/osxcross/lib" \
-    CC="clang-19" CXX="clang++-19" AR="llvm-ar-19" \
+    CC="clang-20" CXX="clang++-20" AR="llvm-ar-20" \
     CC_x86_64-apple-darwin="o64-clang" \
     CXX_x86_64-apple-darwin="o64-clang++" \
     CC_aarch64-apple-darwin="oa64-clang" \
@@ -26,11 +41,13 @@ ENV PATH="/osxcross/bin:$PATH" \
     SHROOMS_CFLAGS_x86_64-unknown-linux-gnu="-flto" \
     CARGO_TARGET_X86_64_UNKNOWN_LINUX_GNU_RUSTFLAGS="-Clinker-plugin-lto -Clinker=clang -Clink-arg=-fuse-ld=lld" \
     SHROOMS_CFLAGS_x86_64-pc-windows-msvc="-flto" \
+    CFLAGS_x86_64-pc-windows-msvc="-I/xwin/crt/include -I/xwin/sdk/include/ucrt -I/xwin/sdk/include/um -I/xwin/sdk/include/shared" \
     CARGO_TARGET_X86_64_PC_WINDOWS_MSVC_RUSTFLAGS="-Lnative=/xwin/crt/lib/x86_64 -Lnative=/xwin/sdk/lib/um/x86_64 -Lnative=/xwin/sdk/lib/ucrt/x86_64 -Clinker-plugin-lto -Clink-arg=-fuse-ld=lld" \
-    CARGO_TARGET_X86_64_PC_WINDOWS_MSVC_LINKER="lld-link-19" \
+    CARGO_TARGET_X86_64_PC_WINDOWS_MSVC_LINKER="lld-link-20" \
     CARGO_TARGET_X86_64_APPLE_DARWIN_LINKER="o64-clang" \
-    CARGO_TARGET_X86_64_APPLE_DARWIN_AR="llvm-ar-19" \
+    CARGO_TARGET_X86_64_APPLE_DARWIN_AR="llvm-ar-20" \
     CARGO_TARGET_AARCH64_APPLE_DARWIN_LINKER="oa64-clang" \
-    CARGO_TARGET_AARCH64_APPLE_DARWIN_AR="llvm-ar-19" \
+    CARGO_TARGET_AARCH64_APPLE_DARWIN_AR="llvm-ar-20" \
-    RC_PATH="llvm-rc-19" \
+    RC_PATH="llvm-rc-20" \
     MACOSX_DEPLOYMENT_TARGET="14.5"
+ENTRYPOINT ["bash"]

build.rs

@@ -18,16 +18,22 @@ fn main() -> Result<(), Box<dyn Error>> {
     };
     builder
         .include(Path::new("shrooms-vb-core/core"))
+        .include(Path::new("shrooms-vb-core/util"))
         .opt_level(opt_level)
         .flag_if_supported("-fno-strict-aliasing")
         .define("VB_LITTLE_ENDIAN", None)
         .define("VB_SIGNED_PROPAGATE", None)
         .define("VB_DIV_GENERIC", None)
+        .define("VB_DIRECT_EXCEPTION", "on_exception")
         .define("VB_DIRECT_EXECUTE", "on_execute")
+        .define("VB_DIRECT_FETCH", "on_fetch")
         .define("VB_DIRECT_FRAME", "on_frame")
         .define("VB_DIRECT_READ", "on_read")
         .define("VB_DIRECT_WRITE", "on_write")
+        .define("VBU_REALLOC", "vbu_realloc_shim")
         .file(Path::new("shrooms-vb-core/core/vb.c"))
+        .file(Path::new("shrooms-vb-core/util/isx.c"))
+        .file(Path::new("shrooms-vb-core/util/vbu.c"))
         .compile("vb");
 
     Ok(())

llvm.sources

@@ -0,0 +1,4 @@
+Types: deb deb-src
+URIs: http://apt.llvm.org/bookworm/
+Suites: llvm-toolchain-bookworm-20
+Components: main

scripts/bundle.sh

@@ -0,0 +1,4 @@
+set -e
+
+docker build --pull -f build.Dockerfile -t lemur-build .
+MSYS_NO_PATHCONV=1 docker run -it --rm -v .:/app -w /app lemur-build /app/scripts/do-bundle.sh

scripts/release.sh

@@ -24,8 +24,7 @@ if ! command -v docker 2>&1 >/dev/null; then
     exit 1
 fi
 
-docker build -f build.Dockerfile -t lemur-build .
+./scripts/bundle.sh
-MSYS_NO_PATHCONV=1 docker run -it --rm -v .:/app -w /app --entrypoint bash lemur-build /app/scripts/do-bundle.sh
 
 body=$(cat <<EOF
 ## How to install

src/app.rs

@@ -24,7 +24,8 @@ use crate::{
     persistence::Persistence,
     window::{
         AboutWindow, AppWindow, BgMapWindow, CharacterDataWindow, FrameBufferWindow, GameWindow,
-        GdbServerWindow, HotkeysWindow, InputWindow, ObjectWindow, RegisterWindow, WorldWindow,
+        GdbServerWindow, HotkeysWindow, InputWindow, ObjectWindow, ProfileWindow, RegisterWindow,
+        TerminalWindow, WorldWindow,
     },
 };
 
@@ -53,6 +54,7 @@ pub struct Application {
     viewports: HashMap<ViewportId, Viewport>,
     focused: Option<ViewportId>,
     init_debug_port: Option<u16>,
+    init_profiling: bool,
 }
 
 impl Application {
@@ -60,6 +62,7 @@ impl Application {
         client: EmulatorClient,
         proxy: EventLoopProxy<UserEvent>,
         debug_port: Option<u16>,
+        profiling: bool,
     ) -> Self {
         let wgpu = WgpuState::new();
         let icon = load_icon().ok().map(Arc::new);
@@ -88,6 +91,7 @@ impl Application {
             viewports: HashMap::new(),
             focused: None,
             init_debug_port: debug_port,
+            init_profiling: profiling,
         }
     }
 
@@ -120,6 +124,11 @@ impl ApplicationHandler<UserEvent> for Application {
             SimId::Player1,
         );
         self.open(event_loop, Box::new(app));
+        if self.init_profiling {
+            let mut profiler = ProfileWindow::new(SimId::Player1, self.client.clone());
+            profiler.launch();
+            self.open(event_loop, Box::new(profiler));
+        }
     }
 
     fn window_event(
@@ -208,11 +217,10 @@ impl ApplicationHandler<UserEvent> for Application {
                     .focused
                     .as_ref()
                     .and_then(|id| self.viewports.get_mut(id))
+                    && viewport.app.handle_gamepad_event(&event)
                 {
-                    if viewport.app.handle_gamepad_event(&event) {
                     return;
                 }
-                }
                 self.controllers.handle_gamepad_event(&event);
             }
             UserEvent::OpenAbout => {
@@ -243,6 +251,14 @@ impl ApplicationHandler<UserEvent> for Application {
                 let registers = RegisterWindow::new(sim_id, &self.memory);
                 self.open(event_loop, Box::new(registers));
             }
+            UserEvent::OpenTerminal(sim_id) => {
+                let terminal = TerminalWindow::new(sim_id, &self.client);
+                self.open(event_loop, Box::new(terminal));
+            }
+            UserEvent::OpenProfiler(sim_id) => {
+                let profile = ProfileWindow::new(sim_id, self.client.clone());
+                self.open(event_loop, Box::new(profile));
+            }
             UserEvent::OpenDebugger(sim_id) => {
                 let debugger =
                     GdbServerWindow::new(sim_id, self.client.clone(), self.proxy.clone());
@@ -284,19 +300,19 @@ impl ApplicationHandler<UserEvent> for Application {
 
     fn exiting(&mut self, _event_loop: &ActiveEventLoop) {
         let (sender, receiver) = oneshot::channel();
-        if self.client.send_command(EmulatorCommand::Exit(sender)) {
+        if self.client.send_command(EmulatorCommand::Exit(sender))
-            if let Err(error) = receiver.recv_timeout(Duration::from_secs(5)) {
+            && let Err(error) = receiver.recv_timeout(Duration::from_secs(5))
+        {
             error!(%error, "could not gracefully exit.");
         }
     }
 }
-}
 
 struct WgpuState {
-    instance: Arc<wgpu::Instance>,
+    instance: wgpu::Instance,
-    adapter: Arc<wgpu::Adapter>,
+    adapter: wgpu::Adapter,
-    device: Arc<wgpu::Device>,
+    device: wgpu::Device,
-    queue: Arc<wgpu::Queue>,
+    queue: wgpu::Queue,
 }
 
 impl WgpuState {
@@ -304,21 +320,21 @@ impl WgpuState {
         #[allow(unused_variables)]
         let egui_wgpu::WgpuConfiguration {
             wgpu_setup:
-                egui_wgpu::WgpuSetup::CreateNew {
+                egui_wgpu::WgpuSetup::CreateNew(egui_wgpu::WgpuSetupCreateNew {
-                    supported_backends,
+                    instance_descriptor: wgpu::InstanceDescriptor { backends, .. },
                     device_descriptor,
                     ..
-                },
+                }),
             ..
         } = egui_wgpu::WgpuConfiguration::default()
         else {
             panic!("required fields not found")
         };
         #[cfg(windows)]
-        let supported_backends = wgpu::util::backend_bits_from_env()
+        let backends = wgpu::Backends::from_env()
             .unwrap_or((wgpu::Backends::PRIMARY | wgpu::Backends::GL) - wgpu::Backends::VULKAN);
-        let instance = wgpu::Instance::new(wgpu::InstanceDescriptor {
+        let instance = wgpu::Instance::new(&wgpu::InstanceDescriptor {
-            backends: supported_backends,
+            backends,
             ..wgpu::InstanceDescriptor::default()
         });
 
@@ -329,17 +345,14 @@ impl WgpuState {
         }))
         .expect("could not create adapter");
 
-        let trace_path = std::env::var("WGPU_TRACE");
+        let (device, queue) =
-        let (device, queue) = pollster::block_on(adapter.request_device(
+            pollster::block_on(adapter.request_device(&(*device_descriptor)(&adapter)))
-            &(*device_descriptor)(&adapter),
-            trace_path.ok().as_ref().map(std::path::Path::new),
-        ))
                 .expect("could not request device");
         Self {
-            instance: Arc::new(instance),
+            instance,
-            adapter: Arc::new(adapter),
+            adapter,
-            device: Arc::new(device),
+            device,
-            queue: Arc::new(queue),
+            queue,
         }
     }
 }
@@ -377,24 +390,30 @@ impl Viewport {
         ctx.set_fonts(fonts);
         ctx.style_mut(|s| {
             s.wrap_mode = Some(TextWrapMode::Extend);
-            s.visuals.menu_rounding = Default::default();
+            s.visuals.menu_corner_radius = Default::default();
             s.spacing.scroll = ScrollStyle::thin();
         });
         egui_extras::install_image_loaders(&ctx);
 
         let wgpu_config = egui_wgpu::WgpuConfiguration {
             present_mode: wgpu::PresentMode::AutoNoVsync,
-            wgpu_setup: egui_wgpu::WgpuSetup::Existing {
+            wgpu_setup: egui_wgpu::WgpuSetup::Existing(egui_wgpu::WgpuSetupExisting {
                 instance: wgpu.instance.clone(),
                 adapter: wgpu.adapter.clone(),
                 device: wgpu.device.clone(),
                 queue: wgpu.queue.clone(),
-            },
+            }),
             ..egui_wgpu::WgpuConfiguration::default()
         };
 
-        let mut painter =
+        let mut painter = pollster::block_on(egui_wgpu::winit::Painter::new(
-            egui_wgpu::winit::Painter::new(ctx.clone(), wgpu_config, 1, None, false, true);
+            ctx.clone(),
+            wgpu_config,
+            1,
+            None,
+            false,
+            true,
+        ));
 
         let mut info = ViewportInfo::default();
         let mut builder = app.initial_viewport();
@@ -513,6 +532,8 @@ pub enum UserEvent {
     OpenWorlds(SimId),
     OpenFrameBuffers(SimId),
     OpenRegisters(SimId),
+    OpenTerminal(SimId),
+    OpenProfiler(SimId),
     OpenDebugger(SimId),
     OpenInput,
     OpenHotkeys,

src/emulator.rs

@@ -1,20 +1,19 @@
 use std::{
     collections::HashMap,
     fmt::Display,
-    fs::{self, File},
-    io::{Read, Seek, SeekFrom, Write},
     path::{Path, PathBuf},
     sync::{
         Arc, Weak,
         atomic::{AtomicBool, Ordering},
         mpsc::{self, RecvError, TryRecvError},
     },
+    time::Duration,
 };
 
 use anyhow::Result;
 use atomic::Atomic;
 use bytemuck::NoUninit;
-use egui_toast::{Toast, ToastKind, ToastOptions};
+use egui_notify::Toast;
 use tracing::{error, warn};
 
 use crate::{
@@ -22,11 +21,19 @@ use crate::{
     graphics::TextureSink,
     memory::{MemoryRange, MemoryRegion},
 };
+use cart::Cart;
+pub use game_info::GameInfo;
+pub use inline_stack_map::InlineStack;
+use inline_stack_map::InlineStackMap;
 use shrooms_vb_core::{EXPECTED_FRAME_SIZE, Sim, StopReason};
-pub use shrooms_vb_core::{VBKey, VBRegister, VBWatchpointType};
+pub use shrooms_vb_core::{SimEvent, VBKey, VBRegister, VBWatchpointType};
 
 mod address_set;
+mod cart;
+mod game_info;
+mod inline_stack_map;
 mod shrooms_vb_core;
+mod shrooms_vb_util;
 
 #[derive(PartialEq, Eq, Hash, Clone, Copy, Debug)]
 pub enum SimId {
@@ -43,6 +50,13 @@ impl SimId {
             Self::Player2 => 1,
         }
     }
+    pub const fn from_index(index: usize) -> Option<Self> {
+        match index {
+            0 => Some(Self::Player1),
+            1 => Some(Self::Player2),
+            _ => None,
+        }
+    }
 }
 impl Display for SimId {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
@@ -53,43 +67,6 @@ impl Display for SimId {
     }
 }
 
-struct Cart {
-    rom_path: PathBuf,
-    rom: Vec<u8>,
-    sram_file: File,
-    sram: Vec<u8>,
-}
-
-impl Cart {
-    fn load(rom_path: &Path, sim_id: SimId) -> Result<Self> {
-        let rom = fs::read(rom_path)?;
-
-        let mut sram_file = File::options()
-            .read(true)
-            .write(true)
-            .create(true)
-            .truncate(false)
-            .open(sram_path(rom_path, sim_id))?;
-        sram_file.set_len(8 * 1024)?;
-
-        let mut sram = vec![];
-        sram_file.read_to_end(&mut sram)?;
-        Ok(Cart {
-            rom_path: rom_path.to_path_buf(),
-            rom,
-            sram_file,
-            sram,
-        })
-    }
-}
-
-fn sram_path(rom_path: &Path, sim_id: SimId) -> PathBuf {
-    match sim_id {
-        SimId::Player1 => rom_path.with_extension("p1.sram"),
-        SimId::Player2 => rom_path.with_extension("p2.sram"),
-    }
-}
-
 pub struct EmulatorBuilder {
     rom: Option<PathBuf>,
     commands: mpsc::Receiver<EmulatorCommand>,
@@ -166,11 +143,13 @@ pub struct Emulator {
     state: Arc<Atomic<EmulatorState>>,
     audio_on: Arc<[AtomicBool; 2]>,
     linked: Arc<AtomicBool>,
+    profilers: [Option<ProfileSender>; 2],
     renderers: HashMap<SimId, TextureSink>,
     messages: HashMap<SimId, mpsc::Sender<Toast>>,
     debuggers: HashMap<SimId, DebugInfo>,
+    stdouts: HashMap<SimId, mpsc::Sender<String>>,
     watched_regions: HashMap<MemoryRange, Weak<MemoryRegion>>,
-    eye_contents: Vec<u8>,
+    eye_contents: [Vec<u8>; 2],
     audio_samples: Vec<f32>,
     buffer: Vec<u8>,
 }
@@ -192,11 +171,13 @@ impl Emulator {
             state,
             audio_on,
             linked,
+            profilers: [None, None],
             renderers: HashMap::new(),
             messages: HashMap::new(),
             debuggers: HashMap::new(),
+            stdouts: HashMap::new(),
             watched_regions: HashMap::new(),
-            eye_contents: vec![0u8; 384 * 224 * 2],
+            eye_contents: [vec![0u8; 384 * 224 * 2], vec![0u8; 384 * 224 * 2]],
             audio_samples: Vec::with_capacity(EXPECTED_FRAME_SIZE),
             buffer: vec![],
         })
@@ -209,12 +190,12 @@ impl Emulator {
     }
 
     pub fn start_second_sim(&mut self, rom: Option<PathBuf>) -> Result<()> {
-        let rom_path = if let Some(path) = rom {
+        let file_path = if let Some(path) = rom {
             Some(path)
         } else {
-            self.carts[0].as_ref().map(|c| c.rom_path.clone())
+            self.carts[0].as_ref().map(|c| c.file_path.clone())
         };
-        let cart = match rom_path {
+        let cart = match file_path {
             Some(rom_path) => Some(Cart::load(&rom_path, SimId::Player2)?),
             None => None,
         };
@@ -228,8 +209,15 @@ impl Emulator {
 
         let index = sim_id.to_index();
         while self.sims.len() <= index {
+            let new_index = self.sims.len();
             self.sims.push(Sim::new());
-            self.sim_state[index].store(SimState::NoGame, Ordering::Release);
+            if self
+                .stdouts
+                .contains_key(&SimId::from_index(new_index).unwrap())
+            {
+                self.sims[new_index].watch_stdout(true);
+            }
+            self.sim_state[new_index].store(SimState::NoGame, Ordering::Release);
         }
         let sim = &mut self.sims[index];
         sim.reset();
@@ -238,6 +226,22 @@ impl Emulator {
             self.carts[index] = Some(cart);
             self.sim_state[index].store(SimState::Ready, Ordering::Release);
         }
+        let mut profiling = false;
+        if let Some(profiler) = self.profilers[sim_id.to_index()].as_ref()
+            && let Some(cart) = self.carts[index].as_ref()
+            && profiler
+                .send(ProfileEvent::Start {
+                    info: cart.info.clone(),
+                })
+                .is_ok()
+        {
+            sim.monitor_events(true, cart.info.inline_stack_map().clone());
+            profiling = true;
+        }
+        if !profiling {
+            sim.monitor_events(false, InlineStackMap::empty());
+        }
+
         if self.sim_state[index].load(Ordering::Acquire) == SimState::Ready {
             self.resume_sims();
         }
@@ -320,8 +324,7 @@ impl Emulator {
         let cart = self.carts[sim_id.to_index()].as_mut();
         if let (Some(sim), Some(cart)) = (sim, cart) {
             sim.read_sram(&mut cart.sram);
-            cart.sram_file.seek(SeekFrom::Start(0))?;
+            cart.save_sram()?;
-            cart.sram_file.write_all(&cart.sram)?;
         }
         Ok(())
     }
@@ -336,6 +339,11 @@ impl Emulator {
         Ok(())
     }
 
+    fn start_profiling(&mut self, sim_id: SimId, sender: ProfileSender) -> Result<()> {
+        self.profilers[sim_id.to_index()] = Some(sender);
+        self.reset_sim(sim_id, None)
+    }
+
     fn start_debugging(&mut self, sim_id: SimId, sender: DebugSender) {
         if self.sim_state[sim_id.to_index()].load(Ordering::Acquire) != SimState::Ready {
             // Can't debug unless a game is connected
@@ -459,25 +467,59 @@ impl Emulator {
         let p1_running = running && p1_state == SimState::Ready;
         let p2_running = running && p2_state == SimState::Ready;
         let mut idle = !p1_running && !p2_running;
-        if p1_running && p2_running {
+
-            Sim::emulate_many(&mut self.sims);
+        let cycles = self.emulate(p1_running, p2_running);
-        } else if p1_running {
+
-            self.sims[SimId::Player1.to_index()].emulate();
+        // if we're profiling, track events
-        } else if p2_running {
+        for ((sim, profiler), running) in self
-            self.sims[SimId::Player2.to_index()].emulate();
+            .sims
+            .iter_mut()
+            .zip(self.profilers.iter_mut())
+            .zip([p1_running, p2_running])
+        {
+            if !running {
+                continue;
+            }
+            if let Some(p) = profiler {
+                let (event, inline_stack) = sim.take_profiler_updates();
+                if p.send(ProfileEvent::Update {
+                    cycles,
+                    event,
+                    inline_stack,
+                })
+                .is_err()
+                {
+                    sim.monitor_events(false, InlineStackMap::empty());
+                    *profiler = None;
+                }
+            }
         }
 
         if state == EmulatorState::Stepping {
             self.state.store(EmulatorState::Paused, Ordering::Release);
         }
 
+        // stdout
+        self.stdouts.retain(|sim_id, stdout| {
+            let Some(sim) = self.sims.get_mut(sim_id.to_index()) else {
+                return true;
+            };
+            if let Some(text) = sim.take_stdout()
+                && stdout.send(text).is_err()
+            {
+                sim.watch_stdout(false);
+                return false;
+            }
+            true
+        });
+
         // Debug state
         if state == EmulatorState::Debugging {
             for sim_id in SimId::values() {
                 let Some(sim) = self.sims.get_mut(sim_id.to_index()) else {
                     continue;
                 };
-                if let Some(reason) = sim.stop_reason() {
+                if let Some(reason) = sim.take_stop_reason() {
                     let stop_reason = match reason {
                         StopReason::Stepped => DebugStopReason::Trace,
                         StopReason::Watchpoint(watch, address) => {
@@ -498,9 +540,12 @@ impl Emulator {
             let Some(sim) = self.sims.get_mut(sim_id.to_index()) else {
                 continue;
             };
-            if sim.read_pixels(&mut self.eye_contents) {
+            if sim.read_pixels(&mut self.eye_contents[sim_id.to_index()]) {
                 idle = false;
-                if renderer.queue_render(&self.eye_contents).is_err() {
+                if renderer
+                    .queue_render(&self.eye_contents[sim_id.to_index()])
+                    .is_err()
+                {
                     self.renderers.remove(&sim_id);
                 }
             }
@@ -533,6 +578,19 @@ impl Emulator {
         idle
     }
 
+    fn emulate(&mut self, p1_running: bool, p2_running: bool) -> u32 {
+        const MAX_CYCLES: u32 = 20_000_000;
+        let mut cycles = MAX_CYCLES;
+        if p1_running && p2_running {
+            Sim::emulate_many(&mut self.sims, &mut cycles);
+        } else if p1_running {
+            self.sims[SimId::Player1.to_index()].emulate(&mut cycles);
+        } else if p2_running {
+            self.sims[SimId::Player2.to_index()].emulate(&mut cycles);
+        }
+        MAX_CYCLES - cycles
+    }
+
     fn handle_command(&mut self, command: EmulatorCommand) {
         match command {
             EmulatorCommand::ConnectToSim(sim_id, renderer, messages) => {
@@ -576,6 +634,11 @@ impl Emulator {
                     self.report_error(SimId::Player1, format!("Error setting speed: {error}"));
                 }
             }
+            EmulatorCommand::StartProfiling(sim_id, profiler) => {
+                if let Err(error) = self.start_profiling(sim_id, profiler) {
+                    self.report_error(SimId::Player1, format!("Error enaling profiler: {error}"));
+                }
+            }
             EmulatorCommand::StartDebugging(sim_id, debugger) => {
                 self.start_debugging(sim_id, debugger);
             }
@@ -645,6 +708,13 @@ impl Emulator {
                 };
                 sim.remove_watchpoint(address, length, watch);
             }
+            EmulatorCommand::WatchStdout(sim_id, stdout_sink) => {
+                self.stdouts.insert(sim_id, stdout_sink);
+                let Some(sim) = self.sims.get_mut(sim_id.to_index()) else {
+                    return;
+                };
+                sim.watch_stdout(true);
+            }
             EmulatorCommand::SetAudioEnabled(p1, p2) => {
                 self.audio_on[SimId::Player1.to_index()].store(p1, Ordering::Release);
                 self.audio_on[SimId::Player2.to_index()].store(p2, Ordering::Release);
@@ -665,6 +735,10 @@ impl Emulator {
                     sim.set_keys(keys);
                 }
             }
+            EmulatorCommand::Screenshot(sim_id, sender) => {
+                let contents = self.eye_contents[sim_id.to_index()].clone();
+                let _ = sender.send(contents);
+            }
             EmulatorCommand::Exit(done) => {
                 for sim_id in SimId::values() {
                     if let Err(error) = self.save_sram(sim_id) {
@@ -682,10 +756,8 @@ impl Emulator {
             .get(&sim_id)
             .or_else(|| self.messages.get(&SimId::Player1));
         if let Some(msg) = messages {
-            let toast = Toast::new()
+            let mut toast = Toast::error(&message);
-                .kind(ToastKind::Error)
+            toast.duration(Some(Duration::from_secs(5)));
-                .options(ToastOptions::default().duration_in_seconds(5.0))
-                .text(&message);
             if msg.send(toast).is_ok() {
                 return;
             }
@@ -704,6 +776,7 @@ pub enum EmulatorCommand {
     Resume,
     FrameAdvance,
     SetSpeed(f64),
+    StartProfiling(SimId, ProfileSender),
     StartDebugging(SimId, DebugSender),
     StopDebugging(SimId),
     DebugInterrupt(SimId),
@@ -718,11 +791,13 @@ pub enum EmulatorCommand {
     RemoveBreakpoint(SimId, u32),
     AddWatchpoint(SimId, u32, usize, VBWatchpointType),
     RemoveWatchpoint(SimId, u32, usize, VBWatchpointType),
+    WatchStdout(SimId, mpsc::Sender<String>),
     SetAudioEnabled(bool, bool),
     Link,
     Unlink,
     Reset(SimId),
     SetKeys(SimId, VBKey),
+    Screenshot(SimId, oneshot::Sender<Vec<u8>>),
     Exit(oneshot::Sender<()>),
 }
 
@@ -743,6 +818,7 @@ pub enum EmulatorState {
     Debugging,
 }
 
+type ProfileSender = tokio::sync::mpsc::UnboundedSender<ProfileEvent>;
 type DebugSender = tokio::sync::mpsc::UnboundedSender<DebugEvent>;
 
 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
@@ -766,6 +842,17 @@ pub enum DebugEvent {
     Stopped(DebugStopReason),
 }
 
+pub enum ProfileEvent {
+    Start {
+        info: Arc<GameInfo>,
+    },
+    Update {
+        cycles: u32,
+        event: Option<SimEvent>,
+        inline_stack: Option<InlineStack>,
+    },
+}
+
 #[derive(Clone)]
 pub struct EmulatorClient {
     queue: mpsc::Sender<EmulatorCommand>,

src/emulator/cart.rs

@@ -0,0 +1,114 @@
+use anyhow::Result;
+use rand::Rng;
+use std::{
+    fs::{self, File},
+    io::{Read, Seek as _, SeekFrom, Write as _},
+    path::{Path, PathBuf},
+    sync::Arc,
+};
+
+use crate::emulator::{SimId, game_info::GameInfo, shrooms_vb_util::rom_from_isx};
+
+pub struct Cart {
+    pub file_path: PathBuf,
+    pub rom: Vec<u8>,
+    sram_file: File,
+    pub sram: Vec<u8>,
+    pub info: Arc<GameInfo>,
+}
+
+impl Cart {
+    pub fn load(file_path: &Path, sim_id: SimId) -> Result<Self> {
+        let rom = fs::read(file_path)?;
+        let (rom, info) = try_parse_isx(file_path, &rom)
+            .or_else(|| try_parse_elf(file_path, &rom))
+            .unwrap_or_else(|| (rom, GameInfo::empty(file_path)));
+
+        let mut sram_file = File::options()
+            .read(true)
+            .write(true)
+            .create(true)
+            .truncate(false)
+            .open(sram_path(file_path, sim_id))?;
+
+        let sram = if sram_file.metadata()?.len() == 0 {
+            // new SRAM file, randomize the contents
+            let mut sram = vec![0; 16 * 1024];
+            let mut rng = rand::rng();
+            for dst in sram.iter_mut().step_by(2) {
+                *dst = rng.random();
+            }
+            sram
+        } else {
+            let mut sram = Vec::with_capacity(16 * 1024);
+            sram_file.read_to_end(&mut sram)?;
+            sram
+        };
+
+        Ok(Cart {
+            file_path: file_path.to_path_buf(),
+            rom,
+            sram_file,
+            sram,
+            info: Arc::new(info),
+        })
+    }
+
+    pub fn save_sram(&mut self) -> Result<()> {
+        self.sram_file.seek(SeekFrom::Start(0))?;
+        self.sram_file.write_all(&self.sram)?;
+        Ok(())
+    }
+}
+
+fn try_parse_isx(file_path: &Path, data: &[u8]) -> Option<(Vec<u8>, GameInfo)> {
+    let rom = rom_from_isx(data)?;
+    let info = GameInfo::from_isx(file_path, data);
+    Some((rom, info))
+}
+
+fn try_parse_elf(file_path: &Path, data: &[u8]) -> Option<(Vec<u8>, GameInfo)> {
+    use object::read::elf::FileHeader;
+    let program = match object::FileKind::parse(data).ok()? {
+        object::FileKind::Elf32 => {
+            let header = object::elf::FileHeader32::parse(data).ok()?;
+            parse_elf_program(header, data)?
+        }
+        object::FileKind::Elf64 => {
+            let header = object::elf::FileHeader64::parse(data).ok()?;
+            parse_elf_program(header, data)?
+        }
+        _ => return None,
+    };
+    let info = GameInfo::from_elf(file_path, data).unwrap_or_else(|_| GameInfo::empty(file_path));
+    Some((program, info))
+}
+
+fn parse_elf_program<Elf: object::read::elf::FileHeader<Endian = object::Endianness>>(
+    header: &Elf,
+    data: &[u8],
+) -> Option<Vec<u8>> {
+    use object::read::elf::ProgramHeader;
+    let endian = header.endian().ok()?;
+    let mut bytes = vec![];
+    let mut pstart = None;
+    for phdr in header.program_headers(endian, data).ok()? {
+        let pma = phdr.p_paddr(endian).into();
+        if pma < 0x07000000 || phdr.p_filesz(endian).into() == 0 {
+            continue;
+        }
+        let start = pstart.unwrap_or(pma);
+        pstart = Some(start);
+        bytes.resize((pma - start) as usize, 0);
+        let data = phdr.data(endian, data).ok()?;
+        bytes.extend_from_slice(data);
+    }
+    Some(bytes)
+}
+
+fn sram_path(file_path: &Path, sim_id: SimId) -> PathBuf {
+    match sim_id {
+        SimId::Player1 => file_path.with_extension("p1.sram"),
+        SimId::Player2 => file_path.with_extension("p2.sram"),
+    }
+}

src/emulator/game_info.rs

@@ -0,0 +1,281 @@
+use std::{borrow::Cow, path::Path, sync::Arc};
+
+use anyhow::{Result, bail};
+use fxprof_processed_profile::{LibraryInfo, Symbol, SymbolTable, debugid::DebugId};
+use object::{Object, ObjectSection, ObjectSymbol};
+use wholesym::samply_symbols::{DebugIdExt, demangle_any};
+
+use crate::emulator::inline_stack_map::{InlineStackMap, InlineStackMapBuilder};
+
+#[derive(Debug)]
+pub struct GameInfo {
+    library_info: LibraryInfo,
+    inline_stack_map: InlineStackMap,
+}
+
+impl GameInfo {
+    pub fn from_elf(file_path: &Path, input: &[u8]) -> Result<Self> {
+        let file = object::File::parse(input)?;
+
+        let (name, path) = name_and_path(file_path);
+        let debug_id = file
+            .build_id()?
+            .map(|id| DebugId::from_identifier(id, true))
+            .unwrap_or_default();
+        let code_id = file.build_id()?.map(hex::encode);
+        let mut symbols = vec![];
+        for sym in file.symbols() {
+            symbols.push(Symbol {
+                address: sym.address() as u32,
+                size: Some(sym.size() as u32),
+                name: demangle_any(sym.name()?),
+            });
+        }
+
+        let inline_stack_map =
+            build_inline_stack_map(file).unwrap_or_else(|_| InlineStackMap::empty());
+
+        let library_info = LibraryInfo {
+            name: name.clone(),
+            debug_name: name,
+            path: path.clone(),
+            debug_path: path,
+            debug_id,
+            code_id,
+            arch: None,
+            symbol_table: Some(Arc::new(SymbolTable::new(symbols))),
+        };
+
+        Ok(Self {
+            library_info,
+            inline_stack_map,
+        })
+    }
+
+    pub fn from_isx(file_path: &Path, input: &[u8]) -> Self {
+        let (name, path) = name_and_path(file_path);
+        let symbols = extract_isx_symbols(input);
+        let library_info = LibraryInfo {
+            name: name.clone(),
+            debug_name: name,
+            path: path.clone(),
+            debug_path: path,
+            debug_id: DebugId::default(),
+            code_id: None,
+            arch: None,
+            symbol_table: symbols.map(|syms| Arc::new(SymbolTable::new(syms))),
+        };
+        let inline_stack_map = InlineStackMap::empty();
+        Self {
+            library_info,
+            inline_stack_map,
+        }
+    }
+
+    pub fn empty(file_path: &Path) -> Self {
+        let (name, path) = name_and_path(file_path);
+        let library_info = LibraryInfo {
+            name: name.clone(),
+            debug_name: name,
+            path: path.clone(),
+            debug_path: path,
+            debug_id: DebugId::default(),
+            code_id: None,
+            arch: None,
+            symbol_table: None,
+        };
+        let inline_stack_map = InlineStackMap::empty();
+        Self {
+            library_info,
+            inline_stack_map,
+        }
+    }
+
+    pub fn name(&self) -> &str {
+        &self.library_info.name
+    }
+
+    pub fn library_info(&self) -> &LibraryInfo {
+        &self.library_info
+    }
+
+    pub fn inline_stack_map(&self) -> &InlineStackMap {
+        &self.inline_stack_map
+    }
+}
+
+fn build_inline_stack_map(file: object::File) -> Result<InlineStackMap> {
+    let endian = if file.is_little_endian() {
+        gimli::RunTimeEndian::Little
+    } else {
+        gimli::RunTimeEndian::Big
+    };
+    fn load_section<'a>(file: &'a object::File, id: gimli::SectionId) -> Result<Cow<'a, [u8]>> {
+        let input = match file.section_by_name(id.name()) {
+            Some(section) => section.uncompressed_data()?,
+            None => Cow::Owned(vec![]),
+        };
+        Ok(input)
+    }
+    let dorf = gimli::DwarfSections::load(|id| load_section(&file, id))?;
+    let dorf = dorf.borrow(|sec| gimli::EndianSlice::new(sec, endian));
+    let mut units = dorf.units();
+    let mut frames = InlineStackMap::builder();
+    while let Some(header) = units.next()? {
+        let unit = dorf.unit(header)?;
+        let mut entree = unit.entries_tree(None)?;
+        let root = entree.root()?;
+        let mut ctx = ParseContext {
+            dorf: &dorf,
+            unit: &unit,
+            frames: &mut frames,
+        };
+        parse_inline(&mut ctx, root)?;
+    }
+    Ok(frames.build())
+}
+
+fn extract_isx_symbols(input: &[u8]) -> Option<Vec<Symbol>> {
+    let mut syms = vec![];
+    let (_, mut buf) = input.split_at_checked(32)?;
+    while !buf.is_empty() {
+        let typ;
+        (typ, buf) = buf.split_first()?;
+        match typ {
+            0x11 => {
+                // Code (Virtual Boy)
+                (_, buf) = buf.split_at_checked(4)?;
+                let len_bytes;
+                (len_bytes, buf) = buf.split_first_chunk()?;
+                let len = u32::from_le_bytes(*len_bytes);
+                (_, buf) = buf.split_at_checked(len as usize)?;
+            }
+            0x13 => {
+                // Range (Virtual Boy)
+                let count_bytes;
+                (count_bytes, buf) = buf.split_first_chunk()?;
+                let count = u16::from_le_bytes(*count_bytes) + 1;
+                (_, buf) = buf.split_at_checked(count as usize * 9)?;
+            }
+            0x14 => {
+                // Symbol (Virtual Boy)
+                let count_bytes;
+                (count_bytes, buf) = buf.split_first_chunk()?;
+                let count = u16::from_le_bytes(*count_bytes) + 1;
+                for _ in 0..count {
+                    let name_len;
+                    (name_len, buf) = buf.split_first()?;
+                    let name_bytes;
+                    (name_bytes, buf) = buf.split_at_checked(*name_len as usize)?;
+                    (_, buf) = buf.split_at_checked(2)?;
+                    let address_bytes;
+                    (address_bytes, buf) = buf.split_first_chunk()?;
+
+                    let name_str = String::from_utf8_lossy(name_bytes);
+                    let address = u32::from_le_bytes(*address_bytes);
+                    syms.push(Symbol {
+                        address: address & 0x07ffffff,
+                        size: Some(4),
+                        name: demangle_any(&name_str),
+                    });
+                }
+            }
+            0x20..=0x22 => {
+                // System (undocumented)
+                let length_bytes;
+                (length_bytes, buf) = buf.split_first_chunk()?;
+                let length = u32::from_le_bytes(*length_bytes);
+                (_, buf) = buf.split_at_checked(length as usize)?;
+            }
+            _ => {
+                return None;
+            }
+        }
+    }
+    Some(syms)
+}
+
+type Reader<'a> = gimli::EndianSlice<'a, gimli::RunTimeEndian>;
+
+struct ParseContext<'a> {
+    dorf: &'a gimli::Dwarf<Reader<'a>>,
+    unit: &'a gimli::Unit<Reader<'a>>,
+    frames: &'a mut InlineStackMapBuilder,
+}
+impl ParseContext<'_> {
+    fn name_attr(&self, attr: gimli::AttributeValue<Reader>) -> Result<Option<String>> {
+        match attr {
+            gimli::AttributeValue::DebugInfoRef(offset) => {
+                let mut units = self.dorf.units();
+                while let Some(header) = units.next()? {
+                    if let Some(offset) = offset.to_unit_offset(&header) {
+                        let unit = self.dorf.unit(header)?;
+                        return self.name_entry(&unit, offset);
+                    }
+                }
+                Ok(None)
+            }
+            gimli::AttributeValue::UnitRef(offset) => self.name_entry(self.unit, offset),
+            other => {
+                bail!("unrecognized attr {other:?}");
+            }
+        }
+    }
+
+    fn name_entry(
+        &self,
+        unit: &gimli::Unit<Reader>,
+        offset: gimli::UnitOffset,
+    ) -> Result<Option<String>> {
+        let abbreviations = self.dorf.abbreviations(&unit.header)?;
+        let mut entries = unit.header.entries_raw(&abbreviations, Some(offset))?;
+        let Some(abbrev) = entries.read_abbreviation()? else {
+            return Ok(None);
+        };
+        let mut name = None;
+        for spec in abbrev.attributes() {
+            let attr = entries.read_attribute(*spec)?;
+            if attr.name() == gimli::DW_AT_linkage_name
+                || (attr.name() == gimli::DW_AT_name && name.is_none())
+            {
+                name = Some(self.dorf.attr_string(unit, attr.value())?)
+            }
+        }
+        Ok(name.map(|n| demangle_any(&String::from_utf8_lossy(&n))))
+    }
+}
+
+fn parse_inline(ctx: &mut ParseContext, node: gimli::EntriesTreeNode<Reader>) -> Result<()> {
+    if node.entry().tag() == gimli::DW_TAG_inlined_subroutine
+        && let Some(attr) = node.entry().attr_value(gimli::DW_AT_abstract_origin)?
+        && let Some(name) = ctx.name_attr(attr)?
+    {
+        let name = Arc::new(name);
+        let mut ranges = ctx.dorf.die_ranges(ctx.unit, node.entry())?;
+        while let Some(range) = ranges.next()? {
+            let start = range.begin as u32 & 0x07ffffff;
+            let end = range.end as u32 & 0x07ffffff;
+            ctx.frames.add(start, end, name.clone());
+        }
+    }
+    let mut children = node.children();
+    while let Some(child) = children.next()? {
+        parse_inline(ctx, child)?;
+    }
+    Ok(())
+}
+
+fn name_and_path(file_path: &Path) -> (String, String) {
+    let normalized = normpath::PathExt::normalize(file_path);
+    let path = normalized
+        .as_ref()
+        .map(|n| n.as_path())
+        .unwrap_or(file_path);
+
+    let name = match path.file_stem() {
+        Some(s) => s.to_string_lossy().into_owned(),
+        None => "game".to_string(),
+    };
+    let path = path.to_string_lossy().into_owned();
+    (name, path)
+}

src/emulator/inline_stack_map.rs

@@ -0,0 +1,87 @@
+use std::{
+    collections::{BTreeMap, HashMap},
+    sync::Arc,
+};
+
+pub type InlineStack = Arc<Vec<Arc<String>>>;
+
+#[derive(Debug, Clone)]
+pub struct InlineStackMap {
+    entries: Vec<(u32, InlineStack)>,
+    empty: InlineStack,
+}
+
+impl InlineStackMap {
+    pub fn empty() -> Self {
+        Self {
+            entries: vec![],
+            empty: Arc::new(vec![]),
+        }
+    }
+    pub fn builder() -> InlineStackMapBuilder {
+        InlineStackMapBuilder {
+            events: BTreeMap::new(),
+        }
+    }
+    pub fn get(&self, address: u32) -> &InlineStack {
+        match self.entries.binary_search_by_key(&address, |(a, _)| *a) {
+            Ok(index) => self.entries.get(index),
+            Err(after) => after.checked_sub(1).and_then(|i| self.entries.get(i)),
+        }
+        .map(|(_, s)| s)
+        .unwrap_or(&self.empty)
+    }
+}
+
+#[derive(Default)]
+struct Event {
+    end: usize,
+    start: Vec<Arc<String>>,
+}
+
+pub struct InlineStackMapBuilder {
+    events: BTreeMap<u32, Event>,
+}
+
+impl InlineStackMapBuilder {
+    pub fn add(&mut self, start: u32, end: u32, name: Arc<String>) {
+        self.events.entry(start).or_default().start.push(name);
+        self.events.entry(end).or_default().end += 1;
+    }
+
+    pub fn build(self) -> InlineStackMap {
+        let empty = Arc::new(vec![]);
+        let mut entries = vec![];
+        let mut stack_indexes = vec![];
+        let mut stack = vec![];
+        let mut string_dedup = HashMap::new();
+        let mut stack_dedup = BTreeMap::new();
+        stack_dedup.insert(vec![], empty.clone());
+
+        for (address, event) in self.events {
+            for _ in 0..event.end {
+                stack.pop();
+                stack_indexes.pop();
+            }
+            for call in event.start {
+                if let Some(index) = string_dedup.get(&call) {
+                    stack.push(call);
+                    stack_indexes.push(*index);
+                } else {
+                    let index = string_dedup.len();
+                    string_dedup.insert(call.clone(), index);
+                    stack.push(call);
+                    stack_indexes.push(index);
+                }
+            }
+            if let Some(stack) = stack_dedup.get(&stack_indexes) {
+                entries.push((address, stack.clone()));
+            } else {
+                let stack = Arc::new(stack.clone());
+                stack_dedup.insert(stack_indexes.clone(), stack.clone());
+                entries.push((address, stack));
+            }
+        }
+        InlineStackMap { entries, empty }
+    }
+}

src/emulator/shrooms_vb_core.rs

@@ -1,10 +1,12 @@
-use std::{ffi::c_void, ptr, slice};
+use std::{borrow::Cow, ffi::c_void, ptr, slice, sync::Arc};
 
 use anyhow::{Result, anyhow};
 use bitflags::bitflags;
 use num_derive::{FromPrimitive, ToPrimitive};
 use serde::{Deserialize, Serialize};
 
+use crate::emulator::inline_stack_map::{InlineStack, InlineStackMap};
+
 use super::address_set::AddressSet;
 
 #[repr(C)]
@@ -71,8 +73,16 @@ pub enum VBWatchpointType {
     Access,
 }
 
+type OnException = extern "C" fn(sim: *mut VB, cause: *mut u16) -> c_int;
 type OnExecute =
     extern "C" fn(sim: *mut VB, address: u32, code: *const u16, length: c_int) -> c_int;
+type OnFetch = extern "C" fn(
+    sim: *mut VB,
+    fetch: c_int,
+    address: u32,
+    value: *mut i32,
+    cycles: *mut u32,
+) -> c_int;
 type OnFrame = extern "C" fn(sim: *mut VB) -> c_int;
 type OnRead = extern "C" fn(
     sim: *mut VB,
@@ -135,8 +145,15 @@ unsafe extern "C" {
     fn vb_set_cart_ram(sim: *mut VB, sram: *mut c_void, size: u32) -> c_int;
     #[link_name = "vbSetCartROM"]
     fn vb_set_cart_rom(sim: *mut VB, rom: *mut c_void, size: u32) -> c_int;
+    #[link_name = "vbSetExceptionCallback"]
+    fn vb_set_exception_callback(
+        sim: *mut VB,
+        callback: Option<OnException>,
+    ) -> Option<OnException>;
     #[link_name = "vbSetExecuteCallback"]
     fn vb_set_execute_callback(sim: *mut VB, callback: Option<OnExecute>) -> Option<OnExecute>;
+    #[link_name = "vbSetFetchCallback"]
+    fn vb_set_fetch_callback(sim: *mut VB, callback: Option<OnFetch>) -> Option<OnFetch>;
     #[link_name = "vbSetFrameCallback"]
     fn vb_set_frame_callback(sim: *mut VB, callback: Option<OnFrame>) -> Option<OnFrame>;
     #[link_name = "vbSetKeys"]
@@ -176,16 +193,27 @@ extern "C" fn on_frame(sim: *mut VB) -> c_int {
     // There is no way for the userdata to be null or otherwise invalid.
     let data: &mut VBState = unsafe { &mut *vb_get_user_data(sim).cast() };
     data.frame_seen = true;
+    if data.monitor.enabled {
+        data.monitor.event = Some(SimEvent::Marker(Cow::Borrowed("Frame Drawn")));
+    }
     1
 }
 
 #[unsafe(no_mangle)]
-extern "C" fn on_execute(sim: *mut VB, address: u32, _code: *const u16, _length: c_int) -> c_int {
+extern "C" fn on_execute(sim: *mut VB, address: u32, code: *const u16, length: c_int) -> c_int {
     // SAFETY: the *mut VB owns its userdata.
     // There is no way for the userdata to be null or otherwise invalid.
     let data: &mut VBState = unsafe { &mut *vb_get_user_data(sim).cast() };
 
-    let mut stopped = data.stop_reason.is_some();
+    if data.monitor.enabled {
+        // SAFETY: length is the length of code, in elements
+        let code = unsafe { slice::from_raw_parts(code, length as usize) };
+        data.monitor.detect_event(sim, address, code);
+        // Something interesting will happen after this instruction is run.
+        // We'll react in the on_fetch callback it does.
+    }
+
+    let mut stopped = data.stop_reason.is_some() || data.monitor.event.is_some();
     if data.step_from.is_some_and(|s| s != address) {
         data.step_from = None;
         data.stop_reason = Some(StopReason::Stepped);
@@ -199,6 +227,49 @@ extern "C" fn on_execute(sim: *mut VB, address: u32, _code: *const u16, _length:
     if stopped { 1 } else { 0 }
 }
 
+#[unsafe(no_mangle)]
+extern "C" fn on_fetch(
+    sim: *mut VB,
+    _fetch: c_int,
+    address: u32,
+    _value: *mut i32,
+    _cycles: *mut u32,
+) -> c_int {
+    // SAFETY: the *mut VB owns its userdata.
+    // There is no way for the userdata to be null or otherwise invalid.
+    let data: &mut VBState = unsafe { &mut *vb_get_user_data(sim).cast() };
+    data.monitor.event = data.monitor.queued_event.take();
+    data.monitor.new_inline_stack = data.monitor.detect_new_inline_stack(address);
+    unsafe { vb_set_exception_callback(sim, Some(on_exception)) };
+    if data.monitor.event.is_some() || data.monitor.new_inline_stack.is_some() {
+        1
+    } else {
+        0
+    }
+}
+
+#[unsafe(no_mangle)]
+extern "C" fn on_exception(sim: *mut VB, cause: *mut u16) -> c_int {
+    // SAFETY: the *mut VB owns its userdata.
+    // There is no way for the userdata to be null or otherwise invalid.
+    let data: &mut VBState = unsafe { &mut *vb_get_user_data(sim).cast() };
+    let cause = unsafe { *cause };
+    let pc = if cause == 0xff70 {
+        0xffffff60
+    } else {
+        (cause & 0xfff0) as u32 | 0xffff0000
+    };
+    data.monitor.event = data.monitor.queued_event.take();
+    data.monitor.new_inline_stack = data.monitor.detect_new_inline_stack(pc);
+    data.monitor.queued_event = Some(SimEvent::Interrupt(cause, pc & 0x07ffffff));
+    unsafe { vb_set_exception_callback(sim, None) };
+    if data.monitor.event.is_some() || data.monitor.new_inline_stack.is_some() {
+        1
+    } else {
+        0
+    }
+}
+
 #[unsafe(no_mangle)]
 extern "C" fn on_read(
     sim: *mut VB,
@@ -229,8 +300,8 @@ extern "C" fn on_read(
 extern "C" fn on_write(
     sim: *mut VB,
     address: u32,
-    _type: VBDataType,
+    typ_: VBDataType,
-    _value: *mut i32,
+    value: *mut i32,
     _cycles: *mut u32,
     _cancel: *mut c_int,
 ) -> c_int {
@@ -238,6 +309,37 @@ extern "C" fn on_write(
     // There is no way for the userdata to be null or otherwise invalid.
     let data: &mut VBState = unsafe { &mut *vb_get_user_data(sim).cast() };
 
+    // If we're monitoring stdout, track this write
+    if let Some(stdout) = data.stdout.as_mut() {
+        let normalized_hw_address = address & 0x0700003f;
+        if normalized_hw_address == 0x02000030 {
+            stdout.push(unsafe { *value } as u8);
+        }
+    }
+
+    // If we have profiling enabled, track custom markers
+    if data.monitor.enabled {
+        let normalized_hw_address = address & 0x0700003f;
+        if normalized_hw_address == 0x02000038 && matches!(typ_, VBDataType::S32) {
+            assert!(data.monitor.queued_event.is_none());
+            // The game has written the address of a null-terminated string
+            // (whose length is at most 64 bytes). Read that string.
+            let str_address = unsafe { *value } as u32;
+            let mut bytes = [0u8; 64];
+            let mut len = 0;
+            for (dst, src_address) in bytes.iter_mut().zip(str_address..str_address + 64) {
+                let char = unsafe { vb_read(sim, src_address, VBDataType::U8) } as u8;
+                if char == 0 {
+                    break;
+                }
+                *dst = char;
+                len += 1;
+            }
+            let name = String::from_utf8_lossy(&bytes[..len]).into_owned();
+            data.monitor.queued_event = Some(SimEvent::Marker(Cow::Owned(name)));
+        }
+    }
+
     if let Some(start) = data.write_watchpoints.start_of_range_containing(address) {
         let watch = if data.read_watchpoints.contains(address) {
             VBWatchpointType::Access
@@ -252,6 +354,119 @@ extern "C" fn on_write(
     0
 }
 
+#[allow(dead_code)]
+#[derive(Debug)]
+pub enum SimEvent {
+    Call(u32),
+    Return,
+    Halt,
+    Interrupt(u16, u32),
+    Reti,
+    Marker(Cow<'static, str>),
+}
+
+struct EventMonitor {
+    enabled: bool,
+    event: Option<SimEvent>,
+    queued_event: Option<SimEvent>,
+    just_halted: bool,
+    inline_stack_map: InlineStackMap,
+    new_inline_stack: Option<InlineStack>,
+    last_inline_stack: InlineStack,
+}
+
+impl EventMonitor {
+    fn new() -> Self {
+        let inline_stack_map = InlineStackMap::empty();
+        let last_inline_stack = inline_stack_map.get(0).clone();
+        Self {
+            enabled: false,
+            event: None,
+            queued_event: None,
+            just_halted: false,
+            inline_stack_map,
+            new_inline_stack: None,
+            last_inline_stack,
+        }
+    }
+
+    fn detect_new_inline_stack(&mut self, address: u32) -> Option<InlineStack> {
+        let stack = self.inline_stack_map.get(address);
+        if Arc::ptr_eq(stack, &self.last_inline_stack) {
+            return None;
+        }
+        self.last_inline_stack = stack.clone();
+        Some(stack.clone())
+    }
+
+    fn detect_event(&mut self, sim: *mut VB, address: u32, code: &[u16]) -> bool {
+        self.queued_event = self.do_detect_event(sim, address, code);
+        self.queued_event.is_some()
+    }
+
+    fn do_detect_event(&mut self, sim: *mut VB, address: u32, code: &[u16]) -> Option<SimEvent> {
+        const HALT_OPCODE: u16 = 0b011010;
+        const JAL_OPCODE: u16 = 0b101011;
+        const JMP_OPCODE: u16 = 0b000110;
+        const RETI_OPCODE: u16 = 0b011001;
+
+        const fn format_i_reg_1(code: &[u16]) -> u8 {
+            (code[0] & 0x1f) as u8
+        }
+
+        const fn format_iv_disp(code: &[u16]) -> i32 {
+            let value = ((code[0] & 0x3ff) as i32) << 16 | (code[1] as i32);
+            value << 6 >> 6
+        }
+
+        let opcode = code[0] >> 10;
+
+        if opcode == HALT_OPCODE {
+            if !self.just_halted {
+                self.just_halted = true;
+                self.event = Some(SimEvent::Halt);
+            } else {
+                self.just_halted = false;
+            }
+            // Don't _return_ an event, we want to emit this right away.
+            // If the CPU is halting, no other callbacks will run for a long time.
+            return None;
+        }
+
+        if opcode == JAL_OPCODE {
+            let disp = format_iv_disp(code);
+            if disp != 4 {
+                // JAL .+4 is how programs get r31 to a known value for indirect calls
+                // (which we detect later.)
+                // Any other JAL is a function call.
+                return Some(SimEvent::Call(
+                    address.wrapping_add_signed(disp) & 0x07ffffff,
+                ));
+            }
+        }
+
+        if opcode == JMP_OPCODE {
+            let jmp_reg = format_i_reg_1(code);
+            if jmp_reg == 31 {
+                // JMP[r31] is a return
+                return Some(SimEvent::Return);
+            }
+            let r31 = unsafe { vb_get_program_register(sim, 31) };
+            if r31 as u32 == address.wrapping_add(2) {
+                // JMP anywhere else, if r31 points to after the JMP, is an indirect call
+                let target = unsafe { vb_get_program_register(sim, jmp_reg as u32) };
+                return Some(SimEvent::Call(target as u32 & 0x07ffffff));
+            }
+        }
+
+        if opcode == RETI_OPCODE {
+            return Some(SimEvent::Reti);
+        }
+
+        None
+    }
+}
+
 const AUDIO_CAPACITY_SAMPLES: usize = 834 * 4;
 const AUDIO_CAPACITY_FLOATS: usize = AUDIO_CAPACITY_SAMPLES * 2;
 pub const EXPECTED_FRAME_SIZE: usize = 834 * 2;
@@ -259,19 +474,26 @@ pub const EXPECTED_FRAME_SIZE: usize = 834 * 2;
 struct VBState {
     frame_seen: bool,
     stop_reason: Option<StopReason>,
+    monitor: EventMonitor,
     step_from: Option<u32>,
     breakpoints: Vec<u32>,
     read_watchpoints: AddressSet,
     write_watchpoints: AddressSet,
+    stdout: Option<Vec<u8>>,
 }
 
 impl VBState {
     fn needs_execute_callback(&self) -> bool {
         self.step_from.is_some()
+            || self.monitor.enabled
             || !self.breakpoints.is_empty()
             || !self.read_watchpoints.is_empty()
             || !self.write_watchpoints.is_empty()
     }
+
+    fn needs_write_callback(&self) -> bool {
+        self.stdout.is_some() || self.monitor.enabled || !self.write_watchpoints.is_empty()
+    }
 }
 
 pub enum StopReason {
@@ -302,10 +524,12 @@ impl Sim {
         let state = VBState {
             frame_seen: false,
             stop_reason: None,
+            monitor: EventMonitor::new(),
             step_from: None,
             breakpoints: vec![],
             read_watchpoints: AddressSet::new(),
             write_watchpoints: AddressSet::new(),
+            stdout: None,
         };
         unsafe { vb_set_user_data(sim, Box::into_raw(Box::new(state)).cast()) };
         unsafe { vb_set_frame_callback(sim, Some(on_frame)) };
@@ -322,6 +546,33 @@ impl Sim {
         unsafe { vb_reset(self.sim) };
     }
 
+    pub fn monitor_events(&mut self, enabled: bool, inline_stack_map: InlineStackMap) {
+        let state = self.get_state();
+        state.monitor.enabled = enabled;
+        state.monitor.event = None;
+        state.monitor.queued_event = None;
+        state.monitor.new_inline_stack = None;
+        state.monitor.last_inline_stack = inline_stack_map.get(0).clone();
+        state.monitor.inline_stack_map = inline_stack_map;
+        if enabled {
+            unsafe { vb_set_execute_callback(self.sim, Some(on_execute)) };
+            unsafe { vb_set_exception_callback(self.sim, Some(on_exception)) };
+            unsafe { vb_set_fetch_callback(self.sim, Some(on_fetch)) };
+            unsafe { vb_set_write_callback(self.sim, Some(on_write)) };
+        } else {
+            let needs_execute = state.needs_execute_callback();
+            let needs_write = state.needs_write_callback();
+            if !needs_execute {
+                unsafe { vb_set_execute_callback(self.sim, None) };
+            }
+            unsafe { vb_set_exception_callback(self.sim, None) };
+            unsafe { vb_set_fetch_callback(self.sim, None) };
+            if !needs_write {
+                unsafe { vb_set_write_callback(self.sim, None) };
+            }
+        }
+    }
+
     pub fn load_cart(&mut self, mut rom: Vec<u8>, mut sram: Vec<u8>) -> Result<()> {
         self.unload_cart();
 
@@ -384,16 +635,14 @@ impl Sim {
         unsafe { vb_set_peer(self.sim, ptr::null_mut()) };
     }
 
-    pub fn emulate(&mut self) {
+    pub fn emulate(&mut self, cycles: &mut u32) {
-        let mut cycles = 20_000_000;
+        unsafe { vb_emulate(self.sim, cycles) };
-        unsafe { vb_emulate(self.sim, &mut cycles) };
     }
 
-    pub fn emulate_many(sims: &mut [Sim]) {
+    pub fn emulate_many(sims: &mut [Sim], cycles: &mut u32) {
-        let mut cycles = 20_000_000;
         let count = sims.len() as c_uint;
         let sims = sims.as_mut_ptr().cast();
-        unsafe { vb_emulate_ex(sims, count, &mut cycles) };
+        unsafe { vb_emulate_ex(sims, count, cycles) };
     }
 
     pub fn read_pixels(&mut self, buffers: &mut [u8]) -> bool {
@@ -562,9 +811,12 @@ impl Sim {
     fn remove_write_watchpoint(&mut self, address: u32, length: usize) {
         let state = self.get_state();
         state.write_watchpoints.remove(address, length);
+        let needs_write = state.needs_write_callback();
         let needs_execute = state.needs_execute_callback();
         if state.write_watchpoints.is_empty() {
+            if !needs_write {
                 unsafe { vb_set_write_callback(self.sim, None) };
+            }
             if !needs_execute {
                 unsafe { vb_set_execute_callback(self.sim, None) };
             }
@@ -586,12 +838,44 @@ impl Sim {
         data.breakpoints.clear();
         data.read_watchpoints.clear();
         data.write_watchpoints.clear();
+        let needs_write = data.needs_write_callback();
+        let needs_execute = data.needs_execute_callback();
         unsafe { vb_set_read_callback(self.sim, None) };
+        if !needs_write {
             unsafe { vb_set_write_callback(self.sim, None) };
+        }
+        if !needs_execute {
             unsafe { vb_set_execute_callback(self.sim, None) };
         }
+    }
 
-    pub fn stop_reason(&mut self) -> Option<StopReason> {
+    pub fn watch_stdout(&mut self, watch: bool) {
+        let data = self.get_state();
+        if watch {
+            if data.stdout.is_none() {
+                data.stdout = Some(vec![]);
+                unsafe { vb_set_write_callback(self.sim, Some(on_write)) };
+            }
+        } else {
+            data.stdout.take();
+            if !data.needs_write_callback() {
+                unsafe { vb_set_write_callback(self.sim, None) };
+            }
+        }
+    }
+
+    pub fn take_stdout(&mut self) -> Option<String> {
+        let data = self.get_state();
+        let stdout = data.stdout.take()?;
+        let string = match String::from_utf8(stdout) {
+            Ok(str) => str,
+            Err(err) => String::from_utf8_lossy(err.as_bytes()).into_owned(),
+        };
+        data.stdout = Some(vec![]);
+        Some(string)
+    }
+
+    pub fn take_stop_reason(&mut self) -> Option<StopReason> {
         let data = self.get_state();
         let reason = data.stop_reason.take();
         if !data.needs_execute_callback() {
@@ -600,6 +884,13 @@ impl Sim {
         reason
     }
 
+    pub fn take_profiler_updates(&mut self) -> (Option<SimEvent>, Option<InlineStack>) {
+        let data = self.get_state();
+        let event = data.monitor.event.take();
+        let inline_stack = data.monitor.new_inline_stack.take();
+        (event, inline_stack)
+    }
+
     fn get_state(&mut self) -> &mut VBState {
         // SAFETY: the *mut VB owns its userdata.
         // There is no way for the userdata to be null or otherwise invalid.

src/emulator/shrooms_vb_util.rs

@@ -0,0 +1,31 @@
+use std::ffi::c_void;
+
+#[unsafe(no_mangle)]
+unsafe fn vbu_realloc_shim(ptr: *mut c_void, new_size: usize) -> *mut c_void {
+    if !ptr.is_null() {
+        // not supporting proper realloc because it needs bookkeeping and it's unnecessary
+        return std::ptr::null_mut();
+    }
+    let allocation = vec![0u8; new_size].into_boxed_slice();
+    Box::into_raw(allocation).cast()
+}
+
+#[link(name = "vb")]
+unsafe extern "C" {
+    #[link_name = "vbuFromISX"]
+    fn vbu_from_isx(bytes: *const c_void, length: usize, rom_length: *mut usize) -> *mut c_void;
+}
+
+pub fn rom_from_isx(bytes: &[u8]) -> Option<Vec<u8>> {
+    if !bytes.starts_with(b"ISX") {
+        return None;
+    }
+    let mut rom_length = 0;
+    let raw_rom = unsafe { vbu_from_isx(bytes.as_ptr().cast(), bytes.len(), &mut rom_length) };
+    if raw_rom.is_null() {
+        return None;
+    }
+    // SAFETY: the rom was allocated by vbu_realloc_shim, which created it from a Vec<u8>.
+    let rom = unsafe { Vec::from_raw_parts(raw_rom.cast(), rom_length, rom_length) };
+    Some(rom)
+}

src/gdbserver/registers.rs

@@ -12,7 +12,7 @@ impl RegisterInfo {
     pub fn to_description(&self) -> String {
         let mut string = format!("name:{}", self.name);
         if let Some(alt) = self.alt_name {
-            string.push_str(&format!(";alt-name:{}", alt));
+            string.push_str(&format!(";alt-name:{alt}"));
         }
         string.push_str(&format!(
             ";bitsize:32;offset:{};encoding:uint;format:hex;set:{};dwarf:{}",
@@ -21,7 +21,7 @@ impl RegisterInfo {
             self.dwarf
         ));
         if let Some(generic) = self.generic {
-            string.push_str(&format!(";generic:{}", generic));
+            string.push_str(&format!(";generic:{generic}"));
         }
         string
     }

src/graphics.rs

@@ -10,7 +10,7 @@ use std::{
 use anyhow::{Result, bail};
 use itertools::Itertools as _;
 use wgpu::{
-    Device, Extent3d, ImageCopyTexture, ImageDataLayout, Origin3d, Queue, Texture,
+    Device, Extent3d, Origin3d, Queue, TexelCopyBufferLayout, TexelCopyTextureInfo, Texture,
     TextureDescriptor, TextureFormat, TextureUsages, TextureView, TextureViewDescriptor,
 };
 
@@ -21,7 +21,7 @@ pub struct TextureSink {
 }
 
 impl TextureSink {
-    pub fn new(device: &Device, queue: Arc<Queue>) -> (Self, TextureView) {
+    pub fn new(device: &Device, queue: Queue) -> (Self, TextureView) {
         let texture = Self::create_texture(device);
         let view = texture.create_view(&TextureViewDescriptor::default());
         let buffers = Arc::new(BufferPool::new());
@@ -72,7 +72,7 @@ impl TextureSink {
     }
 
     fn write_texture(queue: &Queue, texture: &Texture, bytes: &[u8]) {
-        let texture = ImageCopyTexture {
+        let texture = TexelCopyTextureInfo {
             texture,
             mip_level: 0,
             origin: Origin3d::ZERO,
@@ -83,7 +83,7 @@ impl TextureSink {
             height: 224,
             depth_or_array_layers: 1,
         };
-        let data_layout = ImageDataLayout {
+        let data_layout = TexelCopyBufferLayout {
             offset: 0,
             bytes_per_row: Some(384 * 2),
             rows_per_image: Some(224),

src/images.rs

@@ -193,8 +193,8 @@ struct ImageState {
 impl ImageState {
     fn new(size: [usize; 2]) -> Self {
         let buffers = [
-            Arc::new(ColorImage::new(size, Color32::BLACK)),
+            Arc::new(ColorImage::filled(size, Color32::BLACK)),
-            Arc::new(ColorImage::new(size, Color32::BLACK)),
+            Arc::new(ColorImage::filled(size, Color32::BLACK)),
         ];
         let sink = buffers[0].clone();
         Self {

src/input.rs

@@ -227,7 +227,7 @@ impl Mappings for InputMapping {
         for (keyboard_key, keys) in &self.keys {
             let name = match keyboard_key {
                 PhysicalKey::Code(code) => format!("{code:?}"),
-                k => format!("{:?}", k),
+                k => format!("{k:?}"),
             };
             for key in keys.iter() {
                 results.entry(key).or_default().push(name.clone());
@@ -471,11 +471,12 @@ pub enum Command {
     FastForward(u32),
     Reset,
     PauseResume,
+    Screenshot,
     // if you update this, update Command::all and add a default
 }
 
 impl Command {
-    pub fn all() -> [Self; 6] {
+    pub fn all() -> [Self; 7] {
         [
             Self::OpenRom,
             Self::Quit,
@@ -483,6 +484,7 @@ impl Command {
             Self::Reset,
             Self::FrameAdvance,
             Self::FastForward(0),
+            Self::Screenshot,
         ]
     }
 
@@ -494,6 +496,7 @@ impl Command {
             Self::Reset => "Reset",
             Self::FrameAdvance => "Frame Advance",
             Self::FastForward(_) => "Fast Forward",
+            Self::Screenshot => "Screenshot",
         }
     }
 }
@@ -539,6 +542,10 @@ impl Default for Shortcuts {
             Command::FastForward(0),
             KeyboardShortcut::new(Modifiers::NONE, Key::Space),
         );
+        shortcuts.set(
+            Command::Screenshot,
+            KeyboardShortcut::new(Modifiers::NONE, Key::F12),
+        );
         shortcuts
     }
 }

src/main.rs

@@ -22,6 +22,7 @@ mod images;
 mod input;
 mod memory;
 mod persistence;
+mod profiler;
 mod window;
 
 #[derive(Parser)]
@@ -31,6 +32,9 @@ struct Args {
     /// Start a GDB/LLDB debug server on this port.
     #[arg(short, long)]
     debug_port: Option<u16>,
+    /// Enable profiling a game
+    #[arg(short, long)]
+    profile: bool,
 }
 
 fn init_logger() {
@@ -44,9 +48,9 @@ fn set_panic_handler() {
     std::panic::set_hook(Box::new(|info| {
         let mut message = String::new();
         if let Some(msg) = info.payload().downcast_ref::<&str>() {
-            message += &format!("{}\n", msg);
+            message += &format!("{msg}\n");
         } else if let Some(msg) = info.payload().downcast_ref::<String>() {
-            message += &format!("{}\n", msg);
+            message += &format!("{msg}\n");
         }
         if let Some(location) = info.location() {
             message += &format!(
@@ -56,9 +60,9 @@ fn set_panic_handler() {
             );
         }
         let backtrace = std::backtrace::Backtrace::force_capture();
-        message += &format!("stack trace:\n{:#}\n", backtrace);
+        message += &format!("stack trace:\n{backtrace:#}\n");
 
-        eprint!("{}", message);
+        eprint!("{message}");
 
         let Some(project_dirs) = directories::ProjectDirs::from("com", "virtual-boy", "Lemur")
         else {
@@ -72,7 +76,7 @@ fn set_panic_handler() {
             .duration_since(SystemTime::UNIX_EPOCH)
             .unwrap()
             .as_millis();
-        let logfile_name = format!("crash-{}.txt", timestamp);
+        let logfile_name = format!("crash-{timestamp}.txt");
         let _ = std::fs::write(data_dir.join(logfile_name), message);
     }));
 }
@@ -106,6 +110,9 @@ fn main() -> Result<()> {
         }
         builder = builder.start_paused(true);
     }
+    if args.profile {
+        builder = builder.start_paused(true)
+    }
 
     ThreadBuilder::default()
         .name("Emulator".to_owned())
@@ -124,6 +131,11 @@ fn main() -> Result<()> {
     let event_loop = EventLoop::with_user_event().build().unwrap();
     event_loop.set_control_flow(ControlFlow::Poll);
     let proxy = event_loop.create_proxy();
-    event_loop.run_app(&mut Application::new(client, proxy, args.debug_port))?;
+    event_loop.run_app(&mut Application::new(
+        client,
+        proxy,
+        args.debug_port,
+        args.profile,
+    ))?;
     Ok(())
 }

src/memory.rs

@@ -169,7 +169,7 @@ impl MemoryRef<'_> {
         T::from_bytes(&self.inner[from..to])
     }
 
-    pub fn range<T: MemoryValue>(&self, start: usize, count: usize) -> MemoryIter<T> {
+    pub fn range<T: MemoryValue>(&self, start: usize, count: usize) -> MemoryIter<'_, T> {
         let from = start * size_of::<T>();
         let to = from + (count * size_of::<T>());
         MemoryIter::new(&self.inner[from..to])

src/profiler.rs

@@ -0,0 +1,264 @@
+use std::{
+    sync::{Arc, Mutex},
+    thread,
+};
+
+use anyhow::Result;
+use tokio::{select, sync::mpsc};
+
+use crate::emulator::{
+    EmulatorClient, EmulatorCommand, GameInfo, InlineStack, ProfileEvent, SimEvent, SimId,
+};
+use recording::Recording;
+use state::ProgramState;
+
+mod recording;
+mod state;
+
+pub struct Profiler {
+    sim_id: SimId,
+    client: EmulatorClient,
+    status: Arc<Mutex<ProfilerStatus>>,
+    action: Option<mpsc::UnboundedSender<RecordingAction>>,
+    killer: Option<oneshot::Sender<()>>,
+}
+
+impl Profiler {
+    pub fn new(sim_id: SimId, client: EmulatorClient) -> Self {
+        Self {
+            sim_id,
+            client,
+            status: Arc::new(Mutex::new(ProfilerStatus::Disabled)),
+            action: None,
+            killer: None,
+        }
+    }
+
+    pub fn status(&self) -> ProfilerStatus {
+        self.status.lock().unwrap().clone()
+    }
+
+    pub fn enable(&mut self) {
+        let sim_id = self.sim_id;
+        let client = self.client.clone();
+        let status = self.status.clone();
+        let (action_tx, action_rx) = mpsc::unbounded_channel();
+        self.action = Some(action_tx);
+        let (killer_tx, killer_rx) = oneshot::channel();
+        self.killer = Some(killer_tx);
+        thread::spawn(move || {
+            tokio::runtime::Builder::new_current_thread()
+                .enable_all()
+                .build()
+                .unwrap()
+                .block_on(async move {
+                    select! {
+                        _ = run_profile(sim_id, client, status.clone(), action_rx) => {}
+                        _ = killer_rx => {
+                            *status.lock().unwrap() = ProfilerStatus::Disabled;
+                        }
+                    }
+                })
+        });
+    }
+
+    pub fn disable(&mut self) {
+        if let Some(killer) = self.killer.take() {
+            let _ = killer.send(());
+        }
+    }
+
+    pub fn start_recording(&mut self) {
+        if let Some(action) = &self.action {
+            let _ = action.send(RecordingAction::Start);
+        }
+    }
+
+    pub fn finish_recording(&mut self) -> oneshot::Receiver<Vec<u8>> {
+        let (tx, rx) = oneshot::channel();
+        if let Some(action) = &self.action {
+            let _ = action.send(RecordingAction::Finish(tx));
+        }
+        rx
+    }
+
+    pub fn cancel_recording(&mut self) {
+        if let Some(action) = &self.action {
+            let _ = action.send(RecordingAction::Cancel);
+        }
+    }
+}
+
+impl Drop for Profiler {
+    fn drop(&mut self) {
+        self.disable();
+    }
+}
+
+async fn run_profile(
+    sim_id: SimId,
+    client: EmulatorClient,
+    status: Arc<Mutex<ProfilerStatus>>,
+    mut action_source: mpsc::UnboundedReceiver<RecordingAction>,
+) {
+    let (profile_sync, mut profile_source) = mpsc::unbounded_channel();
+    client.send_command(EmulatorCommand::StartProfiling(sim_id, profile_sync));
+
+    *status.lock().unwrap() = ProfilerStatus::Enabled;
+
+    let mut session = ProfilerSession::new();
+    loop {
+        select! {
+            maybe_event = profile_source.recv() => {
+                let Some(event) = maybe_event else {
+                    break; // emulator thread disconnected
+                };
+                if let Err(error) = handle_event(event, &mut session).await {
+                    *status.lock().unwrap() = ProfilerStatus::Error(error.to_string());
+                    return;
+                }
+            }
+            maybe_action = action_source.recv() => {
+                let Some(action) = maybe_action else {
+                    break; // ui thread disconnected
+                };
+                handle_action(action, &mut session, &status);
+            }
+        }
+    }
+
+    *status.lock().unwrap() = ProfilerStatus::Disabled;
+}
+
+async fn handle_event(event: ProfileEvent, session: &mut ProfilerSession) -> Result<()> {
+    match event {
+        ProfileEvent::Start { info } => session.start_profiling(info).await,
+        ProfileEvent::Update {
+            cycles,
+            event,
+            inline_stack,
+        } => {
+            session.track_elapsed_cycles(cycles);
+            if let Some(event) = event {
+                session.track_event(event)?;
+            }
+            if let Some(stack) = inline_stack {
+                session.track_inline_stack(stack);
+            }
+        }
+    }
+    Ok(())
+}
+
+fn handle_action(
+    action: RecordingAction,
+    session: &mut ProfilerSession,
+    status: &Mutex<ProfilerStatus>,
+) {
+    match action {
+        RecordingAction::Start => {
+            session.start_recording();
+            *status.lock().unwrap() = ProfilerStatus::Recording;
+        }
+        RecordingAction::Finish(rx) => {
+            if let Some(bytes) = session.finish_recording() {
+                let _ = rx.send(bytes);
+            }
+            *status.lock().unwrap() = ProfilerStatus::Enabled;
+        }
+        RecordingAction::Cancel => {
+            session.cancel_recording();
+            *status.lock().unwrap() = ProfilerStatus::Enabled;
+        }
+    }
+}
+
+#[derive(Clone)]
+pub enum ProfilerStatus {
+    Disabled,
+    Enabled,
+    Recording,
+    Error(String),
+}
+
+impl ProfilerStatus {
+    pub fn enabled(&self) -> bool {
+        matches!(self, Self::Enabled | Self::Recording)
+    }
+}
+
+enum RecordingAction {
+    Start,
+    Finish(oneshot::Sender<Vec<u8>>),
+    Cancel,
+}
+
+struct ProfilerSession {
+    program: Option<ProgramState>,
+    recording: Option<Recording>,
+}
+
+impl ProfilerSession {
+    fn new() -> Self {
+        Self {
+            program: None,
+            recording: None,
+        }
+    }
+
+    async fn start_profiling(&mut self, info: Arc<GameInfo>) {
+        let program = ProgramState::new(info).await;
+        let recording = if self.recording.is_some() {
+            Some(Recording::new(&program))
+        } else {
+            None
+        };
+        self.program = Some(program);
+        self.recording = recording;
+    }
+
+    fn track_elapsed_cycles(&mut self, cycles: u32) {
+        if let (Some(state), Some(recording)) = (&self.program, &mut self.recording) {
+            recording.track_elapsed_cycles(state, cycles);
+        }
+    }
+
+    fn track_event(&mut self, event: SimEvent) -> Result<()> {
+        let Some(program) = &mut self.program else {
+            return Ok(());
+        };
+        match event {
+            SimEvent::Call(address) => program.track_call(address),
+            SimEvent::Return => program.track_return(),
+            SimEvent::Halt => program.track_halt(),
+            SimEvent::Interrupt(code, address) => program.track_interrupt(code, address),
+            SimEvent::Reti => program.track_reti(),
+            SimEvent::Marker(name) => {
+                if let Some(recording) = &mut self.recording {
+                    recording.track_marker(name);
+                };
+                Ok(())
+            }
+        }
+    }
+
+    fn track_inline_stack(&mut self, inline_stack: InlineStack) {
+        if let Some(program) = &mut self.program {
+            program.track_inline_stack(inline_stack);
+        }
+    }
+
+    fn start_recording(&mut self) {
+        if let Some(program) = &self.program {
+            self.recording = Some(Recording::new(program));
+        }
+    }
+
+    fn finish_recording(&mut self) -> Option<Vec<u8>> {
+        self.recording.take().map(|r| r.finish())
+    }
+
+    fn cancel_recording(&mut self) {
+        self.recording.take();
+    }
+}

src/profiler/recording.rs

@@ -0,0 +1,152 @@
+use std::{borrow::Cow, collections::HashMap};
+
+use fxprof_processed_profile::{
+    CategoryHandle, CpuDelta, Frame, FrameFlags, FrameInfo, MarkerTiming, ProcessHandle, Profile,
+    ReferenceTimestamp, SamplingInterval, StackHandle, StaticSchemaMarker, StringHandle,
+    ThreadHandle, Timestamp,
+};
+
+use crate::profiler::state::{ProgramState, RESET_CODE, StackFrame};
+
+pub struct Recording {
+    profile: Profile,
+    process: ProcessHandle,
+    threads: HashMap<u16, ThreadHandle>,
+    now: u64,
+}
+
+impl Recording {
+    pub fn new(state: &ProgramState) -> Self {
+        let reference_timestamp = ReferenceTimestamp::from_millis_since_unix_epoch(0.0);
+        let interval = SamplingInterval::from_hz(20_000_000.0);
+        let mut profile = Profile::new(state.name(), reference_timestamp, interval);
+
+        let process =
+            profile.add_process(state.name(), 1, Timestamp::from_nanos_since_reference(0));
+
+        let lib = profile.add_lib(state.library_info().clone());
+        profile.add_lib_mapping(process, lib, 0x00000000, 0xffffffff, 0);
+
+        let mut me = Self {
+            profile,
+            process,
+            threads: HashMap::new(),
+            now: 0,
+        };
+        me.track_elapsed_cycles(state, 0);
+        me
+    }
+
+    pub fn track_elapsed_cycles(&mut self, state: &ProgramState, cycles: u32) {
+        self.now += cycles as u64;
+        let timestamp = Timestamp::from_nanos_since_reference(self.now * 50);
+        let weight = 1;
+
+        let active_code = if let Some((code, frames)) = state.current_stack() {
+            let thread = *self.threads.entry(code).or_insert_with(|| {
+                let process = self.process;
+                let tid = code as u32;
+                let start_time = Timestamp::from_nanos_since_reference(self.now * 50);
+                let is_main = code == RESET_CODE;
+                let thread = self.profile.add_thread(process, tid, start_time, is_main);
+                self.profile
+                    .set_thread_name(thread, &thread_name_for_code(code));
+                thread
+            });
+
+            let stack = self.handle_for_stack(thread, frames);
+            let cpu_delta = CpuDelta::from_nanos((self.now - cycles as u64) * 50);
+            self.profile
+                .add_sample(thread, timestamp, stack, cpu_delta, weight);
+            Some(code)
+        } else {
+            None
+        };
+        for (code, thread) in &self.threads {
+            if active_code == Some(*code) {
+                continue;
+            }
+            self.profile
+                .add_sample_same_stack_zero_cpu(*thread, timestamp, weight);
+        }
+    }
+
+    pub fn track_marker(&mut self, name: Cow<'static, str>) {
+        let Some(thread) = self.threads.get(&RESET_CODE) else {
+            return;
+        };
+        let timing = MarkerTiming::Instant(Timestamp::from_nanos_since_reference(self.now * 50));
+        let marker = SimpleMarker(name);
+        self.profile.add_marker(*thread, timing, marker);
+    }
+
+    pub fn finish(self) -> Vec<u8> {
+        serde_json::to_vec(&self.profile).expect("could not serialize profile")
+    }
+
+    fn handle_for_stack(
+        &mut self,
+        thread: ThreadHandle,
+        frames: &[StackFrame],
+    ) -> Option<StackHandle> {
+        let frames = frames
+            .iter()
+            .map(|f| {
+                let frame = match f {
+                    StackFrame::Address(address) => Frame::InstructionPointer(*address as u64),
+                    StackFrame::Label(label) => Frame::Label(self.profile.intern_string(label)),
+                };
+                FrameInfo {
+                    frame,
+                    category_pair: CategoryHandle::OTHER.into(),
+                    flags: FrameFlags::empty(),
+                }
+            })
+            .collect::<Vec<_>>();
+        self.profile.intern_stack_frames(thread, frames.into_iter())
+    }
+}
+
+struct SimpleMarker(Cow<'static, str>);
+
+impl StaticSchemaMarker for SimpleMarker {
+    const UNIQUE_MARKER_TYPE_NAME: &'static str = "Simple";
+    const FIELDS: &'static [fxprof_processed_profile::StaticSchemaMarkerField] = &[];
+
+    fn name(&self, profile: &mut Profile) -> StringHandle {
+        profile.intern_string(&self.0)
+    }
+
+    fn category(&self, _profile: &mut Profile) -> CategoryHandle {
+        CategoryHandle::OTHER
+    }
+
+    fn string_field_value(&self, _field_index: u32) -> StringHandle {
+        unreachable!()
+    }
+
+    fn number_field_value(&self, _field_index: u32) -> f64 {
+        unreachable!()
+    }
+}
+
+fn thread_name_for_code(code: u16) -> std::borrow::Cow<'static, str> {
+    match code {
+        RESET_CODE => "Main".into(),
+        0xffd0 => "Duplexed exception".into(),
+        0xfe40 => "VIP interrupt".into(),
+        0xfe30 => "Communication interrupt".into(),
+        0xfe20 => "Game pak interrupt".into(),
+        0xfe10 => "Timer interrupt".into(),
+        0xfe00 => "Game pad interrupt".into(),
+        0xffc0 => "Address trap".into(),
+        0xffa0..0xffc0 => format!("Trap (vector {})", code - 0xffa0).into(),
+        0xff90 => "Illegal opcode exception".into(),
+        0xff80 => "Zero division exception".into(),
+        0xff60 => "Floating-point reserved operand exception".into(),
+        0xff70 => "Floating-point invalid operation exception".into(),
+        0xff68 => "Floating-point zero division exception".into(),
+        0xff64 => "Floating-point overflow exception".into(),
+        other => format!("Unrecognized handler (0x{other:04x})").into(),
+    }
+}

src/profiler/state.rs

@@ -0,0 +1,124 @@
+use std::{collections::HashMap, sync::Arc};
+
+use anyhow::{Result, bail};
+use fxprof_processed_profile::LibraryInfo;
+
+use crate::emulator::{GameInfo, InlineStack};
+
+pub struct ProgramState {
+    info: Arc<GameInfo>,
+    call_stacks: HashMap<u16, Vec<StackFrame>>,
+    context_stack: Vec<u16>,
+}
+
+pub enum StackFrame {
+    Address(u32),
+    Label(Arc<String>),
+}
+
+pub const RESET_CODE: u16 = 0xfff0;
+impl ProgramState {
+    pub async fn new(info: Arc<GameInfo>) -> Self {
+        let mut call_stacks = HashMap::new();
+        call_stacks.insert(RESET_CODE, vec![StackFrame::Address(0xfffffff0)]);
+        Self {
+            info,
+            call_stacks,
+            context_stack: vec![RESET_CODE],
+        }
+    }
+
+    pub fn name(&self) -> &str {
+        self.info.name()
+    }
+
+    pub fn library_info(&self) -> &LibraryInfo {
+        self.info.library_info()
+    }
+
+    pub fn current_stack(&self) -> Option<(u16, &[StackFrame])> {
+        let code = self.context_stack.last()?;
+        let call_stack = self.call_stacks.get(code)?;
+        Some((*code, call_stack))
+    }
+
+    pub fn track_call(&mut self, address: u32) -> Result<()> {
+        let Some(code) = self.context_stack.last() else {
+            bail!("How did we call anything when we're halted?");
+        };
+        let Some(stack) = self.call_stacks.get_mut(code) else {
+            bail!("missing stack {code:04x}");
+        };
+        stack.push(StackFrame::Address(address));
+        Ok(())
+    }
+
+    pub fn track_return(&mut self) -> Result<()> {
+        let Some(code) = self.context_stack.last() else {
+            bail!("how did we return when we're halted?");
+        };
+        let Some(stack) = self.call_stacks.get_mut(code) else {
+            bail!("missing stack {code:04x}");
+        };
+        if stack.pop().is_none() {
+            bail!("returned from {code:04x} but stack was empty");
+        }
+        if stack.is_empty() {
+            bail!("returned to oblivion");
+        }
+        Ok(())
+    }
+
+    pub fn track_halt(&mut self) -> Result<()> {
+        let Some(RESET_CODE) = self.context_stack.pop() else {
+            bail!("halted when not in an interrupt");
+        };
+        Ok(())
+    }
+
+    pub fn track_interrupt(&mut self, code: u16, address: u32) -> Result<()> {
+        // if the CPU was halted before, wake it up now
+        if self.context_stack.is_empty() {
+            self.context_stack.push(RESET_CODE);
+        }
+
+        self.context_stack.push(code);
+        if self
+            .call_stacks
+            .insert(code, vec![StackFrame::Address(address)])
+            .is_some()
+        {
+            bail!("{code:04x} fired twice");
+        }
+        Ok(())
+    }
+
+    pub fn track_reti(&mut self) -> Result<()> {
+        let Some(code) = self.context_stack.pop() else {
+            bail!("RETI when halted");
+        };
+        if code == RESET_CODE {
+            bail!("RETI when not in interrupt");
+        }
+        if self.call_stacks.remove(&code).is_none() {
+            bail!("{code:04x} popped but never called");
+        }
+        Ok(())
+    }
+
+    pub fn track_inline_stack(&mut self, inline_stack: InlineStack) {
+        let Some(code) = self.context_stack.last() else {
+            return;
+        };
+        let Some(call_stack) = self.call_stacks.get_mut(code) else {
+            return;
+        };
+        while call_stack
+            .pop_if(|f| matches!(f, StackFrame::Label(_)))
+            .is_some()
+        {}
+        for label in inline_stack.iter() {
+            call_stack.push(StackFrame::Label(label.clone()));
+        }
+    }
+}

src/window.rs

@@ -4,6 +4,8 @@ pub use game::GameWindow;
 pub use gdb::GdbServerWindow;
 pub use hotkeys::HotkeysWindow;
 pub use input::InputWindow;
+pub use profile::ProfileWindow;
+pub use terminal::TerminalWindow;
 pub use vip::{
     BgMapWindow, CharacterDataWindow, FrameBufferWindow, ObjectWindow, RegisterWindow, WorldWindow,
 };
@@ -17,6 +19,8 @@ mod game_screen;
 mod gdb;
 mod hotkeys;
 mod input;
+mod profile;
+mod terminal;
 mod utils;
 mod vip;
 

src/window/game.rs

@@ -1,4 +1,4 @@
-use std::sync::mpsc;
+use std::{sync::mpsc, time::Duration};
 
 use crate::{
     app::UserEvent,
@@ -6,11 +6,12 @@ use crate::{
     input::{Command, ShortcutProvider},
     persistence::Persistence,
 };
+use anyhow::Context as _;
 use egui::{
-    Align2, Button, CentralPanel, Color32, Context, Direction, Frame, TopBottomPanel, Ui, Vec2,
+    Align2, Button, CentralPanel, Color32, Context, Frame, MenuBar, TopBottomPanel, Ui, Vec2,
-    ViewportBuilder, ViewportCommand, ViewportId, Window, menu,
+    ViewportBuilder, ViewportCommand, ViewportId, Window,
 };
-use egui_toast::{Toast, Toasts};
+use egui_notify::{Anchor, Toast, Toasts};
 use serde::{Deserialize, Serialize};
 use winit::event_loop::EventLoopProxy;
 
@@ -42,6 +43,7 @@ pub struct GameWindow {
     shortcuts: ShortcutProvider,
     sim_id: SimId,
     config: GameConfig,
+    toasts: Toasts,
     screen: Option<GameScreen>,
     messages: Option<mpsc::Receiver<Toast>>,
     color_picker: Option<ColorPickerState>,
@@ -56,6 +58,10 @@ impl GameWindow {
         sim_id: SimId,
     ) -> Self {
         let config = load_config(&persistence, sim_id);
+        let toasts = Toasts::new()
+            .with_anchor(Anchor::BottomLeft)
+            .with_margin((10.0, 10.0).into())
+            .reverse(true);
         Self {
             client,
             proxy,
@@ -63,6 +69,7 @@ impl GameWindow {
             shortcuts,
             sim_id,
             config,
+            toasts,
             screen: None,
             messages: None,
             color_picker: None,
@@ -113,6 +120,16 @@ impl GameWindow {
                     self.client
                         .send_command(EmulatorCommand::SetSpeed(speed as f64));
                 }
+                Command::Screenshot => {
+                    let autopause = state == EmulatorState::Running && can_pause;
+                    if autopause {
+                        self.client.send_command(EmulatorCommand::Pause);
+                    }
+                    pollster::block_on(self.take_screenshot());
+                    if autopause {
+                        self.client.send_command(EmulatorCommand::Resume);
+                    }
+                }
             }
         }
 
@@ -128,7 +145,6 @@ impl GameWindow {
                     self.client
                         .send_command(EmulatorCommand::LoadGame(self.sim_id, path));
                 }
-                ui.close_menu();
             }
             if ui
                 .add(self.button_for(ui.ctx(), "Quit", Command::Quit))
@@ -147,7 +163,6 @@ impl GameWindow {
                     .clicked()
                 {
                     self.client.send_command(EmulatorCommand::Pause);
-                    ui.close_menu();
                 }
             } else if ui
                 .add_enabled(
@@ -157,7 +172,6 @@ impl GameWindow {
                 .clicked()
             {
                 self.client.send_command(EmulatorCommand::Resume);
-                ui.close_menu();
             }
             if ui
                 .add_enabled(is_ready, self.button_for(ui.ctx(), "Reset", Command::Reset))
@@ -165,7 +179,6 @@ impl GameWindow {
             {
                 self.client
                     .send_command(EmulatorCommand::Reset(self.sim_id));
-                ui.close_menu();
             }
             ui.separator();
             if ui
@@ -176,7 +189,16 @@ impl GameWindow {
                 .clicked()
             {
                 self.client.send_command(EmulatorCommand::FrameAdvance);
-                ui.close_menu();
+            }
+            ui.separator();
+            if ui
+                .add_enabled(
+                    is_ready,
+                    self.button_for(ui.ctx(), "Screenshot", Command::Screenshot),
+                )
+                .clicked()
+            {
+                pollster::block_on(self.take_screenshot());
             }
         });
         ui.menu_button("Options", |ui| self.show_options_menu(ctx, ui));
@@ -189,73 +211,113 @@ impl GameWindow {
                 self.client
                     .send_command(EmulatorCommand::StartSecondSim(None));
                 self.proxy.send_event(UserEvent::OpenPlayer2).unwrap();
-                ui.close_menu();
             }
             if has_player_2 {
                 let linked = self.client.are_sims_linked();
                 if linked && ui.button("Unlink").clicked() {
                     self.client.send_command(EmulatorCommand::Unlink);
-                    ui.close_menu();
                 }
                 if !linked && ui.button("Link").clicked() {
                     self.client.send_command(EmulatorCommand::Link);
-                    ui.close_menu();
                 }
             }
         });
         ui.menu_button("Tools", |ui| {
+            if ui.button("Terminal").clicked() {
+                self.proxy
+                    .send_event(UserEvent::OpenTerminal(self.sim_id))
+                    .unwrap();
+            }
+            if ui.button("Profiler").clicked() {
+                self.proxy
+                    .send_event(UserEvent::OpenProfiler(self.sim_id))
+                    .unwrap();
+            }
             if ui.button("GDB Server").clicked() {
                 self.proxy
                     .send_event(UserEvent::OpenDebugger(self.sim_id))
                     .unwrap();
-                ui.close_menu();
             }
             ui.separator();
             if ui.button("Character Data").clicked() {
                 self.proxy
                     .send_event(UserEvent::OpenCharacterData(self.sim_id))
                     .unwrap();
-                ui.close_menu();
             }
             if ui.button("Background Maps").clicked() {
                 self.proxy
                     .send_event(UserEvent::OpenBgMap(self.sim_id))
                     .unwrap();
-                ui.close_menu();
             }
             if ui.button("Objects").clicked() {
                 self.proxy
                     .send_event(UserEvent::OpenObjects(self.sim_id))
                     .unwrap();
-                ui.close_menu();
             }
             if ui.button("Worlds").clicked() {
                 self.proxy
                     .send_event(UserEvent::OpenWorlds(self.sim_id))
                     .unwrap();
-                ui.close_menu();
             }
             if ui.button("Frame Buffers").clicked() {
                 self.proxy
                     .send_event(UserEvent::OpenFrameBuffers(self.sim_id))
                     .unwrap();
-                ui.close_menu();
             }
             if ui.button("Registers").clicked() {
                 self.proxy
                     .send_event(UserEvent::OpenRegisters(self.sim_id))
                     .unwrap();
-                ui.close_menu();
             }
         });
         ui.menu_button("Help", |ui| {
             if ui.button("About").clicked() {
                 self.proxy.send_event(UserEvent::OpenAbout).unwrap();
-                ui.close_menu();
             }
         });
     }
 
+    async fn take_screenshot(&mut self) {
+        match self.try_take_screenshot().await {
+            Ok(Some(path)) => {
+                let mut toast = Toast::info(format!("Saved to {path}"));
+                toast.duration(Some(Duration::from_secs(5)));
+                self.toasts.add(toast);
+            }
+            Ok(None) => {}
+            Err(error) => {
+                let mut toast = Toast::error(format!("{error:#}"));
+                toast.duration(Some(Duration::from_secs(5)));
+                self.toasts.add(toast);
+            }
+        }
+    }
+
+    async fn try_take_screenshot(&self) -> anyhow::Result<Option<String>> {
+        let (tx, rx) = oneshot::channel();
+        self.client
+            .send_command(EmulatorCommand::Screenshot(self.sim_id, tx));
+        let bytes = rx.await.context("Could not take screenshot")?;
+        let file = rfd::FileDialog::new()
+            .add_filter("PNG images", &["png"])
+            .set_file_name("screenshot.png")
+            .save_file();
+        let Some(path) = file else {
+            return Ok(None);
+        };
+        if bytes.len() != 384 * 224 * 2 {
+            anyhow::bail!("Unexpected screenshot size");
+        }
+        let mut screencap = image::GrayImage::new(384 * 2, 224);
+        for (index, pixel) in bytes.into_iter().enumerate() {
+            let x = (index / 2) % 384 + ((index % 2) * 384);
+            let y = (index / 2) / 384;
+            screencap.put_pixel(x as u32, y as u32, image::Luma([pixel]));
+        }
+        screencap.save(&path).context("Could not save screenshot")?;
+        Ok(Some(path.display().to_string()))
+    }
+
     fn show_options_menu(&mut self, ctx: &Context, ui: &mut Ui) {
         ui.menu_button("Video", |ui| {
             ui.menu_button("Screen Size", |ui| {
@@ -273,7 +335,6 @@ impl GameWindow {
                         .clicked()
                     {
                         ctx.send_viewport_cmd(ViewportCommand::InnerSize(dims));
-                        ui.close_menu();
                     }
                 }
             });
@@ -310,13 +371,11 @@ impl GameWindow {
                     c.display_mode = display_mode;
                     c.dimensions = current_dims * scale;
                 });
-                ui.close_menu();
             });
             ui.menu_button("Colors", |ui| {
                 for preset in COLOR_PRESETS {
                     if ui.color_pair_button(preset[0], preset[1]).clicked() {
                         self.update_config(|c| c.colors = preset);
-                        ui.close_menu();
                     }
                 }
                 ui.with_layout(ui.layout().with_cross_align(egui::Align::Center), |ui| {
@@ -337,7 +396,6 @@ impl GameWindow {
                             just_opened: true,
                             unpause_on_close: is_running,
                         });
-                        ui.close_menu();
                     }
                 });
             });
@@ -348,23 +406,19 @@ impl GameWindow {
             if ui.selectable_button(p1_enabled, "Player 1").clicked() {
                 self.client
                     .send_command(EmulatorCommand::SetAudioEnabled(!p1_enabled, p2_enabled));
-                ui.close_menu();
             }
             if ui.selectable_button(p2_enabled, "Player 2").clicked() {
                 self.client
                     .send_command(EmulatorCommand::SetAudioEnabled(p1_enabled, !p2_enabled));
-                ui.close_menu();
             }
         });
         ui.menu_button("Input", |ui| {
             if ui.button("Bind Inputs").clicked() {
                 self.proxy.send_event(UserEvent::OpenInput).unwrap();
-                ui.close_menu();
             }
         });
         if ui.button("Hotkeys").clicked() {
             self.proxy.send_event(UserEvent::OpenHotkeys).unwrap();
-            ui.close_menu();
         }
     }
 
@@ -408,7 +462,7 @@ impl GameWindow {
         self.config = new_config;
     }
 
-    fn button_for(&self, ctx: &Context, text: &str, command: Command) -> Button {
+    fn button_for(&self, ctx: &Context, text: &str, command: Command) -> Button<'_> {
         let button = Button::new(text);
         match self.shortcuts.shortcut_for(command) {
             Some(shortcut) => button.shortcut_text(ctx.format_shortcut(&shortcut)),
@@ -460,18 +514,15 @@ impl AppWindow for GameWindow {
         };
         self.update_config(|c| c.dimensions = dimensions);
 
-        let mut toasts = Toasts::new()
-            .anchor(Align2::LEFT_BOTTOM, (10.0, 10.0))
-            .direction(Direction::BottomUp);
         if let Some(messages) = self.messages.as_mut() {
             while let Ok(toast) = messages.try_recv() {
-                toasts.add(toast);
+                self.toasts.add(toast);
             }
         }
         TopBottomPanel::top("menubar")
             .exact_height(22.0)
             .show(ctx, |ui| {
-                menu::bar(ui, |ui| {
+                MenuBar::new().ui(ui, |ui| {
                     self.show_menu(ctx, ui);
                 });
             });
@@ -491,7 +542,7 @@ impl AppWindow for GameWindow {
                 ui.add(screen);
             }
         });
-        toasts.show(ctx);
+        self.toasts.show(ctx);
     }
 
     fn on_init(&mut self, _ctx: &Context, render_state: &egui_wgpu::RenderState) {

src/window/game_screen.rs

@@ -71,7 +71,7 @@ impl GameScreen {
                     module: &shader,
                     entry_point: Some(entry_point),
                     targets: &[Some(wgpu::ColorTargetState {
-                        format: wgpu::TextureFormat::Bgra8Unorm,
+                        format: render_state.target_format,
                         blend: Some(wgpu::BlendState::REPLACE),
                         write_mask: wgpu::ColorWrites::ALL,
                     })],

src/window/hotkeys.rs

@@ -62,8 +62,8 @@ impl HotkeysWindow {
                     }
                 });
         });
-        if let Some(command) = self.now_binding {
+        if let Some(command) = self.now_binding
-            if let Some(shortcut) = ui.input_mut(|i| {
+            && let Some(shortcut) = ui.input_mut(|i| {
                 i.events.iter().find_map(|event| match event {
                     Event::Key {
                         key,
@@ -73,12 +73,12 @@ impl HotkeysWindow {
                     } => Some(KeyboardShortcut::new(*modifiers, *key)),
                     _ => None,
                 })
-            }) {
+            })
+        {
             self.shortcuts.set(command, shortcut);
             self.now_binding = None;
         }
     }
-    }
 
     fn show_ff_settings(&mut self, ui: &mut Ui) {
         let row_height = ui.spacing().interact_size.y;

src/window/profile.rs

@@ -0,0 +1,162 @@
+use std::{fs, time::Duration};
+
+use anyhow::Result;
+use egui::{Button, CentralPanel, Checkbox, Label, ViewportBuilder, ViewportId};
+use egui_notify::{Anchor, Toast, Toasts};
+
+use crate::{
+    emulator::{EmulatorClient, EmulatorCommand, EmulatorState, SimId},
+    profiler::{Profiler, ProfilerStatus},
+    window::AppWindow,
+};
+
+pub struct ProfileWindow {
+    sim_id: SimId,
+    client: EmulatorClient,
+    profiler: Profiler,
+    toasts: Toasts,
+}
+
+impl ProfileWindow {
+    pub fn new(sim_id: SimId, client: EmulatorClient) -> Self {
+        Self {
+            sim_id,
+            client: client.clone(),
+            profiler: Profiler::new(sim_id, client),
+            toasts: Toasts::new()
+                .with_anchor(Anchor::BottomLeft)
+                .with_margin((10.0, 10.0).into())
+                .reverse(true),
+        }
+    }
+
+    pub fn launch(&mut self) {
+        self.profiler.enable();
+    }
+
+    fn finish_recording(&mut self) {
+        let pause = matches!(self.client.emulator_state(), EmulatorState::Running);
+        if pause {
+            self.client.send_command(EmulatorCommand::Pause);
+        }
+        match self.try_finish_recording() {
+            Ok(Some(path)) => {
+                let mut toast = Toast::info(format!("Saved to {path}"));
+                toast.duration(Some(Duration::from_secs(5)));
+                self.toasts.add(toast);
+            }
+            Ok(None) => {}
+            Err(error) => {
+                let mut toast = Toast::error(format!("{error:#}"));
+                toast.duration(Some(Duration::from_secs(5)));
+                self.toasts.add(toast);
+            }
+        }
+        if pause {
+            self.client.send_command(EmulatorCommand::Resume);
+        }
+    }
+
+    fn try_finish_recording(&mut self) -> Result<Option<String>> {
+        let bytes_receiver = self.profiler.finish_recording();
+        let file = rfd::FileDialog::new()
+            .add_filter("Profiler files", &["json"])
+            .set_file_name("profile.json")
+            .save_file();
+        if let Some(path) = file {
+            let bytes = pollster::block_on(bytes_receiver)?;
+            fs::write(&path, bytes)?;
+            Ok(Some(path.display().to_string()))
+        } else {
+            self.profiler.cancel_recording();
+            Ok(None)
+        }
+    }
+}
+
+impl AppWindow for ProfileWindow {
+    fn viewport_id(&self) -> ViewportId {
+        ViewportId::from_hash_of(format!("Profile-{}", self.sim_id))
+    }
+
+    fn sim_id(&self) -> SimId {
+        self.sim_id
+    }
+
+    fn initial_viewport(&self) -> ViewportBuilder {
+        ViewportBuilder::default()
+            .with_title(format!("Profiler ({})", self.sim_id))
+            .with_inner_size((300.0, 200.0))
+    }
+
+    fn show(&mut self, ctx: &egui::Context) {
+        let status = self.profiler.status();
+        let recording = matches!(status, ProfilerStatus::Recording);
+        CentralPanel::default().show(ctx, |ui| {
+            ui.horizontal_wrapped(|ui| {
+                ui.spacing_mut().item_spacing.x = 0.0;
+                ui.add(
+                    Label::new(
+                        "Use this tool to record performance profiles of your game, for use in ",
+                    )
+                    .wrap_mode(egui::TextWrapMode::Wrap),
+                );
+                ui.hyperlink("https://profiler.firefox.com");
+                ui.label(".");
+            });
+            ui.horizontal_wrapped(|ui| {
+                ui.spacing_mut().item_spacing.x = 0.0;
+                ui.add(
+                    Label::new("For more instructions, see ").wrap_mode(egui::TextWrapMode::Wrap),
+                );
+                ui.hyperlink_to(
+                    "the Lemur wiki",
+                    "https://git.virtual-boy.com/PVB/lemur/wiki/Profiling-with-Lemur",
+                );
+                ui.label(".");
+            });
+            ui.separator();
+
+            let mut enabled = status.enabled();
+            let enabled_checkbox = Checkbox::new(&mut enabled, "Enable profiling");
+            if ui.add_enabled(!recording, enabled_checkbox).changed() {
+                if enabled {
+                    self.profiler.enable();
+                } else {
+                    self.profiler.disable();
+                }
+            }
+            if !enabled {
+                ui.label("Enabling profiling will restart your current game.");
+            } else {
+                ui.horizontal(|ui| {
+                    if !recording {
+                        let record_button = Button::new("Record");
+                        let can_record = matches!(status, ProfilerStatus::Enabled);
+                        if ui.add_enabled(can_record, record_button).clicked() {
+                            self.profiler.start_recording();
+                        }
+                    } else {
+                        if ui.button("Finish recording").clicked() {
+                            self.finish_recording();
+                        }
+                        if ui.button("Cancel recording").clicked() {
+                            self.profiler.cancel_recording();
+                        }
+                    }
+                });
+            }
+
+            match &status {
+                ProfilerStatus::Recording => {
+                    ui.label("Recording...");
+                }
+                ProfilerStatus::Error(message) => {
+                    ui.label(message);
+                }
+                _ => {}
+            }
+        });
+        self.toasts.show(ctx);
+    }
+}

src/window/terminal.rs

@@ -0,0 +1,79 @@
+use std::{collections::VecDeque, sync::mpsc};
+
+use egui::{
+    Align, CentralPanel, Context, FontFamily, Label, RichText, ScrollArea, ViewportBuilder,
+    ViewportId,
+};
+
+use crate::emulator::{EmulatorClient, EmulatorCommand, SimId};
+
+use super::AppWindow;
+
+const SCROLLBACK: usize = 1000;
+
+pub struct TerminalWindow {
+    sim_id: SimId,
+    receiver: mpsc::Receiver<String>,
+    lines: VecDeque<String>,
+}
+
+impl TerminalWindow {
+    pub fn new(sim_id: SimId, client: &EmulatorClient) -> Self {
+        let (sender, receiver) = mpsc::channel();
+        client.send_command(EmulatorCommand::WatchStdout(sim_id, sender));
+        let mut lines = VecDeque::new();
+        lines.push_back(String::new());
+        Self {
+            sim_id,
+            receiver,
+            lines,
+        }
+    }
+}
+
+impl AppWindow for TerminalWindow {
+    fn viewport_id(&self) -> ViewportId {
+        ViewportId::from_hash_of(format!("terminal-{}", self.sim_id))
+    }
+
+    fn sim_id(&self) -> SimId {
+        self.sim_id
+    }
+
+    fn initial_viewport(&self) -> ViewportBuilder {
+        ViewportBuilder::default()
+            .with_title(format!("Terminal ({})", self.sim_id))
+            .with_inner_size((640.0, 480.0))
+    }
+
+    fn show(&mut self, ctx: &Context) {
+        if let Ok(text) = self.receiver.try_recv() {
+            let mut rest = text.as_str();
+            while let Some(index) = rest.find('\n') {
+                let (line, lines) = rest.split_at(index);
+                let current = self.lines.back_mut().unwrap();
+                current.push_str(line);
+                self.lines.push_back(String::new());
+                if self.lines.len() > SCROLLBACK {
+                    self.lines.pop_front();
+                }
+                rest = &lines[1..];
+            }
+            self.lines.back_mut().unwrap().push_str(rest);
+        }
+        CentralPanel::default().show(ctx, |ui| {
+            ScrollArea::vertical()
+                .stick_to_bottom(true)
+                .auto_shrink([false, false])
+                .animated(false)
+                .show(ui, |ui| {
+                    for line in &self.lines {
+                        let label = Label::new(RichText::new(line).family(FontFamily::Monospace))
+                            .halign(Align::LEFT)
+                            .wrap();
+                        ui.add(label);
+                    }
+                });
+        });
+    }
+}

src/window/utils.rs

@@ -6,8 +6,8 @@ use std::{
 
 use atoi::FromRadix16;
 use egui::{
-    Align, Color32, CursorIcon, Event, Frame, Key, Layout, Margin, Rect, Response, RichText,
+    Align, Color32, CornerRadius, CursorIcon, Event, Frame, Key, Layout, Margin, Rect, Response,
-    Rounding, Sense, Shape, Stroke, TextEdit, Ui, UiBuilder, Vec2, Widget, WidgetText,
+    RichText, Sense, Shape, Stroke, StrokeKind, TextEdit, Ui, UiBuilder, Vec2, Widget, WidgetText,
     ecolor::HexColor,
 };
 use num_traits::{CheckedAdd, CheckedSub, One};
@@ -37,8 +37,8 @@ impl UiExt for Ui {
     fn section(&mut self, title: impl Into<String>, add_contents: impl FnOnce(&mut Ui)) {
         let title: String = title.into();
         let mut frame = Frame::group(self.style());
-        frame.outer_margin.top += 10.0;
+        frame.outer_margin.top += 10;
-        frame.inner_margin.top += 2.0;
+        frame.inner_margin.top += 2;
         let res = self.push_id(&title, |ui| {
             frame.show(ui, |ui| {
                 ui.set_max_width(ui.available_width());
@@ -49,7 +49,7 @@ impl UiExt for Ui {
         let old_rect = res.response.rect;
         let mut text_rect = old_rect;
         text_rect.min.x += 6.0;
-        self.allocate_new_ui(UiBuilder::new().max_rect(text_rect), |ui| ui.label(text));
+        self.scope_builder(UiBuilder::new().max_rect(text_rect), |ui| ui.label(text));
         if old_rect.width() > 0.0 {
             self.advance_cursor_after_rect(old_rect);
         }
@@ -73,7 +73,8 @@ impl UiExt for Ui {
         self.painter().rect_filled(right_rect, 0.0, right);
 
         let style = self.style().interact(&response);
-        self.painter().rect_stroke(rect, 0.0, style.fg_stroke);
+        self.painter()
+            .rect_stroke(rect, 0.0, style.fg_stroke, StrokeKind::Inside);
         response
     }
 
@@ -85,11 +86,11 @@ impl UiExt for Ui {
                 let (rect, _) = ui.allocate_at_least(Vec2::new(100.0, 100.0), Sense::hover());
                 ui.painter().rect_filled(rect, 0.0, *color);
                 let resp = ui.text_edit_singleline(hex);
-                if resp.changed() {
+                if resp.changed()
-                    if let Ok(new_color) = HexColor::from_str_without_hash(hex) {
+                    && let Ok(new_color) = HexColor::from_str_without_hash(hex)
+                {
                     *color = new_color.color();
                 }
-                }
                 resp
             },
         )
@@ -265,10 +266,10 @@ impl<T: Number> Widget for NumberEdit<'_, T> {
             .id(id)
             .desired_width(desired_width)
             .margin(Margin {
-                left: 4.0,
+                left: 4,
-                right: if self.arrows { 20.0 } else { 4.0 },
+                right: if self.arrows { 20 } else { 4 },
-                top: 2.0,
+                top: 2,
-                bottom: 2.0,
+                bottom: 2,
             });
         let mut res = if valid {
             ui.add(text)
@@ -300,11 +301,11 @@ impl<T: Number> Widget for NumberEdit<'_, T> {
 
         let mut delta = None;
         if self.arrows {
-            let arrow_left = res.rect.max.x + 4.0;
+            let arrow_left = res.rect.max.x - 16.0;
-            let arrow_right = res.rect.max.x + 20.0;
+            let arrow_right = res.rect.max.x;
-            let arrow_top = res.rect.min.y - 2.0;
+            let arrow_top = res.rect.min.y;
             let arrow_middle = (res.rect.min.y + res.rect.max.y) / 2.0;
-            let arrow_bottom = res.rect.max.y + 2.0;
+            let arrow_bottom = res.rect.max.y;
 
             let top_arrow_rect = Rect {
                 min: (arrow_left, arrow_top).into(),
@@ -337,7 +338,7 @@ impl<T: Number> Widget for NumberEdit<'_, T> {
             }
             str = to_string(self.value);
             stale = true;
-        } else if res.changed {
+        } else if res.changed() {
             if let Some(new_value) = from_string(&str).filter(in_range) {
                 if *self.value != new_value {
                     res.mark_changed();
@@ -355,27 +356,20 @@ impl<T: Number> Widget for NumberEdit<'_, T> {
 
 fn draw_arrow(ui: &mut Ui, rect: Rect, up: bool) -> Response {
     let arrow_res = ui
-        .allocate_rect(
+        .allocate_rect(rect, Sense::all())
-            rect,
-            Sense {
-                click: true,
-                drag: true,
-                focusable: false,
-            },
-        )
         .on_hover_cursor(CursorIcon::Default);
     let visuals = ui.style().visuals.widgets.style(&arrow_res);
     let painter = ui.painter_at(arrow_res.rect);
 
     let rounding = if up {
-        Rounding {
+        CornerRadius {
-            ne: 2.0,
+            ne: 2,
-            ..Rounding::ZERO
+            ..CornerRadius::ZERO
         }
     } else {
-        Rounding {
+        CornerRadius {
-            se: 2.0,
+            se: 2,
-            ..Rounding::ZERO
+            ..CornerRadius::ZERO
         }
     };
     painter.rect_filled(arrow_res.rect, rounding, visuals.bg_fill);