Add support for moar commands

.gitattributes

@@ -4,6 +4,7 @@
 *.html  text eol=lf diff=html
 *.java  text eol=lf diff=java
 *.js    text eol=lf diff=js
+*.sh    text eol=lf
 *.txt   text eol=lf
 
 *.class binary

.gitea/workflows/release.yaml

@@ -1,42 +0,0 @@
-name: Release New Version
-run-name: ${{ gitea.actor }} is releasing a new version
-on: [push]
-
-jobs:
-  Release:
-    runs-on: lemur-build
-    steps:
-      - name: Check out repository code
-        uses: taiki-e/checkout-action@v1
-      - name: Prepare artifacts dir
-        run: mkdir -p /artifacts
-      - name: Build for Linux
-        run: |
-          cargo build --release
-          cp target/release/lemur /artifacts/lemur-linux
-      - name: Bundle for Linux
-        run: |
-          cargo bundle --release --format deb
-          cp target/release/bundle/deb/*.deb /artifacts
-      - name: Build for Windows
-        run: |
-          cargo build --release --target x86_64-pc-windows-msvc
-          cp target/x86_64-pc-windows-msvc/release/lemur.exe /artifacts
-      - name: Bundle for Windows
-        run: |
-          cargo bundle --release --target x86_64-pc-windows-msvc --format msi
-          cp target/x86_64-pc-windows-msvc/release/bundle/msi/Lemur.msi /artifacts
-      - name: Build for MacOS
-        run: |
-          cargo build --release --target x86_64-apple-darwin
-          cp target/x86_64-apple-darwin/release/lemur /artifacts/lemur-osx
-      - name: Bundle for MacOS
-        run: |
-          cargo bundle --release --target x86_64-apple-darwin --format osx
-          genisoimage -V lemur -D -R -apple -no-pad -o /artifacts/Lemur.dmg target/x86_64-apple-darwin/release/bundle/osx/Lemur.app
-      - name: Create Release
-        uses: https://gitea.com/actions/release-action@main
-        with:
-          files: |-
-            /artifacts/**
-          api-key: '${{secrets.RELEASE_TOKEN}}'

Cargo.toml

@@ -1,7 +1,10 @@
 [package]
 name = "lemur"
 description = "An emulator for the Virtual Boy."
-version = "0.1.0"
+repository = "https://git.virtual-boy.com/PVB/lemur"
+publish = false
+license = "MIT"
+version = "0.2.5"
 edition = "2021"
 
 [dependencies]
@@ -11,12 +14,13 @@ bytemuck = { version = "1", features = ["derive"] }
 clap = { version = "4", features = ["derive"] }
 cpal = { git = "https://github.com/sidit77/cpal.git", rev = "66ed6be" }
 directories = "5"
-egui = { version = "0.29", features = ["serde"] }
-egui_extras = { version = "0.29", features = ["image"] }
-egui-toast = "0.15"
-egui-winit = "0.29"
-egui-wgpu = { version = "0.29", features = ["winit"] }
+egui = { version = "0.30", features = ["serde"] }
+egui_extras = { version = "0.30", features = ["image"] }
+egui-toast = { git = "https://github.com/urholaukkarinen/egui-toast.git", rev = "d0bcf97" }
+egui-winit = "0.30"
+egui-wgpu = { version = "0.30", features = ["winit"] }
 gilrs = { version = "0.11", features = ["serde-serialize"] }
+hex = "0.4"
 image = { version = "0.25", default-features = false, features = ["png"] }
 itertools = "0.13"
 num-derive = "0.4"
@@ -29,7 +33,8 @@ rubato = "0.16"
 serde = { version = "1", features = ["derive"] }
 serde_json = "1"
 thread-priority = "1"
-wgpu = "22.1"
+tokio = { version = "1", features = ["io-util", "macros", "net", "rt", "sync"] }
+wgpu = "23"
 winit = { version = "0.30", features = ["serde"] }
 
 [target.'cfg(windows)'.dependencies]
@@ -37,6 +42,7 @@ windows = { version = "0.58", features = ["Win32_System_Threading"] }
 
 [build-dependencies]
 cc = "1"
+winresource = "0.1"
 
 [profile.release]
 lto = true
@@ -45,4 +51,4 @@ lto = true
 name = "Lemur"
 identifier = "com.virtual-boy.Lemur"
 icon = ["assets/lemur-256x256.png"]
-category = "games"
+category = "games"

README.md

@@ -12,4 +12,14 @@ Run
 cargo build --release
 ```
 
-The executable will be in `target/release/lemur[.exe]`
+The executable will be in `target/release/lemur[.exe]`
+
+## Release
+
+Bump the version number in `Cargo.toml`, then run this script:
+
+```sh
+./scripts/release.sh
+```
+
+It uses docker to cross compile for Windows, MacOS, and Linux. All binaries are left in the `output` directory.

build.Dockerfile

@@ -6,18 +6,29 @@ FROM crazymax/osxcross:latest-ubuntu AS osxcross
 FROM rust:latest
 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 lld libc6-dev libasound2-dev libudev-dev genisoimage && \
-    cargo install cargo-bundle xwin
+    apt-get install -y clang-19 lld-19 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 $(which clang++-19) /usr/bin/clang++
 COPY --from=osxcross /osxcross /osxcross
-RUN xwin --accept-license splat --output xwin && rm -rf .xwin-cache
+
 ENV PATH="/osxcross/bin:$PATH" \
     LD_LIBRARY_PATH="/osxcross/lib" \
-    CC="clang" CXX="clang++" AR="llvm-ar-14" \
+    CC="clang-19" CXX="clang++-19" AR="llvm-ar-19" \
     CC_x86_64-apple-darwin="o64-clang" \
     CXX_x86_64-apple-darwin="o64-clang++" \
-    CARGO_TARGET_X86_64_PC_WINDOWS_MSVC_LINKER="lld-link" \
+    CC_aarch64-apple-darwin="oa64-clang" \
+    CXX_aarch64-apple-darwin="o6a4-clang++" \
+    CARGO_TARGET_X86_64_PC_WINDOWS_MSVC_LINKER="lld-link-19" \
     CARGO_TARGET_X86_64_APPLE_DARWIN_LINKER="o64-clang" \
-    CARGO_TARGET_X86_64_APPLE_DARWIN_AR="llvm-ar-14" \
+    CARGO_TARGET_X86_64_APPLE_DARWIN_AR="llvm-ar-19" \
+    CARGO_TARGET_AARCH64_APPLE_DARWIN_LINKER="oa64-clang" \
+    CARGO_TARGET_AARCH64_APPLE_DARWIN_AR="llvm-ar-19" \
+    CROSS_COMPILE="setting-this-to-silence-a-warning-" \
+    RC_PATH="llvm-rc-19" \
     RUSTFLAGS="-Lnative=/xwin/crt/lib/x86_64 -Lnative=/xwin/sdk/lib/um/x86_64 -Lnative=/xwin/sdk/lib/ucrt/x86_64" \
     MACOSX_DEPLOYMENT_TARGET="14.5"

build.rs

@@ -1,6 +1,12 @@
-use std::path::Path;
+use std::{error::Error, path::Path};
+
+fn main() -> Result<(), Box<dyn Error>> {
+    if std::env::var("CARGO_CFG_TARGET_OS")? == "windows" {
+        let mut res = winresource::WindowsResource::new();
+        res.set_icon("assets/lemur.ico");
+        res.compile()?;
+    }
 
-fn main() {
     println!("cargo::rerun-if-changed=shrooms-vb-core");
     cc::Build::new()
         .include(Path::new("shrooms-vb-core/core"))
@@ -11,4 +17,6 @@ fn main() {
         .define("VB_DIV_GENERIC", None)
         .file(Path::new("shrooms-vb-core/core/vb.c"))
         .compile("vb");
+
+    Ok(())
 }

scripts/do-bundle.sh

@@ -0,0 +1,35 @@
+# Set everything up
+rm -rf output
+mkdir -p output
+cargo clean
+
+# Build for linux
+cargo build --release
+cp target/release/lemur output/lemur-linux
+
+# Bundle for Linux
+cargo bundle --release --format deb
+cp target/release/bundle/deb/*.deb output
+
+# Build for Windows
+cargo build --release --target x86_64-pc-windows-msvc
+cp target/x86_64-pc-windows-msvc/release/lemur.exe output
+
+# Build for MacOS Intel
+cargo build --release --target x86_64-apple-darwin
+cp target/x86_64-apple-darwin/release/lemur output/lemur-osx-intel
+
+# Bundle for MacOS Intel
+cargo bundle --release --target x86_64-apple-darwin --format osx
+genisoimage -V lemur -D -R -apple -no-pad -o output/Lemur-Intel.dmg target/x86_64-apple-darwin/release/bundle/osx
+
+# Build for MacOS Apple Silicon
+cargo build --release --target aarch64-apple-darwin
+cp target/aarch64-apple-darwin/release/lemur output/lemur-osx-apple-silicon
+
+# Bundle for MacOS Apple Silicon
+cargo bundle --release --target aarch64-apple-darwin --format osx
+genisoimage -V lemur -D -R -apple -no-pad -o output/Lemur-Apple-Silicon.dmg target/aarch64-apple-darwin/release/bundle/osx
+
+# Clean up after ourselves
+cargo clean

scripts/release.sh

@@ -0,0 +1,72 @@
+set -e
+version=$(cat Cargo.toml | sed -n -e '/version/ {s/.* = *//p;q}' | tr -d '"')
+
+read -p "You wanted to release $version, right? [Y/n] " -n 1 -r
+echo
+case "$REPLY" in
+    n|N ) exit 1;;
+esac
+
+if [ -z "${RELEASE_TOKEN}" ]; then
+    echo "Please set the RELEASE_TOKEN env var."
+    exit 1
+fi
+if ! command -v curl 2>&1 >/dev/null; then
+    echo "Please install curl."
+    exit 1
+fi
+if ! command -v jq 2>&1 >/dev/null; then
+    echo "Please install jq."
+    exit 1
+fi
+if ! command -v docker 2>&1 >/dev/null; then
+    echo "Please install docker."
+    exit 1
+fi
+
+docker build -f build.Dockerfile -t lemur-build .
+MSYS_NO_PATHCONV=1 docker run -it --rm -v .:/app -w /app --entrypoint bash lemur-build /app/scripts/do-bundle.sh
+
+body=$(cat <<EOF
+## How to install
+
+The emulator can be found in the "Downloads" section of this release.
+
+### Windows users
+
+Download \`lemur.exe\`.
+
+### MacOS users
+
+If your Mac uses an Intel processor, download and install \`Lemur-Intel.dmg\`.
+
+If it uses Apple Silicon, download and install \`Lemur-Apple-Silicon.dmg\`.
+
+If you're not sure which to choose, use [this guide](https://support.apple.com/en-us/116943) to find out.
+
+### Linux users
+
+You can either download and run \`lemur-linux\`, or download and install the attached .deb file.
+EOF
+)
+
+payload=$(cat <<EOF
+{
+  "body": $(echo "$body" | jq -Rsa .),
+  "draft": false,
+  "name": "v${version}",
+  "prerelease": false,
+  "tag_name": "v${version}"
+}
+EOF
+)
+
+echo "Creating release..."
+response=$(curl -s --json "$payload" "https://git.virtual-boy.com/api/v1/repos/PVB/lemur/releases?token=$RELEASE_TOKEN")
+echo "$response"
+upload_url=$(echo "$response" | jq -r '.upload_url')
+for file in output/*; do
+    echo "Uploading $(basename "$file")..."
+    upload_res=$(curl -s -F "attachment=@$file" "$upload_url?name=$(basename "$file")&token=$RELEASE_TOKEN")
+    echo "$upload_res"
+done

src/app.rs

@@ -18,7 +18,7 @@ use crate::{
     emulator::{EmulatorClient, EmulatorCommand, SimId},
     input::MappingProvider,
     persistence::Persistence,
-    window::{AboutWindow, AppWindow, GameWindow, InputWindow},
+    window::{AboutWindow, AppWindow, GameWindow, GdbServerWindow, InputWindow},
 };
 
 fn load_icon() -> anyhow::Result<IconData> {
@@ -183,6 +183,10 @@ impl ApplicationHandler<UserEvent> for Application {
                 let about = AboutWindow;
                 self.open(event_loop, Box::new(about));
             }
+            UserEvent::OpenDebugger(sim_id) => {
+                let debugger = GdbServerWindow::new(sim_id, self.client.clone());
+                self.open(event_loop, Box::new(debugger));
+            }
             UserEvent::OpenInput => {
                 let input = InputWindow::new(self.mappings.clone());
                 self.open(event_loop, Box::new(input));
@@ -231,22 +235,13 @@ impl Viewport {
         icon: Option<Arc<IconData>>,
         mut app: Box<dyn AppWindow>,
     ) -> Self {
-        let mut painter = egui_wgpu::winit::Painter::new(
-            egui_wgpu::WgpuConfiguration {
-                present_mode: wgpu::PresentMode::AutoNoVsync,
-                ..egui_wgpu::WgpuConfiguration::default()
-            },
-            1,
-            None,
-            false,
-            true,
-        );
-
         let ctx = Context::default();
         let mut fonts = FontDefinitions::default();
         fonts.font_data.insert(
             "Selawik".into(),
-            FontData::from_static(include_bytes!("../assets/selawik.ttf")),
+            Arc::new(FontData::from_static(include_bytes!(
+                "../assets/selawik.ttf"
+            ))),
         );
         fonts
             .families
@@ -260,6 +255,18 @@ impl Viewport {
         });
         egui_extras::install_image_loaders(&ctx);
 
+        let mut painter = egui_wgpu::winit::Painter::new(
+            ctx.clone(),
+            egui_wgpu::WgpuConfiguration {
+                present_mode: wgpu::PresentMode::AutoNoVsync,
+                ..egui_wgpu::WgpuConfiguration::default()
+            },
+            1,
+            None,
+            false,
+            true,
+        );
+
         let mut info = ViewportInfo::default();
         let mut builder = app.initial_viewport();
         if let Some(icon) = icon {
@@ -325,7 +332,7 @@ impl Viewport {
             [0.0, 0.0, 0.0, 0.0],
             &clipped_primitives,
             &output.textures_delta,
-            false,
+            vec![],
         );
 
         self.state
@@ -371,6 +378,7 @@ impl Drop for Viewport {
 pub enum UserEvent {
     GamepadEvent(gilrs::Event),
     OpenAbout,
+    OpenDebugger(SimId),
     OpenInput,
     OpenPlayer2,
 }

src/emulator.rs

@@ -1,5 +1,6 @@
 use std::{
     collections::HashMap,
+    fmt::Display,
     fs::{self, File},
     io::{Read, Seek, SeekFrom, Write},
     path::{Path, PathBuf},
@@ -45,6 +46,14 @@ impl SimId {
         }
     }
 }
+impl Display for SimId {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.write_str(match self {
+            Self::Player1 => "Player 1",
+            Self::Player2 => "Player 2",
+        })
+    }
+}
 
 struct Cart {
     rom_path: PathBuf,
@@ -141,6 +150,8 @@ pub struct Emulator {
     linked: Arc<AtomicBool>,
     renderers: HashMap<SimId, TextureSink>,
     messages: HashMap<SimId, mpsc::Sender<Toast>>,
+    eye_contents: Vec<u8>,
+    audio_samples: Vec<f32>,
 }
 
 impl Emulator {
@@ -164,6 +175,8 @@ impl Emulator {
             linked,
             renderers: HashMap::new(),
             messages: HashMap::new(),
+            eye_contents: vec![0u8; 384 * 224 * 2],
+            audio_samples: vec![0.0; EXPECTED_FRAME_SIZE],
         })
     }
 
@@ -257,56 +270,8 @@ impl Emulator {
     }
 
     pub fn run(&mut self) {
-        let mut eye_contents = vec![0u8; 384 * 224 * 2];
-        let mut audio_samples = vec![];
         loop {
-            let p1_running = self.running[SimId::Player1.to_index()].load(Ordering::Acquire);
-            let p2_running = self.running[SimId::Player2.to_index()].load(Ordering::Acquire);
-            let mut idle = p1_running || p2_running;
-            if p1_running && p2_running {
-                Sim::emulate_many(&mut self.sims);
-            } else if p1_running {
-                self.sims[SimId::Player1.to_index()].emulate();
-            } else if p2_running {
-                self.sims[SimId::Player2.to_index()].emulate();
-            }
-
-            for sim_id in SimId::values() {
-                let Some(renderer) = self.renderers.get_mut(&sim_id) else {
-                    continue;
-                };
-                let Some(sim) = self.sims.get_mut(sim_id.to_index()) else {
-                    continue;
-                };
-                if sim.read_pixels(&mut eye_contents) {
-                    idle = false;
-                    if renderer.queue_render(&eye_contents).is_err() {
-                        self.renderers.remove(&sim_id);
-                    }
-                }
-            }
-            let p1_audio =
-                p1_running && self.audio_on[SimId::Player1.to_index()].load(Ordering::Acquire);
-            let p2_audio =
-                p2_running && self.audio_on[SimId::Player2.to_index()].load(Ordering::Acquire);
-            let weight = if p1_audio && p2_audio { 0.5 } else { 1.0 };
-            if p1_audio {
-                if let Some(sim) = self.sims.get_mut(SimId::Player1.to_index()) {
-                    sim.read_samples(&mut audio_samples, weight);
-                }
-            }
-            if p2_audio {
-                if let Some(sim) = self.sims.get_mut(SimId::Player2.to_index()) {
-                    sim.read_samples(&mut audio_samples, weight);
-                }
-            }
-            if audio_samples.is_empty() {
-                audio_samples.resize(EXPECTED_FRAME_SIZE, 0.0);
-            } else {
-                idle = false;
-            }
-            self.audio.update(&audio_samples);
-            audio_samples.clear();
+            let idle = self.tick();
             if idle {
                 // The game is paused, and we have output all the video/audio we have.
                 // Block the thread until a new command comes in.
@@ -331,6 +296,58 @@ impl Emulator {
         }
     }
 
+    // returns true if the emulator is "idle" (i.e. this didn't output anything)
+    pub fn tick(&mut self) -> bool {
+        let p1_running = self.running[SimId::Player1.to_index()].load(Ordering::Acquire);
+        let p2_running = self.running[SimId::Player2.to_index()].load(Ordering::Acquire);
+        let mut idle = p1_running || p2_running;
+        if p1_running && p2_running {
+            Sim::emulate_many(&mut self.sims);
+        } else if p1_running {
+            self.sims[SimId::Player1.to_index()].emulate();
+        } else if p2_running {
+            self.sims[SimId::Player2.to_index()].emulate();
+        }
+
+        for sim_id in SimId::values() {
+            let Some(renderer) = self.renderers.get_mut(&sim_id) else {
+                continue;
+            };
+            let Some(sim) = self.sims.get_mut(sim_id.to_index()) else {
+                continue;
+            };
+            if sim.read_pixels(&mut self.eye_contents) {
+                idle = false;
+                if renderer.queue_render(&self.eye_contents).is_err() {
+                    self.renderers.remove(&sim_id);
+                }
+            }
+        }
+        let p1_audio =
+            p1_running && self.audio_on[SimId::Player1.to_index()].load(Ordering::Acquire);
+        let p2_audio =
+            p2_running && self.audio_on[SimId::Player2.to_index()].load(Ordering::Acquire);
+        let weight = if p1_audio && p2_audio { 0.5 } else { 1.0 };
+        if p1_audio {
+            if let Some(sim) = self.sims.get_mut(SimId::Player1.to_index()) {
+                sim.read_samples(&mut self.audio_samples, weight);
+            }
+        }
+        if p2_audio {
+            if let Some(sim) = self.sims.get_mut(SimId::Player2.to_index()) {
+                sim.read_samples(&mut self.audio_samples, weight);
+            }
+        }
+        if self.audio_samples.is_empty() {
+            self.audio_samples.resize(EXPECTED_FRAME_SIZE, 0.0);
+        } else {
+            idle = false;
+        }
+        self.audio.update(&self.audio_samples);
+        self.audio_samples.clear();
+        idle
+    }
+
     fn handle_command(&mut self, command: EmulatorCommand) {
         match command {
             EmulatorCommand::ConnectToSim(sim_id, renderer, messages) => {

src/gdbserver.rs

@@ -0,0 +1,294 @@
+use anyhow::{bail, Result};
+use std::{
+    sync::{Arc, Mutex},
+    thread,
+};
+use tokio::{
+    io::{AsyncReadExt, AsyncWriteExt as _, BufReader, BufWriter},
+    net::{
+        tcp::{OwnedReadHalf, OwnedWriteHalf},
+        TcpListener, TcpStream,
+    },
+    select,
+    sync::oneshot,
+};
+
+use crate::emulator::{EmulatorClient, EmulatorCommand, SimId};
+
+pub struct GdbServer {
+    sim_id: SimId,
+    client: EmulatorClient,
+    status: Arc<Mutex<GdbServerStatus>>,
+    killer: Option<oneshot::Sender<()>>,
+}
+
+impl GdbServer {
+    pub fn new(sim_id: SimId, client: EmulatorClient) -> Self {
+        Self {
+            sim_id,
+            client,
+            status: Arc::new(Mutex::new(GdbServerStatus::Stopped)),
+            killer: None,
+        }
+    }
+
+    pub fn status(&self) -> GdbServerStatus {
+        self.status.lock().unwrap().clone()
+    }
+
+    pub fn start(&mut self, port: u16) {
+        let sim_id = self.sim_id;
+        let client = self.client.clone();
+        let status = self.status.clone();
+        let (tx, rx) = oneshot::channel();
+        self.killer = Some(tx);
+        thread::spawn(move || {
+            tokio::runtime::Builder::new_current_thread()
+                .enable_all()
+                .build()
+                .unwrap()
+                .block_on(async move {
+                    select! {
+                        _ = run_server(sim_id, client, port, &status) => {}
+                        _ = rx => {
+                            *status.lock().unwrap() = GdbServerStatus::Stopped;
+                        }
+                    }
+                })
+        });
+    }
+
+    pub fn stop(&mut self) {
+        if let Some(killer) = self.killer.take() {
+            let _ = killer.send(());
+        }
+    }
+}
+
+async fn run_server(
+    sim_id: SimId,
+    client: EmulatorClient,
+    port: u16,
+    status: &Mutex<GdbServerStatus>,
+) {
+    client.send_command(EmulatorCommand::Pause);
+    let Some(stream) = try_connect(port, status).await else {
+        return;
+    };
+    let connection = GdbConnection::new(sim_id, client, stream);
+    match connection.run().await {
+        Ok(()) => {
+            *status.lock().unwrap() = GdbServerStatus::Stopped;
+        }
+        Err(error) => {
+            *status.lock().unwrap() = GdbServerStatus::Error(error.to_string());
+        }
+    }
+}
+
+async fn try_connect(port: u16, status: &Mutex<GdbServerStatus>) -> Option<TcpStream> {
+    *status.lock().unwrap() = GdbServerStatus::Connecting;
+    let listener = match TcpListener::bind(("127.0.0.1", port)).await {
+        Ok(l) => l,
+        Err(err) => {
+            *status.lock().unwrap() = GdbServerStatus::Error(err.to_string());
+            return None;
+        }
+    };
+    match listener.accept().await {
+        Ok((stream, _)) => {
+            *status.lock().unwrap() = GdbServerStatus::Running;
+            Some(stream)
+        }
+        Err(err) => {
+            *status.lock().unwrap() = GdbServerStatus::Error(err.to_string());
+            None
+        }
+    }
+}
+
+#[derive(Clone)]
+pub enum GdbServerStatus {
+    Stopped,
+    Connecting,
+    Running,
+    Error(String),
+}
+
+impl GdbServerStatus {
+    pub fn running(&self) -> bool {
+        matches!(self, Self::Connecting | Self::Running)
+    }
+}
+
+struct GdbConnection {
+    sim_id: SimId,
+    client: EmulatorClient,
+    stream_in: BufReader<OwnedReadHalf>,
+    stream_out: BufWriter<OwnedWriteHalf>,
+    ack_messages: bool,
+}
+
+impl GdbConnection {
+    fn new(sim_id: SimId, client: EmulatorClient, stream: TcpStream) -> Self {
+        let (rx, tx) = stream.into_split();
+        Self {
+            sim_id,
+            client,
+            stream_in: BufReader::new(rx),
+            stream_out: BufWriter::new(tx),
+            ack_messages: true,
+        }
+    }
+    async fn run(mut self) -> Result<()> {
+        println!("Connected for {}", self.sim_id);
+        self.client.send_command(EmulatorCommand::Resume);
+        loop {
+            let message = self.read_message().await?;
+            println!("received {:?}", message);
+
+            let mut res = ResponseWriter::new(&mut self.stream_out);
+            res.init(self.ack_messages).await?;
+
+            let body = match &message {
+                Message::String(str) => str.as_str(),
+                Message::Signal => {
+                    // TODO: handle this
+                    res.send().await?;
+                    continue;
+                }
+            };
+
+            if body == "QStartNoAckMode" {
+                self.ack_messages = false;
+                res.send_ok().await?;
+            } else if body.starts_with("qSupported:") {
+                res.write_str("multiprocess+;swbreak+;vContSupported+")
+                    .await?;
+                res.send().await?;
+            } else if body == "QThreadSuffixSupported" || body == "QListThreadsInStopReply" {
+                res.send_ok().await?;
+            } else if body == "qHostInfo" || body == "qProcessInfo" {
+                res.write_str(&format!(
+                    "triple:{};endian:little;ptrsize:4;",
+                    hex::encode("v810-unknown-vb")
+                ))
+                .await?;
+                res.send().await?;
+            } else if body == "k" {
+                return Ok(());
+            } else {
+                // unrecognized command
+                res.send().await?;
+            }
+        }
+    }
+
+    async fn read_message(&mut self) -> Result<Message> {
+        let mut char = self.read_byte().await?;
+        while char == b'+' {
+            // just ignore positive acks
+            char = self.read_byte().await?;
+        }
+        if char == b'-' {
+            bail!("no support for negative acks");
+        }
+        if char == 0x03 {
+            // This is how the client "cancels an in-flight request"
+            return Ok(Message::Signal);
+        }
+        if char != b'$' {
+            // Messages are supposed to start with a dollar sign
+            bail!("malformed message");
+        }
+
+        // now read the body
+        let mut checksum = 0u8;
+        let mut body = vec![];
+        char = self.read_byte().await?;
+        while char != b'#' {
+            if char == b'}' {
+                // escape character
+                checksum = checksum.wrapping_add(char);
+                char = self.read_byte().await?;
+                checksum = checksum.wrapping_add(char);
+                body.push(char ^ 0x20);
+            } else {
+                checksum = checksum.wrapping_add(char);
+                body.push(char);
+            }
+            char = self.read_byte().await?;
+        }
+
+        let mut checksum_bytes = [b'0'; 2];
+        self.stream_in.read_exact(&mut checksum_bytes).await?;
+        let checksum_str = std::str::from_utf8(&checksum_bytes)?;
+        let real_checksum = u8::from_str_radix(checksum_str, 16)?;
+        if checksum != real_checksum {
+            bail!("invalid checksum");
+        }
+
+        let string = String::from_utf8(body)?;
+        Ok(Message::String(string))
+    }
+
+    async fn read_byte(&mut self) -> std::io::Result<u8> {
+        self.stream_in.read_u8().await
+    }
+}
+
+struct ResponseWriter<'a> {
+    inner: &'a mut BufWriter<OwnedWriteHalf>,
+    checksum: u8,
+}
+impl<'a> ResponseWriter<'a> {
+    fn new(inner: &'a mut BufWriter<OwnedWriteHalf>) -> Self {
+        Self { inner, checksum: 0 }
+    }
+
+    async fn init(&mut self, ack: bool) -> std::io::Result<()> {
+        if ack {
+            self.inner.write_u8(b'+').await?;
+        }
+        self.inner.write_u8(b'$').await
+    }
+
+    async fn write_str(&mut self, str: &str) -> std::io::Result<()> {
+        for byte in str.bytes() {
+            self.checksum = self.checksum.wrapping_add(byte);
+        }
+        self.inner.write_all(str.as_bytes()).await
+    }
+
+    async fn write_hex_u8(&mut self, value: u8) -> std::io::Result<()> {
+        for digit in [(value >> 4), (value & 0xf)] {
+            let char = if digit > 9 {
+                b'a' + digit - 10
+            } else {
+                b'0' + digit
+            };
+            self.checksum = self.checksum.wrapping_add(char);
+            self.inner.write_u8(char).await?;
+        }
+        Ok(())
+    }
+
+    async fn send_ok(mut self) -> std::io::Result<()> {
+        self.write_str("OK").await?;
+        self.send().await
+    }
+
+    async fn send(mut self) -> std::io::Result<()> {
+        let final_checksum = self.checksum;
+        self.inner.write_u8(b'#').await?;
+        self.write_hex_u8(final_checksum).await?;
+        println!("{:?}", std::str::from_utf8(self.inner.buffer()));
+        self.inner.flush().await
+    }
+}
+
+#[derive(Debug)]
+enum Message {
+    String(String),
+    Signal,
+}

src/main.rs

@@ -1,4 +1,7 @@
-use std::{path::PathBuf, process};
+// hide console in release mode
+#![cfg_attr(not(debug_assertions), windows_subsystem = "windows")]
+
+use std::{path::PathBuf, process, time::SystemTime};
 
 use anyhow::Result;
 use app::Application;
@@ -11,6 +14,7 @@ mod app;
 mod audio;
 mod controller;
 mod emulator;
+mod gdbserver;
 mod graphics;
 mod input;
 mod persistence;
@@ -21,6 +25,43 @@ struct Args {
     rom: Option<PathBuf>,
 }
 
+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);
+        } else if let Some(msg) = info.payload().downcast_ref::<String>() {
+            message += &format!("{}\n", msg);
+        }
+        if let Some(location) = info.location() {
+            message += &format!(
+                "    in file '{}' at line {}\n",
+                location.file(),
+                location.line()
+            );
+        }
+        let backtrace = std::backtrace::Backtrace::force_capture();
+        message += &format!("stack trace:\n{:#}\n", backtrace);
+
+        eprint!("{}", message);
+
+        let Some(project_dirs) = directories::ProjectDirs::from("com", "virtual-boy", "Lemur")
+        else {
+            return;
+        };
+        let data_dir = project_dirs.data_dir();
+        if std::fs::create_dir_all(data_dir).is_err() {
+            return;
+        }
+        let timestamp = SystemTime::now()
+            .duration_since(SystemTime::UNIX_EPOCH)
+            .unwrap()
+            .as_millis();
+        let logfile_name = format!("crash-{}.txt", timestamp);
+        let _ = std::fs::write(data_dir.join(logfile_name), message);
+    }));
+}
+
 #[cfg(windows)]
 fn set_process_priority_to_high() -> Result<()> {
     use windows::Win32::{Foundation, System::Threading};
@@ -31,6 +72,8 @@ fn set_process_priority_to_high() -> Result<()> {
 }
 
 fn main() -> Result<()> {
+    set_panic_handler();
+
     #[cfg(windows)]
     set_process_priority_to_high()?;
 

src/window.rs

@@ -1,12 +1,14 @@
 pub use about::AboutWindow;
 use egui::{Context, ViewportBuilder, ViewportId};
 pub use game::GameWindow;
+pub use gdb::GdbServerWindow;
 pub use input::InputWindow;
 use winit::event::KeyEvent;
 
 mod about;
 mod game;
 mod game_screen;
+mod gdb;
 mod input;
 
 pub trait AppWindow {

src/window/game.rs

@@ -121,6 +121,14 @@ impl GameWindow {
                 }
             }
         });
+        ui.menu_button("Tools", |ui| {
+            if ui.button("GDB Server").clicked() {
+                self.proxy
+                    .send_event(UserEvent::OpenDebugger(self.sim_id))
+                    .unwrap();
+                ui.close_menu();
+            }
+        });
         ui.menu_button("About", |ui| {
             self.proxy.send_event(UserEvent::OpenAbout).unwrap();
             ui.close_menu();

src/window/game_screen.rs

@@ -63,13 +63,13 @@ impl GameScreen {
                 layout: Some(&render_pipeline_layout),
                 vertex: wgpu::VertexState {
                     module: &shader,
-                    entry_point: "vs_main",
+                    entry_point: Some("vs_main"),
                     buffers: &[],
                     compilation_options: wgpu::PipelineCompilationOptions::default(),
                 },
                 fragment: Some(wgpu::FragmentState {
                     module: &shader,
-                    entry_point,
+                    entry_point: Some(entry_point),
                     targets: &[Some(wgpu::ColorTargetState {
                         format: wgpu::TextureFormat::Bgra8Unorm,
                         blend: Some(wgpu::BlendState::REPLACE),
@@ -235,7 +235,7 @@ impl egui_wgpu::CallbackTrait for GameScreenCallback {
             .get(&self.display_mode)
             .unwrap_or_else(|| panic!("Unrecognized display mode {:?}", self.display_mode));
         render_pass.set_pipeline(pipeline);
-        render_pass.set_bind_group(0, &self.bind_group, &[]);
+        render_pass.set_bind_group(0, Some(self.bind_group.as_ref()), &[]);
         render_pass.set_viewport(x, y, w, h, 0.0, 1.0);
         render_pass.draw(0..6, 0..1);
     }

src/window/gdb.rs

@@ -0,0 +1,80 @@
+use egui::{Button, CentralPanel, TextEdit, ViewportBuilder, ViewportId};
+
+use crate::{
+    emulator::{EmulatorClient, SimId},
+    gdbserver::{GdbServer, GdbServerStatus},
+};
+
+use super::AppWindow;
+
+pub struct GdbServerWindow {
+    sim_id: SimId,
+    port_str: String,
+    server: GdbServer,
+}
+
+impl GdbServerWindow {
+    pub fn new(sim_id: SimId, client: EmulatorClient) -> Self {
+        Self {
+            sim_id,
+            port_str: (8080 + sim_id.to_index()).to_string(),
+            server: GdbServer::new(sim_id, client),
+        }
+    }
+}
+
+impl AppWindow for GdbServerWindow {
+    fn viewport_id(&self) -> ViewportId {
+        ViewportId::from_hash_of(format!("Debugger-{}", self.sim_id))
+    }
+
+    fn initial_viewport(&self) -> ViewportBuilder {
+        ViewportBuilder::default()
+            .with_title(format!("GDB Server ({})", self.sim_id))
+            .with_inner_size((300.0, 200.0))
+    }
+
+    fn show(&mut self, ctx: &egui::Context) {
+        let port_num: Option<u16> = self.port_str.parse().ok();
+        let status = self.server.status();
+        CentralPanel::default().show(ctx, |ui| {
+            ui.horizontal(|ui| {
+                if port_num.is_none() {
+                    let style = ui.style_mut();
+                    let error = style.visuals.error_fg_color;
+                    style.visuals.widgets.active.bg_stroke.color = error;
+                    style.visuals.widgets.hovered.bg_stroke.color = error;
+                }
+                ui.label("Port");
+                let port_editor = TextEdit::singleline(&mut self.port_str).desired_width(100.0);
+                ui.add_enabled(!status.running(), port_editor);
+            });
+
+            if !status.running() {
+                let start_button = Button::new("Start");
+                if ui.add_enabled(port_num.is_some(), start_button).clicked() {
+                    let port = port_num.unwrap();
+                    self.server.start(port);
+                }
+            } else {
+                let stop_button = Button::new("Stop");
+                if ui.add(stop_button).clicked() {
+                    self.server.stop();
+                }
+            }
+
+            match &status {
+                GdbServerStatus::Stopped => {}
+                GdbServerStatus::Connecting => {
+                    ui.label("Connecting...");
+                }
+                GdbServerStatus::Running => {
+                    ui.label("Running");
+                }
+                GdbServerStatus::Error(message) => {
+                    ui.label(message);
+                }
+            }
+        });
+    }
+}