emscripten friendly sdl loop

docs/Caveats.md

@@ -258,6 +258,8 @@ If running under Firefox and you hit "out of memory" on dev console, close the e
 
 To run the binary (after building) you should be fine with `node ./eden-cli.js`. For obvious reasons no Qt frontend is available on WASM, support for Vulkan is done charily via [llvmpipe2wasm](https://github.com/Devsh-Graphics-Programming/llvmpipe2wasm).
 
+If you run into the error "acorn.js can't be found" check [this associated issue](https://github.com/emscripten-core/emscripten/issues/13368), the fix in short is `npm --global install acorn`. On FreeBSD you could run `npm` under root, or you could do the sane thing and do `sudo chown -R $USER /usr/local/lib/node_modules/ /usr/local/bin/` (remember to restore permissions afterwards!) unless you wish to run `npm` under root which is generally a bad idea.
+
 2026-06-09: As of writing, no Dynarmic-based JIT is possible on this target, full interpreted emulation is the only reasonable option. While there is some efforts on making a JIT like [here](https://github.com/wingo/wasm-jit) or [here](https://wingolog.org/archives/2022/08/18/just-in-time-code-generation-within-webassembly), the result is so latency expensive we're better off using an interpreter instead.
 
 ## Windows

src/yuzu_cmd/CMakeLists.txt

@@ -77,12 +77,13 @@ if (NOT MSVC)
 endif()
 
 if (PLATFORM_EMSCRIPTEN)
-    # 10GB is required... yikes!
+    # 10GB is required at max... yikes!
     target_link_options(yuzu-cmd PRIVATE
         -sALLOW_MEMORY_GROWTH=1
+        -sINITIAL_MEMORY=33554432
         -sMAXIMUM_MEMORY=10737418240
         -sGLOBAL_BASE=16777216
-        -sEXPORTED_RUNTIME_METHODS="['FS']"
+        -sEXPORTED_RUNTIME_METHODS=['FS']
         -sPTHREAD_POOL_SIZE_STRICT=0
         -sPTHREAD_POOL_SIZE=navigator.hardwareConcurrency)
 endif()

src/yuzu_cmd/emu_window/emu_window_sdl3.cpp

@@ -32,9 +32,6 @@ EmuWindow_SDL3::EmuWindow_SDL3(InputCommon::InputSubsystem* input_subsystem_, Co
 }
 
 EmuWindow_SDL3::~EmuWindow_SDL3() {
-#ifdef __EMSCRIPTEN__
-    emscripten_cancel_main_loop();
-#endif
     system.HIDCore().UnloadInputDevices();
     input_subsystem->Shutdown();
     SDL_Quit();
@@ -169,23 +166,8 @@ void EmuWindow_SDL3::Fullscreen() {
     }
 }
 
-void EmuWindow_SDL3::WaitEvent() {
+void EmuWindow_SDL3::OnEvent(SDL_Event& event) {
     // Called on main thread
-    SDL_Event event;
-
-    if (!SDL_WaitEvent(&event)) {
-        const char* error = SDL_GetError();
-        if (!error || strcmp(error, "") == 0) {
-            // https://github.com/libsdl-org/SDL/issues/5780
-            // Sometimes SDL will return without actually having hit an error condition;
-            // just ignore it in this case.
-            return;
-        }
-
-        LOG_CRITICAL(Frontend, "SDL_WaitEvent failed: {}", error);
-        exit(1);
-    }
-
     switch (event.type) {
     case SDL_EVENT_WINDOW_RESIZED:
     case SDL_EVENT_WINDOW_PIXEL_SIZE_CHANGED:
@@ -255,6 +237,9 @@ void EmuWindow_SDL3::WaitEvent() {
 
 // Credits to Samantas5855 and others for this function.
 void EmuWindow_SDL3::SetWindowIcon() {
+#if defined(__EMSCRIPTEN__) || defined(__wasi__)
+    // Icons do not work yet
+#else
     SDL_IOStream* const yuzu_icon_stream = SDL_IOFromConstMem((void*)yuzu_icon, yuzu_icon_size);
     if (yuzu_icon_stream == nullptr) {
         LOG_WARNING(Frontend, "Failed to create Eden icon stream.");
@@ -268,6 +253,7 @@ void EmuWindow_SDL3::SetWindowIcon() {
     // The icon is attached to the window pointer
     SDL_SetWindowIcon(render_window, window_icon);
     SDL_DestroySurface(window_icon);
+#endif
 }
 
 void EmuWindow_SDL3::OnMinimalClientAreaChangeRequest(std::pair<u32, u32> minimal_size) {

src/yuzu_cmd/emu_window/emu_window_sdl3.h

@@ -13,6 +13,7 @@
 #include "core/frontend/graphics_context.h"
 
 struct SDL_Window;
+union SDL_Event;
 
 namespace Core {
 class System;
@@ -35,7 +36,7 @@ public:
     bool IsShown() const override;
 
     /// Wait for the next event on the main thread.
-    void WaitEvent();
+    void OnEvent(SDL_Event& event);
 
     // Sets the window icon from yuzu.bmp
     void SetWindowIcon();

src/yuzu_cmd/yuzu.cpp

@@ -11,6 +11,8 @@
 #ifdef __EMSCRIPTEN__
 #include <emscripten.h>
 #endif
+#define SDL_MAIN_USE_CALLBACKS 1
+#include <SDL3/SDL_main.h>
 
 #include <fmt/ostream.h>
 
@@ -43,9 +45,7 @@
 #ifdef _WIN32
 // windows.h needs to be included before shellapi.h
 #include <windows.h>
-
 #include <shellapi.h>
-
 #include "common/windows/timer_resolution.h"
 #endif
 
@@ -178,8 +178,15 @@ static void OnStatusMessageReceived(const Network::StatusMessageEntry& msg) {
         std::cout << std::endl << "* " << message << std::endl << std::endl;
 }
 
-/// Application entry point
+struct SdlState {
-int main(int argc, char** argv) {
+    Common::DetachedTasks detached_tasks{};
+    Core::System system{};
+    std::unique_ptr<EmuWindow_SDL3> emu_window;
+};
+
+extern "C" SDL_AppResult SDL_AppInit(void **appstate, int argc, char **argv) {
+    SdlState* state = new SdlState();
+
 #ifdef _WIN32
     if (AttachConsole(ATTACH_PARENT_PROCESS)) {
         freopen("CONOUT$", "wb", stdout);
@@ -190,16 +197,14 @@ int main(int argc, char** argv) {
     Common::Log::Initialize();
     Common::Log::SetColorConsoleBackendEnabled(true);
     Common::Log::Start();
-    Common::DetachedTasks detached_tasks;
 
     int option_index = 0;
 #ifdef _WIN32
     int argc_w;
     auto argv_w = CommandLineToArgvW(GetCommandLineW(), &argc_w);
-
     if (argv_w == nullptr) {
         LOG_CRITICAL(Frontend, "Failed to get command line arguments");
-        return -1;
+        return SDL_APP_FAILURE;
     }
 #endif
     std::string filepath;
@@ -247,7 +252,7 @@ int main(int argc, char** argv) {
                 break;
             case 'h':
                 PrintHelp(argv[0]);
-                return 0;
+                return SDL_APP_FAILURE;
             case 'g':
                 filepath = std::string(optarg);
                 break;
@@ -264,7 +269,7 @@ int main(int argc, char** argv) {
                 if (!std::regex_match(str_arg, re)) {
                     std::cout << "Wrong format for option --multiplayer\n";
                     PrintHelp(argv[0]);
-                    return 0;
+                    return SDL_APP_FAILURE;
                 }
 
                 std::smatch match;
@@ -274,17 +279,16 @@ int main(int argc, char** argv) {
                 password = match[2];
                 address = match[3];
                 if (!match[4].str().empty()) {
-                    port = static_cast<u16>(std::strtoul(match[4].str().c_str(), nullptr, 0));
+                    port = u16(std::strtoul(match[4].str().c_str(), nullptr, 0));
                 }
                 std::regex nickname_re("^[a-zA-Z0-9._\\- ]+$");
                 if (!std::regex_match(nickname, nickname_re)) {
-                    std::cout
+                    LOG_ERROR(Frontend, "Nickname is not valid. Must be 4 to 20 alphanumeric characters");
-                        << "Nickname is not valid. Must be 4 to 20 alphanumeric characters.\n";
+                    return SDL_APP_FAILURE;
-                    return 0;
                 }
                 if (address.empty()) {
-                    std::cout << "Address to room must not be empty.\n";
+                    LOG_ERROR(Frontend, "Address to room must not be empty");
-                    return 0;
+                    return SDL_APP_FAILURE;
                 }
                 break;
             }
@@ -297,7 +301,7 @@ int main(int argc, char** argv) {
                 break;
             case 'v':
                 PrintVersion();
-                return 0;
+                return SDL_APP_FAILURE;
             }
         } else {
 #ifdef _WIN32
@@ -341,79 +345,73 @@ int main(int argc, char** argv) {
 
     if (filepath.empty()) {
         LOG_CRITICAL(Frontend, "Failed to load ROM: No ROM specified");
-        return -1;
+        return SDL_APP_FAILURE;
     }
 
-    Core::System system{};
+    state->system.Initialize();
-    system.Initialize();
 
     InputCommon::InputSubsystem input_subsystem{};
 
     // Apply the command line arguments
-    system.ApplySettings();
+    state->system.ApplySettings();
 
-    std::unique_ptr<EmuWindow_SDL3> emu_window;
     switch (Settings::values.renderer_backend.GetValue()) {
 #ifdef HAS_OPENGL
     case Settings::RendererBackend::OpenGL_GLSL:
     case Settings::RendererBackend::OpenGL_GLASM:
     case Settings::RendererBackend::OpenGL_SPIRV:
-        emu_window = std::make_unique<EmuWindow_SDL3_GL>(&input_subsystem, system, fullscreen);
+        state->emu_window = std::make_unique<EmuWindow_SDL3_GL>(&input_subsystem, state->system, fullscreen);
         break;
 #endif
     case Settings::RendererBackend::Vulkan:
-        emu_window = std::make_unique<EmuWindow_SDL3_VK>(&input_subsystem, system, fullscreen);
+        state->emu_window = std::make_unique<EmuWindow_SDL3_VK>(&input_subsystem, state->system, fullscreen);
         break;
     case Settings::RendererBackend::Null:
-        emu_window = std::make_unique<EmuWindow_SDL3_Null>(&input_subsystem, system, fullscreen);
+        state->emu_window = std::make_unique<EmuWindow_SDL3_Null>(&input_subsystem, state->system, fullscreen);
         break;
     default:
         LOG_CRITICAL(Frontend, "Invalid renderer backend");
-        return -1;
+        return SDL_APP_FAILURE;
     }
 
 #ifdef _WIN32
     Common::Windows::SetCurrentTimerResolutionToMaximum();
-    system.CoreTiming().SetTimerResolutionNs(Common::Windows::GetCurrentTimerResolution());
+    state->system.CoreTiming().SetTimerResolutionNs(Common::Windows::GetCurrentTimerResolution());
 #endif
 
-    system.SetContentProvider(std::make_unique<FileSys::ContentProviderUnion>());
+    state->system.SetContentProvider(std::make_unique<FileSys::ContentProviderUnion>());
-    system.SetFilesystem(std::make_shared<FileSys::RealVfsFilesystem>());
+    state->system.SetFilesystem(std::make_shared<FileSys::RealVfsFilesystem>());
-    system.GetFileSystemController().CreateFactories(*system.GetFilesystem());
+    state->system.GetFileSystemController().CreateFactories(*state->system.GetFilesystem());
-    system.GetUserChannel().clear();
+    state->system.GetUserChannel().clear();
 
     Service::AM::FrontendAppletParameters load_parameters{
         .applet_id = Service::AM::AppletId::Application,
     };
-    const Core::SystemResultStatus load_result{system.Load(*emu_window, filepath, load_parameters)};
+    const Core::SystemResultStatus load_result = state->system.Load(*state->emu_window, filepath, load_parameters);
-
     switch (load_result) {
-    case Core::SystemResultStatus::ErrorGetLoader:
-        LOG_CRITICAL(Frontend, "Failed to obtain loader for {}!", filepath);
-        return -1;
-    case Core::SystemResultStatus::ErrorLoader:
-        LOG_CRITICAL(Frontend, "Failed to load ROM!");
-        return -1;
-    case Core::SystemResultStatus::ErrorNotInitialized:
-        LOG_CRITICAL(Frontend, "CPUCore not initialized");
-        return -1;
-    case Core::SystemResultStatus::ErrorVideoCore:
-        LOG_CRITICAL(Frontend, "Failed to initialize VideoCore!");
-        return -1;
     case Core::SystemResultStatus::Success:
         break; // Expected case
+    case Core::SystemResultStatus::ErrorGetLoader:
+        LOG_CRITICAL(Frontend, "Failed to obtain loader for {}!", filepath);
+        return SDL_APP_FAILURE;
+    case Core::SystemResultStatus::ErrorLoader:
+        LOG_CRITICAL(Frontend, "Failed to load ROM!");
+        return SDL_APP_FAILURE;
+    case Core::SystemResultStatus::ErrorNotInitialized:
+        LOG_CRITICAL(Frontend, "CPUCore not initialized");
+        return SDL_APP_FAILURE;
+    case Core::SystemResultStatus::ErrorVideoCore:
+        LOG_CRITICAL(Frontend, "Failed to initialize VideoCore!");
+        return SDL_APP_FAILURE;
     default:
-        if (static_cast<u32>(load_result) >
+        const u16 loader_id = u16(Core::SystemResultStatus::ErrorLoader);
-            static_cast<u32>(Core::SystemResultStatus::ErrorLoader)) {
+        const u16 error_id = u16(load_result) - loader_id;
-            const u16 loader_id = static_cast<u16>(Core::SystemResultStatus::ErrorLoader);
+        LOG_CRITICAL(Frontend,
-            const u16 error_id = static_cast<u16>(load_result) - loader_id;
+            "While attempting to load the ROM requested, an error occurred. Please "
-            LOG_CRITICAL(Frontend,
+            "refer to the Eden wiki for more information or the Eden discord for "
-                         "While attempting to load the ROM requested, an error occurred. Please "
+            "additional help.\n\nError Code: {:04X}-{:04X}\nError Description: {}",
-                         "refer to the Eden wiki for more information or the Eden discord for "
+            loader_id, error_id, Loader::ResultStatus(error_id));
-                         "additional help.\n\nError Code: {:04X}-{:04X}\nError Description: {}",
+        return SDL_APP_FAILURE;
-                         loader_id, error_id, static_cast<Loader::ResultStatus>(error_id));
-        }
-        break;
     }
 
     if (use_multiplayer) {
@@ -422,49 +420,47 @@ int main(int argc, char** argv) {
             member->BindOnStatusMessageReceived(OnStatusMessageReceived);
             member->BindOnStateChanged(OnStateChanged);
             member->BindOnError(OnNetworkError);
-            LOG_DEBUG(Network, "Start connection to {}:{} with nickname {}", address, port,
+            LOG_DEBUG(Network, "Start connection to {}:{} with nickname {}", address, port, nickname);
-                      nickname);
             member->Join(nickname, address.c_str(), port, 0, Network::NoPreferredIP, password);
         } else {
             LOG_ERROR(Network, "Could not access RoomMember");
-            return 0;
+            return SDL_APP_FAILURE;
         }
     }
 
     // Core is loaded, start the GPU (makes the GPU contexts current to this thread)
-    system.GPU().Start();
+    state->system.GPU().Start();
-    system.GetCpuManager().OnGpuReady();
+    state->system.GetCpuManager().OnGpuReady();
 
     if (Settings::values.use_disk_shader_cache.GetValue()) {
-        system.Renderer().ReadRasterizer()->LoadDiskResources(
+        state->system.Renderer().ReadRasterizer()->LoadDiskResources(
-            system.GetApplicationProcessProgramID(), std::stop_token{},
+            state->system.GetApplicationProcessProgramID(), std::stop_token{},
             [](VideoCore::LoadCallbackStage, size_t value, size_t total) {});
     }
 
-    system.RegisterExitCallback([&] {
+    // don't do anything, SDL3 already exists for us :D
-        // Just exit right away.
+    state->system.RegisterExitCallback([] {});
-        exit(0);
+    void(state->system.Run());
-    });
+    if (state->system.DebuggerEnabled())
-    void(system.Run());
+        state->system.InitializeDebugger();
-    if (system.DebuggerEnabled()) {
+    return SDL_APP_SUCCESS;
-        system.InitializeDebugger();
+}
-    }
+extern "C" SDL_AppResult SDL_AppIterate(void *appstate) {
-
+    SdlState *state = (SdlState *)appstate;
-#ifdef __EMSCRIPTEN__
+    return state->emu_window->IsOpen() ? SDL_APP_CONTINUE : SDL_APP_SUCCESS;
-    // Required so lambda fits snuggly into our "main loop"
+}
-    static EmuWindow_SDL3* static_ems_emu_window = emu_window.get();
+extern "C" SDL_AppResult SDL_AppEvent(void *appstate, SDL_Event *event) {
-    emscripten_set_main_loop([]() {
+    SdlState *state = (SdlState *)appstate;
-        static_ems_emu_window->WaitEvent();
+    state->emu_window->OnEvent(*event);
-    }, 0, 1);
+    return SDL_APP_SUCCESS;
-#else
+}
-    while (emu_window->IsOpen())
+extern "C" void SDL_AppQuit(void *appstate, SDL_AppResult result) {
-        emu_window->WaitEvent();
+    SdlState *state = (SdlState *)appstate;
-#endif
+    state->system.DetachDebugger();
-    system.DetachDebugger();
+    void(state->system.Pause());
-    void(system.Pause());
+    state->system.ShutdownMainProcess();
-    system.ShutdownMainProcess();
+    state->detached_tasks.WaitForAllTasks();
-    detached_tasks.WaitForAllTasks();
+    delete state;
-    return 0;
 }
 
 #define VMA_IMPLEMENTATION

tools/miniserver.js

@@ -1,4 +1,4 @@
-#!/usr/local/env node
+#!/usr/bin/env node
 // SPDX-FileCopyrightText: Copyright 2026 Eden Emulator Project
 // SPDX-License-Identifier: GPL-3.0-or-later
 
@@ -21,51 +21,61 @@ const server = createServer((req, res) => {
 <html>
 <head>
 <title>eden-cli</title>
+</head>
+<body style="margin:0;padding:0;background-color:black;font-family:Monospace,Tahoma,Arial;">
 <script>
-var Module = {}; // MUST be global otherwise wasm does wawawawa
+var Module = { //do not prepend var
-function finished_body() {
+    mainScriptUrlOrBlob: 'eden-cli.js',
-    Module = { //do not prepend var
+    print: (e) => {
-        print: (e) => {
+        e = e.replace('[1;31m', '<span style="color:red;font-weight:bold;">');
-            e = e.replace('[1;31m', '<span style="color:red;font-weight:bold;">');
+        e = e.replace('[0;37m', '<span style="color:white;font-weight:bold;">');
-            e = e.replace('[0;37m', '<span style="color:white;font-weight:bold;">');
+        e = e.replace('[1;35m', '<span style="color:pink;font-weight:bold;">');
-            e = e.replace('[1;35m', '<span style="color:pink;font-weight:bold;">');
+        e = e.replace('[1;33m', '<span style="color:yellow;font-weight:bold;">');
-            e = e.replace('[1;33m', '<span style="color:yellow;font-weight:bold;">');
+        e = e.replace('[0m', '</span>');
-            e = e.replace('[0m', '</span>');
+        tty_stdout.innerHTML += \`\${e}</br>\`;
-            tty_stdout.innerHTML += e + '</br>';
+    },
-        },
+    printErr: (e) => {
-        printErr: (e) => {
+        tty_stdout.innerHTML += \`<span style="color:red">\${e}</span></br>\`;
-            tty_stdout.innerHTML += '<span style="color:red">' + e + '</span></br>';
+    },
-        },
+    // not a wasm func but idc
-        // not a wasm func but idc
+    printInternal: (e) => {
-        printInternal: (e) => {
+        tty_stdout.innerHTML += \`<span style="color:pink">Internal WASM: \${e}</span></br>\`;
-            tty_stdout.innerHTML += '<span style="color:pink">Internal WASM: ' + e + '</span></br>';
+    },
-        },
+    onRuntimeInitialized: () => { Module.printInternal("runtime ok"); },
-        onRuntimeInitialized: () => { Module.printInternal("runtime ok"); },
+    setStatus: (e) => { Module.printInternal(e); },
-        setStatus: (e) => { Module.printInternal(e); },
+    monitorRunDependencies: (e) => { Module.printInternal("monitor deps: " + e); },
-        monitorRunDependencies: (e) => { Module.printInternal("monitor deps: " + e); },
+    __wasm_call_ctors: () => { Module.printInternal("ctors beep"); },
-        __wasm_call_ctors: () => { Module.printInternal("ctors beep"); },
+};
-    };
+var tty_stdout = document.createElement('div');
+document.body.appendChild(tty_stdout);
+Module.arguments = ['game.nro'];
 
-    var tty_stdout = document.createElement('div');
+var gameNroFileBuffer = {};
-    document.body.appendChild(tty_stdout);
-    Module.printInternal("loading from ${build_dir}/eden-cli.js");
 
-    Module.arguments = ['game.nro'];
+Module.printInternal("Atomics: " + window.Atomics);
+Module.printInternal("SharedArrayBuffer: " + window.SharedArrayBuffer);
+Module.printInternal("trying to load script (if it hangs here check console)");
 
+fetch('game.nro').then((resp) => {
+    if (!resp.ok)
+        throw Error(\`\${resp.status}\`);
+    return resp.arrayBuffer();
+}).then((buffer) => {
+    gameNroFileBuffer = buffer;
+    Module.printInternal("buffer: " + gameNroFileBuffer);
+
+    // load the thingy AFTER loading the nro
+    Module.printInternal(\`loading from ${build_dir}\${Module.mainScriptUrlOrBlob}\`);
     var script = document.createElement('script');
     script.src = '/eden-cli.js';
     script.onload = () => {
-        Module.printInternal("Atomics: " + window.Atomics);
+        // copy just most relevant :)
-        Module.printInternal("SharedArrayBuffer: " + window.SharedArrayBuffer);
+        console.log(Module);
-        Module.printInternal("trying to load script (if it hangs here check console)");
+        Module.FS.writeFile('/game.nro', new DataView(gameNroFileBuffer));
-
-        Module.FS.writeFile('/game.nro', [1,2,3]);
     };
     document.head.appendChild(script);
-}
+}).catch(Module.printErr);
 </script>
-</head>
-<body style="margin:0;padding:0;background-color:black;font-family:Monospace,Tahoma,Arial;" onload="finished_body();">
 </body>
 </html>`);
     } else if (req.url === '/eden-cli.js') {
@@ -86,12 +96,25 @@ function finished_body() {
             });
             res.end(content, 'utf-8');
         });
+    } else if (req.url === '/game.nro') {
+        readFile(nro_file, (err, content) => {
+            res.writeHead(200, {
+                'Content-Type': 'application/wasm',
+                'Cross-Origin-Opener-Policy': 'same-origin',
+                'Cross-Origin-Embedder-Policy': 'require-corp'
+            });
+            res.end(content, 'utf-8');
+        });
+    } else {
+        res.writeHead(404, {});
+        res.end('', 'utf-8');
     }
 });
 
 const build_dir = process.argv[2];
-if (build_dir === undefined) {
+const nro_file = process.argv[3];
-    console.log(`Usage: ${process.argv[0]} ${process.argv[1]} [build directory]`);
+if (typeof build_dir == "undefined" || typeof nro_file == "undefined") {
+    console.log(`Usage: ${process.argv[0]} ${process.argv[1]} [build directory] [NRO file]`);
 } else {
     server.listen(2210, () => {
         console.log(`${process.argv[0]} ${process.argv[1]} http://localhost:2210`);