prepare

.ci/wasm/build.sh

@@ -0,0 +1,92 @@
+#!/bin/sh -ex
+
+# SPDX-FileCopyrightText: Copyright 2026 Eden Emulator Project
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+NUM_JOBS=$(nproc 2>/dev/null || getconf _NPROCESSORS_ONLN 2>/dev/null || echo 2)
+
+: "${CCACHE:=false}"
+RETURN=0
+
+usage() {
+    cat <<EOF
+Usage: $0 [-b|--build-type BUILD_TYPE] [-o|--outdir OUTPUT_DIRECTORY]
+
+Build script for Emscripten (using wasm64).
+
+Options:
+    --build-type    Set the CMake build type (Release|RelWithDebInfo|MinSizeRel|Debug)
+                    Default: Release
+    --outdir        Set the output directory
+                    Default: build
+
+EOF
+    exit "$RETURN"
+}
+
+die() {
+	echo "-- ! $*" >&2
+	RETURN=1 usage
+}
+
+type() {
+    [ -z "$1" ] && die "You must specify a valid type."
+    TYPE="$1"
+}
+
+outdir() {
+    [ -z "$1" ] && die "You must specify a valid output directory."
+    OUTDIR="$1"
+}
+
+while true; do
+	case "$1" in
+		-r|--release) DEVEL=false ;;
+		-b|--build-type) type "$2"; shift ;;
+		-o|--outdir) outdir "$2"; shift ;;
+		-h|--help) usage ;;
+		*) break ;;
+	esac
+	shift
+done
+
+: "${TYPE:=Release}"
+: "${DEVEL:=true}"
+: "${OUTDIR:=build}"
+
+# -sMEMORY64 must be specified twice, see below
+# The CMake toolchain file will match against MEMORY64 but will fail to match if:
+# - it's either -sMEMORY64
+# - or it's either -sMEMORY64=1
+# The line in question:
+# if (CMAKE_C_FLAGS MATCHES "MEMORY64")
+# However why need to specify -sMEMORY64=1 then? Oh that's because if you didn't set
+# the =1, it would assume you meant =0, which equates to not specifying it at all
+# This seems to be fixed in later versions but occurs atleast on 4.0.3-git and below.
+emcmake cmake -B "$OUTDIR" -G "Unix Makefiles" \
+    -DCMAKE_BUILD_TYPE=${TYPE} \
+    -DENABLE_OPENGL=OFF \
+    -DENABLE_LTO=OFF \
+    -DENABLE_QT=OFF \
+    -DENABLE_UNITY_BUILD=OFF \
+    -DENABLE_QT_TRANSLATION=OFF \
+    -DENABLE_CUBEB=OFF \
+    -DENABLE_LIBUSB=OFF \
+    -DENABLE_UPDATE_CHECKER=OFF \
+    -DENABLE_WEB_SERVICE=OFF \
+    -DUSE_DISCORD_PRESENCE=OFF \
+    -DENABLE_WIFI_SCAN=OFF \
+    -DUSE_FASTER_LINKER=ON \
+    -DYUZU_STATIC_BUILD=ON \
+    -DYUZU_USE_BUNDLED_OPENSSL=OFF \
+    -DYUZU_USE_EXTERNAL_FFMPEG=ON \
+    -Dzstd_FORCE_BUNDLED=ON \
+    -DOpenSSL_FORCE_BUNDLED=ON \
+    -DEMSCRIPTEN_SYSTEM_PROCESSOR=wasm \
+    -DCMAKE_C_FLAGS="-s MEMORY64 -m64 -pipe -sMEMORY64=1" \
+    -DCMAKE_CXX_FLAGS="-s MEMORY64 -m64 -pipe -sMEMORY64=1" \
+    -DCMAKE_EXE_LINKER_FLAGS="-sMEMORY64=1 -m64 -Wl,-mwasm64 -sASYNCIFY=1" \
+    -DCMAKE_C_LINK_FLAGS="-sMEMORY64=1 -m64 -Wl,-mwasm64 -sASYNCIFY=1" \
+    -DCMAKE_CXX_LINK_FLAGS="-sMEMORY64=1 -m64 -Wl,-mwasm64 -sASYNCIFY=1"
+
+cmake --build "$OUTDIR" -- -j$NUM_JOBS

.patch/openssl-cmake/0005-wasm-support.patch

@@ -0,0 +1,40 @@
+diff --git a/cmake/ConfigureOpenSSL.cmake b/cmake/ConfigureOpenSSL.cmake
+index 3012e05..2ae23ff 100644
+--- a/cmake/ConfigureOpenSSL.cmake
++++ b/cmake/ConfigureOpenSSL.cmake
+@@ -108,7 +108,8 @@ function(configure_openssl)
+     )
+ 
+     if(NOT "${CONFIGURE_OPTIONS_OLD}" STREQUAL "")
+-        if(CONFIGURE_OPTIONS STREQUAL CONFIGURE_OPTIONS_OLD)
++        # TODO(lizzie): Emscripten has issues with rebuilding due to the wrapper it uses
++        if(CMAKE_SYSTEM_NAME MATCHES "Emscripten" OR CONFIGURE_OPTIONS STREQUAL CONFIGURE_OPTIONS_OLD)
+             message(STATUS "Found previous configure results. Don't perform configuration")
+             return()
+         endif()
+@@ -134,10 +135,24 @@ function(configure_openssl)
+         set(VERBOSE_OPTION OUTPUT_QUIET)
+     endif()
+ 
++    if (CMAKE_SYSTEM_NAME MATCHES "Emscripten")
++        set(EMSCRIPTEN_CMAKE_WRAPPER "emcmake")
++        find_program(EMCC emcc REQUIRED)
++        set(EMSCRIPTEN_LINKER ${EMCC})
++        list(APPEND CONFIGURE_COMMAND wasm64)
++    else()
++        set(EMSCRIPTEN_CMAKE_WRAPPER "")
++        set(EMSCRIPTEN_LINKER ${CMAKE_LINKER})
++    endif ()
++
+     execute_process(
+-        COMMAND ${CMAKE_COMMAND} -E env
++        COMMAND ${EMSCRIPTEN_CMAKE_WRAPPER} ${CMAKE_COMMAND} -E env
+             "CFLAGS=${CMAKE_C_FLAGS}"
+             "CXXFLAGS=${CMAKE_CXX_FLAGS}"
++            "LDFLAGS=${CMAKE_CXX_LINK_FLAGS}"
++            "CC=${CMAKE_C_COMPILER}"
++            "CXX=${CMAKE_CXX_COMPILER}"
++            "LD=${EMSCRIPTEN_LINKER}"
+             ${CONFIGURE_COMMAND}
+         WORKING_DIRECTORY ${CONFIGURE_BUILD_DIR}
+         ${VERBOSE_OPTION}

.patch/openssl/0002-wasm-support.patch

@@ -0,0 +1,112 @@
+diff --git a/Configurations/10-main.conf b/Configurations/10-main.conf
+index e62721e..243feb4 100644
+--- a/Configurations/10-main.conf
++++ b/Configurations/10-main.conf
+@@ -1970,6 +1970,26 @@ my %targets = (
+         multilib         => "64",
+     },
+ 
++    "wasm32" => {
++        inherit_from     => [ "BASE_unix" ],
++        CC               => "emcc",
++        CXX              => "emc++",
++        cflags           => combine("--target=wasm32-unknown-emscripten", threads("-pthread")),
++        cxxflags         => combine("--target=wasm32-unknown-emscripten", threads("-pthread")),
++        lib_cppflags     => add("-DL_ENDIAN"),
++        bn_ops           => "THIRTY_TWO_BIT",
++    },
++    "wasm64" => {
++        inherit_from     => [ "BASE_unix" ],
++        CC               => "emcc",
++        CXX              => "emc++",
++        cflags           => combine("--target=wasm64-unknown-emscripten", threads("-pthread")),
++        cxxflags         => combine("--target=wasm64-unknown-emscripten", threads("-pthread")),
++        lib_cppflags     => add("-DL_ENDIAN"),
++        bn_ops           => "SIXTY_FOUR_BIT_LONG",
++    },
++
++
+ #### uClinux
+     "uClinux-dist" => {
+         inherit_from     => [ "BASE_unix" ],
+diff --git a/crypto/rand/rand_lib.c b/crypto/rand/rand_lib.c
+index d9e8f02..7faf347 100644
+--- a/crypto/rand/rand_lib.c
++++ b/crypto/rand/rand_lib.c
+@@ -379,17 +379,27 @@ void RAND_add(const void *buf, int num, double randomness)
+ #if !defined(OPENSSL_NO_DEPRECATED_1_1_0)
+ int RAND_pseudo_bytes(unsigned char *buf, int num)
+ {
++#if defined(__wasi__)
++    arc4random_buf(buf, num);
++    return 1;
++#elif defined(__EMSCRIPTEN__)
++    return 1;
++#else
+     const RAND_METHOD *meth = RAND_get_rand_method();
+ 
+     if (meth != NULL && meth->pseudorand != NULL)
+         return meth->pseudorand(buf, num);
+     ERR_raise(ERR_LIB_RAND, RAND_R_FUNC_NOT_IMPLEMENTED);
+     return -1;
++#endif
+ }
+ #endif
+ 
+ int RAND_status(void)
+ {
++#if defined(__EMSCRIPTEN__) || defined(__wasi__)
++    return 1;
++#else
+     EVP_RAND_CTX *rand;
+ #ifndef OPENSSL_NO_DEPRECATED_3_0
+     const RAND_METHOD *meth = RAND_get_rand_method();
+@@ -401,6 +411,7 @@ int RAND_status(void)
+     if ((rand = RAND_get0_primary(NULL)) == NULL)
+         return 0;
+     return EVP_RAND_get_state(rand) == EVP_RAND_STATE_READY;
++#endif
+ }
+ #else /* !FIPS_MODULE */
+ 
+@@ -420,6 +431,12 @@ const RAND_METHOD *RAND_get_rand_method(void)
+ int RAND_priv_bytes_ex(OSSL_LIB_CTX *ctx, unsigned char *buf, size_t num,
+     unsigned int strength)
+ {
++#if defined(__wasi__)
++    arc4random_buf(buf, num);
++    return 1;
++#elif defined(__EMSCRIPTEN__)
++    return 1;
++#else
+     RAND_GLOBAL *dgbl;
+     EVP_RAND_CTX *rand;
+ #if !defined(OPENSSL_NO_DEPRECATED_3_0) && !defined(FIPS_MODULE)
+@@ -451,6 +468,7 @@ int RAND_priv_bytes_ex(OSSL_LIB_CTX *ctx, unsigned char *buf, size_t num,
+         return EVP_RAND_generate(rand, buf, num, strength, 0, NULL, 0);
+ 
+     return 0;
++#endif
+ }
+ 
+ int RAND_priv_bytes(unsigned char *buf, int num)
+diff --git a/ssl/ssl_cert.c b/ssl/ssl_cert.c
+index 3d21801..e026f8f 100644
+--- a/ssl/ssl_cert.c
++++ b/ssl/ssl_cert.c
+@@ -941,6 +941,7 @@ done:
+     return ret;
+ }
+ 
++#ifndef OPENSSL_NO_POSIX_IO
+ int SSL_add_dir_cert_subjects_to_stack(STACK_OF(X509_NAME) *stack,
+     const char *dir)
+ {
+@@ -1016,6 +1017,7 @@ err:
+ 
+     return ret;
+ }
++#endif
+ 
+ static int add_uris_recursive(STACK_OF(X509_NAME) *stack,
+     const char *uri, int depth)

CMakeLists.txt

@@ -375,6 +375,15 @@ set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${PROJECT_BINARY_DIR}/bin)
 # Prefer the -pthread flag on Linux.
 set(THREADS_PREFER_PTHREAD_FLAG ON)
 find_package(Threads REQUIRED)
+# It is absolutely promordial to enable on Emscripten
+# Not only this allows to use std::thread and std::jthread without exceptions
+# but it also fixes several issues related to MT operations.
+# ...and CMake doesn't include it by default even when we specify
+# that we prefer the pthread flag; why is that? I don't know.
+if (PLATFORM_EMSCRIPTEN)
+    add_compile_options($<$<COMPILE_LANGUAGE:C,CXX>:-pthread>)
+    add_link_options($<$<COMPILE_LANGUAGE:C,CXX>:-pthread>)
+endif()
 
 find_package(RenderDoc MODULE)
 
@@ -403,7 +412,12 @@ set(BUILD_TESTING OFF)
 set(ENABLE_TESTING OFF)
 
 # boost
-set(BOOST_INCLUDE_LIBRARIES algorithm icl pool container heap asio headers process filesystem crc variant)
+if (PLATFORM_EMSCRIPTEN)
+    set(BOOST_INCLUDE_LIBRARIES algorithm icl pool container heap headers filesystem crc variant)
+    set(BOOST_CONTAINER_HEADER_ONLY ON)
+else()
+    set(BOOST_INCLUDE_LIBRARIES algorithm icl pool container heap asio headers process filesystem crc variant)
+endif()
 
 AddJsonPackage(boost)
 
@@ -424,10 +438,12 @@ if (Boost_ADDED)
 
         target_compile_options(boost_heap INTERFACE $<$<COMPILE_LANGUAGE:C,CXX>:-Wno-shadow>)
         target_compile_options(boost_icl INTERFACE $<$<COMPILE_LANGUAGE:C,CXX>:-Wno-shadow>)
-        target_compile_options(boost_asio INTERFACE
-            $<$<COMPILE_LANGUAGE:C,CXX>:-Wno-conversion>
-            $<$<COMPILE_LANGUAGE:C,CXX>:-Wno-implicit-fallthrough>
-        )
+        # May not exist (i.e emscripten)
+        if (TARGET boost_asio)
+            target_compile_options(boost_asio INTERFACE
+                $<$<COMPILE_LANGUAGE:C,CXX>:-Wno-conversion>
+                $<$<COMPILE_LANGUAGE:C,CXX>:-Wno-implicit-fallthrough>)
+        endif()
     endif()
 endif()
 

cpmfile.json

@@ -108,7 +108,7 @@
         "find_args": "MODULE GLOBAL",
         "hash": "159ed94965018f2a371d45a3bfc1961e5fb1549e501ded70a6b4532d7fe99d0579c18b5195aff6e35f96f399b426cea2650ec9fb75ef80d4c9edeccb51f2e6c9",
         "options": [
-            "HTTPLIB_REQUIRE_OPENSSL ON",
+            "HTTPLIB_REQUIRE_OPENSSL OFF",
             "HTTPLIB_DISABLE_MACOSX_AUTOMATIC_ROOT_CERTIFICATES ON"
         ],
         "patches": [
@@ -190,7 +190,8 @@
         "min_version": "3.0.0",
         "package": "OpenSSL",
         "patches": [
-            "0001-add-bundled-cert.patch"
+            "0001-add-bundled-cert.patch",
+            "0002-wasm-support.patch"
         ],
         "repo": "openssl/openssl",
         "version": "openssl-3.6.2"
@@ -213,7 +214,8 @@
             "0001-cpmutil-compat.patch",
             "0002-use-ccache.patch",
             "0003-use-cmake-compiler-flags.patch",
-            "0004-use-shell-wrapper.patch"
+            "0004-use-shell-wrapper.patch",
+            "0005-wasm-support.patch"
         ],
         "repo": "jimmy-park/openssl-cmake",
         "version": "3.6.2"

docs/Caveats.md

@@ -12,6 +12,7 @@
 - [NetBSD](#netbsd)
 - [MSYS2](#msys2)
 - [RedoxOS](#redoxos)
+- [WebAssembly](#webassembly)
 - [Windows](#windows)
   - [Windows 7, Windows 8 and Windows 8.1](#windows-7-windows-8-and-windows-81)
   - [Windows Vista and below](#windows-vista-and-below)
@@ -245,6 +246,22 @@ The package install may randomly hang at times, in which case it has to be resta
 
 When CMake invokes certain file syscalls - it may sometimes cause crashes or corruptions on the (kernel?) address space - so reboot the system if there is a "hang" in CMake.
 
+## WebAssembly
+
+**It doesn't run on a browser yet.**
+
+WebAssembly or "WASM" for short is a *mainly 32-bit* virtual "architecture" which we only bootstrap on 64-bit only. This means not only the program runs 2x slower than it would due to using JS BigInt, it also means we need to go out of our way to enable proper 64-bit support via `-sMEMORY64=1`, however once again, some Emscripten quirks force us to specify `-s MEMORY64` and `-sMEMORY64=1` at the same time: see the [CI build script](../.ci/wasm/build.sh).
+
+The WebAssembly target is very heavy on resources and requires at least 4 times the normal amount of resources that a native build would. Additionally, the only supported environment is Firefox at the moment, node.js and `wasmtime are not supported (PRs welcome!)
+
+If running under Firefox and you hit "out of memory" on dev console, close the entire tab, then open it back again, see [this issue](https://github.com/emscripten-core/emscripten/issues/8126).
+
+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
 
 ### Windows 7, Windows 8 and Windows 8.1

docs/Deps.md

@@ -359,6 +359,14 @@ pkgman install git cmake patch libfmt_devel nlohmann_json lz4_devel opus_devel b
 
 [Caveats](./Caveats.md#haikuos).
 
+</details>
+<details>
+<summary>WebAssembly</summary>
+
+Emscripten: The default installation should provide enough.
+
+[Caveats](./Caveats.md#wasm).
+
 </details>
 <details>
 <summary>RedoxOS</summary>

externals/cmake-modules/DetectArchitecture.cmake

@@ -94,6 +94,10 @@ function(detect_architecture_symbols)
 endfunction()
 
 # arches here are put in a sane default order of importance
+# EXCEPT FOR WASM, which must be probed for FIRST, because some genius
+# decided to also allow the host architecture to be defined when building
+# for the emscripten target, absolutely lovely detail.
+#
 # notably, amd64, arm64, and riscv (in order) are BY FAR the most common
 # mips is pretty popular in embedded
 # ppc64 is pretty popular in supercomputing
@@ -101,6 +105,11 @@ endfunction()
 # ia64 exists
 # the rest exist, but are probably less popular than ia64
 
+detect_architecture_symbols(
+    ARCH wasm
+    SYMBOLS
+        "__EMSCRIPTEN__")
+
 detect_architecture_symbols(
     ARCH arm64
     SYMBOLS
@@ -203,11 +212,6 @@ detect_architecture_symbols(
         "__loongarch__"
         "__loongarch64")
 
-detect_architecture_symbols(
-    ARCH wasm
-    SYMBOLS
-        "__EMSCRIPTEN__")
-
 # "generic" target
 # If you have reached this point, you're on some as-of-yet unsupported architecture.
 # See the docs up above for known unsupported architectures

externals/cmake-modules/DetectPlatform.cmake

@@ -20,6 +20,9 @@ elseif (${CMAKE_SYSTEM_NAME} STREQUAL "managarm")
     set(MANAGARM ON)
 elseif (${CMAKE_SYSTEM_NAME} STREQUAL "Haiku")
     set(HAIKUOS ON)
+elseif (${CMAKE_SYSTEM_NAME} STREQUAL "Emscripten")
+    set(EMSCRIPTEN ON)
+    message(WARNING "${CMAKE_LIBRARY_ARCHITECTURE} support is highly experimental!!!")
 endif()
 
 # BSD
@@ -97,3 +100,25 @@ if (MINGW)
     set(CMAKE_EXE_LINKER_FLAGS_RELEASE
         "${CMAKE_EXE_LINKER_FLAGS_RELEASE} ${MINGW_FLAGS}")
 endif()
+
+if (PLATFORM_EMSCRIPTEN)
+    set(EMSCRIPTEN_C_FLAGS "-s MEMORY64 -m64 -pipe -sMEMORY64=1")
+    set(EMSCRIPTEN_LINK_FLAGS "-sMEMORY64=1 -m64 -Wl,-mwasm64 -sASYNCIFY=1")
+
+    # This prevents FFmpeg and other libraries from assuming it's the host's CPU
+    # Additionally some Emscripten installs may not be very good... generally
+    set(EMSCRIPTEN_SYSTEM_PROCESSOR wasm)
+    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${EMSCRIPTEN_C_FLAGS}")
+    set(CMAKE_CXX_FLAGS "${CMAKE_C_FLAGS} ${EMSCRIPTEN_C_FLAGS}")
+    set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} ${EMSCRIPTEN_LINK_FLAGS}")
+    set(CMAKE_C_LINK_FLAGS "${CMAKE_C_LINK_FLAGS} ${EMSCRIPTEN_LINK_FLAGS}")
+    set(CMAKE_CXX_LINK_FLAGS "${CMAKE_CXX_LINK_FLAGS} ${EMSCRIPTEN_LINK_FLAGS}")
+
+    unset(EMSCRIPTEN_C_FLAGS)
+    unset(EMSCRIPTEN_LINK_FLAGS)
+endif()
+
+# awesome
+if (PLATFORM_FREEBSD OR PLATFORM_DRAGONFLYBSD)
+    set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -L${CMAKE_SYSROOT}/usr/local/lib")
+endif()

externals/ffmpeg/CMakeLists.txt

@@ -37,26 +37,39 @@ if (NOT YUZU_USE_BUNDLED_FFMPEG)
     elseif (NOT (CMAKE_HOST_SYSTEM_PROCESSOR MATCHES CMAKE_SYSTEM_PROCESSOR
     AND CMAKE_HOST_SYSTEM_NAME MATCHES CMAKE_SYSTEM_NAME))
         string(TOLOWER "${CMAKE_SYSTEM_NAME}" FFmpeg_SYSTEM_NAME)
-        if (FFmpeg_SYSTEM_NAME STREQUAL "openorbis" OR FFmpeg_SYSTEM_NAME STREQUAL "managarm")
+        # All of these platforms are supported by ffmpeg as native build OSes
+        # anything else (like Redox or Managarm or PS4) is NOT natively supported
+        # hence, assume the "unix like" is just "none" for the sake of OUR sanity.
+        # If YOUR OS/platform has actual native support:
+        # 1. fucking congrats
+        # 2. feel free to add it on the condition below
+        if (NOT (PLATFORM_NETBSD OR PLATFORM_SUN OR PLATFORM_FREEBSD
+        OR PLATFORM_OPENBSD OR PLATFORM_DRAGONFLYBSD OR PLATFORM_HAIKU
+        OR PLATFORM_LINUX OR PLATFORM_MSYS OR WIN32 OR ANDROID OR APPLE))
             set(FFmpeg_SYSTEM_NAME "none")
         endif()
         # TODO: Can we really do better? Auto-detection? Something clever?
         list(APPEND FFmpeg_CROSS_COMPILE_FLAGS
             --enable-cross-compile
             --arch="${CMAKE_SYSTEM_PROCESSOR}"
-            --target-os="${FFmpeg_SYSTEM_NAME}"
-            --sysroot="${CMAKE_SYSROOT}"
-        )
+            --target-os="${FFmpeg_SYSTEM_NAME}")
+        if (PLATFORM_EMSCRIPTEN)
+            # funniest trolling from emscripten, such a classic!
+            # maybe I should PR so they use CMAKE_SYSROOT... y'know?
+            list(APPEND FFmpeg_CROSS_COMPILE_FLAGS --sysroot="${EMSCRIPTEN_SYSROOT}")
+        else()
+            list(APPEND FFmpeg_CROSS_COMPILE_FLAGS --sysroot="${CMAKE_SYSROOT}")
+        endif()
         if (DEFINED FFmpeg_CROSS_PREFIX)
             list(APPEND FFmpeg_CROSS_COMPILE_FLAGS --cross-prefix="${FFmpeg_CROSS_PREFIX}")
         else()
-            message(WARNING "Please set FFmpeg_CROSS_PREFIX to your cross toolchain prefix, for example: \${CMAKE_STAGING_PREFIX}/bin/${CMAKE_SYSTEM_PROCESSOR}-${CMAKE_SYSTEM_NAME}-")
+            message(WARNING "Please set FFmpeg_CROSS_PREFIX to your cross toolchain prefix, for example: ${CMAKE_STAGING_PREFIX}/bin/${CMAKE_SYSTEM_PROCESSOR}-${CMAKE_SYSTEM_NAME}")
         endif()
         set(FFmpeg_IS_CROSS_COMPILING TRUE)
     endif()
 endif()
 
-if (OPENORBIS OR MANAGARM)
+if (OPENORBIS OR MANAGARM OR EMSCRIPTEN)
     # Doesn't support VA-API, don't go thru the embarrassment of trying to enable it
     list(APPEND FFmpeg_HWACCEL_FLAGS --disable-vaapi)
 elseif (ANDROID)
@@ -164,8 +177,7 @@ if (OPENORBIS)
         -lSceUserService
         -lSceSysmodule
         -lSceNet
-        -lSceLibcInternal
-    )
+        -lSceLibcInternal)
     list(APPEND FFmpeg_CROSS_COMPILE_FLAGS
         --disable-pthreads
         --extra-cflags=${CMAKE_SYSROOT}/usr/include
@@ -176,8 +188,18 @@ elseif (MANAGARM)
     # Required for proper stuff
     list(APPEND FFmpeg_CROSS_COMPILE_FLAGS
         --disable-pthreads
-        --extra-libs="${FFmpeg_CROSS_COMPILE_LIBS}"
-    )
+        --extra-libs="${FFmpeg_CROSS_COMPILE_LIBS}")
+endif()
+
+# Usually used by Emscripten
+if (DEFINED CMAKE_AR)
+    list(APPEND FFmpeg_CROSS_COMPILE_FLAGS --ar=${CMAKE_AR})
+endif()
+if (DEFINED CMAKE_NM)
+    list(APPEND FFmpeg_CROSS_COMPILE_FLAGS --nm=${CMAKE_NM})
+endif()
+if (DEFINED CMAKE_RANLIB)
+    list(APPEND FFmpeg_CROSS_COMPILE_FLAGS --ranlib=${CMAKE_RANLIB})
 endif()
 
 if (YUZU_USE_BUNDLED_FFMPEG)
@@ -207,6 +229,7 @@ else()
     # Build FFmpeg from externals
     message(STATUS "Using FFmpeg from externals")
 
+    set(FFmpeg_LD ${CMAKE_LINKER})
     if (CMAKE_SYSTEM_PROCESSOR MATCHES "(x86_64|amd64)")
         # FFmpeg has source that requires one of nasm or yasm to assemble it.
         # REQUIRED throws an error if not found here during configuration rather than during compilation.
@@ -215,6 +238,12 @@ else()
             message(FATAL_ERROR "One of either `nasm` or `yasm` not found but is required.")
         endif()
     endif()
+    if (CMAKE_SYSTEM_NAME STREQUAL "Emscripten")
+        # TODO: this is 100% redundant but we need it because CMAKE_LINKER can resolve to ld.lld
+        # which is NOT compatible
+        find_program(EMCC NAMES emcc REQUIRED)
+        set(FFmpeg_LD ${EMCC})
+    endif()
 
     find_program(AUTOCONF autoconf)
     if ("${AUTOCONF}" STREQUAL "AUTOCONF-NOTFOUND")
@@ -248,7 +277,13 @@ else()
             CACHE PATH "Paths to FFmpeg libraries" FORCE)
     endforeach()
 
-    find_program(BASH_PROGRAM bash REQUIRED)
+    # Some SDKs (especially wasm) require us, actually, WANT us to use their "emconfigure"
+    # otherwise they will cry a billion tears
+    if (PLATFORM_EMSCRIPTEN)
+        find_program(FFmpeg_CONFIGURE_WRAPPER emconfigure REQUIRED)
+    else()
+        find_program(FFmpeg_CONFIGURE_WRAPPER bash REQUIRED)
+    endif()
 
     # `configure` parameters builds only exactly what yuzu needs from FFmpeg
     # `--disable-vdpau` is needed to avoid linking issues
@@ -258,7 +293,7 @@ else()
         OUTPUT
             ${FFmpeg_MAKEFILE}
         COMMAND
-            ${BASH_PROGRAM} ${FFmpeg_PREFIX}/configure
+            ${FFmpeg_CONFIGURE_WRAPPER} ${FFmpeg_PREFIX}/configure
                 --disable-avdevice
                 --disable-avformat
                 --disable-doc
@@ -267,6 +302,10 @@ else()
                 --disable-ffprobe
                 --disable-network
                 --disable-swresample
+                --disable-autodetect
+                --disable-runtime-cpudetect
+                --disable-debug
+                --disable-programs
                 --enable-decoder=h264
                 --enable-decoder=vp8
                 --enable-decoder=vp9
@@ -274,7 +313,7 @@ else()
                 --enable-pic
                 --cc=${FFmpeg_CC}
                 --cxx=${FFmpeg_CXX}
-                --ld=${CMAKE_LINKER}
+                --ld=${FFmpeg_LD}
                 --extra-cflags=${CMAKE_C_FLAGS}
                 --extra-cxxflags=${CMAKE_CXX_FLAGS}
                 --extra-ldflags=${CMAKE_C_LINK_FLAGS}
@@ -290,11 +329,7 @@ else()
 
     # Workaround for Ubuntu 18.04's older version of make not being able to call make as a child
     # with context of the jobserver. Also helps ninja users.
-    execute_process(
-        COMMAND
-            nproc
-        OUTPUT_VARIABLE
-            SYSTEM_THREADS)
+    cmake_host_system_information(RESULT SYSTEM_THREADS QUERY NUMBER_OF_LOGICAL_CORES)
 
     set(FFmpeg_BUILD_LIBRARIES ${FFmpeg_LIBRARIES})
 
@@ -302,6 +337,8 @@ else()
     if (LINUX OR ANDROID OR APPLE OR WIN32 OR FREEBSD)
         set(FFmpeg_MAKE_ARGS -j${SYSTEM_THREADS})
     else()
+        # No GNU make implies that this system may be highly non-GNU
+        find_program(MAKE make required)
         set(FFmpeg_MAKE_ARGS "")
     endif()
 
@@ -309,7 +346,7 @@ else()
         OUTPUT
             ${FFmpeg_BUILD_LIBRARIES}
         COMMAND
-            gmake ${FFmpeg_MAKE_ARGS}
+            ${MAKE} ${FFmpeg_MAKE_ARGS}
         WORKING_DIRECTORY
             ${FFmpeg_BUILD_DIR}
     )

externals/tz/tz/tz.cpp

@@ -14,7 +14,9 @@
 namespace Tz {
 
 namespace {
+#ifndef EINVAL
 #define EINVAL 22
+#endif
 
 static Rule gmtmem{};
 static Rule* const gmtptr = &gmtmem;

src/CMakeLists.txt

@@ -177,7 +177,6 @@ else()
         $<$<COMPILE_LANGUAGE:C,CXX>:-Wno-invalid-offsetof>
         $<$<COMPILE_LANGUAGE:C,CXX>:-Wno-unused-parameter>
         $<$<COMPILE_LANGUAGE:C,CXX>:-Wno-missing-field-initializers>)
-
     if (CXX_CLANG OR CXX_ICC OR CXX_APPLE) # Clang, AppleClang, or Intel C++
         if (NOT MSVC)
             add_compile_options(
@@ -191,7 +190,11 @@ else()
             $<$<COMPILE_LANGUAGE:C,CXX>:-Wno-nullability-completeness>)
     endif()
 
-    if (ARCHITECTURE_x86_64)
+    if (ARCHITECTURE_wasm)
+        # we are evil but fmt is even more evil
+        add_compile_options(
+            $<$<COMPILE_LANGUAGE:C,CXX>:-Wno-shorten-64-to-32>)
+    elseif (ARCHITECTURE_x86_64)
         add_compile_options($<$<COMPILE_LANGUAGE:C,CXX>:-mcx16>)
         if (LINUX OR FREEBSD)
             add_compile_options($<$<COMPILE_LANGUAGE:C,CXX>:-mtls-dialect=gnu2>)

src/common/CMakeLists.txt

@@ -235,7 +235,11 @@ else()
     target_link_libraries(common PUBLIC Boost::headers)
 endif()
 target_link_libraries(common PRIVATE OpenSSL::SSL)
-target_link_libraries(common PUBLIC Boost::filesystem Boost::context httplib::httplib nlohmann_json::nlohmann_json)
+target_link_libraries(common PUBLIC Boost::filesystem httplib::httplib nlohmann_json::nlohmann_json)
+if (NOT PLATFORM_EMSCRIPTEN)
+    # Emscripten is: "bring your own implementation", boost doesn't add upstream support sadly
+    target_link_libraries(common PRIVATE Boost::context)
+endif()
 
 if (lz4_ADDED)
     target_include_directories(common PRIVATE ${lz4_SOURCE_DIR}/lib)

src/common/fiber.cpp

@@ -11,7 +11,12 @@
 #include "common/fiber.h"
 #include "common/virtual_buffer.h"
 
+#ifdef __EMSCRIPTEN__
+#include <emscripten.h>
+#include <emscripten/fiber.h>
+#else
 #include <boost/context/detail/fcontext.hpp>
+#endif
 
 namespace Common {
 
@@ -22,36 +27,103 @@ constexpr size_t DEFAULT_STACK_SIZE = 512 * 4096;
 #endif
 constexpr u32 CANARY_VALUE = 0xDEADBEEF;
 
+#ifdef __EMSCRIPTEN__
 struct Fiber::FiberImpl {
     FiberImpl() {}
 
     u32 canary_1 = CANARY_VALUE;
     std::array<u8, DEFAULT_STACK_SIZE> stack{};
-    std::array<u8, DEFAULT_STACK_SIZE> rewind_stack{};
+    std::array<u8, DEFAULT_STACK_SIZE> astack{};
     u32 canary_2 = CANARY_VALUE;
 
-    boost::context::detail::fcontext_t context{};
-    boost::context::detail::fcontext_t rewind_context{};
+    emscripten_fiber_t* context{nullptr};
 
     std::mutex guard;
     std::function<void()> entry_point;
-    std::function<void()> rewind_point;
     std::shared_ptr<Fiber> previous_fiber;
-
-    u8* stack_limit = nullptr;
-    u8* rewind_stack_limit = nullptr;
     bool is_thread_fiber = false;
     bool released = false;
 };
 
-void Fiber::SetRewindPoint(std::function<void()>&& rewind_func) {
-    impl->rewind_point = std::move(rewind_func);
+Fiber::Fiber(std::function<void()>&& entry_point_func) : impl{std::make_unique<FiberImpl>()} {
+    impl->entry_point = std::move(entry_point_func);
+    emscripten_fiber_init(impl->context, [](void *user_data) -> void {
+        auto* fiber = static_cast<Fiber*>(user_data);
+        ASSERT(fiber && fiber->impl && fiber->impl->previous_fiber && fiber->impl->previous_fiber->impl);
+        ASSERT(fiber->impl->canary_1 == CANARY_VALUE);
+        ASSERT(fiber->impl->canary_2 == CANARY_VALUE);
+        fiber->impl->previous_fiber->impl->context = fiber->impl->context;
+        fiber->impl->previous_fiber->impl->guard.unlock();
+        fiber->impl->previous_fiber.reset();
+        fiber->impl->entry_point();
+        UNREACHABLE();
+    }, impl.get(), impl->stack.data(), impl->stack.size(), impl->astack.data(), impl->astack.size());
 }
 
+Fiber::Fiber() : impl{std::make_unique<FiberImpl>()} {}
+
+Fiber::~Fiber() {
+    if (!impl->released) {
+        // Make sure the Fiber is not being used
+        const bool locked = impl->guard.try_lock();
+        ASSERT(locked && "Destroying a fiber that's still running");
+        if (locked) {
+            impl->guard.unlock();
+        }
+    }
+}
+
+void Fiber::Exit() {
+    ASSERT(impl->is_thread_fiber && "Exiting non main thread fiber");
+    if (impl->is_thread_fiber) {
+        impl->guard.unlock();
+        impl->released = true;
+    }
+}
+
+void Fiber::YieldTo(std::weak_ptr<Fiber> weak_from, Fiber& to) {
+    to.impl->guard.lock();
+    to.impl->previous_fiber = weak_from.lock();
+    emscripten_fiber_swap(to.impl->context, to.impl->previous_fiber->impl->context);
+    // "from" might no longer be valid if the thread was killed
+    if (auto from = weak_from.lock()) {
+        if (from->impl->previous_fiber == nullptr) {
+            ASSERT(false && "previous_fiber is nullptr!");
+        } else {
+            from->impl->previous_fiber->impl->guard.unlock();
+            from->impl->previous_fiber.reset();
+        }
+    }
+}
+
+std::shared_ptr<Fiber> Fiber::ThreadToFiber() {
+    std::shared_ptr<Fiber> fiber = std::shared_ptr<Fiber>{new Fiber()};
+    fiber->impl->guard.lock();
+    fiber->impl->is_thread_fiber = true;
+    return fiber;
+}
+#else
+struct Fiber::FiberImpl {
+    FiberImpl() {}
+
+    u32 canary_1 = CANARY_VALUE;
+    std::array<u8, DEFAULT_STACK_SIZE> stack{};
+    u32 canary_2 = CANARY_VALUE;
+
+    boost::context::detail::fcontext_t context{};
+
+    std::mutex guard;
+    std::function<void()> entry_point;
+    std::shared_ptr<Fiber> previous_fiber;
+
+    u8* stack_limit = nullptr;
+    bool is_thread_fiber = false;
+    bool released = false;
+};
+
 Fiber::Fiber(std::function<void()>&& entry_point_func) : impl{std::make_unique<FiberImpl>()} {
     impl->entry_point = std::move(entry_point_func);
     impl->stack_limit = impl->stack.data();
-    impl->rewind_stack_limit = impl->rewind_stack.data();
     u8* stack_base = impl->stack_limit + DEFAULT_STACK_SIZE;
     impl->context = boost::context::detail::make_fcontext(stack_base, impl->stack.size(), [](boost::context::detail::transfer_t transfer) -> void {
         auto* fiber = static_cast<Fiber*>(transfer.data);
@@ -72,7 +144,7 @@ Fiber::~Fiber() {
     if (!impl->released) {
         // Make sure the Fiber is not being used
         const bool locked = impl->guard.try_lock();
-        ASSERT_MSG(locked, "Destroying a fiber that's still running");
+        ASSERT(locked && "Destroying a fiber that's still running");
         if (locked) {
             impl->guard.unlock();
         }
@@ -80,7 +152,7 @@ Fiber::~Fiber() {
 }
 
 void Fiber::Exit() {
-    ASSERT_MSG(impl->is_thread_fiber, "Exiting non main thread fiber");
+    ASSERT(impl->is_thread_fiber && "Exiting non main thread fiber");
     if (impl->is_thread_fiber) {
         impl->guard.unlock();
         impl->released = true;
@@ -110,5 +182,6 @@ std::shared_ptr<Fiber> Fiber::ThreadToFiber() {
     fiber->impl->is_thread_fiber = true;
     return fiber;
 }
+#endif
 
 } // namespace Common

src/common/fiber.h

@@ -1,4 +1,4 @@
-// SPDX-FileCopyrightText: Copyright 2025 Eden Emulator Project
+// SPDX-FileCopyrightText: Copyright 2026 Eden Emulator Project
 // SPDX-License-Identifier: GPL-3.0-or-later
 
 // SPDX-FileCopyrightText: Copyright 2020 yuzu Emulator Project
@@ -45,7 +45,6 @@ public:
     /// Fiber 'from' must be the currently running fiber.
     static void YieldTo(std::weak_ptr<Fiber> weak_from, Fiber& to);
     [[nodiscard]] static std::shared_ptr<Fiber> ThreadToFiber();
-    void SetRewindPoint(std::function<void()>&& rewind_func);
     /// Only call from main thread's fiber
     void Exit();
 private:

src/common/fs/path_util.cpp

@@ -136,6 +136,11 @@ public:
             eden_path = GetDataDirectory("XDG_DATA_HOME") / EDEN_DIR;
             eden_path_cache = GetDataDirectory("XDG_CACHE_HOME") / EDEN_DIR;
             eden_path_config = GetDataDirectory("XDG_CONFIG_HOME") / EDEN_DIR;
+#if defined(__EMSCRIPTEN__) || defined(__wasi__) || defined(__managarm__)
+            // folders MAY not exist in this distrobution/OS
+            CreateParentDir(GetDataDirectory("XDG_CONFIG_HOME"));
+            CreateParentDir(GetDataDirectory("XDG_CACHE_HOME"));
+#endif
         } else {
             eden_path_cache = eden_path / CACHE_DIR;
             eden_path_config = eden_path / CONFIG_DIR;

src/common/host_memory.cpp

@@ -394,7 +394,7 @@ private:
     ankerl::unordered_dense::map<size_t, size_t> placeholder_host_pointers; ///< Placeholder backing offset
 };
 
-#elif defined(__OPENORBIS__) || defined(__managarm__)
+#elif defined(__OPENORBIS__) || defined(__managarm__) || defined(__wasi__) || defined(__EMSCRIPTEN__)
 // None of the luxuries of POSIX, all of the suffering
 // For managarm: see https://github.com/managarm/managarm/issues/1370
 #else // ^^^ Windows ^^^ vvv POSIX vvv
@@ -689,7 +689,7 @@ HostMemory::HostMemory(size_t backing_size_, size_t virtual_size_)
     : backing_size(backing_size_)
     , virtual_size(virtual_size_)
 {
-#if defined(__OPENORBIS__) || defined(__managarm__)
+#if defined(__OPENORBIS__) || defined(__managarm__) || defined(__wasi__) || defined(__EMSCRIPTEN__)
     LOG_WARNING(HW_Memory, "Platform doesn't support fastmem");
     fallback_buffer.emplace(backing_size);
     backing_base = fallback_buffer->data();
@@ -723,7 +723,7 @@ HostMemory::HostMemory(HostMemory&&) noexcept = default;
 HostMemory& HostMemory::operator=(HostMemory&&) noexcept = default;
 
 void HostMemory::Map(size_t virtual_offset, size_t host_offset, size_t length, MemoryPermission perms, bool separate_heap) {
-#if !(defined(__OPENORBIS__) || defined(__managarm__))
+#if !(defined(__OPENORBIS__) || defined(__managarm__) || defined(__wasi__) || defined(__EMSCRIPTEN__))
     ASSERT(virtual_offset % PageAlignment == 0);
     ASSERT(host_offset % PageAlignment == 0);
     ASSERT(length % PageAlignment == 0);
@@ -737,7 +737,7 @@ void HostMemory::Map(size_t virtual_offset, size_t host_offset, size_t length, M
 }
 
 void HostMemory::Unmap(size_t virtual_offset, size_t length, bool separate_heap) {
-#if !(defined(__OPENORBIS__) || defined(__managarm__))
+#if !(defined(__OPENORBIS__) || defined(__managarm__) || defined(__wasi__) || defined(__EMSCRIPTEN__))
     ASSERT(virtual_offset % PageAlignment == 0);
     ASSERT(length % PageAlignment == 0);
     ASSERT(virtual_offset + length <= virtual_size);
@@ -749,7 +749,7 @@ void HostMemory::Unmap(size_t virtual_offset, size_t length, bool separate_heap)
 }
 
 void HostMemory::Protect(size_t virtual_offset, size_t length, MemoryPermission perm) {
-#if !(defined(__OPENORBIS__) || defined(__managarm__))
+#if !(defined(__OPENORBIS__) || defined(__managarm__) || defined(__wasi__) || defined(__EMSCRIPTEN__))
     ASSERT(virtual_offset % PageAlignment == 0);
     ASSERT(length % PageAlignment == 0);
     ASSERT(virtual_offset + length <= virtual_size);
@@ -768,7 +768,7 @@ void HostMemory::ClearBackingRegion(size_t physical_offset, size_t length, u32 f
 }
 
 void HostMemory::EnableDirectMappedAddress() {
-#if !(defined(__OPENORBIS__) || defined(__managarm__))
+#if !(defined(__OPENORBIS__) || defined(__managarm__) || defined(__wasi__) || defined(__EMSCRIPTEN__))
     if (impl) {
         impl->EnableDirectMappedAddress();
         virtual_size += reinterpret_cast<uintptr_t>(virtual_base);

src/common/host_memory.h

@@ -77,7 +77,7 @@ private:
     size_t backing_size{};
     size_t virtual_size{};
 
-#if !(defined(__OPENORBIS__) || defined(__managarm__))
+#if !(defined(__OPENORBIS__) || defined(__managarm__) || defined(__wasi__) || defined(__EMSCRIPTEN__))
     // Low level handler for the platform dependent memory routines
     class Impl;
     std::unique_ptr<Impl> impl;

src/common/thread.cpp

@@ -490,6 +490,8 @@ void SetCurrentThreadPriority(ThreadPriority new_priority) {
         LOG_DEBUG(Common, "Could not set thread nice value to {}: {}", nice_value,
                   GetLastErrorMsg());
     }
+#elif defined(__EMSCRIPTEN__)
+    // TODO: set priority?
 #else
     const s32 max_prio = sched_get_priority_max(SCHED_OTHER);
     const s32 min_prio = sched_get_priority_min(SCHED_OTHER);
@@ -534,6 +536,8 @@ void SetCurrentThreadName(const char* name) {
     // See for reference
     // https://gitlab.freedesktop.org/mesa/mesa/-/blame/main/src/util/u_thread.c?ref_type=heads#L75
     (void)name;
+#elif defined(__EMSCRIPTEN__)
+    // TODO: set thread name?
 #else
     pthread_setname_np(pthread_self(), name);
 #endif

src/core/CMakeLists.txt

@@ -38,10 +38,6 @@ add_library(core STATIC
     debugger/debugger.cpp
     debugger/debugger.h
     debugger/debugger_interface.h
-    debugger/gdbstub.cpp
-    debugger/gdbstub.h
-    debugger/gdbstub_arch.cpp
-    debugger/gdbstub_arch.h
     device_memory.cpp
     device_memory.h
     device_memory_manager.h
@@ -1170,6 +1166,14 @@ add_library(core STATIC
     tools/freezer.h
     tools/renderdoc.cpp
     tools/renderdoc.h)
+if (NOT PLATFORM_EMSCRIPTEN)
+    # incompatible with wasm's async model
+    target_sources(core PRIVATE
+        debugger/gdbstub.cpp
+        debugger/gdbstub.h
+        debugger/gdbstub_arch.cpp
+        debugger/gdbstub_arch.h)
+endif()
 
 if (ENABLE_WIFI_SCAN)
     target_sources(core PRIVATE internal_network/wifi_scanner.cpp)
@@ -1213,7 +1217,10 @@ target_include_directories(core PRIVATE ${OPUS_INCLUDE_DIRS})
 target_link_libraries(core PUBLIC common PRIVATE audio_core hid_core network video_core nx_tzdb tz)
 
 if (BOOST_NO_HEADERS)
-    target_link_libraries(core PUBLIC Boost::container Boost::heap Boost::asio Boost::process Boost::crc)
+    target_link_libraries(core PUBLIC Boost::container Boost::heap Boost::crc)
+    if (NOT PLATFORM_EMSCRIPTEN)
+        target_link_libraries(core PUBLIC Boost::asio Boost::process)
+    endif()
 else()
     target_link_libraries(core PUBLIC Boost::headers)
 endif()

src/core/arm/dynarmic/arm_dynarmic.h

@@ -6,19 +6,20 @@
 
 #pragma once
 
+#ifndef __EMSCRIPTEN__
 #include <dynarmic/interface/halt_reason.h>
-
+#endif
 #include "core/arm/arm_interface.h"
 
 namespace Core {
 
+#ifndef __EMSCRIPTEN__
 constexpr Dynarmic::HaltReason StepThread = Dynarmic::HaltReason::Step;
 constexpr Dynarmic::HaltReason DataAbort = Dynarmic::HaltReason::MemoryAbort;
 constexpr Dynarmic::HaltReason BreakLoop = Dynarmic::HaltReason::UserDefined2;
 constexpr Dynarmic::HaltReason SupervisorCall = Dynarmic::HaltReason::UserDefined3;
 constexpr Dynarmic::HaltReason InstructionBreakpoint = Dynarmic::HaltReason::UserDefined4;
 constexpr Dynarmic::HaltReason PrefetchAbort = Dynarmic::HaltReason::UserDefined6;
-
 constexpr HaltReason TranslateHaltReason(Dynarmic::HaltReason hr) {
     static_assert(u64(HaltReason::StepThread) == u64(StepThread));
     static_assert(u64(HaltReason::DataAbort) == u64(DataAbort));
@@ -28,5 +29,6 @@ constexpr HaltReason TranslateHaltReason(Dynarmic::HaltReason hr) {
     static_assert(u64(HaltReason::PrefetchAbort) == u64(PrefetchAbort));
     return HaltReason(hr);
 }
+#endif
 
 } // namespace Core

src/core/debugger/debugger.cpp

@@ -6,30 +6,54 @@
 
 #include <mutex>
 #include <utility>
+
+#if defined(__EMSCRIPTEN__) || defined(__wasi__)
+// TODO: gdb stub compat with emscripten?
+#else
 #include <boost/asio.hpp>
 #include <boost/version.hpp>
-
 #if BOOST_VERSION > 108400 && (!defined(_WINDOWS) && !defined(__ANDROID__)) || defined(YUZU_BOOST_v1)
 #define USE_BOOST_v1
 #endif
-
 #ifdef USE_BOOST_v1
 #include <boost/process/v1/async_pipe.hpp>
 #else
 #include <boost/process/async_pipe.hpp>
 #endif
+#endif
 
 #include "common/logging.h"
 #include "common/polyfill_thread.h"
 #include "common/thread.h"
 #include "core/core.h"
 #include "core/debugger/debugger.h"
+#if defined(__EMSCRIPTEN__) || defined(__wasi__)
+// TODO: gdbstub with emscripten?
+#else
 #include "core/debugger/debugger_interface.h"
 #include "core/debugger/gdbstub.h"
+#endif
 #include "core/hle/kernel/global_scheduler_context.h"
 #include "core/hle/kernel/k_process.h"
 #include "core/hle/kernel/k_scheduler.h"
 
+#if defined(__EMSCRIPTEN__) || defined(__wasi__)
+namespace Core {
+// Dummy
+class DebuggerImpl {
+    char pad;
+};
+Debugger::Debugger(Core::System& system, u16 port) {}
+Debugger::~Debugger() = default;
+bool Debugger::NotifyThreadStopped(Kernel::KThread* thread) {
+    return false;
+}
+bool Debugger::NotifyThreadWatchpoint(Kernel::KThread* thread, const Kernel::DebugWatchpoint& watch) {
+    return false;
+}
+void Debugger::NotifyShutdown() {}
+} // namespace Core
+#else
 template <typename Readable, typename Buffer, typename Callback>
 static void AsyncReceiveInto(Readable& r, Buffer& buffer, Callback&& c) {
     static_assert(std::is_trivial_v<Buffer>);
@@ -400,3 +424,4 @@ void Debugger::NotifyShutdown() {
 }
 
 } // namespace Core
+#endif

src/core/hle/kernel/k_process.cpp

@@ -7,8 +7,14 @@
 #include <random>
 #include "common/scope_exit.h"
 #include "common/settings.h"
+
+#include "core/arm/exclusive_monitor.h"
+#ifndef __EMSCRIPTEN__
 #include "core/arm/dynarmic/arm_dynarmic.h"
 #include "core/arm/dynarmic/dynarmic_exclusive_monitor.h"
+#include "core/arm/dynarmic/arm_dynarmic_32.h"
+#include "core/arm/dynarmic/arm_dynarmic_64.h"
+#endif
 #include "core/core.h"
 #include "core/hle/kernel/k_process.h"
 #include "core/hle/kernel/k_scoped_resource_reservation.h"
@@ -18,8 +24,6 @@
 #include "core/hle/kernel/k_thread_queue.h"
 #include "core/hle/kernel/k_worker_task_manager.h"
 
-#include "core/arm/dynarmic/arm_dynarmic_32.h"
-#include "core/arm/dynarmic/arm_dynarmic_64.h"
 #ifdef HAS_NCE
 #include "core/arm/nce/arm_nce.h"
 #endif
@@ -1300,9 +1304,11 @@ void KProcess::LoadModule(KernelCore& kernel, CodeSet code_set, KProcessAddress
 }
 
 void KProcess::InitializeInterfaces(KernelCore& kernel) {
+#ifdef __EMSCRIPTEN__
+    ASSERT(false && "unimplemented");
+#else
     m_exclusive_monitor =
         Core::MakeExclusiveMonitor(this->GetMemory(), Core::Hardware::NUM_CPU_CORES);
-
 #ifdef HAS_NCE
     if (this->IsApplication() && Settings::IsNceEnabled()) {
         for (size_t i = 0; i < Core::Hardware::NUM_CPU_CORES; i++)
@@ -1322,6 +1328,7 @@ void KProcess::InitializeInterfaces(KernelCore& kernel) {
                 static_cast<Core::DynarmicExclusiveMonitor&>(*m_exclusive_monitor), i);
         }
     }
+#endif
 }
 
 bool KProcess::InsertWatchpoint(KernelCore& kernel, KProcessAddress addr, u64 size, DebugWatchpointType type) {

src/core/hle/service/services.cpp

@@ -86,15 +86,22 @@ Services::Services(std::shared_ptr<SM::ServiceManager>& sm, Core::System& system
 
     // BEGONE cold clones of lambdas, for I have merged you all into a SINGLE lambda instead of
     // spamming lambdas like it's some kind of lambda calculus class
-    for (auto const& e : std::vector<std::pair<std::string_view, void (*)(Core::System&)>>{
+    std::vector<std::pair<std::string_view, void (*)(Core::System&)>> rt_services{
         {"audio",      &Audio::LoopProcess},
         {"FS",         &FileSystem::LoopProcess},
         {"ldn",        &LDN::LoopProcess},
         {"nvservices", &Nvidia::LoopProcess},
         {"bsdsocket",  &Sockets::LoopProcess},
-    })
+    };
+#if defined(__EMSCRIPTEN__) || defined(__wasi__) || defined(__OPENORBIS__)
+    for (auto const& e : rt_services)
+        kernel.RunOnGuestCoreProcess(std::string(e.first), [&system, f = e.second] { f(system); });
+    kernel.RunOnGuestCoreProcess("vi", [&, token] { VI::LoopProcess(system, token); });
+#else
+    for (auto const& e : rt_services)
         kernel.RunOnHostCoreProcess(std::string(e.first), [&system, f = e.second] { f(system); }).detach();
-    kernel.RunOnHostCoreProcess("vi",         [&, token] { VI::LoopProcess(system, token); }).detach();
+    kernel.RunOnHostCoreProcess("vi", [&, token] { VI::LoopProcess(system, token); }).detach();
+#endif
     // Avoid cold clones of lambdas -- succintly
     for (auto const& e : std::vector<std::pair<std::string_view, void (*)(Core::System&)>>{
         {"sm",         &SM::LoopProcess},
@@ -118,7 +125,10 @@ Services::Services(std::shared_ptr<SM::ServiceManager>& sm, Core::System& system
         {"glue",       &Glue::LoopProcess},
         {"grc",        &GRC::LoopProcess},
         {"hid",        &HID::LoopProcess},
+// Must match with src/core/CMakeLists.txt for target_source of jit.cpp
+#if defined(ARCHITECTURE_x86_64) || defined(ARCHITECTURE_arm64) || defined(ARCHITECTURE_riscv64) || defined(ARCHITECTURE_loongarch64)
         {"jit",        &JIT::LoopProcess},
+#endif
         {"lbl",        &LBL::LoopProcess},
         {"Loader",     &LDR::LoopProcess},
         {"LogManager.Prod", &LM::LoopProcess},

src/hid_core/resources/abstracted_pad/abstract_mcu_handler.h

@@ -28,7 +28,10 @@ enum class NpadMcuState : u32 {
 struct NpadMcuHolder {
     NpadMcuState state;
     INSERT_PADDING_BYTES(0x4);
-    IAbstractedPad* abstracted_pad;
+    union {
+        IAbstractedPad* abstracted_pad;
+        u64 abstracted_pad_raw;
+    };
 };
 static_assert(sizeof(NpadMcuHolder) == 0x10, "NpadMcuHolder is an invalid size");
 

src/hid_core/resources/shared_memory_holder.h

@@ -33,9 +33,15 @@ public:
     bool is_created{};
     bool is_mapped{};
     INSERT_PADDING_BYTES(0x5);
-    Kernel::KSharedMemory* shared_memory;
+    union {
+        Kernel::KSharedMemory* shared_memory = nullptr;
+        u64 shared_memory_raw;
+    };
     INSERT_PADDING_BYTES(0x38);
-    SharedMemoryFormat* address = nullptr;
+    union {
+        SharedMemoryFormat* address = nullptr;
+        u64 address_raw;
+    };
 };
 // Correct size is 0x50 bytes
 static_assert(sizeof(SharedMemoryHolder) == 0x50, "SharedMemoryHolder is an invalid size");

src/input_common/CMakeLists.txt

@@ -15,8 +15,6 @@ add_library(input_common STATIC
     drivers/tas_input.h
     drivers/touch_screen.cpp
     drivers/touch_screen.h
-    drivers/udp_client.cpp
-    drivers/udp_client.h
     drivers/virtual_amiibo.cpp
     drivers/virtual_amiibo.h
     drivers/virtual_gamepad.cpp
@@ -34,8 +32,12 @@ add_library(input_common STATIC
     input_poller.cpp
     input_poller.h
     main.cpp
-    main.h
-)
+    main.h)
+if (NOT PLATFORM_EMSCRIPTEN)
+    target_sources(input_common PRIVATE
+        drivers/udp_client.cpp
+        drivers/udp_client.h)
+endif()
 
 if (MSVC)
     target_compile_options(input_common PRIVATE

src/input_common/main.cpp

@@ -12,7 +12,6 @@
 #include "input_common/drivers/mouse.h"
 #include "input_common/drivers/tas_input.h"
 #include "input_common/drivers/touch_screen.h"
-#include "input_common/drivers/udp_client.h"
 #include "input_common/drivers/virtual_amiibo.h"
 #include "input_common/drivers/virtual_gamepad.h"
 #include "input_common/helpers/stick_from_buttons.h"
@@ -21,6 +20,9 @@
 #include "input_common/input_mapping.h"
 #include "input_common/input_poller.h"
 #include "input_common/main.h"
+#ifndef __EMSCRIPTEN__
+#include "input_common/drivers/udp_client.h"
+#endif
 
 #ifdef ENABLE_LIBUSB
 #include "input_common/drivers/gc_adapter.h"
@@ -82,7 +84,9 @@ struct InputSubsystem::Impl {
 #ifdef ENABLE_LIBUSB
         RegisterEngine("gcpad", gcadapter);
 #endif
+#ifndef __EMSCRIPTEN__
         RegisterEngine("cemuhookudp", udp_client);
+#endif
         RegisterEngine("tas", tas_input);
         RegisterEngine("camera", camera);
 #ifdef __ANDROID__
@@ -116,7 +120,9 @@ struct InputSubsystem::Impl {
 #ifdef ENABLE_LIBUSB
         UnregisterEngine(gcadapter);
 #endif
+#ifndef __EMSCRIPTEN__
         UnregisterEngine(udp_client);
+#endif
         UnregisterEngine(tas_input);
         UnregisterEngine(camera);
 #ifdef __ANDROID__
@@ -152,8 +158,10 @@ struct InputSubsystem::Impl {
         auto gcadapter_devices = gcadapter->GetInputDevices();
         devices.insert(devices.end(), gcadapter_devices.begin(), gcadapter_devices.end());
 #endif
+#ifndef __EMSCRIPTEN__
         auto udp_devices = udp_client->GetInputDevices();
         devices.insert(devices.end(), udp_devices.begin(), udp_devices.end());
+#endif
 #ifdef HAVE_SDL3
         auto joycon_devices = joycon->GetInputDevices();
         devices.insert(devices.end(), joycon_devices.begin(), joycon_devices.end());
@@ -186,9 +194,11 @@ struct InputSubsystem::Impl {
             return gcadapter;
         }
 #endif
+#ifndef __EMSCRIPTEN__
         if (engine == udp_client->GetEngineName()) {
             return udp_client;
         }
+#endif
 #ifdef HAVE_SDL3
         if (engine == sdl->GetEngineName()) {
             return sdl;
@@ -271,9 +281,11 @@ struct InputSubsystem::Impl {
             return true;
         }
 #endif
+#ifndef __EMSCRIPTEN__
         if (engine == udp_client->GetEngineName()) {
             return true;
         }
+#endif
         if (engine == tas_input->GetEngineName()) {
             return true;
         }
@@ -300,7 +312,9 @@ struct InputSubsystem::Impl {
 #ifdef ENABLE_LIBUSB
         gcadapter->BeginConfiguration();
 #endif
+#ifndef __EMSCRIPTEN__
         udp_client->BeginConfiguration();
+#endif
 #ifdef HAVE_SDL3
         sdl->BeginConfiguration();
         joycon->BeginConfiguration();
@@ -316,7 +330,9 @@ struct InputSubsystem::Impl {
 #ifdef ENABLE_LIBUSB
         gcadapter->EndConfiguration();
 #endif
+#ifndef __EMSCRIPTEN__
         udp_client->EndConfiguration();
+#endif
 #ifdef HAVE_SDL3
         sdl->EndConfiguration();
         joycon->EndConfiguration();
@@ -341,7 +357,9 @@ struct InputSubsystem::Impl {
     std::shared_ptr<Mouse> mouse;
     std::shared_ptr<TouchScreen> touch_screen;
     std::shared_ptr<TasInput::Tas> tas_input;
+#ifndef __EMSCRIPTEN__
     std::shared_ptr<CemuhookUDP::UDPClient> udp_client;
+#endif
     std::shared_ptr<Camera> camera;
     std::shared_ptr<VirtualAmiibo> virtual_amiibo;
     std::shared_ptr<VirtualGamepad> virtual_gamepad;
@@ -470,7 +488,9 @@ bool InputSubsystem::IsStickInverted(const Common::ParamPackage& params) const {
 }
 
 void InputSubsystem::ReloadInputDevices() {
+#ifndef __EMSCRIPTEN__
     impl->udp_client.get()->ReloadSockets();
+#endif
 }
 
 void InputSubsystem::BeginMapping(Polling::InputType type) {

src/shader_recompiler/CMakeLists.txt

@@ -257,8 +257,7 @@ else()
         # Bracket depth determines maximum size of a fold expression in Clang since 9c9974c3ccb6.
         # And this in turns limits the size of a std::array.
         $<$<CXX_COMPILER_ID:Clang>:-fbracket-depth=1024>
-        $<$<CXX_COMPILER_ID:AppleClang>:-fbracket-depth=1024>
-    )
+        $<$<CXX_COMPILER_ID:AppleClang>:-fbracket-depth=1024>)
 endif()
 
 create_target_directory_groups(shader_recompiler)

src/shader_recompiler/environment.h

@@ -31,7 +31,7 @@ struct CbufWordKey {
 
 struct CbufWordKeyHash {
     constexpr size_t operator()(const CbufWordKey& k) const noexcept {
-        return (size_t(k.index) << 32) ^ k.offset;
+        return size_t((u64(k.index) << 32) ^ u64(k.offset));
     }
 };
 

src/shader_recompiler/frontend/maxwell/translate/impl/texture_fetch_swizzled.cpp

@@ -1,3 +1,6 @@
+// SPDX-FileCopyrightText: Copyright 2026 Eden Emulator Project
+// SPDX-License-Identifier: GPL-3.0-or-later
+
 // SPDX-FileCopyrightText: Copyright 2021 yuzu Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
 
@@ -157,16 +160,14 @@ IR::Value Sample(TranslatorVisitor& v, u64 insn) {
 
 unsigned Swizzle(u64 insn) {
     const Encoding texs{insn};
-    const size_t encoding{texs.swizzle};
+    u8 const encoding = u8(texs.swizzle);
     if (texs.dest_reg_b == IR::Reg::RZ) {
-        if (encoding >= RG_LUT.size()) {
+        if (encoding >= RG_LUT.size())
             throw NotImplementedException("Illegal RG encoding {}", encoding);
-        }
         return RG_LUT[encoding];
     } else {
-        if (encoding >= RGBA_LUT.size()) {
+        if (encoding >= RGBA_LUT.size())
             throw NotImplementedException("Illegal RGBA encoding {}", encoding);
-        }
         return RGBA_LUT[encoding];
     }
 }

src/shader_recompiler/frontend/maxwell/translate/impl/texture_load_swizzled.cpp

@@ -1,3 +1,6 @@
+// SPDX-FileCopyrightText: Copyright 2026 Eden Emulator Project
+// SPDX-License-Identifier: GPL-3.0-or-later
+
 // SPDX-FileCopyrightText: Copyright 2021 yuzu Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
 
@@ -142,16 +145,14 @@ IR::Value Sample(TranslatorVisitor& v, u64 insn) {
 
 unsigned Swizzle(u64 insn) {
     const Encoding tlds{insn};
-    const size_t encoding{tlds.swizzle};
+    u8 const encoding = u8(tlds.swizzle);
     if (tlds.dest_reg_b == IR::Reg::RZ) {
-        if (encoding >= RG_LUT.size()) {
+        if (encoding >= RG_LUT.size())
             throw NotImplementedException("Illegal RG encoding {}", encoding);
-        }
         return RG_LUT[encoding];
     } else {
-        if (encoding >= RGBA_LUT.size()) {
+        if (encoding >= RGBA_LUT.size())
             throw NotImplementedException("Illegal RGBA encoding {}", encoding);
-        }
         return RGBA_LUT[encoding];
     }
 }

src/yuzu_cmd/CMakeLists.txt

@@ -75,3 +75,15 @@ if (NOT MSVC)
         $<$<COMPILE_LANGUAGE:C,CXX>:-Wno-unused-parameter>
         $<$<COMPILE_LANGUAGE:C,CXX>:-Wno-missing-field-initializers>)
 endif()
+
+if (PLATFORM_EMSCRIPTEN)
+    # 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']
+        -sPTHREAD_POOL_SIZE_STRICT=0
+        -sPTHREAD_POOL_SIZE=navigator.hardwareConcurrency)
+endif()

tools/README.md

@@ -30,6 +30,7 @@ Tools for Eden and other subprojects. When adding new scripts please use `#!/bin
 - `find-unused-strings.sh`: Find any unused strings in the Android app (XML -> Kotlin).
 - `cpp-lint.sh`: Homemade dumb C++ linter.
 - `fuzzsettings.cpp`: Fuzz settings files.
+- `miniserver.js`: Make a quick server that serves a page with the WASM on it, takes a single argument which is the path to the build directory containing *both* `eden-cli.js` and `eden-cli.wasm`. Run via `node.js`, `wasmtime` isn't supported.
 
 ## Android
 It's recommended to run these scritps after almost any Android change, as they are relatively fast and important both for APK bloat and CI.

tools/miniserver.js

@@ -0,0 +1,127 @@
+#!/usr/bin/env node
+// SPDX-FileCopyrightText: Copyright 2026 Eden Emulator Project
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+import { createServer } from 'http';
+import { readFile } from 'fs';
+import { join } from 'path';
+console.log(`dont forget to run: "npm --global install @jdmichaud/dwarf-2-sourcemap" for better debugging!`);
+const server = createServer((req, res) => {
+    console.log(`get ${req.url}`);
+    if (req.url === '/') {
+        // https://developer.mozilla.org/en-US/docs/WebAssembly/Guides/Loading_and_running
+        // If your browser doesn't support fetch... HAHA GET FUCKED
+        res.writeHead(200, {
+            'Content-Type': 'text/html',
+            'Cross-Origin-Opener-Policy': 'same-origin',
+            'Cross-Origin-Embedder-Policy': 'require-corp'
+        });
+        res.end(`<!DOCTYPE html>
+<html>
+<head>
+<title>eden-cli</title>
+</head>
+<body style="margin:0;padding:0;background-color:black;color:white;font-family:Monospace,Tahoma,Arial;">
+<div style="display:grid;grid-template-columns:1fr 1fr;gap:2px;width:100%;height:100vh;">
+    <canvas id="canvas" oncontextmenu="event.preventDefault()" style="width:100%;height:100%;background-color:gray;"></canvas>
+    <div id="tty-stdout"></div>
+</div>
+<script>
+var Module = { //do not prepend var
+    mainScriptUrlOrBlob: 'eden-cli.js',
+    arguments: ['--null-render', '--singlecore', '--filter', '*:Trace', '/home/web_user/game.nro'],
+    canvas: document.getElementById('canvas'),
+    print: (e) => {
+        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('[1;35m', '<span style="color:pink;font-weight:bold;">');
+        e = e.replace('[1;33m', '<span style="color:yellow;font-weight:bold;">');
+        e = e.replace('[0;36m', '<span style="color:white;font-weight:bold;">');
+        e = e.replace('[0m', '</span>');
+        document.getElementById('tty-stdout').innerHTML += \`\${e}</br>\`;
+    },
+    printErr: (e) => {
+        document.getElementById('tty-stdout').innerHTML += \`<span style="color:red">\${e}</span></br>\`;
+    },
+    // not a wasm func but idc
+    printInternal: (e) => {
+        document.getElementById('tty-stdout').innerHTML += \`<span style="color:white">Internal WASM: \${e}</span></br>\`;
+    },
+    preInit: [
+        () => {
+            // copy just most relevant :)
+            Module.FS.mkdir('/home/web_user/.local');
+            Module.FS.mkdir('/home/web_user/.local/share');
+            Module.FS.mkdir('/home/web_user/.local/share/eden');
+            Module.FS.mkdir('/home/web_user/.config');
+            Module.FS.mkdir('/home/web_user/.config/eden');
+            Module.FS.createDataFile('/home/web_user', 'game.nro', gameNroFileBuffer, true, false, true);
+        }
+    ],
+    onRuntimeInitialized: () => { Module.printInternal("runtime ok"); },
+    setStatus: (e) => { Module.printInternal(e); },
+    monitorRunDependencies: (e) => { Module.printInternal("monitor deps: " + e); },
+    __wasm_call_ctors: () => { Module.printInternal("ctors beep"); },
+};
+var gameNroFileBuffer = {};
+Module.printInternal(\`Atomics: \${window.Atomics}, 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.bytes();
+}).then((buffer) => {
+    gameNroFileBuffer = buffer;
+    // 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 = (e) => Module.printInternal(\`loaded WASMy script \${e}!!\`);
+    document.head.appendChild(script);
+}).catch(Module.printErr);
+</script>
+</body>
+</html>`);
+    } else if (req.url === '/eden-cli.js') {
+        readFile(join(build_dir, 'eden-cli.js'), (err, content) => {
+            res.writeHead(200, {
+                'Content-Type': 'application/javascript',
+                'Cross-Origin-Opener-Policy': 'same-origin',
+                'Cross-Origin-Embedder-Policy': 'require-corp'
+            });
+            res.end(content, 'utf-8');
+        });
+    } else if (req.url === '/eden-cli.wasm') {
+        readFile(join(build_dir, 'eden-cli.wasm'), (err, content) => {
+            res.writeHead(200, {
+                'Content-Type': 'application/wasm',
+                'Cross-Origin-Opener-Policy': 'same-origin',
+                'Cross-Origin-Embedder-Policy': 'require-corp'
+            });
+            res.end(content);
+        });
+    } else if (req.url === '/game.nro') {
+        readFile(nro_file, (err, content) => {
+            res.writeHead(200, {
+                'Content-Type': 'application/octet-stream',
+                'Cross-Origin-Opener-Policy': 'same-origin',
+                'Cross-Origin-Embedder-Policy': 'require-corp'
+            });
+            res.end(content);
+        });
+    } else {
+        res.writeHead(404, {});
+        res.end('', 'utf-8');
+    }
+});
+
+const build_dir = process.argv[2];
+const nro_file = process.argv[3];
+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`);
+        console.log(`build dir = ${build_dir}`);
+    });
+}