jpolo1224
0ce28165e5
A simpleperf profile of the RSX thread during Arkham City gameplay, 83261 samples:
24.91% vk::query_pool_manager::get_query_result
11.63% [kernel]
10.16% rsx::nv406e::semaphore_acquire
9.37% rsx::FIFO::FIFO_control::fetch_u32_refill
3.96% memcpy_opt
3.26% VKGSRender::do_local_task
get_query_result is a quarter of the thread on its own, and what it does is spin:
pause(), re-poke the query, repeat, until the GPU has the result. That is a
defensible trade on a desktop, where the answer lands in microseconds and there
are cores going spare. On a tiled mobile GPU the result is not available until
the tile pass resolves, so the wait is much longer, and this device runs eleven
hot emulator threads across five usable cores. The spin does not make the result
arrive sooner; it just denies the core to an SPU thread that had work.
Keeps a short 64-iteration spin so a nearly-ready result still returns without a
scheduler round trip, then yields. Android only.
Also scopes the wait as fence_wait, which is what it is. This was completely
invisible before: the bucket report attributed 0.072ms/frame to ZCULL and showed
nothing here, because the ZCULL scope covers zcull_ctrl->update and this is
reached by another path. A bucket reading zero means no scope reached it, not
that the work is free.
ARMSX3
Proof of concept Android port of RPCS3.
Uses the latest RPCS3 upstream code (the recent ARM64 improvements included).
Status
From my testing, I only tried Skate 3. It boots, loads and reaches gameplay at roughly 20 to 30 fps on a Snapdragon 8 Gen 2. Rendering, audio, touch controls and physical controllers work. Almost nothing else has been tested. So the main stop gap at the moment is performance/speed.
Differences from upstream RPCS3
Some of the fixes here are not in upstream and affect any ARM64 build, not only Android:
-
Shaders declared runtime sized arrays inside uniform blocks, which requires VK_EXT_shader_uniform_buffer_unsized_array. Adreno does not support that extension, so every game pipeline failed to compile and nothing rendered. Concrete array bounds are emitted when the extension is missing.
-
The ARM64 SPU block verification checksum folded two thirds of every block through an absolute difference. That collides on the near identical job binaries an SPU job manager streams through the same local store address, so a cached block could end up running against another job's code. It sums now.
-
Thread affinity was compiled out on Android, and the core had no ARM big.LITTLE topology, so SPU and RSX threads were never placed on the fast cores.
-
The LLVM JIT target was pinned to cortex-a34, an in order core from 2016. It detects the host now.
Building
Only arm64-v8a is supported. You need the Android SDK with NDK r27 or newer, CMake 3.30 or newer, and a JDK 17. Android Studio ships all of these.
Clone with submodules, then fetch the two third party checkouts that are not submodules:
git clone --recursive https://github.com/ARMSX2/ARMSX3.git
cd ARMSX3
git clone https://github.com/SnowflakePowered/librashader 3rdparty/librashader
git clone https://github.com/bylaws/libadrenotools android/armsx3-ui/app/src/main/cpp/libadrenotools
Build the core. This is the long part and produces an unstripped library of around 1.3 GB:
export ANDROID_HOME=$HOME/Library/Android/sdk
cmake -B build-android -G Ninja \
-DCMAKE_TOOLCHAIN_FILE=$ANDROID_HOME/ndk/<version>/build/cmake/android.toolchain.cmake \
-DANDROID_ABI=arm64-v8a -DANDROID_PLATFORM=android-31 \
-DCMAKE_BUILD_TYPE=RelWithDebInfo
cmake --build build-android --target rpcsx-android -j8
Strip it and put it where the app expects it:
llvm-strip --strip-unneeded build-android/android/libarmsx3-core.so
cp build-android/android/libarmsx3-core.so \
android/armsx3-ui/app/src/main/jniLibs/arm64-v8a/
Then build the app:
cd android/armsx3-ui
export JAVA_HOME="/Applications/Android Studio.app/Contents/jbr/Contents/Home"
./gradlew :app:assembleRelease
The apk lands in app/build/outputs/apk/release/.
Note that the core library has to be rebuilt and copied again whenever anything under rpcs3/ or android/src/ changes. Gradle does not build it for you.
The Discord Social SDK is proprietary and is not redistributed here. Get it from Discord's developer portal and drop it in app/libs/ and app/src/main/cpp/discord_sdk/ if you want that feature. The build skips it otherwise.
Running it needs PS3 firmware, which is not included. License
GPL-2.0-only, the same as RPCS3. See LICENSE. Some files may be licensed differently, check the file headers.
Based on RPCS3, https://github.com/RPCS3/rpcs3