vkCmdClearAttachments needs the pass open, and the pass opens with LOAD_OP_LOAD, so clearing a target reads the whole framebuffer into tile memory and then throws it away. LOAD_OP_CLEAR skips the read. On a tiler that read is the whole attachment every time, and this title runs about thirty passes a frame at 720p with colour and depth. Taken only when the clear covers the entire render area and no pass is already open. A partial clear is not a load op, and ending an open pass to change its load ops would store the framebuffer in order to discard it, which costs more than it saves. Colour is all attachments or none, since a load op applies to the attachment as a whole. Depth and stencil get separate bits because clearing one and keeping the other is common. Whether an open instance can serve a request now compares the key with the clear bits masked off rather than the pass pointer. Load ops do not affect render pass compatibility, so the two variants are interchangeable for an open instance and for the pipelines inside it; comparing pointers would have ended the instance to begin an equivalent one, paying the store and reload this is meant to avoid and discarding the clear on the way. Callers that pass no key keep the old pointer comparison.
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:
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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.
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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.
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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.
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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