llama.cpp/docs/android.md

104 lines
5.7 KiB
Markdown
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

# Android
## Build with Android Studio
Import the `examples/llama.android` directory into Android Studio, then perform a Gradle sync and build the project.
![Project imported into Android Studio](./android/imported-into-android-studio.png)
This Android binding supports hardware acceleration up to `SME2` for **Arm** and `AMX` for **x86-64** CPUs on Android and ChromeOS devices.
It automatically detects the host's hardware to load compatible kernels. As a result, it runs seamlessly on both the latest premium devices and older devices that may lack modern CPU features or have limited RAM, without requiring any manual configuration.
A minimal Android app frontend is included to showcase the bindings core functionalities:
1. **Parse GGUF metadata** via `GgufMetadataReader` from either a `ContentResolver` provided `Uri` or a local `File`.
2. **Obtain a `TierDetection` or `InferenceEngine`** instance through the high-level facade APIs.
3. **Send a raw user prompt** for automatic template formatting, prefill, and decoding. Then collect the generated tokens in a Kotlin `Flow`.
For a production-ready experience that leverages advanced features such as system prompts and benchmarks, check out [Arm AI Chat](https://play.google.com/store/apps/details?id=com.arm.aichat) on Google Play.
This project is made possible through a collaborative effort by Arm's **CT-ML**, **CE-ML** and **STE** groups:
| ![Home screen](./android/arm-ai-chat-home-screen.png) | ![System prompt](./android/system-prompt-setup.png) | !["Haiku"](./android/chat-with-system-prompt-haiku.png) |
|:------------------------------------------------------:|:----------------------------------------------------:|:--------------------------------------------------------:|
| Home screen | System prompt | "Haiku" |
## Build on Android using Termux
[Termux](https://termux.dev/en/) is an Android terminal emulator and Linux environment app (no root required). As of writing, Termux is available experimentally in the Google Play Store; otherwise, it may be obtained directly from the project repo or on F-Droid.
With Termux, you can install and run `llama.cpp` as if the environment were Linux. Once in the Termux shell:
```
$ apt update && apt upgrade -y
$ apt install git cmake
```
Then, follow the [build instructions](https://github.com/ggml-org/llama.cpp/blob/master/docs/build.md), specifically for CMake.
Once the binaries are built, download your model of choice (e.g., from Hugging Face). It's recommended to place it in the `~/` directory for best performance:
```
$ curl -L {model-url} -o ~/{model}.gguf
```
Then, if you are not already in the repo directory, `cd` into `llama.cpp` and:
```
$ ./build/bin/llama-cli -m ~/{model}.gguf -c {context-size} -p "{your-prompt}"
```
Here, we show `llama-cli`, but any of the executables under `examples` should work, in theory. Be sure to set `context-size` to a reasonable number (say, 4096) to start with; otherwise, memory could spike and kill your terminal.
To see what it might look like visually, here's an old demo of an interactive session running on a Pixel 5 phone:
https://user-images.githubusercontent.com/271616/225014776-1d567049-ad71-4ef2-b050-55b0b3b9274c.mp4
## Cross-compile using Android NDK
It's possible to build `llama.cpp` for Android on your host system via CMake and the Android NDK. If you are interested in this path, ensure you already have an environment prepared to cross-compile programs for Android (i.e., install the Android SDK). Note that, unlike desktop environments, the Android environment ships with a limited set of native libraries, and so only those libraries are available to CMake when building with the Android NDK (see: https://developer.android.com/ndk/guides/stable_apis.)
Once you're ready and have cloned `llama.cpp`, invoke the following in the project directory:
```
$ cmake \
-DCMAKE_TOOLCHAIN_FILE=$ANDROID_NDK/build/cmake/android.toolchain.cmake \
-DANDROID_ABI=arm64-v8a \
-DANDROID_PLATFORM=android-28 \
-DCMAKE_C_FLAGS="-march=armv8.7a" \
-DCMAKE_CXX_FLAGS="-march=armv8.7a" \
-DGGML_OPENMP=OFF \
-DGGML_LLAMAFILE=OFF \
-B build-android
```
Notes:
- While later versions of Android NDK ship with OpenMP, it must still be installed by CMake as a dependency, which is not supported at this time
- `llamafile` does not appear to support Android devices (see: https://github.com/Mozilla-Ocho/llamafile/issues/325)
The above command should configure `llama.cpp` with the most performant options for modern devices. Even if your device is not running `armv8.7a`, `llama.cpp` includes runtime checks for available CPU features it can use.
Feel free to adjust the Android ABI for your target. Once the project is configured:
```
$ cmake --build build-android --config Release -j{n}
$ cmake --install build-android --prefix {install-dir} --config Release
```
After installing, go ahead and download the model of your choice to your host system. Then:
```
$ adb shell "mkdir /data/local/tmp/llama.cpp"
$ adb push {install-dir} /data/local/tmp/llama.cpp/
$ adb push {model}.gguf /data/local/tmp/llama.cpp/
$ adb shell
```
In the `adb shell`:
```
$ cd /data/local/tmp/llama.cpp
$ LD_LIBRARY_PATH=lib ./bin/llama-simple -m {model}.gguf -c {context-size} -p "{your-prompt}"
```
That's it!
Be aware that Android will not find the library path `lib` on its own, so we must specify `LD_LIBRARY_PATH` in order to run the installed executables. Android does support `RPATH` in later API levels, so this could change in the future. Refer to the previous section for information about `context-size` (very important!) and running other `examples`.