Build sherpa-onnx for SpacemiT CPUs

This page documents the basic build flow for enabling the SpacemiT execution provider in sherpa-onnx.

Cross-compilation prerequisites

The provided build script targets SpacemiT RISC-V Linux.

If RISCV_ROOT_PATH is already set to a valid SpacemiT toolchain directory, the script will reuse it. Otherwise, it will download a toolchain archive automatically.

Quick start

The repository already provides a dedicated build script:

git clone https://github.com/k2-fsa/sherpa-onnx
cd sherpa-onnx
./build-riscv64-linux-gnu-spacemit.sh

If you want to use a local toolchain, set:

export RISCV_ROOT_PATH=/path/to/spacemit-toolchain
./build-riscv64-linux-gnu-spacemit.sh

The script enables the following CMake option:

-DSHERPA_ONNX_ENABLE_SPACEMIT=ON

It also uses the SpacemiT RISC-V toolchain file:

-DCMAKE_TOOLCHAIN_FILE=../toolchains/riscv64-linux-gnu-spacemit.toolchain.cmake

Build notes

The build script cross-compiles alsa-lib when needed.
The default build directory is build-riscv64-linux-gnu-spacemit.
The default install prefix is build-riscv64-linux-gnu-spacemit/install.
Shared libraries are enabled by default in the build script.
SHERPA_ONNX_ENABLE_C_API and SHERPA_ONNX_ENABLE_WEBSOCKET are enabled by the script.
SHERPA_ONNX_ENABLE_PYTHON and tests are disabled in the script.

Manual CMake flow

If you prefer to drive CMake manually, the skeleton command looks like this:

cmake \
  -DCMAKE_INSTALL_PREFIX=./install \
  -DCMAKE_BUILD_TYPE=Release \
  -DBUILD_SHARED_LIBS=ON \
  -DSHERPA_ONNX_ENABLE_SPACEMIT=ON \
  -DCMAKE_TOOLCHAIN_FILE=../toolchains/riscv64-linux-gnu-spacemit.toolchain.cmake \
  ..

make -j4
make install

Build outputs

After a successful build, you can usually find artifacts in both of the following locations:

build-riscv64-linux-gnu-spacemit/bin and build-riscv64-linux-gnu-spacemit/lib
build-riscv64-linux-gnu-spacemit/install/bin and build-riscv64-linux-gnu-spacemit/install/lib

What to verify after build

After the build finishes, you can start by checking the generated binaries:

ls -lh build-riscv64-linux-gnu-spacemit/install/bin/
ls -lh build-riscv64-linux-gnu-spacemit/install/lib/

Typical binaries to verify first:

sherpa-onnx
sherpa-onnx-offline
sherpa-onnx-offline-tts

Board-side run

If you copy the install directory to your board, a minimal smoke test looks like this:

export LD_LIBRARY_PATH=./lib
./bin/sherpa-onnx --help
./bin/sherpa-onnx-offline --help
./bin/sherpa-onnx-offline-tts --help

If --help works, it usually means the binary and runtime libraries are in a good state for the next step of model testing.

QEMU smoke test

The CI workflow also validates the generated binaries with qemu-riscv64. The minimal pattern is:

export PATH=/path/to/toolchain/bin:$PATH
export PATH=/path/to/qemu/bin:$PATH
export QEMU_LD_PREFIX=/path/to/toolchain/sysroot
export LD_LIBRARY_PATH=/path/to/toolchain/sysroot/lib
export QEMU_ARGS="-cpu max,vlen=256,elen=64,vext_spec=v1.0"

qemu-riscv64 ${QEMU_ARGS} ./build-riscv64-linux-gnu-spacemit/bin/sherpa-onnx --help
qemu-riscv64 ${QEMU_ARGS} ./build-riscv64-linux-gnu-spacemit/bin/sherpa-onnx-offline --help
qemu-riscv64 ${QEMU_ARGS} ./build-riscv64-linux-gnu-spacemit/bin/sherpa-onnx-offline-tts --help

This is a convenient way to do a quick verification on the host before copying artifacts to a board.