Building RISC-V Target with Cmake

Warning We cannot detect rvv support at runtime, running the rvv code on a no-rvv target is a risk. Users should disable the rvv when the target does not support it.

We will have a better solution when the kernels update hwcap or hwprobe for risc-v.

Prerequisite: Build RISC-V Clang Toolchain and QEMU

If you don't have prebuilt clang and riscv64 qemu, you can refer to the script to get the source. Copy the script to the zlib-ng root directory, and run it to download the source and build them. Modify the content according to your conditions (e.g., toolchain version).

./prepare_riscv_toolchain_qemu.sh

After running script, clang & qemu are built in build-toolchain-qemu/riscv-clang/ & build-toolchain-qemu/riscv-qemu/.

build-toolchain-qemu/riscv-clang/ is your TOOLCHAIN_PATH. build-toolchain-qemu/riscv-qemu/bin/qemu-riscv64 is your QEMU_PATH.

You can also download the prebuilt toolchain & qemu from the release page, and enjoy using them.

Cross-Compile for RISC-V Target

cmake -G Ninja -B ./build-riscv \
  -D CMAKE_TOOLCHAIN_FILE=./cmake/toolchain-riscv.cmake \
  -D CMAKE_INSTALL_PREFIX=./build-riscv/install \
  -D TOOLCHAIN_PATH={TOOLCHAIN_PATH} \
  -D QEMU_PATH={QEMU_PATH} \
  .

cmake --build ./build-riscv

Disable the option if there is no RVV support:

-D WITH_RVV=OFF

Run Unittests on User Mode QEMU

cd ./build-riscv && ctest --verbose