commit 39d45a1c4ab68cc0ab21f55d5d8b470178c54468
author Yun Hsiang <hsiang023167@gmail.com> Thu Jun 22 00:03:01 2023 +0800
committer GitHub <noreply@github.com> Wed Jun 21 09:03:01 2023 -0700
tree c5c53b61ba17e7dfe5415637057b6f3870610bbb
parent cd0d1f11713e48c2b17945520602e7ea9f6498c9

Add riscv64 baremetal runtime (#14105)

This patch add a build rule for riscv64 baremetal runtime.

The riscv64 baremetal toolchain can get from
https://github.com/riscv-collab/riscv-gnu-toolchain.
riscv64 baremetal toolchain build command:
```
git clone https://github.com/riscv-collab/riscv-gnu-toolchain.git
cd riscv-gnu-toolchain
mkdir -p build/install && cd build
../configure --enable-llvm --prefix=`realpath install`
make -j8
```

Build command
```
cmake -G Ninja \
    -B ../iree-baremetal-rv64 \
    -DCMAKE_TOOLCHAIN_FILE="./build_tools/cmake/riscv.toolchain.cmake" \
    -DRISCV_TOOLCHAIN_ROOT=<riscv64 baremetal toolchain root> \
    -DRISCV_CPU="generic-riscv_64" \
    -DRISCV_TOOLCHAIN_PREFIX="riscv64-unknown-elf-" \
    -DIREE_HOST_BIN_DIR=<host tool bin path> \
    -DRISCV_COMPILER_FLAGS="-O2" \
    -DIREE_BUILD_COMPILER=OFF \
    -DIREE_ENABLE_CPUINFO=OFF \
    -DIREE_BUILD_TESTS=OFF \
    -DIREE_ENABLE_ASSERTIONS=ON \
    -DIREE_BUILD_SAMPLES=ON \
    .
    
cmake --build ../iree-baremetal-rv64
```

Test Command
```
qemu-riscv64 -cpu rv64 -B 0x100000  ../iree-baremetal-rv64-gnu/samples/simple_embedding/simple_embedding_embedded_sync
```