add basic CMakeLists.txt

add build instructions

CMakeLists.txt

@@ -0,0 +1,6 @@
+# Match the minimum required version of onnx-mlir
+cmake_minimum_required(VERSION 3.20.0)
+
+project(raptor)
+
+add_subdirectory(onnx-mlir)

README.md

@@ -1 +1,37 @@
 # Raptor
+
+## Build
+
+### Mlir
+
+Follow the first part of instructions [here](onnx-mlir/docs/BuildOnLinuxOSX.md) to build mlir.
+
+Remember to set ```-DCMAKE_BUILD_TYPE=Debug``` for developing on Raptor
+
+Moreover, if compiling with build type debug, it is also suggested to use
+mold as linker (you will need to install it if you don't have it already)
+to reduce memory usage during linking. You can use it with:
+```
+-DCMAKE_EXE_LINKER_FLAGS="-fuse-ld=mold" \
+-DCMAKE_SHARED_LINKER_FLAGS="-fuse-ld=mold"
+```
+
+### Raptor
+
+Use the following commands to build Raptor.
+Remember to set ```-DCMAKE_BUILD_TYPE=Debug``` for developing on Raptor.
+
+```
+git submodule update --init --recursive
+
+MLIR_DIR=$(pwd)/onnx-mlir/llvm-project/build/lib/cmake/mlir
+mkdir build && cd build
+cmake .. -G Ninja \
+  -DCMAKE_BUILD_TYPE=Release \
+  -DLLVM_ENABLE_ASSERTIONS=ON \
+  -DMLIR_DIR=${MLIR_DIR}
+cmake --build .
+```
+
+If the build fails because of protobuf missing uint definitions,
+just patch the problematic files by adding ```#include <cstdint>``` to their includes.