add protobuf installation as requirement

remove cmake patch for abseil/protobuf

CMakeLists.txt

@@ -61,15 +61,7 @@ endfunction()
 
 set(ONNX_MLIR_DIR "${CMAKE_CURRENT_SOURCE_DIR}/onnx-mlir")
 
-# 1) Disable the absl dependency
-raptor_apply_patch(
-  "${ONNX_MLIR_DIR}/CMakeLists.txt"
-  "find_package(absl REQUIRED)"
-  "#find_package(absl REQUIRED)"
-  "Disable find_package(absl)"
-)
-
-# 2) Register PIM compiler options alongside NNPA
+# Register PIM compiler options alongside NNPA
 raptor_apply_patch(
   "${ONNX_MLIR_DIR}/src/Accelerators/Accelerator.hpp"
   "#include \"src/Accelerators/NNPA/Compiler/NNPACompilerOptions.hpp\""
@@ -77,7 +69,7 @@ raptor_apply_patch(
   "Add PIM compiler options include"
 )
 
-# 3) Short-circuit output emission for the PIM accelerator
+# Short-circuit output emission for the PIM accelerator
 raptor_apply_patch(
   "${ONNX_MLIR_DIR}/src/Compiler/CompilerUtils.cpp"
   "switch (emissionTarget) {\n  case EmitObj: {"

README.md

@@ -2,6 +2,25 @@
 
 ## Build
 
+### Protobuf
+
+Use the following commands to install protobuf:
+```
+git clone https://github.com/protocolbuffers/protobuf
+cd protobuf
+mkdir build
+cd build
+cmake .. -G Ninja -DCMAKE_BUILD_TYPE=Release
+ninja
+sudo ninja install
+```
+
+You can now remove the protobuf repo directory with:
+```
+cd ../..
+rm -rf protobuf
+```
+
 ### Mlir
 
 Follow the first part of instructions [here](onnx-mlir/docs/BuildOnLinuxOSX.md) to build mlir.