Arm backend: Generate kernel registration lib from .pte (#13220)

- Moves the arm_portable_op_lib target into the executor_runner
CMakeLists.txt
- Use the OPS_FROM_MODEL arg to generate the arm_portable_op_lib if
possible
- Adds possibility of setting EXECUTORCH_ENABLE_DTYPE_SELECTIVE_BUILD
when building the executor_runner.
- Makes cortex_m targets findeable using find_package to avoid
rebuilding.

+ run cmake-format

Signed-off-by: Adrian Lundell <[email protected]>

Author: AdrianLundell

backends/arm/scripts/build_executor_runner.sh

@@ -25,6 +25,7 @@ output_folder_set=false
 output_folder="."
 et_build_root="${et_root_dir}/arm_test"
 ethosu_tools_dir=${et_root_dir}/examples/arm/ethos-u-scratch
+select_ops_list=""
 
 build_bundleio_flags=" -DET_BUNDLE_IO=OFF "
 build_with_etdump_flags=" -DEXECUTORCH_ENABLE_EVENT_TRACER=OFF "
@@ -47,7 +48,10 @@ help() {
     echo "  --et_build_root=<FOLDER>        Build output root folder to use, defaults to ${et_build_root}"
     echo "  --ethosu_tools_dir=<FOLDER>     Path to your Ethos-U tools dir if you not using default: ${ethosu_tools_dir}"
     echo "  --toolchain=<TOOLCHAIN>         Toolchain can be specified (e.g. bare metal as arm-none-eabi-gcc or zephyr as arm-zephyr-eabi-gcc"
-    exit 0
+    echo "  --select_ops_list=<OPS>         Comma separated list of portable (non delagated) kernels to include Default: ${select_ops_list}"
+    echo "                                     NOTE: This is used when select_ops_model is not possible to use, e.g. for semihosting or bundleio."
+    echo "                                     See https://docs.pytorch.org/executorch/stable/kernel-library-selective-build.html for more information."
+   exit 0
 }
 
 for arg in "$@"; do
@@ -65,6 +69,7 @@ for arg in "$@"; do
       --et_build_root=*) et_build_root="${arg#*=}";;
       --ethosu_tools_dir=*) ethosu_tools_dir="${arg#*=}";;
       --toolchain=*) toolchain="${arg#*=}";;
+      --select_ops_list=*) select_ops_list="${arg#*=}";;
       *)
       ;;
     esac
@@ -157,6 +162,7 @@ cmake \
     -DPYTHON_EXECUTABLE=$(which python3)        \
     -DSYSTEM_CONFIG=${system_config}            \
     -DMEMORY_MODE=${memory_mode}                \
+    -DEXECUTORCH_SELECT_OPS_LIST="${select_ops_list}" \
     ${extra_build_flags}                        \
     -B ${output_folder}/cmake-out
 

backends/arm/scripts/build_portable_kernels.sh

@@ -4,92 +4,4 @@
 # This source code is licensed under the BSD-style license found in the
 # LICENSE file in the root directory of this source tree.
 
-# Optional parameter:
-# --build_type= "Release" | "Debug" | "RelWithDebInfo"
-# --etdump      build with devtools-etdump support
-
-set -eu
-
-script_dir=$(cd -- "$( dirname -- "${BASH_SOURCE[0]}" )" &> /dev/null && pwd)
-et_root_dir=$(cd ${script_dir}/../../.. && pwd)
-et_root_dir=$(realpath ${et_root_dir})
-toolchain=arm-none-eabi-gcc
-setup_path_script=${et_root_dir}/examples/arm/ethos-u-scratch/setup_path.sh
-_setup_msg="please refer to ${et_root_dir}/examples/arm/setup.sh to properly install necessary tools."
-
-
-et_build_root="${et_root_dir}/arm_test"
-build_type="Release"
-portable_kernels="aten::_softmax.out"
-
-help() {
-    echo "Usage: $(basename $0) [options]"
-    echo "Options:"
-    echo "  --et_build_root=<FOLDER>   Build output root folder to use, defaults to ${et_build_root}"
-    echo "  --build_type=<TYPE>        Build with Release, Debug or RelWithDebInfo, default is ${build_type}"
-    echo "  --portable_kernels=<OPS>   Comma separated list of portable (non delagated) kernels to include Default: ${portable_kernels}"
-    echo "  --toolchain=<TOOLCHAIN>    Toolchain can be specified (e.g. bare metal as arm-none-eabi-gcc or zephyr as arm-zephyr-eabi-gcc"
-    exit 0
-}
-
-for arg in "$@"; do
-    case $arg in
-      -h|--help) help ;;
-      --et_build_root=*) et_build_root="${arg#*=}";;
-      --build_type=*) build_type="${arg#*=}";;
-      --portable_kernels=*) portable_kernels="${arg#*=}";;
-      --toolchain=*) toolchain="${arg#*=}";;
-      *)
-      ;;
-    esac
-done
-
-if [[ ${toolchain} == "arm-none-eabi-gcc" ]]; then
-    toolchain_cmake=${et_root_dir}/examples/arm/ethos-u-setup/${toolchain}.cmake
-elif [[ ${toolchain} == "arm-zephyr-eabi-gcc" ]]; then 
-    toolchain_cmake=${et_root_dir}/examples/zephyr/x86_64-linux-arm-zephyr-eabi-gcc.cmake
-else
-    echo "Error: Invalid toolchain selection, provided: ${tolchain}"
-    echo "    Valid options are {arm-none-eabi-gcc, arm-zephyr-eabi-gcc}"
-    exit 1;
-fi
-toolchain_cmake=$(realpath ${toolchain_cmake})
-
-# Source the tools
-# This should be prepared by the setup.sh
-[[ -f ${setup_path_script} ]] \
-    || { echo "Missing ${setup_path_script}. ${_setup_msg}"; exit 1; }
-
-source ${setup_path_script}
-
-et_build_dir=${et_build_root}/cmake-out
-
-cd "${et_root_dir}"
-
-echo "--------------------------------------------------------------------------------" ;
-echo "Build ExecuTorch Libraries ${build_type} portable kernels: ${portable_kernels} into '${et_build_dir}'" ;
-echo "--------------------------------------------------------------------------------"
-
-if ! [[ $portable_kernels =~ ^((^|,)aten::[a-zA-Z0-9_]+\.[a-zA-Z0-9_]*out)*$ ]]; then
-    echo " ERROR: specified argument --portable_kernels=${portable_kernels}"
-    echo "        is in the wrong format please use \"aten::<OP1>.out,aten::<OP2>.out,...\""
-    echo "        e.g. \"aten::_softmax.out,aten::add.out\""
-    exit 1
-fi
-
-set -x
-
-cmake                                                 \
-    -DCMAKE_INSTALL_PREFIX=${et_build_dir}            \
-    -DCMAKE_BUILD_TYPE=${build_type}                  \
-    -DCMAKE_TOOLCHAIN_FILE="${toolchain_cmake}"       \
-    -DEXECUTORCH_SELECT_OPS_LIST=${portable_kernels}  \
-    -B"${et_build_dir}/examples/arm"                  \
-    "${et_root_dir}/examples/arm"
-
-cmake --build "${et_build_dir}/examples/arm" -j$(nproc) --config ${build_type} --
-
-set +x
-
-echo "[$(basename $0)] Generated static libraries for ExecuTorch:"
-find "${et_build_dir}/examples/arm" -name "*.a" -exec ls -al {} \;
+echo "DEPRECATED: build_portable_kernels.sh is deprecated and will be removed. The kernel registration library is now built directly with the arm_executor_runner."

backends/arm/test/test_arm_baremetal.sh

@@ -117,7 +117,6 @@ test_pytest_ops_ethosu_fvp() { # Same as test_pytest but also sometime verify us
 
     # Prepare Corstone-3x0 FVP for pytest
     backends/arm/scripts/build_executorch.sh
-    backends/arm/scripts/build_portable_kernels.sh
     # Build semihosting version of the runner used by pytest testing. This builds:
     # arm_test/arm_semihosting_executor_runner_corstone-300
     # arm_test/arm_semihosting_executor_runner_corstone-320
@@ -133,7 +132,6 @@ test_pytest_models_ethosu_fvp() { # Same as test_pytest but also sometime verify
 
     # Prepare Corstone-3x0 FVP for pytest
     backends/arm/scripts/build_executorch.sh
-    backends/arm/scripts/build_portable_kernels.sh
     # Build semihosting version of the runner used by pytest testing. This builds:
     # arm_test/arm_semihosting_executor_runner_corstone-300
     # arm_test/arm_semihosting_executor_runner_corstone-320

backends/arm/test/test_model.py

@@ -110,15 +110,6 @@ def build_libs(et_build_root: str, script_path: str):
             "--etdump",
         ]
     )
-    run_external_cmd(
-        [
-            "bash",
-            os.path.join(script_path, "build_portable_kernels.sh"),
-            f"--et_build_root={et_build_root}",
-            "--build_type=Release",
-            "--portable_kernels=aten::_softmax.out",
-        ]
-    )
 
 
 def build_pte(

backends/cortex_m/CMakeLists.txt

@@ -1,10 +1,12 @@
 # Copyright (c) Meta Platforms, Inc. and affiliates.
 # All rights reserved.
+# Copyright 2025 Arm Limited and/or its affiliates.
 #
 # This source code is licensed under the BSD-style license found in the
 # LICENSE file in the root directory of this source tree.
 
-# Kernel library for Cortex-M operators. Please keep this file formatted by running:
+# Kernel library for Cortex-M operators. Please keep this file formatted by
+# running:
 # ~~~
 # cmake-format -i CMakeLists.txt
 # ~~~
@@ -29,8 +31,8 @@ set(_cortex_m_kernels__srcs
     ${CMAKE_CURRENT_SOURCE_DIR}/ops/op_dequantize_per_tensor.cpp
 )
 
-# Generate C++ bindings to register kernels into Executorch (for runtime).
-# Here select all ops in operators.yaml
+# Generate C++ bindings to register kernels into Executorch (for runtime). Here
+# select all ops in operators.yaml
 set(_yaml_file ${CMAKE_CURRENT_LIST_DIR}/ops/operators.yaml)
 gen_selected_ops(LIB_NAME "cortex_m_ops_lib" OPS_SCHEMA_YAML "${_yaml_file}")
 
@@ -52,6 +54,7 @@ gen_operators_lib(
 
 install(
   TARGETS cortex_m_kernels cortex_m_ops_lib
+  EXPORT ExecuTorchTargets
   DESTINATION lib
   PUBLIC_HEADER DESTINATION include/executorch/backends/cortex_m/ops/
 )

docs/source/tutorial-arm-ethos-u.md

@@ -300,17 +300,13 @@ To run a `.pte` file with the Arm backend delegate call instructions, you will n
 
 - `libexecutorch_delegate_ethos_u.a`
 
-These libraries are generated by the `backends/arm/scripts/build_executorch.sh` and `backends/arm/scripts/build_portable_kernels.sh` scripts called from the `run.sh` script.
-
-The `--portable_kernels` flag can be used to set the build flag `EXECUTORCH_SELECT_OPS_LIST` when running `backends/arm/scripts/build_portable_kernels.sh` that will decide the number of portable operators included in the build and are available at runtime. It must match with `.pte` file's requirements, otherwise you will get `Missing Operator` error at runtime.
-
-For example, there  in the command line above, to run SoftmaxModule, you only included the softmax CPU operator. Similarly, to run AddModule in a non-delegated manner you will need add op and so on. As you might have already realized, for the delegated operators, which will be executed by the Arm backend delegate, you do not need to include those operators in this list. This is only for *non-delegated* operators.
+These libraries are generated by the `backends/arm/scripts/build_executorch.sh` script called from the `run.sh` script.
 
 ### Building the executor_runner Bare-Metal Application
 
 The SDK dir is the same one prepared [earlier](#setup-the-arm-ethos-u-software-development). And, you will be passing the `.pte` file (any one of them) generated above.
 
-Note, you have to generate a new `executor-runner` binary if you want to change the model or the `.pte` file. This constraint is from the constrained bare-metal runtime environment you have for Corstone-300/Corstone-320 platforms.
+Note, you have to generate a new `executor-runner` binary if you want to change the model or the `.pte` file. This constraint is from the constrained bare-metal runtime environment you have for Corstone-300/Corstone-320 platforms. The build also generates a kernel registration library for the relevant operators which could not be delegated to the EthosU, see the [Kernel Library Selective Build documentation](https://docs.pytorch.org/executorch/stable/kernel-library-selective-build.html).
 
 This step is executed by the build_executor_runner.sh script, which is invoked from the run.sh in the backends/arm/scripts folder.
 

examples/arm/CMakeLists.txt

@@ -180,10 +180,9 @@
    "source": [
     "## Build executor runtime\n",
     "\n",
-    "After the AOT compilation flow is done, the runtime can be cross compiled and linked to the produced .pte-file using the Arm cross-compilation toolchain. This is done in three steps:\n",
-    "1. Build the executorch library and EthosUDelegate.\n",
-    "2. Build any external kernels required. In this example this is not needed as the graph is fully delegated, but its included for completeness.\n",
-    "3. Build and link the `arm_executor_runner`."
+    "After the AOT compilation flow is done, the runtime can be cross compiled and linked to the produced .pte-file using the Arm cross-compilation toolchain. This is done in two steps:\n",
+    "1. Build and install the executorch library and EthosUDelegate.\n",
+    "2. Build and link the `arm_executor_runner` and generate kernel bindings for any non delegated ops."
    ]
   },
   {
@@ -202,9 +201,6 @@
     "# Cross-compile executorch \n",
     "subprocess.run(os.path.join(script_dir, \"build_executorch.sh\"), shell=True, cwd=et_dir)\n",
     "\n",
-    "# Cross-compile portable kernels\n",
-    "subprocess.run(os.path.join(script_dir, \"build_portable_kernels.sh\"), shell=True, cwd=et_dir)\n",
-    "\n",
     "# Cross-compile executorch runner\n",
     "args = f\"--pte={pte_path} --target={target}\"\n",
     "subprocess.run(os.path.join(script_dir, \"build_executor_runner.sh\") + \" \" + args, shell=True, cwd=et_dir)\n",
@@ -235,7 +231,7 @@
  ],
  "metadata": {
   "kernelspec": {
-   "display_name": ".venv",
+   "display_name": ".venv (3.10.15)",
    "language": "python",
    "name": "python3"
   },