Arm backend: Get ethos-u dependency using FetchContent (#7882)

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

Author: Erik-Lundell

examples/arm/executor_runner/CMakeLists.txt

@@ -1,4 +1,4 @@
-# Copyright 2023-2024 Arm Limited and/or its affiliates.
+# Copyright 2023-2025 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.
@@ -44,6 +44,37 @@ set(PYTHON_EXECUTABLE
     CACHE PATH "Define to override python executable used"
 )
 
+# Download ethos_u dependency if needed.
+include(FetchContent)
+set(ethos_u_base_rev "24.08")
+FetchContent_Declare(
+  ethos_u
+  GIT_REPOSITORY https://git.gitlab.arm.com/artificial-intelligence/ethos-u/ethos-u.git
+  GIT_TAG ${ethos_u_base_rev}
+  SOURCE_DIR ${ETHOS_SDK_PATH}
+  BINARY_DIR ${ETHOS_SDK_PATH}
+  SUBBUILD_DIR ${ETHOS_SDK_PATH}/../ethos_u-subbuild
+  SOURCE_SUBDIR none
+  )
+
+FetchContent_MakeAvailable(ethos_u)
+
+# Get ethos_u externals only if core_platform folder does not already exist.
+if(NOT EXISTS "${ETHOS_SDK_PATH}/core_platform")
+  execute_process(COMMAND ${PYTHON_EXECUTABLE} fetch_externals.py -c ${ethos_u_base_rev}.json fetch
+                  WORKING_DIRECTORY ${ETHOS_SDK_PATH}
+                  COMMAND_ECHO STDOUT
+  )
+endif()
+
+# Always patch the core_platform repo since this is fast enough.
+set(core_platform_base_rev "b728c774158248ba2cad8e78a515809e1eb9b77f")
+set(patch_dir "examples/arm/ethos-u-setup")
+execute_process(COMMAND bash -c "pwd && source backends/arm/scripts/utils.sh && patch_repo ${ETHOS_SDK_PATH}/core_platform ${core_platform_base_rev} ${patch_dir}"
+  WORKING_DIRECTORY ${ET_DIR_PATH}
+  COMMAND_ECHO STDOUT
+)
+
 # Selects timing adapter values matching system_config.
 # Default is Ethos_U55_High_End_Embedded, simulating optimal hardware for the Corestone-300.
 set(SYSTEM_CONFIG "Ethos_U55_High_End_Embedded" CACHE STRING "System config")

examples/arm/run.sh

@@ -81,8 +81,8 @@ else
 fi
 executor_runner_path=$(realpath ${executor_runner_path})
 
+mkdir -p ${root_dir}/ethos-u
 ethos_u_root_dir="$(cd ${root_dir}/ethos-u && pwd)"
-ethos_u_build_dir=${ethos_u_root_dir}/core_platform/build
 setup_path_script=${root_dir}/setup_path.sh
 
 # Executorch

examples/arm/setup.sh

@@ -179,23 +179,7 @@ function setup_toolchain() {
     echo "export PATH=\${PATH}:${toolchain_bin_path}" >> ${setup_path_script}
 }
 
-function setup_ethos_u() {
-    # This is the main dir which will pull more repos to do baremetal software dev for cs300
-    echo "[${FUNCNAME[0]}] Setting up the repo"
-    cd "${root_dir}"
-    [[ ! -d ethos-u ]] && \
-        git clone ${ethos_u_repo_url}
-    cd ethos-u
-    git reset --hard ${ethos_u_base_rev}
-    python3 ./fetch_externals.py -c ${ethos_u_base_rev}.json fetch
-
-    pip install pyelftools
-    echo "[${FUNCNAME[0]}] Done @ $(git describe --all --long 3> /dev/null) in ${root_dir}/ethos-u dir."
-}
-
-
 function setup_tosa_reference_model() {
-    
     # reference_model flatbuffers version clashes with Vela.
     # go with Vela's since it newer.
     # Vela's flatbuffer requirement is expected to loosen, then remove this. MLETORCH-565
@@ -236,15 +220,6 @@ source $et_dir/backends/arm/scripts/utils.sh
 # Setup toolchain
 setup_toolchain
 
-# Setup the ethos-u dev environment
-setup_ethos_u
-
-# Patch the ethos-u dev environment to include executorch application
-repo_dir="${root_dir}/ethos-u/core_platform"
-base_rev=b728c774158248ba2cad8e78a515809e1eb9b77f
-patch_dir=${script_dir}/ethos-u-setup/
-patch_repo $repo_dir $base_rev $patch_dir
-
 # Setup the tosa_reference_model
 setup_tosa_reference_model