Arm backend: Add tools for finding pte info

backends/arm/scripts/build_executor_runner.sh

@@ -15,7 +15,7 @@ _setup_msg="please refer to ${et_root_dir}/examples/arm/setup.sh to properly ins
 source "${script_dir}/utils.sh"
 
 pte_file=""
-target="ethos-u55-128"
+target=""
 build_type="Release"
 bundleio=false
 system_config=""
@@ -37,14 +37,15 @@ help() {
     echo "  --pte=<PTE_FILE>|<ADDR>|semihosting  Set to a pte file (generated by the aot_arm_compier) to include the model in the elf."
     echo "                                       Or a hex address in the format of 0x00000000 if placed in memory you need to place it on this ADDR on your target, with your flash tool or other means."
     echo "                                       Or specify the word 'semihosting' to supply pte at runtime."
-    echo "  --target=<TARGET>                    Target to build and run for Default: ${target}"
+    echo "  --target=<TARGET>                    Target to build and run for. Defaults to the PTE Ethos-U compile spec target when available, otherwise ethos-u55-128"
     echo "  --build_type=<TYPE>                  Build with Release, Debug or RelWithDebInfo, default is ${build_type}"
     echo "  --bundleio                           Support both pte and Bundle IO bpte using Devtools BundelIO with Input/RefOutput included"
-    echo "  --system_config=<CONFIG>             System configuration to select from the Vela configuration file (see vela.ini). Default: Ethos_U55_High_End_Embedded for EthosU55 targets, Ethos_U85_SYS_DRAM_Mid for EthosU85 targets."
+    echo "                                       Defaults to ON when --pte points to a .bpte file."
+    echo "  --system_config=<CONFIG>             System configuration to select from the Vela configuration file (see vela.ini). Defaults to the Ethos-U delegate compile spec in the PTE when available, otherwise target-specific defaults."
     echo "                                         NOTE: If given, this option must match the given target. This option along with the memory_mode sets timing adapter values customized for specific hardware, see ./executor_runner/CMakeLists.txt."
     echo "  --memory_mode=<CONFIG>               Vela memory mode, used for setting the Timing Adapter parameters of the Corstone platforms."
     echo "                                       Valid values are Shared_Sram(for Ethos-U55, Ethos-U65, Ethos-85), Sram_Only(for Ethos-U55, Ethos-U65, Ethos-U85) or Dedicated_Sram(for Ethos-U65, Ethos-U85)."
-    echo "                                       Default: Shared_Sram for the Ethos-U55 and Sram_Only for the Ethos-U85"
+    echo "                                       Defaults to the Ethos-U delegate compile spec in the PTE when available, otherwise target-specific defaults."
     echo "  --etdump                             Adds Devtools etdump support to track timing and output, etdump area will be base64 encoded in the log"
     echo "  --extra_build_flags=<FLAGS>          Extra flags to pass to cmake like -DET_ARM_BAREMETAL_METHOD_ALLOCATOR_POOL_SIZE=60000 Default: none "
     echo "  --output=<FOLDER>                    Output folder Default: <MODEL>/<MODEL>_<TARGET INFO>.pte"
@@ -114,6 +115,9 @@ else
     else
         echo "PTE included in elf from file ${pte_file}"
         pte_file=$(realpath ${pte_file})
+        if [[ ${pte_file} == *.bpte ]]; then
+            bundleio=true
+        fi
         pte_data="-DET_PTE_FILE_PATH:PATH=${pte_file}"
         if [ "$output_folder_set" = false ] ; then
             # remove file ending
@@ -130,6 +134,36 @@ et_build_dir=${et_build_root}/cmake-out
 mkdir -p ${et_build_dir}
 et_build_dir=$(realpath ${et_build_dir})
 
+# If a PTE file is supplied, derive any unset Ethos-U runtime config from it.
+if [[ -f "${pte_file}" ]] && [[ -z "${target}" || -z "${system_config}" || -z "${memory_mode}" ]]; then
+    set +e
+    extracted_config=$(python3 "${script_dir}/ethosu_pte_info.py" --format=tsv "${pte_file}")
+    extracted_status=$?
+    set -e
+
+    if [[ ${extracted_status} -eq 0 ]]; then
+        IFS=$'\t' read -r extracted_target extracted_system_config extracted_memory_mode <<< "${extracted_config}"
+
+        if [[ ${target} == "" ]]; then
+            target="${extracted_target}"
+        fi
+        if [[ ${system_config} == "" ]]; then
+            system_config="${extracted_system_config}"
+        fi
+        if [[ ${memory_mode} == "" ]]; then
+            memory_mode="${extracted_memory_mode}"
+        fi
+    else
+        echo "Warning: Failed to derive Ethos-U compile spec defaults from ${pte_file}"
+    fi
+fi
+
+# Default values if getting defaults from compile spec failed.
+if [[ ${target} == "" ]]
+then
+    target="ethos-u55-128"
+fi
+
 if [[ ${system_config} == "" ]]
 then
     system_config="Ethos_U55_High_End_Embedded"

backends/arm/scripts/ethosu_pte_info.py

@@ -0,0 +1,143 @@
+#!/usr/bin/env python3
+
+# Copyright 2026 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.
+
+from __future__ import annotations
+
+import argparse
+import json
+from dataclasses import asdict, dataclass
+from pathlib import Path
+
+from executorch.backends.arm.ethosu import EthosUBackend, EthosUCompileSpec
+from executorch.devtools.pte_tool.pte_info import (
+    DelegateInfo,
+    get_delegate_infos_from_pte,
+)
+
+
+@dataclass(frozen=True)
+class EthosUDelegateConfig:
+    target: str
+    system_config: str
+    memory_mode: str
+
+
+def _extract_flag_value(flags: list[str], prefix: str) -> str | None:
+    for flag in flags:
+        if flag.startswith(prefix):
+            return flag.removeprefix(prefix)
+    return None
+
+
+def _config_from_delegate(delegate_info: DelegateInfo) -> EthosUDelegateConfig:
+    compile_spec = EthosUCompileSpec._from_list(delegate_info.compile_specs)
+    if compile_spec.target is None:
+        raise ValueError("Missing Ethos-U target in delegate compile spec.")
+
+    system_config = _extract_flag_value(compile_spec.compiler_flags, "--system-config=")
+    if system_config is None:
+        raise ValueError(
+            f"Missing --system-config flag in Ethos-U compile spec for {compile_spec.target}."
+        )
+
+    memory_mode = _extract_flag_value(compile_spec.compiler_flags, "--memory-mode=")
+    if memory_mode is None:
+        raise ValueError(
+            f"Missing --memory-mode flag in Ethos-U compile spec for {compile_spec.target}."
+        )
+
+    return EthosUDelegateConfig(
+        target=compile_spec.target,
+        system_config=system_config,
+        memory_mode=memory_mode,
+    )
+
+
+def get_ethosu_delegate_configs_from_pte(
+    pte_path: str | Path,
+) -> list[EthosUDelegateConfig]:
+    configs: list[EthosUDelegateConfig] = []
+    for delegate_info in get_delegate_infos_from_pte(pte_path):
+        if delegate_info.delegate_id != EthosUBackend.__name__:
+            continue
+        configs.append(_config_from_delegate(delegate_info))
+    return configs
+
+
+def get_ethosu_delegate_config_from_pte(
+    pte_path: str | Path,
+) -> EthosUDelegateConfig | None:
+    configs = get_ethosu_delegate_configs_from_pte(pte_path)
+    if not configs:
+        return None
+
+    unique_configs = sorted(
+        {
+            (config.target, config.system_config, config.memory_mode)
+            for config in configs
+        }
+    )
+    if len(unique_configs) != 1:
+        joined = ", ".join(
+            f"target={target} system_config={system_config} memory_mode={memory_mode}"
+            for target, system_config, memory_mode in unique_configs
+        )
+        raise ValueError(
+            "Found multiple Ethos-U delegate compile spec configurations in "
+            f"{pte_path}: {joined}"
+        )
+
+    target, system_config, memory_mode = unique_configs[0]
+    return EthosUDelegateConfig(
+        target=target,
+        system_config=system_config,
+        memory_mode=memory_mode,
+    )
+
+
+def _get_args() -> argparse.Namespace:
+    parser = argparse.ArgumentParser(
+        description=(
+            "Read the Ethos-U delegate compile spec from a .pte/.bpte file and "
+            "print the resolved target, system_config and memory_mode."
+        )
+    )
+    parser.add_argument("pte_path", help="Path to a .pte or .bpte file.")
+    parser.add_argument(
+        "--format",
+        choices=("pretty", "json", "tsv"),
+        default="pretty",
+        help="Output format. Default: %(default)s.",
+    )
+    return parser.parse_args()
+
+
+def _print_config(config: EthosUDelegateConfig, output_format: str) -> None:
+    if output_format == "json":
+        print(json.dumps(asdict(config), sort_keys=True))
+        return
+    if output_format == "tsv":
+        print(f"{config.target}\t{config.system_config}\t{config.memory_mode}")
+        return
+
+    print(f"target={config.target}")
+    print(f"system_config={config.system_config}")
+    print(f"memory_mode={config.memory_mode}")
+
+
+def main() -> int:
+    args = _get_args()
+    config = get_ethosu_delegate_config_from_pte(args.pte_path)
+    if config is None:
+        return 2
+
+    _print_config(config, args.format)
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())

backends/arm/test/misc/test_ethosu_pte_info.py

@@ -0,0 +1,131 @@
+# Copyright 2026 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.
+
+from executorch.backends.arm.ethosu import EthosUCompileSpec
+from executorch.backends.arm.scripts.ethosu_pte_info import (
+    get_ethosu_delegate_config_from_pte,
+)
+from executorch.exir._serialize import _PTEFile, _serialize_pte_binary
+from executorch.exir.backend.compile_spec_schema import CompileSpec
+from executorch.exir.schema import (
+    BackendDelegate,
+    BackendDelegateDataReference,
+    BackendDelegateInlineData,
+    Buffer,
+    Chain,
+    ContainerMetadata,
+    DataLocation,
+    ExecutionPlan,
+    Program,
+    SubsegmentOffsets,
+)
+from pytest import raises
+
+
+def _make_pte_bytes(*, delegates: list[BackendDelegate]) -> bytes:
+    program = Program(
+        version=0,
+        execution_plan=[
+            ExecutionPlan(
+                name="forward",
+                container_meta_type=ContainerMetadata(
+                    encoded_inp_str="[]", encoded_out_str="[]"
+                ),
+                values=[],
+                inputs=[],
+                outputs=[],
+                chains=[Chain(inputs=[], outputs=[], instructions=[], stacktrace=None)],
+                operators=[],
+                delegates=delegates,
+                non_const_buffer_sizes=[0],
+            )
+        ],
+        constant_buffer=[Buffer(storage=b"")],
+        backend_delegate_data=[BackendDelegateInlineData(data=b"delegate-data")],
+        segments=[],
+        constant_segment=SubsegmentOffsets(segment_index=0, offsets=[]),
+        mutable_data_segments=[],
+        named_data=[],
+    )
+    return bytes(_serialize_pte_binary(_PTEFile(program)))
+
+
+def _write_pte(tmp_path, *delegates: BackendDelegate):
+    pte_path = tmp_path / "model.pte"
+    pte_path.write_bytes(_make_pte_bytes(delegates=list(delegates)))
+    return pte_path
+
+
+def _ethosu_delegate(
+    target: str,
+    system_config: str,
+    memory_mode: str,
+    index: int = 0,
+) -> BackendDelegate:
+    return BackendDelegate(
+        id="EthosUBackend",
+        processed=BackendDelegateDataReference(
+            location=DataLocation.INLINE, index=index
+        ),
+        compile_specs=EthosUCompileSpec(
+            target=target,
+            system_config=system_config,
+            memory_mode=memory_mode,
+        )._to_list(),
+    )
+
+
+def test_ethosu_pte_info_no_target(tmp_path) -> None:
+    pte_path = _write_pte(
+        tmp_path,
+        _ethosu_delegate(
+            target="ethos-u85-256",
+            system_config="Ethos_U85_SYS_DRAM_Mid",
+            memory_mode="Dedicated_Sram_384KB",
+        ),
+    )
+
+    config = get_ethosu_delegate_config_from_pte(pte_path)
+
+    assert config is not None
+    assert config.target == "ethos-u85-256"
+    assert config.system_config == "Ethos_U85_SYS_DRAM_Mid"
+    assert config.memory_mode == "Dedicated_Sram_384KB"
+
+
+def test_ethosu_pte_info_returns_none_without_ethosu_delegate_no_target(
+    tmp_path,
+) -> None:
+    pte_path = _write_pte(
+        tmp_path,
+        BackendDelegate(
+            id="OtherBackend",
+            processed=BackendDelegateDataReference(
+                location=DataLocation.INLINE, index=0
+            ),
+            compile_specs=[CompileSpec(key="k", value=b"v")],
+        ),
+    )
+
+    assert get_ethosu_delegate_config_from_pte(pte_path) is None
+
+
+def test_ethosu_pte_info_rejects_mixed_configs_no_target(tmp_path) -> None:
+    pte_path = _write_pte(
+        tmp_path,
+        _ethosu_delegate(
+            target="ethos-u55-128",
+            system_config="Ethos_U55_High_End_Embedded",
+            memory_mode="Shared_Sram",
+        ),
+        _ethosu_delegate(
+            target="ethos-u85-256",
+            system_config="Ethos_U85_SYS_DRAM_Mid",
+            memory_mode="Sram_Only",
+        ),
+    )
+
+    with raises(ValueError, match="multiple Ethos-U delegate compile spec"):
+        get_ethosu_delegate_config_from_pte(pte_path)

devtools/pte_tool/BUCK

@@ -15,6 +15,18 @@ fbcode_target(_kind = runtime.python_library,
     ],
 )
 
+fbcode_target(_kind = runtime.python_library,
+    name = "pte_info_lib",
+    srcs = [
+        "pte_info.py",
+    ],
+    deps = [
+        "//executorch/devtools/bundled_program/serialize:lib",
+        "//executorch/exir/_serialize:lib",
+        "//executorch/exir/backend:compile_spec_schema",
+    ],
+)
+
 fbcode_target(_kind = runtime.python_binary,
     name = "diff_pte",
     srcs = [
@@ -27,3 +39,16 @@ fbcode_target(_kind = runtime.python_binary,
         "//executorch/exir/_serialize:lib",
     ],
 )
+
+fbcode_target(_kind = runtime.python_binary,
+    name = "pte_info",
+    srcs = [
+        "pte_info.py",
+    ],
+    main_function = "executorch.devtools.pte_tool.pte_info.main",
+    deps = [
+        "//executorch/devtools/bundled_program/serialize:lib",
+        "//executorch/exir/_serialize:lib",
+        "//executorch/exir/backend:compile_spec_schema",
+    ],
+)