[Arm] Size-test: Run the binary on CI

[digantdesai]

🚀 The feature, motivation and pitch

Today we just build and test for size, but we also want to run it to make sure the build is viable.

Alternatives

No response

Additional context

• CI job -

  executorch/.github/workflows/trunk.yml

  Line 220 in 8da2ea6

  test-arm-cortex-m-size-test:

• We may run into size_test.cpp using FileDataLoader which may not be supported on the baremetal platforms. See arm_executor_runner.cpp for BufferDataLoader use.

RFC (Optional)

No response

[mayank-agrwl]

Hey @digantdesai, I am interested in working on this.

[mayank-agrwl]

Thanks for the issue description! I have a few questions/clarifications as I get started on this:

Understanding of size_test: My understanding is that size_test is a minimal ExecuTorch runtime test designed to validate that ExecuTorch can build and execute model inference in memory-constrained embedded environments (like ARM Cortex-M). Currently, it only validates compilation and binary size, but doesn't verify runtime functionality.

Goal: The goal is to actually execute the size_test binary on CI with a real model.

Challenges:

1. The current implementation uses FileDataLoader which relies on filesystem operations (open system call.). These system calls are not supported in baremetal because of lack of filesystems. So we are looking to replace it with BufferDataLoader.

2. Additional File Operations: I also noticed fopen/fwrite calls for profiling output here, I suppose these would also be problematic for bare metal.

Solution: replace FileDataLoader with BufferDataLoader. BufferDataLoader expects the address and size in it's parameters. So I was thinking to modify the interface to accept model memory address and size as CLI arguments:
interface to accept model memory address and size as CLI arguments:
./size_test <model_address> <model_size>

Questions:

• Is the CLI args approach (address + size) the right direction?
• Should I also replace the profiling file output with logging-only for bare metal compatibility?

Thanks for your patience as I work through these low level systems concepts for the first time!