Arm backend: Introduce documentation for VGF

[robell]

Revising documentation for a number of historical changes, and to add the recently introduced VGF backend.

cc @digantdesai @freddan80 @per @zingo @oscarandersson8218

[pytorch-bot]

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❌ 2 New Failures, 49 Unrelated Failures

As of commit bd066a4 with merge base 9cfb684 ():

NEW FAILURES - The following jobs have failed:

• Build documentation / build (buck2) / Build doc (gh)
  At least one of the pre-conditions you specified did not hold
• trunk / test-huggingface-optimum-coreml (llama3|coreml_fp32_gpu|--quantize) / macos-job (gh)
  RuntimeError: Command bash /Users/runner/work/_temp/exec_script failed with exit code 1

FLAKY - The following jobs failed but were likely due to flakiness present on trunk:

• pull / unittest-editable / macos / macos-job (gh) (similar failure)
  RuntimeError: Command bash /Users/ec2-user/runner/_work/_temp/exec_script failed with exit code 1
• trunk / test-huggingface-optimum-coreml (olmo|coreml_fp32_gpu|--quantize) / macos-job (gh) (similar failure)
  RuntimeError: Command bash /Users/runner/work/_temp/exec_script failed with exit code 1
• trunk / test-huggingface-optimum-coreml (qwen3|coreml_fp32_gpu|--quantize) / macos-job (gh) (similar failure)
  RuntimeError: Command bash /Users/runner/work/_temp/exec_script failed with exit code 1
• trunk / test-huggingface-optimum-coreml (smollm|coreml_fp32_gpu|--quantize) / macos-job (gh) (similar failure)
  RuntimeError: Command bash /Users/runner/work/_temp/exec_script failed with exit code 1
• trunk / test-llama-runner-mac (fp32, coreml) / macos-job (gh) (similar failure)
  RuntimeError: Command bash /Users/ec2-user/runner/_work/_temp/exec_script failed with exit code 1
• trunk / test-models-arm-zephyr (mv2) / linux-job (gh) (similar failure)
  /pytorch/executorch/zephyr_scratch/modules/lib/executorch/kernels/portable/cpu/op__clone_dim_order.cpp:64:49: error: expected primary-expression before ‘>’ token

BROKEN TRUNK - The following jobs failed but were present on the merge base:

👉 Rebase onto the `viable/strict` branch to avoid these failures

• Apple / build-benchmark-app / macos-job (gh) (trunk failure)
  RuntimeError: Command bash /Users/runner/work/_temp/exec_script failed with exit code 1
• Apple / build-demo-ios / macos-job (gh) (trunk failure)
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• Apple / build-frameworks-ios / macos-job (gh) (trunk failure)
  RuntimeError: Command bash /Users/runner/work/_temp/exec_script failed with exit code 1
• pull / unittest / macos / macos-job (gh) (trunk failure)
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• pull / unittest-buck / macos / macos-job (gh) (trunk failure)
  RuntimeError: Command bash /Users/ec2-user/runner/_work/_temp/exec_script failed with exit code 1
• trunk / test-coreml-delegate / macos-job (gh) (trunk failure)
  RuntimeError: Command bash /Users/runner/work/_temp/exec_script failed with exit code 1
• trunk / test-custom-ops-macos (cmake) / macos-job (gh) (trunk failure)
  RuntimeError: Command bash /Users/ec2-user/runner/_work/_temp/exec_script failed with exit code 1
• trunk / test-huggingface-optimum-coreml (bert|coreml_fp32_gpu|--quantize) / macos-job (gh) (trunk failure)
  RuntimeError: Command bash /Users/runner/work/_temp/exec_script failed with exit code 1
• trunk / test-huggingface-optimum-coreml (distilbert|coreml_fp32_gpu|--quantize) / macos-job (gh) (trunk failure)
  RuntimeError: Command bash /Users/runner/work/_temp/exec_script failed with exit code 1
• trunk / test-llama-runner-mac (fp32, mps) / macos-job (gh) (trunk failure)
  RuntimeError: Command bash /Users/ec2-user/runner/_work/_temp/exec_script failed with exit code 1
• trunk / test-llama-runner-mac (fp32, xnnpack+custom+quantize_kv) / macos-job (gh) (trunk failure)
  RuntimeError: Command bash /Users/ec2-user/runner/_work/_temp/exec_script failed with exit code 1
• trunk / test-llama-torchao-lowbit / macos-job (gh) (trunk failure)
  RuntimeError: Command bash /Users/ec2-user/runner/_work/_temp/exec_script failed with exit code 1
• trunk / test-models-arm-zephyr (add) / linux-job (gh) (trunk failure)
  /pytorch/executorch/zephyr_scratch/modules/lib/executorch/kernels/portable/cpu/op__clone_dim_order.cpp:64:49: error: expected primary-expression before ‘>’ token
• trunk / test-models-arm-zephyr (softmax) / linux-job (gh) (trunk failure)
  /pytorch/executorch/zephyr_scratch/modules/lib/executorch/kernels/portable/cpu/op__clone_dim_order.cpp:64:49: error: expected primary-expression before ‘>’ token
• trunk / test-models-macos-coreml (dl3) / macos-job (gh) (trunk failure)
  RuntimeError: Command bash /Users/ec2-user/runner/_work/_temp/exec_script failed with exit code 1
• trunk / test-models-macos-coreml (edsr) / macos-job (gh) (trunk failure)
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• trunk / test-models-macos-coreml (efficient_sam) / macos-job (gh) (trunk failure)
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• trunk / test-models-macos-coreml (emformer_join) / macos-job (gh) (trunk failure)
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• trunk / test-models-macos-coreml (emformer_transcribe) / macos-job (gh) (trunk failure)
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• trunk / test-models-macos-coreml (ic3) / macos-job (gh) (trunk failure)
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• trunk / test-models-macos-coreml (ic4) / macos-job (gh) (trunk failure)
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• trunk / test-models-macos-coreml (mobilebert) / macos-job (gh) (trunk failure)
  RuntimeError: Command bash /Users/ec2-user/runner/_work/_temp/exec_script failed with exit code 1
• trunk / test-models-macos-coreml (mv2) / macos-job (gh) (trunk failure)
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• trunk / test-models-macos-coreml (mv3) / macos-job (gh) (trunk failure)
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• trunk / test-models-macos-coreml (resnet50) / macos-job (gh) (trunk failure)
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• trunk / test-models-macos-coreml (vit) / macos-job (gh) (trunk failure)
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• trunk / test-models-macos-cpu (efficient_sam, portable) / macos-job (gh) (trunk failure)
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• trunk / test-models-macos-cpu (emformer_join, xnnpack-quantization-delegation) / macos-job (gh) (trunk failure)
  RuntimeError: Command bash /Users/ec2-user/runner/_work/_temp/exec_script failed with exit code 1
• trunk / test-models-macos-cpu (ic4, xnnpack-quantization-delegation) / macos-job (gh) (trunk failure)
  RuntimeError: Command bash /Users/ec2-user/runner/_work/_temp/exec_script failed with exit code 1
• trunk / test-models-macos-cpu (llama, portable) / macos-job (gh) (trunk failure)
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• trunk / test-models-macos-cpu (llama2, xnnpack-quantization-delegation) / macos-job (gh) (trunk failure)
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• trunk / test-models-macos-cpu (llama3_2_vision_encoder, portable) / macos-job (gh) (trunk failure)
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• trunk / test-models-macos-cpu (mobilebert, xnnpack-quantization-delegation) / macos-job (gh) (trunk failure)
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• trunk / test-models-macos-cpu (mv3, portable) / macos-job (gh) (trunk failure)
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• trunk / test-models-macos-cpu (mv3, xnnpack-quantization-delegation) / macos-job (gh) (trunk failure)
  RuntimeError: Command bash /Users/ec2-user/runner/_work/_temp/exec_script failed with exit code 1
• trunk / test-models-macos-cpu (resnet50, xnnpack-quantization-delegation) / macos-job (gh) (trunk failure)
  RuntimeError: Command bash /Users/ec2-user/runner/_work/_temp/exec_script failed with exit code 1
• trunk / test-models-macos-cpu (vit, xnnpack-quantization-delegation) / macos-job (gh) (trunk failure)
  RuntimeError: Command bash /Users/ec2-user/runner/_work/_temp/exec_script failed with exit code 1
• trunk / test-models-macos-cpu (w2l, xnnpack-quantization-delegation) / macos-job (gh) (trunk failure)
  RuntimeError: Command bash /Users/ec2-user/runner/_work/_temp/exec_script failed with exit code 1
• trunk / test-models-macos-mps / macos-job (gh) (trunk failure)
  RuntimeError: Command bash /Users/ec2-user/runner/_work/_temp/exec_script failed with exit code 1
• trunk / test-selective-build-macos (cmake) / macos-job (gh) (trunk failure)
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• trunk / test-static-llama-ane / macos-job (gh) (trunk failure)
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• trunk / unittest-release / macos / macos-job (gh) (trunk failure)
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This comment was automatically generated by Dr. CI and updates every 15 minutes.

[robell]

lint-check urls is expected until the new urls are made live in upstream documentation.
the failure is unrelated - this change does not modify code.

[robell]

Thanks Mergen, comments addressed.
Thanks for the update/merge commit Zingo - for some reason it's saying out of date, but i'd rebased to executorch/main a couple hours ago and force pushed but it doesn't seem to resolve the message.

I don't beleive we need to merge as there are no conflicts.

[zingo]

Most tests fails are unrelated but I see this stopping the merged

https://github.com/pytorch/executorch/actions/runs/16943915693/job/48019945078?pr=13369

---- log snippet ----

FAIL 000 https://github.com/pytorch/executorch/blob/main/examples/arm/vgf_minimal_example.ipynb docs/source/tutorial-arm.md
FAIL 404 https://docs.pytorch.org/executorch/main/tutorial-arm.html backends/arm/README.md
FAIL 404 https://docs.pytorch.org/executorch/main/tutorial-arm.html examples/arm/ethos_u_minimal_example.ipynb

[robell]

Hi Zingo - if there's a better way to handle URLs introduced by the commit, or use abstracted links between the readme's and rendered docs, let me know, but I expect those to be populated on main once this review is comitted.

For example, tutorial-arm exists in the rendered docs for this PR: https://docs-preview.pytorch.org/pytorch/executorch/13369/tutorial-arm.html

[zingo]

Hi Zingo - if there's a better way to handle URLs introduced by the commit, or use abstracted links between the readme's and rendered docs, let me know, but I expect those to be populated on main once this review is comitted.

For example, tutorial-arm exists in the rendered docs for this PR: https://docs-preview.pytorch.org/pytorch/executorch/13369/tutorial-arm.html

I have no idea maybe @digantdesai or someone can override to merge.
Maybe some sort of relative links can be used, or we have to do it in 2 PRs.

[robell]

Ok, i've gone with removing them for now. The other problem with those links is they're to a specific branch (in this case main) whereas they'd ideally link to the relevant release/main/stable, which again doesn't seem technically possible.

[zingo]

Test fails are unrelated

[robell]

and, another go - i've removed the skip-url-lint because it stops that job reporting (as suggested in the error output) but that also means a required job doesn't report, blocking merge.
Hopefully this time the job runs and the spurious errors have cleared, and we can get this in.