From 5c23ff5649b4ca4587f30c46187b611b00e93b98 Mon Sep 17 00:00:00 2001
From: Sebastian Larsson <sebastian.larsson@arm.com>
Date: Mon, 19 Oct 2026 11:32:27 +0200
Subject: [PATCH] Arm backend: Require safetensors for VGF DeiT export

Require safetensors when loading the fine-tuned DeiT checkpoint so
export does not select legacy pickle-based PyTorch weights. Document
the required format in the CLI help and export instructions.

Signed-off-by: Sebastian Larsson <sebastian.larsson@arm.com>
Change-Id: If852d40ee063e14efdedb1601ae716f26c238192
---
 .../image_classification_example_vgf/model_export/README.md   | 3 +++
 .../model_export/export_deit.py                               | 4 ++--
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/examples/arm/image_classification_example_vgf/model_export/README.md b/examples/arm/image_classification_example_vgf/model_export/README.md
index 1513a393011..df5fd6e35db 100644
--- a/examples/arm/image_classification_example_vgf/model_export/README.md
+++ b/examples/arm/image_classification_example_vgf/model_export/README.md
@@ -25,6 +25,9 @@ python examples/arm/image_classification_example_vgf/model_export/train_deit.py
 
 ## Export and quantize for VGF
 
+The exporter requires a safetensors checkpoint. The training script saves
+this format by default. Legacy PyTorch `.bin` checkpoints are not accepted.
+
 ```bash
 python examples/arm/image_classification_example_vgf/model_export/export_deit.py \
   --model-path ./deit-tiny-oxford-pet/final_model \
diff --git a/examples/arm/image_classification_example_vgf/model_export/export_deit.py b/examples/arm/image_classification_example_vgf/model_export/export_deit.py
index a46d157bfa5..76a6b4845a7 100644
--- a/examples/arm/image_classification_example_vgf/model_export/export_deit.py
+++ b/examples/arm/image_classification_example_vgf/model_export/export_deit.py
@@ -93,7 +93,7 @@ def measure_accuracy(quantized_model, test_set):
         type=str,
         default="./deit-tiny-oxford-pet/final_model",
         required=True,
-        help="Path to the fine-tuned ViT model.",
+        help="Path to the fine-tuned ViT model saved in safetensors format.",
     )
     argparser.add_argument(
         "--output-path",
@@ -120,7 +120,7 @@ def measure_accuracy(quantized_model, test_set):
         num_labels=37,
         ignore_mismatched_sizes=True,
         revision="b3428f18dcc7b543470d07f14b4a4157815d1880",
-        use_safetensors=False,
+        use_safetensors=True,
     ).eval()
     image_preprocessor = AutoImageProcessor.from_pretrained(
         "facebook/deit-tiny-patch16-224",