chore: import upstream snapshot with attribution

examples/custom_bootloader/bootloader_multiboot/pytest_custom_bootloader_multiboot.py

@@ -0,0 +1,24 @@
+# SPDX-FileCopyrightText: 2024-2026 Espressif Systems (Shanghai) CO LTD
+# SPDX-License-Identifier: CC0-1.0
+import pytest
+from pytest_embedded import Dut
+from pytest_embedded_idf.app import IdfApp
+from pytest_embedded_idf.utils import idf_parametrize
+
+
+@pytest.mark.generic
+@idf_parametrize('target', ['esp32c3', 'esp32s3'], indirect=['target'])
+def test_custom_bootloader_multiboot_example(app: IdfApp, dut: Dut) -> None:
+    # Wait for the bootloader menu before matching entry names so flashing logs do not
+    # satisfy the expectations prematurely.
+    dut.expect_exact('Please select a partition to boot.')
+    dut.expect_exact('FOUND 3 BOOT PARTITIONS:')
+    dut.expect_exact('main')
+    dut.expect_exact('hello_world')
+    dut.expect_exact('console')
+    # Send "down arrow" signal to select the second image, which should be `hello_world`
+    dut.write('\x1b[B')
+    # Send Enter to validate and start the image
+    dut.write('\n')
+    # Make sure the example booted properly
+    dut.expect('Hello world!')