* [PATCH 2/2] test: py: add test for FIT images in global.of.overlay.path
2026-10-15 11:29 [PATCH 1/2] Documentation: devicetree: document overlays in a FIT image Ahmad Fatoum
@ 2026-10-15 11:29 ` Ahmad Fatoum
2026-10-15 12:49 ` [PATCH 1/2] Documentation: devicetree: document overlays in a FIT image Sascha Hauer
1 sibling, 0 replies; 3+ messages in thread
From: Ahmad Fatoum @ 2026-10-15 11:29 UTC (permalink / raw)
To: barebox; +Cc: Ahmad Fatoum
From: Ahmad Fatoum <a.fatoum@barebox.org>
Applying overlays from a FIT image in global.of.overlay.path has no test
coverage so far.
Let's add a test that builds a FIT with three overlay configurations and
a kernel configuration and checks the fixed-up device tree: the kernel
configuration is skipped, the pattern and compatible filters are honoured
and an overlay with a bad hash is not applied.
Assisted-by: Claude:opus-5.5
Signed-off-by: Ahmad Fatoum <a.fatoum@barebox.org>
---
test/py/test_of_overlay.py | 204 +++++++++++++++++++++++++++++++++++++
1 file changed, 204 insertions(+)
create mode 100644 test/py/test_of_overlay.py
diff --git a/test/py/test_of_overlay.py b/test/py/test_of_overlay.py
new file mode 100644
index 000000000000..8eb2e5e30aa7
--- /dev/null
+++ b/test/py/test_of_overlay.py
@@ -0,0 +1,204 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+import os
+import shutil
+import subprocess
+import pytest
+from .helper import skip_disabled, filter_errors
+
+TESTNODE = "/barebox-fit-overlay-test"
+
+# name: (compatible, value of the order property)
+OVERLAYS = {
+ "a": (None, "a"),
+ "b": ("barebox,fit-overlay-test-b", "b"),
+ "c": ("barebox,fit-overlay-test-c", "c"),
+ "kernel": (None, "kernel"),
+}
+
+ITS = """/dts-v1/;
+
+/ {
+ description = "global.of.overlay.path test";
+ #address-cells = <1>;
+
+ images {
+ kernel {
+ data = /incbin/("kernel.bin");
+ type = "kernel";
+ arch = "arm64";
+ os = "linux";
+ compression = "none";
+ hash-1 {
+ algo = "sha256";
+ };
+ };
+%s };
+
+ configurations {
+ /* has a kernel, so it is not an overlay configuration */
+ conf-kernel {
+ kernel = "kernel";
+ fdt = "overlay-kernel";
+ };
+%s };
+};
+"""
+
+ITS_OVERLAY = """ overlay-%s {
+ data = /incbin/("%s.dtbo");
+ type = "flat_dt";
+ arch = "arm64";
+ compression = "none";
+ hash-1 {
+ algo = "sha256";
+ };
+ };
+"""
+
+ITS_CONFIG = """ conf-%s {
+ fdt = "overlay-%s";
+ };
+"""
+
+
+def mkdtso(name, compatible, order):
+ compat = f'\tcompatible = "{compatible}";\n' if compatible else ""
+
+ return f"""/dts-v1/;
+/plugin/;
+
+/ {{
+{compat} fragment@0 {{
+ target-path = "/";
+ __overlay__ {{
+ {TESTNODE[1:]} {{
+ applied-{name};
+ order = "{order}";
+ }};
+ }};
+ }};
+}};
+"""
+
+
+def run(cmd, **kwargs):
+ subprocess.run(cmd, check=True, **kwargs)
+
+
+@pytest.fixture(scope="module")
+def overlay_fit(testfs):
+ path = os.path.join(testfs, "of-overlay")
+ os.makedirs(path, exist_ok=True)
+
+ images = configs = ""
+ for name, (compatible, order) in OVERLAYS.items():
+ with open(os.path.join(path, f"{name}.dtso"), "w") as f:
+ f.write(mkdtso(name, compatible, order))
+
+ if name != "kernel":
+ images += ITS_OVERLAY % (name, name)
+ configs += ITS_CONFIG % (name, name)
+
+ images += ITS_OVERLAY % ("kernel", "kernel")
+
+ with open(os.path.join(path, "overlays.its"), "w") as f:
+ f.write(ITS % (images, configs))
+ with open(os.path.join(path, "kernel.bin"), "wb") as f:
+ f.write(b"not a kernel")
+
+ try:
+ for name in OVERLAYS:
+ run(["dtc", "-I", "dts", "-O", "dtb", "-o", f"{name}.dtbo",
+ f"{name}.dtso"], cwd=path)
+ run(["mkimage", "-f", "overlays.its", "overlays.fit"], cwd=path,
+ stdout=subprocess.DEVNULL)
+ except FileNotFoundError as e:
+ shutil.rmtree(path)
+ pytest.skip(f"missing dependency: {e}")
+
+ # Change a property name in overlay-b, so its hash no longer matches
+ with open(os.path.join(path, "overlays.fit"), "rb") as f:
+ fit = f.read()
+ assert fit.count(b"applied-b") == 1
+ with open(os.path.join(path, "tampered.fit"), "wb") as f:
+ f.write(fit.replace(b"applied-b", b"applied-x"))
+
+ yield "/mnt/9p/testfs/of-overlay"
+
+ shutil.rmtree(path)
+
+
+@pytest.fixture(scope="function")
+def overlay_vars(barebox, barebox_config):
+ skip_disabled(barebox_config, "CONFIG_FITIMAGE", "CONFIG_OF_OVERLAY",
+ "CONFIG_CMD_OF_DUMP")
+
+ yield
+
+ barebox.run_check('global.of.overlay.path=""')
+ barebox.run_check('global.of.overlay.pattern="*"')
+ barebox.run_check('global.of.overlay.compatible=""')
+
+
+def fixed_testnode(barebox):
+ """Return the applied overlays and the order property of the test node
+ in the device tree a kernel would be started with"""
+ stdout, _, returncode = barebox.run(f"of_dump -F -p {TESTNODE}")
+ if returncode != 0:
+ return set(), None, stdout
+
+ applied = {line[len("applied-"):-1] for line in stdout
+ if line.startswith("applied-")}
+ order = next((line.split('"')[1] for line in stdout
+ if line.startswith("order = ")), None)
+
+ return applied, order, stdout
+
+
+def test_of_overlay_fit(barebox, overlay_vars, overlay_fit):
+ barebox.run_check(f"global.of.overlay.path={overlay_fit}/overlays.fit")
+
+ applied, order, stdout = fixed_testnode(barebox)
+
+ assert filter_errors(stdout) == [], stdout
+ # conf-kernel is skipped, the others are applied in FIT order
+ assert applied == {"a", "b", "c"}, stdout
+ assert order == "c", stdout
+
+ # Only the device tree passed to the kernel is changed
+ _, _, returncode = barebox.run(f"of_dump {TESTNODE}")
+ assert returncode != 0
+
+
+def test_of_overlay_fit_pattern(barebox, overlay_vars, overlay_fit):
+ barebox.run_check(f"global.of.overlay.path={overlay_fit}/overlays.fit")
+
+ # The pattern matches on the configuration name
+ barebox.run_check('global.of.overlay.pattern="conf-a overlay-b *-c"')
+ applied, order, stdout = fixed_testnode(barebox)
+ assert applied == {"a", "c"}, stdout
+ assert order == "c", stdout
+
+ barebox.run_check('global.of.overlay.pattern="conf-kernel"')
+ applied, _, stdout = fixed_testnode(barebox)
+ assert applied == set(), stdout
+
+
+def test_of_overlay_fit_compatible(barebox, overlay_vars, overlay_fit):
+ barebox.run_check(f"global.of.overlay.path={overlay_fit}/overlays.fit")
+
+ # Overlays without a compatible are always applied
+ barebox.run_check("global.of.overlay.compatible=barebox,fit-overlay-test-b")
+ applied, order, stdout = fixed_testnode(barebox)
+ assert applied == {"a", "b"}, stdout
+ assert order == "b", stdout
+
+
+def test_of_overlay_fit_bad_hash(barebox, overlay_vars, overlay_fit):
+ barebox.run_check(f"global.of.overlay.path={overlay_fit}/tampered.fit")
+
+ # overlay-b sets applied-x instead of applied-b in tampered.fit
+ applied, _, stdout = fixed_testnode(barebox)
+ assert "x" not in applied, stdout
+ assert any("hash BAD" in line for line in stdout), stdout
--
2.47.3
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