Re: [PATCH] test: lib/uuid: Fix endianness for dynamic GUIDs

On Thu, Aug 27, 2026 at 5:39 PM Heinrich Schuchardt
<[email protected]> wrote:
>
> On 8/27/26 15:00, Alexey Charkov wrote:
> > If LIB_UUID is enabled on a big-endian board, such as when it is pulled
> > in by EFI_PARTITION, its tests will fail due to the dynamic capsule GUIDs
> > computed by lib_test_dynamic_uuid() using native endianness for the UTF-16
> > image name, instead of little-endian:
> >
> >    malta # ut lib lib_test_dynamic_uuid
> >    Test: dynamic_uuid: uuid.c
> >    test/lib/uuid.c:114, lib_test_dynamic_uuid_case(): expected_uuid = uuid_str: Expected "985f2937-7c2e-5e9a-8a5e-8e063312964b", got "829f5cb0-1a07-5718-8774-4514bda82c39"
> >    Test 'dynamic_uuid' failed 1 times
> >    Tests run: 1, 2 ms, average: 2 ms, failures: 1
> >    exit not allowed from main input shell.
> >    malta #
> >
> > Add explicit endianness conversion to the test and to other similar
> > callers of gen_v5_guid() to make sure they work uniformly regardless of
> > the host or target endianness.
> >
> > Signed-off-by: Alexey Charkov <[email protected]>
>
> Thank you for reporting that the test fails on big endian systems.
>
> In lib_test_dynamic_uuid() we define define dynamic_uuid_test_data
> test_data[].images as u16 string. On a big endian system the characters
> of the string will not be stored in the same sequence as on a low endian
> system so the UUID generated in gen_v5_guid() is expected to be different.
>
> test_data[].images should contain unique sequences of bytes.
>
> The relevant code was introduced with
> 26e16a850e64 ("test: lib/uuid: add unit tests for dynamic UUIDs")

Thanks for looking into this!

Do I get it right that you'd rather have the test_data[].images bytes
untouched, and instead select different test_data[].expected_uuids
based on the CPU endianness, rather than patching
lib_test_dynamic_uuid_case()? Or shall I make the test_data[].images a
plain byte array to remove the endianness concern altogether?

> With that I don't think that the EFI changes are needed. Anyway UEFI is
> little endian only.

Happy to drop the hunks touching files other than the test
expectation. However, the test expectation needs an update one way or
another, as we can't test GPT on BE without it.

Best regards,
Alexey