[PATCH] Documentation: migration-2025.06.0: mention char becoming unsigned

[Ahmad Fatoum]

unsigned chars are the default on ARM, so breakage is probably limited,
but let's point it out to be sure anyways.

Signed-off-by: Ahmad Fatoum <a.fatoum at pengutronix.de>
---
 Documentation/migration-guides/migration-2025.06.0.rst | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/Documentation/migration-guides/migration-2025.06.0.rst b/Documentation/migration-guides/migration-2025.06.0.rst
index ce39b117c8cb..54d9d0f132d7 100644
--- a/Documentation/migration-guides/migration-2025.06.0.rst
+++ b/Documentation/migration-guides/migration-2025.06.0.rst
@@ -6,3 +6,9 @@ Configuration options
 
 * ``CONFIG_USB_ONBOARD_HUB`` has been renamed to ``CONFIG_USB_ONBOARD_DEV``
   for compatibility with Linux.
+
+Board code
+----------
+
+The C ``char`` data type is now always unsigned. This may affect code
+assuming ``char`` to be signed as was the default on x86, mips and kvx.
-- 
2.39.5