[Buildroot] [PATCH 1/3] package/libcamera: Prevent builds on m68k

[Kieran Bingham]

The ControlValue structure is currently defined with a 16-bit hole
(causing unaligned access to the numElements_ field, though that's a
separate topic).

This structure has a static assertion to ensure that its size does not
change without due care, as it forms part of our ABI and is used in
Serialisation between the pipeline handlers and IPA componenents.

The m68k architecture is the only target which fails this assertion,
which is likely because it can pack the structure more efficiently,
producing a different binary size.

This is likely an area we will tackle before stabilising our ABI, but
until then, disable m68k builds as libcamera is not expected to be
supported on this target.

Signed-off-by: Kieran Bingham <kieran.bingham at ideasonboard.com>
---
 package/libcamera/Config.in | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/package/libcamera/Config.in b/package/libcamera/Config.in
index 960d78b82e95..1ea747d1c57e 100644
--- a/package/libcamera/Config.in
+++ b/package/libcamera/Config.in
@@ -5,6 +5,8 @@ menuconfig BR2_PACKAGE_LIBCAMERA
 	depends on BR2_TOOLCHAIN_GCC_AT_LEAST_5 # C++14
 	depends on !BR2_STATIC_LIBS # gnutls
 	depends on BR2_USE_WCHAR # gnutls
+	# Invalid packing size of ControlValue struct on m68k
+	depends on !BR2_m68k
 	select BR2_PACKAGE_GNUTLS
 	select BR2_PACKAGE_LIBCAMERA_PIPELINE_UVCVIDEO if !BR2_PACKAGE_LIBCAMERA_HAS_PIPELINE
 	help
-- 
2.25.1