[Buildroot] [PATCH v2 0/2] add support for libcamera's qcam

[Quentin Schulz]

This adds support for qcam example GUI from libcamera. It is based on
Qt6 and uses openGL.

Sadly, the qt module from meson is currently broken[1]. The v1 of this
series patched host-meson but the v2 now patches BR_PATH to contain
/libexec from the Buildroot host dir. This was done as suggested by
Peter in the review of v1 to avoid carrying the meson patch that the
meson community isn't too happy about. The downside with the BR_PATH
patch is that /libexec technically shouldn't be used to store binaries
the user (or shell scripts) should execute, and Buildroot is mostly
that. Additionally, meson qt module will say it's looking for runtime
dependencies when looking for the uic, moc, rcc, ... binaries in
/libexec, while they are used at build time, so this is kinda wrong. But
it works. Both approaches make meson find the qt tools, and they are not
exclusive (we can have both).

qcam requires a font to be installed (e.g. cantarell or dejavu)
otherwise characters are renders as square characters.

This is based on top of
https://lore.kernel.org/buildroot/20250404-libcamera-0-5-0-v1-0-e2ca9d029aeb@cherry.de/T/#t

[1] https://github.com/mesonbuild/meson/pull/14381

Signed-off-by: Quentin Schulz <quentin.schulz at cherry.de>
---
Changes in v2:
- removed host-meson patch in favor of BR_PATH patch in Makefile for
  meson qt6 module to find the qt tools,
- added dependency on QT6BASE_FONTCONFIG which seems to be required,
- added comment that a font needs to be installed,
- Link to v1: https://lore.kernel.org/r/20250408-libcamera-qcam-v1-0-680c8a48dc17@cherry.de

---
Quentin Schulz (2):
      Makefile: add libexec to BR_PATH
      package/libcamera: add Qt6 qcam support

 Makefile                       | 2 +-
 package/libcamera/libcamera.mk | 6 ++++++
 2 files changed, 7 insertions(+), 1 deletion(-)
---
base-commit: 43abcd4c7dd8ad65d2f2012f3d4292362550a3ed
change-id: 20250404-libcamera-qcam-e8269c47e2f9
prerequisite-change-id: 20250404-libcamera-0-5-0-b9ecf899ddb4:v1
prerequisite-patch-id: 854e58d76fc57aa774ca0d315ecae56b67c00c8a
prerequisite-patch-id: 4873ac99203f0d789d64aec048249d9ba6a15a82
prerequisite-patch-id: c4d504c6563a911ba550be263063cfd7bf04bcbe
prerequisite-patch-id: 4a74788db759d3b67650f1456ee4d64f9394f50a
prerequisite-patch-id: 73a4b5a3204b1a901da74a3ffe1672055404dd2f
prerequisite-patch-id: 90b567b9a37abb58747d965ea2e0fef41358844b
prerequisite-patch-id: 946aac34b70f001c24fc6fe86caab759a4591359
prerequisite-patch-id: cee428a4219c83704347f6f194694f21093034da
prerequisite-patch-id: 6bbbdc80dc639a1b2918d79ae101e1030f3312bd

Best regards,
-- 
Quentin Schulz <quentin.schulz at cherry.de>