Enable graphics for imx6ul/ull boards. Add panel and backlight drivers

Set environment variables for impoved menuconfig support

- Move xxd-native dependency from hosttools in layer to recipe
- Set license flag to newer value

With the upstream display driver stack the DRI paths are different.
Fix them.

Use generic names for the boot scripts for booting from a single
partition and for doing A/B boots from two separate partitions.

Use the generic 'load' command instead of specific filesystem
commands.

Also sync the environment for i.MX6UL/ULL with the one for i.MX8MM.

This way we can boot i.MX8M devices with a boot logo and splash
screen as the display pipeline is available before the userspace and
filesystem are ready.

In the future we will reference the BSP as meta-ked-bsp. Adjust names
of layers, files, etc. accordingly. Only some OE metadata like image,
distro or machine override names are keeping the 'ktn' for now.

KED stands for Kontron Electronics Deutschland GmbH where the BSP
is maintained. Nowadays it support only products of the KED branch
and products of the Kontron Europe GmbH or other branches are not
supported.

Michael Walle authored 1 year ago and Frieder Schrempf committed 1 year ago

If bootcfg is unset, the default fit image configuration will be used.

FILESEXTRAPATHS_prepend uses old override syntax and is not required
anyway in the base recipe. Remove it and also fix some othe minor
style issues.

This backports the latest libgpiod recipes from meta-oe master. The
new libgpiod v2 includes major changes and improvements and might be
required in certain use cases.

For now the default remains v1.6 while someone who needs the v2 can
set PREFERRED_VERSION_libgpiod = "2.0".

This can be used by WIC or other tools that work with file system images
instead of TAR archives.

Eberhard Stoll authored 2 years ago and Frieder Schrempf committed 1 year ago

Use drm interface for Qt backend linuxfb. This fixes some bugs when scaling
some UI elements. These bugs are visible with the 'gallery' app on pages
with choices: The circles are misaligned and misscaled when 'QT_QPA_FB_DRM'
is not set. If it is set, all elements are error free.
Currently this setting is only activated for the STM32MP1 platform. Maybe this would be sensible for the imx platforms also. Enabling this for the imx
platforms needs currently some testing.