Custom distribution based on OpenSTLinux

[PGE]

I am currently building a dedicated image for our custom board based on STM32MP1. According to the wiki and OE mega-manual, I need to create a custom distribution to be able to customize it according to our needs.

I am following the steps described here to build my own distribution which is basically the same as openstlinux-eglfs for now but in my own layer. I tried to run the init script (layers/meta-st/scripts/envsetup.sh) with my own distribution instead of openstlinux-eglfs but get the following error:

[ERROR] No 'customdistro-eglfs.conf' file available in layers/meta-st

This is normal as my customdistro-eglfs.conf file is in another layers than meta-st as recommended. Do I have to copy scripts directory from meta-st to my layers ? Or do I have to source the script in another way ?

I can see on others documentation the usual way is to source openembedded-core/oe-init-build-env. Why ST use a custom different script for OpenSTLinux ?

In a more general ways I have the feeling ST customized many things on OpenSTLinux instead of relying on yocto mechanism, why ? Is it recommended to build custom distro on top of OpenSTLinux or on top of yocto ? What exactly OpenSTLinux do provide on top of yocto ?

Thanks in advance for any help

[PGE]

I (partially) reply myself.

I had to add META_LAYER_ROOT like this:

DISTRO=customdistro MACHINE=stm32mp1-custom META_LAYER_ROOT=layers/meta-custom source layers/meta-st/scripts/envsetup.sh

I also had to copy all meta-st/conf/distro/include and meta-st/conf/distro/template to my own layers (meta-custom). I don't know if this the recommended way or if I should be able to include files directly from meta-st/conf/distro/include without copying them.

Any reply from ST support about this and other question in my original post would be appreciated