Re: [yocto] How to switch between package version ?

[Mikko Rapeli <mikko.rapeli@linaro.org>]

Hi,

On Wed, Aug 16, 2023 at 04:55:53AM -0700, Nicolas Wirth via lists.yoctoproject.org wrote:
> Hi Mikko, thank you for you're answer which was very insightful.
> 
> > 
> > If that is not available, check if you can change the branch of an existing
> > meta layer to provide what you need. Note that mixing
> > layer branch names is frequently possible with minor changes, e.g. using
> > meta-security master branch with kirkstone LTS poky.
> 
> Could I ask you to elaborate on this subject or share some resources about mixing layer branches ?

There isn't much documentation. It's more about just doing it and resolving any issues
you find. For example BSP deliveries from vendors frequently only support older yocto branches.
These should not dictate the poky release for the full SW stack when for example only kernel
and bootloader are needed from their delivery. Thus using older BSP layer with the kernel
and other recipes with a newer poky is a matter of configuring the build system and resolving
any build failures from e.g. newer poky and gcc. The layer compatibility setting meant to warn
and prohibit from doing this, but this can be overruled in other layers by setting
e.g. LAYERSERIES_COMPAT_security-layer += "mickledore kirkstone" in layer.conf of your own
layers. If large parts of a layer (BSP) are not needed in your configuration and cause
build issues, then those can be hidden by setting BBMASK for those paths.

Hope this helps,

-Mikko