[3/3] migration-5.3: replace kernel-fitimage by kernel-fit-image

From: Adrian Freihofer <adrian.freihofer@siemens.com>

Add migration documentation for users moving from the removed
kernel-fitimage.bbclass to the new kernel-fit-image.bbclass.

Signed-off-by: Adrian Freihofer <adrian.freihofer@siemens.com>
---
 .../migration-guides/migration-5.3.rst        | 35 +++++++++++++++++++
 1 file changed, 35 insertions(+)

On Fri Jun 6, 2025 at 4:06 PM CEST, Adrian Freihofer via lists.yoctoproject.org wrote:
> From: Adrian Freihofer <adrian.freihofer@siemens.com>
>
> Add migration documentation for users moving from the removed
> kernel-fitimage.bbclass to the new kernel-fit-image.bbclass.
>
> Signed-off-by: Adrian Freihofer <adrian.freihofer@siemens.com>
> ---
>  .../migration-guides/migration-5.3.rst        | 35 +++++++++++++++++++
>  1 file changed, 35 insertions(+)
>
> diff --git a/documentation/migration-guides/migration-5.3.rst b/documentation/migration-guides/migration-5.3.rst
> index 22653fc911e..4e03d075b5e 100644
> --- a/documentation/migration-guides/migration-5.3.rst
> +++ b/documentation/migration-guides/migration-5.3.rst
> @@ -59,6 +59,41 @@ Removed classes
>  
>  The following classes have been removed in this release:
>  
> +-  ``kernel-fitimage.bbclass``: the class has been replaced by the
> +   :ref:`ref-classes-kernel-fit-image` class. The new implementation resolves
> +   a long-standing issue with the previous implementation (see
> +   `bug #12912 <https://bugzilla.yoctoproject.org/show_bug.cgi?id=12912>`__).

You can use:

  :yocto_bugs:`bug 12912</show_bug.cgi?id=12912>`

> +
> +   If you are using the kernel FIT image support, you will need to:
> +
> +   1. Make sure to include ``kernel-fit-extra-artifacts`` in your :term:`KERNEL_CLASSES`

You should use the "#." rst syntax here instead:

"""
#.  Make sure...

#.  Use the...
"""

> +      variable to ensure the required files are exposed to the :term:`DEPLOY_DIR_IMAGE`
> +      directory::
> +
> +         KERNEL_CLASSES += "kernel-fit-extra-artifacts"
> +
> +   2. Use the specific FIT image recipe rather than the base kernel recipe.
> +      For example, instead of::
> +
> +         bitbake linux-yocto
> +
> +      You now need to use::
> +
> +         bitbake linux-yocto-fitimage

Could we also suggest that the kernel-fit-image class should be inherited by the
custom kernel recipe or that an extra recipe should be created for the fitimage?
(I don't know what's the best option).

> +
> +   3. If you want to use the FIT image as a replacement for the kernel image in the
> +      root filesystem, add the following configuration to your machine configuration file::
> +
> +         # Do not install the kernel image package
> +         RRECOMMENDS:${KERNEL_PACKAGE_NAME}-base = ""
> +
> +         # Install the FIT image package
> +         MACHINE_EXTRA_RDEPENDS += "${PREFERRED_PROVIDER_virtual/kernel}-fitimage"
> +
> +         # Configure the image.bbclass to depend on the fitImage instead of only
> +         # the kernel to ensure the fitImage is built with the image
> +         KERNEL_DEPLOY_DEPEND = "${PREFERRED_PROVIDER_virtual/kernel}-fitimage:do_deploy"

I would suggest a last sentence:

"""
See the the :ref:`ref-classes-kernel-fit-image` section for more information.
"""

> +
>  Removed features
>  ~~~~~~~~~~~~~~~~
>  

Thanks!
Antonin