Re: [OE-core] [PATCH v2 1/3] kernel-uboot: move FIT_KERNEL_COMP_ALG to image-fitimage.conf

[Richard Purdie <richard.purdie@linuxfoundation.org>]

On Mon, 2026-07-27 at 11:05 +0200, Nora Schiffer via lists.openembedded.org wrote:
> It is a bit weird that FIT_KERNEL_COMP_ALG also affects uImage creation,
> as kernel-uboot.bbclass is used for both, but fixing that would
> unnecessarily break backwards compatibility.
> 
> Signed-off-by: Nora Schiffer <nora.schiffer@ew.tq-group.com>
> ---
>  meta/classes-recipe/kernel-uboot.bbclass | 3 +--
>  meta/conf/image-fitimage.conf            | 3 +++
>  2 files changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/meta/classes-recipe/kernel-uboot.bbclass b/meta/classes-recipe/kernel-uboot.bbclass
> index fa28be1715..9beccc2dff 100644
> --- a/meta/classes-recipe/kernel-uboot.bbclass
> +++ b/meta/classes-recipe/kernel-uboot.bbclass
> @@ -4,8 +4,7 @@
>  # SPDX-License-Identifier: MIT
>  #
>  
> -# fitImage kernel compression algorithm
> -FIT_KERNEL_COMP_ALG ?= "gzip"
> +require conf/image-fitimage.conf
>  
>  # Kernel image type passed to mkimage (i.e. kernel kernel_noload...)
>  UBOOT_MKIMAGE_KERNEL_TYPE ?= "kernel"
> diff --git a/meta/conf/image-fitimage.conf b/meta/conf/image-fitimage.conf
> index a06d30e494..abb17186a5 100644
> --- a/meta/conf/image-fitimage.conf
> +++ b/meta/conf/image-fitimage.conf
> @@ -48,6 +48,9 @@ FIT_OS ?= "linux"
>  # DTBs are provided separately in a FIT image.
>  FIT_LINUX_BIN ?= "linux.bin"
>  
> +# fitImage kernel compression algorithm
> +FIT_KERNEL_COMP_ALG ?= "gzip"
> +
>  # Additional mkimage options for FIT image creation
>  FIT_MKIMAGE_EXTRA_OPTS ?= ""
> 

We're realising that the kernel classes are a bit of a tangled spiders
web and we want to improve things and clean things up.

Adding a dependency on "fit" from the "uboot" class does therefore feed
a bit backward as you note.

You mention not breaking backwards compatibility. I think given the
other work we're thinking about, it might be worth considering that and
seeing if we can avoid tangling things up even further.

Cheers,

Richard