[PATCH v5 6/8] kbuild: Allow adding modules into the FIT ramdisk

[Thomas Weißschuh]

On Fri, Nov 14, 2025 at 07:27:32AM -0700, Simon Glass wrote:
> Support 'make image.fit FIT_MODULES=1' to put all the modules into a
> ramdisk image within the FIT.
> 
> Add image.fit as a target which requires modules, so that modules will
> built automatically when using FIT_MODULES=1
> 
> Signed-off-by: Simon Glass <sjg at chromium.org>
> Suggested-by: Ahmad Fatoum <a.fatoum at pengutronix.de>
> Suggested-by: Reviewed-by: Nicolas Schier <nsc at kernel.org>
> Acked-by: Nathan Chancellor <nathan at kernel.org>
> ---
> 
> Changes in v5:
> - Build modules automatically if needed (fix from Nicolas Schier)
> 
> Changes in v4:
> - Rename the Makefile variable from 'EXTRA' to 'MAKE_FIT_FLAGS'
> - Use an empty FIT_MODULES to disable the feature, instead of '0'
> - Make use of the 'modules' dependency to ensure modules are built
> - Pass the list of modules to the script
> 
>  Makefile             |  1 +
>  arch/arm64/Makefile  |  1 +
>  scripts/Makefile.lib | 10 ++++++++--
>  3 files changed, 10 insertions(+), 2 deletions(-)
> 
> diff --git a/Makefile b/Makefile
> index 8cd46222fc48..4eccaef95826 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -773,6 +773,7 @@ endif
>  # Just "make" or "make all" shall build modules as well
>  
>  modules-targets := all
> +modules-targets += $(if $(FIT_MODULES),image.fit)
>  modules-targets += modules
>  modules-targets += nsdeps
>  modules-targets += compile_commands.json
> diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile
> index 73a10f65ce8b..7036f251ab40 100644
> --- a/arch/arm64/Makefile
> +++ b/arch/arm64/Makefile
> @@ -174,6 +174,7 @@ endif
>  all:	$(notdir $(KBUILD_IMAGE))
>  
>  image.fit: dtbs
> +image.fit: $(if $(FIT_MODULES),modules)
>  
>  vmlinuz.efi image.fit: Image
>  $(BOOT_TARGETS): vmlinux
> diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
> index 1d581ba5df66..c6a3aa653035 100644
> --- a/scripts/Makefile.lib
> +++ b/scripts/Makefile.lib
> @@ -398,11 +398,17 @@ MAKE_FIT := $(srctree)/scripts/make_fit.py
>  # Use this to override the compression algorithm
>  FIT_COMPRESSION ?= gzip
>  
> +# Set this to 1 to include an initrd with all the kernel modules
> +FIT_MODULES ?=

'0' will also trigger that behavior.

> +
>  quiet_cmd_fit = FIT     $@
> -      cmd_fit = $(MAKE_FIT) -o $@ --arch $(UIMAGE_ARCH) --os linux \
> -		--name '$(UIMAGE_NAME)' \
> +      cmd_fit = $(if $(FIT_MODULES), \
> +		find $(objtree) -name '*.ko' > $(objtree)/.modules-list 2>/dev/null &&) \

This will include stale module files. You can get an up-to-date list from
$(objtree)/modules.order with a bit post-processing.
Maybe kbuild can be extended to also create a list of the .ko files.
(I would be interested in that for my own usecases, too)

> +		$(MAKE_FIT) -o $@ --arch $(UIMAGE_ARCH) --os linux \
> +		--name '$(UIMAGE_NAME)' $(MAKE_FIT_FLAGS) \
>  		$(if $(findstring 1,$(KBUILD_VERBOSE)),-v) \
>  		$(if $(FIT_DECOMPOSE_DTBS),--decompose-dtbs) \
> +		$(if $(FIT_MODULES),--modules @$(objtree)/.modules-list) \
>  		--compress $(FIT_COMPRESSION) -k $< @$(word 2,$^)
>  
>  # XZ
> -- 
> 2.43.0
>