[Buildroot] [PATCH 3/9 v2] linux: meddle not in the affairs of filesystems, for you are tasty with bacon

[Romain Naour]

Hi Yann, All,

Le 11/03/2016 19:41, Yann E. MORIN a écrit :
> Currently, the rule to rebuild the Linux kernel with an initramfs
> directly depends on the filesystem image filename.
> 
> This is inherently "bad" from a purity point of view. linux.mk should
> not have to delve into the fs internals.
> 
> Rather, make it directly depend on the "frontal" rule that generates the
> cpio image.
> 
> Drop the comment for linux-rebuild-with-initramfs, it was misleading
> (talking about generating "the initramfs list of files", which is not
> what was done, since we use a cpio as source of initramfs, not a list of
> files).
> 
> Signed-off-by: "Yann E. MORIN" <yann.morin.1998 at free.fr>
> Cc: Thomas Petazzoni <thomas.petazzoni at free-electrons.com>
> Cc: Arnout Vandecappelle <arnout at mind.be>
> 
> ---
> Changes v1 -> v2:
>   - drop intermediate, unneeded stamp-file
>   - drop misleading comment
> 
> ---
> This, too, will be useful for the initramfs patch coming next.
> ---
>  linux/linux.mk | 16 ++++++----------
>  1 file changed, 6 insertions(+), 10 deletions(-)
> 
> diff --git a/linux/linux.mk b/linux/linux.mk
> index ea90918..c0d760a 100644
> --- a/linux/linux.mk
> +++ b/linux/linux.mk
> @@ -438,11 +438,12 @@ endif # BR_BUILDING
>  $(eval $(kconfig-package))
>  
>  # Support for rebuilding the kernel after the cpio archive has
> -# been generated in $(BINARIES_DIR)/rootfs.cpio.
> -$(LINUX_DIR)/.stamp_initramfs_rebuilt: $(LINUX_DIR)/.stamp_target_installed
> -$(LINUX_DIR)/.stamp_initramfs_rebuilt: $(LINUX_DIR)/.stamp_images_installed
> -$(LINUX_DIR)/.stamp_initramfs_rebuilt: $(BINARIES_DIR)/rootfs.cpio
> -$(LINUX_DIR)/.stamp_initramfs_rebuilt:
> +# been generated.
> +.PHONY: linux-rebuild-with-initramfs
> +linux-rebuild-with-initramfs: $(LINUX_DIR)/.stamp_target_installed
> +linux-rebuild-with-initramfs: $(LINUX_DIR)/.stamp_images_installed
> +linux-rebuild-with-initramfs: rootfs-cpio
> +linux-rebuild-with-initramfs:
>  	@$(call MESSAGE,"Rebuilding kernel with initramfs")
>  	# Build the kernel.
>  	$(LINUX_MAKE_ENV) $(MAKE) $(LINUX_MAKE_FLAGS) -C $(@D) $(LINUX_TARGET_NAME)
> @@ -451,8 +452,3 @@ $(LINUX_DIR)/.stamp_initramfs_rebuilt:
>  	cp $(LINUX_IMAGE_PATH) $(BINARIES_DIR)
>  	# If there is a .ub file copy it to the final destination
>  	test ! -f $(LINUX_IMAGE_PATH).ub || cp $(LINUX_IMAGE_PATH).ub $(BINARIES_DIR)
> -	$(Q)touch $@

IIUC, the stamp file can be removed since the target is now PHONY, right ?

But latter in the patch 4/9 in the comment there is a reference to this file:
# Note: ordering of the dependencies is not guaranteed here, but in
# linux/linux.mk, via the .stamp_initramfs_rebuilt stamp file, which depends
# on the rootfs-cpio filesystem rule.

> -
> -# The initramfs building code must make sure this target gets called
> -# after it generated the initramfs list of files.
> -linux-rebuild-with-initramfs: $(LINUX_DIR)/.stamp_initramfs_rebuilt
> 

Something is wrong...
With this patch applied, I have the following error when rebuilding the kernel
with initramfs:

make[2]: *** No rule to make target 'bzImage'. Arrêt.
linux/linux.mk:447: recipe for target 'linux-rebuild-with-initramfs' failed

Best regards,
Romain