[Buildroot] [PATCH] linux: Fix uImage with appended DTs generation

[Peter Korsgaard <jacmet@uclibc.org>]

>>>>> "Maxime" == Maxime Ripard <maxime.ripard@free-electrons.com> writes:

 Maxime> Fixes bug #5516 - appended device tree blobs on uImage fails
 Maxime> Before version 3.7 of the kernel, building the zImage and then the
 Maxime> uImage will rewrite the zImage in the process, removing the device tree
 Maxime> we just appended.

 Maxime> Use mkimage to append the device tree to the uImage and rebuild the
 Maxime> headers directly.

 Maxime> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
 Maxime> ---
 Maxime>  linux/linux.mk | 14 +++++++++++---
 Maxime>  1 file changed, 11 insertions(+), 3 deletions(-)

 Maxime> diff --git a/linux/linux.mk b/linux/linux.mk
 Maxime> index 3877c35..a1166e5 100644
 Maxime> --- a/linux/linux.mk
 Maxime> +++ b/linux/linux.mk
 Maxime> @@ -228,9 +228,17 @@ define LINUX_APPEND_DTB
 Maxime>  	fi >> $(KERNEL_ARCH_PATH)/boot/zImage
 Maxime>  endef
 Maxime>  ifeq ($(BR2_LINUX_KERNEL_APPENDED_UIMAGE),y)
 Maxime> -# We need to generate the uImage here after that so that the uImage is
 Maxime> -# generated with the right image size.
 Maxime> -LINUX_APPEND_DTB += $(sep)$(TARGET_MAKE_ENV) $(MAKE) $(LINUX_MAKE_FLAGS) -C $(@D) uImage
 Maxime> +# We need to generate a new u-boot image that takes into
 Maxime> +# account the extra-size added by the device tree at the end
 Maxime> +# of the image. To do so, we first need to retrieve both load
 Maxime> +# address and entry point for the kernel from the already
 Maxime> +# generate uboot image before using mkimage -l.

This doesn't seem right. APPENDED_UIMAGE implies APPENDED_DTB, which
only builds a zImage, so there isn't any uImage to get the load address
/ entry point from.


 Maxime> +LINUX_APPEND_DTB += $(sep) LOAD=`$(HOST_DIR)/usr/bin/mkimage -l $(LINUX_IMAGE_PATH) |\
 Maxime> +                    sed -n 's/Load Address: \([0-9]*\)/\1/p'`; \
 Maxime> +                    ENTRY=`$(HOST_DIR)/usr/bin/mkimage -l $(LINUX_IMAGE_PATH) |\
 Maxime> +                    sed -n 's/Entry Point: \([0-9]*\)/\1/p'`; \
 Maxime> +                    $(HOST_DIR)/usr/bin/mkimage -A $(KERNEL_ARCH) -O linux -T kernel -C none -a $${LOAD} -e $${ENTRY} \
 Maxime> +                    -n 'Linux Buildroot' -d $(KERNEL_ARCH_PATH)/boot/zImage $(LINUX_IMAGE_PATH);

These regexps don't make much sense to me as the values are in
hexidecimal (E.G. prefixed with 0x) and the Entry Point: line as an
extra space before the numbers.

It would also be good to keep the previous name instead of hardcoding
Linux Buildroot.

I think it is simpler and cleaner to simply create the mkimage command
line with a single sed invocation, E.G. something like:

LINUX_APPEND_DTB += $(sep) MKIMAGE_ARGS=`$(HOST_DIR)/usr/bin/mkimage -l $(LINUX_IMAGE_PATH) |\
	sed -n -e 's/Image Name:[ ]*\(.*\)/-n "\1"/p' -e 's/Load Address:/-a/' -e 's/Entry Point:/-e/'`; \
	$(HOST_DIR)/usr/bin/mkimage -A $(KERNEL_ARCH) -O linux \
	-T kernel -C none $${MKIMAGE_ARGS} \
	-d $(KERNEL_ARCH_PATH)/boot/zImage $(LINUX_IMAGE_PATH);

(Construct the needed -n / -a / -e options in place).

-- 
Bye, Peter Korsgaard