[OE-core] [PATCH] linux-dtb: Use kernel build system to generate the dtb files

Bruce Ashfield bruce.ashfield at windriver.com
Tue Aug 13 03:40:39 UTC 2013 

On 13-08-12 11:37 AM, Otavio Salvador wrote:
> As the Linux kernel, unconditionally, builds the dtc application and
> it is the compatible version with the DeviceTree files shipped within
> the kernel it is better to use it and the kernel build system to
> generate the dtb files.

 From my point of view, I agree with this. I've always pushed for using
all of the artifacts from the kernel built (uImage, dtb, etc) and this
is consistent with that approach.

>
> Some DeviceTree files rely on CPP and kernel headers to be able to
> generate the dtb binary contents and it is harder to replicate it
> outside of Linux kernel build system so we /use/ it.
>
> Signed-off-by: Otavio Salvador <otavio at ossystems.com.br>
> ---
> NOTE: This depends on 'linux-dtb.inc: Replace /boot/ with /${KERNEL_IMAGEDEST}/' patch
>
>   meta/recipes-kernel/linux/linux-dtb.inc | 59 +++++++++++++++------------------
>   1 file changed, 27 insertions(+), 32 deletions(-)
>
> diff --git a/meta/recipes-kernel/linux/linux-dtb.inc b/meta/recipes-kernel/linux/linux-dtb.inc
> index 41dd599..a65f8bd 100644
> --- a/meta/recipes-kernel/linux/linux-dtb.inc
> +++ b/meta/recipes-kernel/linux/linux-dtb.inc
> @@ -1,44 +1,39 @@
>   # Support for device tree generation
>   FILES_kernel-devicetree = "/${KERNEL_IMAGEDEST}/devicetree*"
> -KERNEL_DEVICETREE_FLAGS ?= "-R 8 -p 0x3000"
>
>   python __anonymous () {
> -    devicetree = d.getVar("KERNEL_DEVICETREE", True) or ''
> -    if devicetree:
> -        depends = d.getVar("DEPENDS", True)
> -        d.setVar("DEPENDS", "%s dtc-native" % depends)
> -        packages = d.getVar("PACKAGES", True)
> -        d.setVar("PACKAGES", "%s kernel-devicetree" % packages)
> +    d.appendVar("PACKAGES", " kernel-devicetree")

What if someone, somewhere needs a custom dtc. Can we still trigger
a dependency on dtc-native is a different flag is set ?

>   }
>
>   do_install_append() {
> +	bbwarn "ARRG"
>   	if test -n "${KERNEL_DEVICETREE}"; then
> -		for DTS_FILE in ${KERNEL_DEVICETREE}; do
> -			if [ ! -f ${DTS_FILE} ]; then
> -				echo "Warning: ${DTS_FILE} is not available!"
> -				continue
> +		for DTB in ${KERNEL_DEVICETREE}; do
> +			if echo ${DTB} | grep -q '/dts/'; then
> +				bbwarn "${DTB} points to the full path dts file while it should have the target for use."

This isn't reading right to me. What are you trying to say ? That
KERNEL_DEVICE_TREE should be the name of the dts and not the path
to that dts ? I'd say 'name' versus target.

What about testing for it's existence ? The old code used to do that.

> +				DTB=`basename ${DTB} | sed 's,\.dts$,.dtb,g'`

 From the description of the patch .. this part is unexpected.
You are changing more than what is used to compile the dtb,
but the processing of the options.

>   			fi
> -			DTS_BASE_NAME=`basename ${DTS_FILE} | awk -F "." '{print $1}'`
> -			DTB_NAME=`echo ${KERNEL_IMAGE_BASE_NAME} | sed "s/${MACHINE}/${DTS_BASE_NAME}/g"`
> -			DTB_SYMLINK_NAME=`echo ${KERNEL_IMAGE_SYMLINK_NAME} | sed "s/${MACHINE}/${DTS_BASE_NAME}/g"`
> -			dtc -I dts -O dtb ${KERNEL_DEVICETREE_FLAGS} -o ${DTS_BASE_NAME} ${DTS_FILE}
> -			install -m 0644 ${DTS_BASE_NAME} ${D}/${KERNEL_IMAGEDEST}/devicetree-${DTB_SYMLINK_NAME}.dtb
> +			DTB_BASE_NAME=`basename ${DTB} .dtb`
> +			DTB_NAME=`echo ${KERNEL_IMAGE_BASE_NAME} | sed "s/${MACHINE}/${DTB_BASE_NAME}/g"`
> +			DTB_SYMLINK_NAME=`echo ${KERNEL_IMAGE_SYMLINK_NAME} | sed "s/${MACHINE}/${DTB_BASE_NAME}/g"`
> +			oe_runmake ${DTB}

The change log should explain this as well. You are switching the
naming to DTB from the old DTS .. because ? The kernel build
requires it ? something else ? You tell me :)

> +			install -m 0644 ${B}/arch/${ARCH}/boot/${DTB} ${D}/${KERNEL_IMAGEDEST}/devicetree-${DTB_SYMLINK_NAME}.dtb
>   		done
>   	fi
>   }
>
>   do_deploy_append() {
>   	if test -n "${KERNEL_DEVICETREE}"; then
> -		for DTS_FILE in ${KERNEL_DEVICETREE}; do
> -			if [ ! -f ${DTS_FILE} ]; then
> -				echo "Warning: ${DTS_FILE} is not available!"
> -				continue
> +		for DTB in ${KERNEL_DEVICETREE}; do
> +			if echo ${DTB} | grep -q '/dts/'; then
> +				bbwarn "${DTB} points to the full path dts file while it should have the target for use. "
> +				DTB=`basename ${DTB} | sed 's,\.dts$,.dtb,g'`

Given that the old and new code repeats this block .. is there an
opportunity to factor it out into a function ?

>   			fi
> -			DTS_BASE_NAME=`basename ${DTS_FILE} | awk -F "." '{print $1}'`
> -			DTB_NAME=`echo ${KERNEL_IMAGE_BASE_NAME} | sed "s/${MACHINE}/${DTS_BASE_NAME}/g"`
> -			DTB_SYMLINK_NAME=`echo ${KERNEL_IMAGE_SYMLINK_NAME} | sed "s/${MACHINE}/${DTS_BASE_NAME}/g"`
> +			DTB_BASE_NAME=`basename ${DTB} .dtb`
> +			DTB_NAME=`echo ${KERNEL_IMAGE_BASE_NAME} | sed "s/${MACHINE}/${DTB_BASE_NAME}/g"`
> +			DTB_SYMLINK_NAME=`echo ${KERNEL_IMAGE_SYMLINK_NAME} | sed "s/${MACHINE}/${DTB_BASE_NAME}/g"`
>   			install -d ${DEPLOYDIR}
> -			install -m 0644 ${B}/${DTS_BASE_NAME} ${DEPLOYDIR}/${DTB_NAME}.dtb
> +			install -m 0644 ${B}/arch/${ARCH}/boot/${DTB} ${DEPLOYDIR}/${DTB_NAME}.dtb

Same question, we switch to DTB from DTS for technical or clarity/cosmetic
reasons ?

>   			cd ${DEPLOYDIR}
>   			ln -sf ${DTB_NAME}.dtb ${DTB_SYMLINK_NAME}.dtb
>   			cd -
> @@ -48,20 +43,20 @@ do_deploy_append() {
>
>   pkg_postinst_kernel-devicetree () {
>   	cd /${KERNEL_IMAGEDEST}
> -	for DTS_FILE in ${KERNEL_DEVICETREE}
> +	for DTB_FILE in ${KERNEL_DEVICETREE}
>   	do
> -		DTS_BASE_NAME=`basename ${DTS_FILE} | awk -F "." '{print $1}'`
> -		DTB_SYMLINK_NAME=`echo ${KERNEL_IMAGE_SYMLINK_NAME} | sed "s/${MACHINE}/${DTS_BASE_NAME}/g"`
> -		update-alternatives --install /${KERNEL_IMAGEDEST}/${DTS_BASE_NAME}.dtb ${DTS_BASE_NAME}.dtb devicetree-${DTB_SYMLINK_NAME}.dtb ${KERNEL_PRIORITY} || true
> +		DTB_BASE_NAME=`basename ${DTB_FILE} | awk -F "." '{print $1}'`
> +		DTB_SYMLINK_NAME=`echo ${KERNEL_IMAGE_SYMLINK_NAME} | sed "s/${MACHINE}/${DTB_BASE_NAME}/g"`
> +		update-alternatives --install /${KERNEL_IMAGEDEST}/${DTB_BASE_NAME}.dtb ${DTB_BASE_NAME}.dtb devicetree-${DTB_SYMLINK_NAME}.dtb ${KERNEL_PRIORITY} || true

The DTS -> DTB name change is making the patch look bigger than it is,
and really should be separate from the switch to the in tree dtc.

Bruce

>   	done
>   }
>
>   pkg_postrm_kernel-devicetree () {
>   	cd /${KERNEL_IMAGEDEST}
> -	for DTS_FILE in ${KERNEL_DEVICETREE}
> +	for DTB_FILE in ${KERNEL_DEVICETREE}
>   	do
> -		DTS_BASE_NAME=`basename ${DTS_FILE} | awk -F "." '{print $1}'`
> -		DTB_SYMLINK_NAME=`echo ${KERNEL_IMAGE_SYMLINK_NAME} | sed "s/${MACHINE}/${DTS_BASE_NAME}/g"`
> -		update-alternatives --remove ${DTS_BASE_NAME}.dtb devicetree-${DTB_SYMLINK_NAME}.dtb ${KERNEL_PRIORITY} || true
> +		DTB_BASE_NAME=`basename ${DTB_FILE} | awk -F "." '{print $1}'`
> +		DTB_SYMLINK_NAME=`echo ${KERNEL_IMAGE_SYMLINK_NAME} | sed "s/${MACHINE}/${DTB_BASE_NAME}/g"`
> +		update-alternatives --remove ${DTB_BASE_NAME}.dtb devicetree-${DTB_SYMLINK_NAME}.dtb ${KERNEL_PRIORITY} || true
>   	done
>   }
>

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