use kernel build system for dtb compilation

* use kernel build system for dtb compilation
@ 2013-07-15 16:50 Andre Draszik
  2013-07-22 14:02 ` [PATCH] linux-dtb: allow to build dtb using support from kernel André Draszik
  0 siblings, 1 reply; 4+ messages in thread
From: Andre Draszik @ 2013-07-15 16:50 UTC (permalink / raw)
  To: openembedded-core


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Hi,

I have a use-case where I need to compile the dtb using the kernel build
system, and the kernel's device tree compiler:
- In dylan, dtc is outdated and can not compile our dts, as that needs
additional include files. dtc in dylan does not understand the include path
option -i, although the dtc that comes with linux-3.4.x does support it.
- Irrespective of the version of the dtc (dylan vs. master), the kernel
build system supports running dtsp files through CPP, which we also need

The attached patch changes linux-dtb.inc to support such a use-case

If KERNEL_DEVICETREE points to file(s) in arch/${ARCH}/boot/dts, instead of
full paths (relative to ${S}), kbuild is used, otherwise behaviour is
unchanged.

An alternative would be to copy what the kernel's Makefile is doing, but
that seems pointless, and still requires updating dtc to something more
recent in dylan.


What do you think about attached (incomplete) patch?


Cheers,
Andre'

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From 73bc3f26265dc46cba578c1da080a2d4002de195 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Andr=C3=A9=20Draszik?= <andre.draszik@st.com>
Date: Mon, 15 Jul 2013 16:42:15 +0100
Subject: [PATCH] linux-dtb: allow to build dtb using kernel build system
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

The kernel build system has native support for device tree
source files that /include/ additional files from standard
directories, and it also supports the pre-processing of
source file(s) using CPP.

This commits lets OE use the kbuild system if
$KERNEL_DEVICETREE points to file(s) that are located in
arch/${ARCH}/boot/dts/

Still missing is a change to the dependency tracking python
code after which we would only add the dtc-native dependency
if the kernel build system is not used.

Signed-off-by: André Draszik <andre.draszik@st.com>
---
 meta/recipes-kernel/linux/linux-dtb.inc | 60 +++++++++++++++++++++++++++------
 1 file changed, 50 insertions(+), 10 deletions(-)

diff --git a/meta/recipes-kernel/linux/linux-dtb.inc b/meta/recipes-kernel/linux/linux-dtb.inc
index 7747718..7eea83a 100644
--- a/meta/recipes-kernel/linux/linux-dtb.inc
+++ b/meta/recipes-kernel/linux/linux-dtb.inc
@@ -1,3 +1,5 @@
+inherit kernel-arch
+
 # Support for device tree generation
 FILES_kernel-devicetree = "/boot/devicetree*"
 KERNEL_DEVICETREE_FLAGS ?= "-R 8 -p 0x3000"
@@ -5,24 +7,49 @@ KERNEL_DEVICETREE_FLAGS ?= "-R 8 -p 0x3000"
 python __anonymous () {
     devicetree = d.getVar("KERNEL_DEVICETREE", True) or ''
     if devicetree:
+        # fixme: add dependency only if file not found
         depends = d.getVar("DEPENDS", True)
         d.setVar("DEPENDS", "%s dtc-native" % depends)
         packages = d.getVar("PACKAGES", True)
         d.setVar("PACKAGES", "%s kernel-devicetree" % packages)
 }
 
-do_install_append() {
+do_compile_append() {
 	if test -n "${KERNEL_DEVICETREE}"; then
 		for DTS_FILE in ${KERNEL_DEVICETREE}; do
 			if [ ! -f ${DTS_FILE} ]; then
-				echo "Warning: ${DTS_FILE} is not available!"
-				continue
+				if [ ! -f arch/${ARCH}/boot/dts/${DTS_FILE} ]; then
+					echo "Warning: ${DTS_FILE} is not available!"
+					continue
+				fi
+
+				# standard build using kbuild
+				echo "Info: standard kbuild for device tree blob"
+				DTS_BASE_NAME=`basename ${DTS_FILE} | awk -F "." '{print $1}'`
+
+				unset CFLAGS CPPFLAGS CXXFLAGS LDFLAGS MACHINE
+				oe_runmake ${DTS_BASE_NAME}.dtb CC="${KERNEL_CC}" LD="${KERNEL_LD}" ${KERNEL_EXTRA_ARGS}
 			fi
+		done
+	fi
+}
+
+do_install_append() {
+	if test -n "${KERNEL_DEVICETREE}"; then
+		for DTS_FILE in ${KERNEL_DEVICETREE}; do
 			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} ${D}/boot/devicetree-${DTB_SYMLINK_NAME}.dtb
+			if [ ! -f ${DTS_FILE} ]; then
+				if [ ! -f arch/${ARCH}/boot/dts/${DTS_FILE} ]; then
+					echo "Warning: ${DTS_FILE} is not available!"
+					continue
+				fi
+
+				install -m 0644 arch/${ARCH}/boot/${DTS_BASE_NAME}.dtb ${D}/boot/devicetree-${DTB_SYMLINK_NAME}.dtb
+				continue
+			fi
+			dtc -I dts -O dtb ${KERNEL_DEVICETREE_FLAGS} -o ${DTS_BASE_NAME}.dtb ${DTS_FILE}
+			install -m 0644 ${DTS_BASE_NAME}.dtb ${D}/boot/devicetree-${DTB_SYMLINK_NAME}.dtb
 		done
 	fi
 }
@@ -30,15 +57,28 @@ do_install_append() {
 do_deploy_append() {
 	if test -n "${KERNEL_DEVICETREE}"; then
 		for DTS_FILE in ${KERNEL_DEVICETREE}; do
+			DTS_BASE_NAME=`basename ${DTS_FILE} | awk -F "." '{print $1}'`
 			if [ ! -f ${DTS_FILE} ]; then
-				echo "Warning: ${DTS_FILE} is not available!"
-				continue
+				if [ ! -f arch/${ARCH}/boot/dts/${DTS_FILE} ]; then
+					echo "Warning: ${DTS_FILE} is not available!"
+					continue
+				fi
+
+				# standard build using kbuild
+				echo "Info: standard kbuild for device tree blob"
 			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"`
+
 			install -d ${DEPLOYDIR}
-			install -m 0644 ${B}/${DTS_BASE_NAME} ${DEPLOYDIR}/${DTB_NAME}.dtb
+
+			if [ -f arch/${ARCH}/boot/dts/${DTS_FILE} ]; then
+				install -m 0644 ${B}/arch/${ARCH}/boot/${DTS_BASE_NAME}.dtb ${DEPLOYDIR}/${DTB_NAME}.dtb
+			else
+				install -m 0644 ${B}/${DTS_BASE_NAME}.dtb ${DEPLOYDIR}/${DTB_NAME}.dtb
+			fi
+
 			cd ${DEPLOYDIR}
 			ln -sf ${DTB_NAME}.dtb ${DTB_SYMLINK_NAME}.dtb
 			cd -
-- 
1.8.2


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