scripts/dtc: Add a script to update to mainline dtc source

A very simple script that automates pulling in a newer version of DTC.
Not particularly robust, but a whole lot better than doing it by hand
every time.

Signed-off-by: Grant Likely <grant.likely@linaro.org>

scripts/dtc/update-dtc-source.sh

+#!/bin/sh
+# Simple script to update the version of DTC carried by the Linux kernel
+#
+# This script assumes that the dtc and the linux git trees are in the
+# same directory. After building dtc in the dtc directory, it copies the
+# source files and generated source files into the scripts/dtc directory
+# in the kernel and creates a git commit updating them to the new
+# version.
+#
+# Usage: from the top level Linux source tree, run:
+# $ ./scripts/dtc/update-dtc-source.sh
+#
+# The script will change into the dtc tree, build and test dtc, copy the
+# relevant files into the kernel tree and create a git commit. The commit
+# message will need to be modified to reflect the version of DTC being
+# imported
+#
+# TODO:
+# This script is pretty basic, but it is seldom used so a few manual tasks
+# aren't a big deal. If anyone is interested in making it more robust, the
+# the following would be nice:
+# * Actually fail to complete if any testcase fails.
+#   - The dtc "make check" target needs to return a failure
+# * Extract the version number from the dtc repo for the commit message
+# * Build dtc in the kernel tree
+# * run 'make check" on dtc built from the kernel tree
+
+set -ev
+
+DTC_UPSTREAM_PATH=`pwd`/../dtc
+DTC_LINUX_PATH=`pwd`/scripts/dtc
+
+DTC_SOURCE="checks.c data.c dtc.c dtc.h flattree.c fstree.c livetree.c srcpos.c \
+		srcpos.h treesource.c util.c util.h version_gen.h Makefile.dtc \
+		dtc-lexer.l dtc-parser.y"
+DTC_GENERATED="dtc-lexer.lex.c dtc-parser.tab.c dtc-parser.tab.h"
+
+# Build DTC
+cd $DTC_UPSTREAM_PATH
+make clean
+make check
+
+# Copy the files into the Linux tree
+cd $DTC_LINUX_PATH
+for f in $DTC_SOURCE; do
+	cp ${DTC_UPSTREAM_PATH}/${f} ${f}
+	git add ${f}
+done
+for f in $DTC_GENERATED; do
+	cp ${DTC_UPSTREAM_PATH}/$f ${f}_shipped
+	git add ${f}_shipped
+done
+
+git commit -e -v -m "scripts/dtc: Update to upstream version [CHANGEME]"

scripts/dtc/version_gen.h

-#define DTC_VERSION "DTC 1.4.0"
+#define DTC_VERSION "DTC 1.4.0-dirty"