Change method of configuration generation

The existing method of managing configuration files gets unweildy.
Changing individual lines in text files gets difficult without
manual organization. Switch to a method of configuration generation
that's inspired from the method used inside Red Hat. Each configuration
option gets its own file which are then combined to form the
configuration files. This makes confirming what's actually enabled much
easier.

1 files changed, 91 insertions, 0 deletions

diff --git a/build_configs.sh b/build_configs.sh
new file mode 100755
index 000000000..55fb89d01
--- /dev/null
+++ b/build_configs.sh
@@ -0,0 +1,91 @@
+#!/bin/bash
+#
+# This script merges together the hierarchy of CONFIG_* files under generic
+# and debug to form the necessary $PACKAGE_NAME<version>-<arch>-<variant>.config
+# files for building RHEL kernels, based on the contents of a control file
+
+PACKAGE_NAME=kernel # defines the package name used
+
+set errexit
+set nounset
+
+control_file="config_generation"
+
+function combine_config_layer()
+{
+	dir=$1
+	file="config-$(echo $dir | sed -e 's|/|-|g')"
+
+	if [ $(ls $dir/ | grep -c "^CONFIG_") -eq 0 ]; then
+		touch $file
+		return
+	fi
+
+	cat $dir/CONFIG_* > $file
+}
+
+function merge_configs()
+{
+	archvar=$1
+	arch=$(echo "$archvar" | cut -f1 -d"-")
+	configs=$2
+	name=$PACKAGE_NAME-$archvar.config
+	echo -n "Building $name ... "
+	touch config-merging config-merged
+	for config in $(echo $configs | sed -e 's/:/ /g')
+	do
+		perl merge.pl config-$config config-merging > config-merged
+		if [ ! $? -eq 0 ]; then
+			exit
+		fi
+		mv config-merged config-merging
+	done
+	if [ "x$arch" == "xaarch64" ]; then
+		echo "# arm64" > $name
+	elif [ "x$arch" == "xppc64" ]; then
+		echo "# powerpc" > $name
+	elif [ "x$arch" == "xppc64le" ]; then
+		echo "# powerpc" > $name
+	elif [ "x$arch" == "xppc64p7" ]; then
+		echo "# powerpc" > $name
+	elif [ "x$arch" == "xs390x" ]; then
+		echo "# s390" > $name
+	elif [ "x$arch" == "xarmv7hl" ]; then
+		echo "# arm" > $name
+	elif [ "x$arch" == "xi686" ]; then
+		echo "# i386" > $name
+	else
+		echo "# $arch" > $name
+	fi
+	sort config-merging >> $name
+	rm -f config-merged config-merging
+	echo "done"
+}
+
+glist=$(find baseconfig -type d)
+dlist=$(find debugconfig -type d)
+
+for d in $glist $dlist
+do
+	combine_config_layer $d
+done
+
+while read line
+do
+	if [ $(echo "$line" | grep -c "^#") -ne 0 ]; then
+		continue
+	elif [ $(echo "$line" | grep -c "^$") -ne 0 ]; then
+		continue
+	else
+		arch=$(echo "$line" | cut -f1 -d"=")
+		configs=$(echo "$line" | cut -f2 -d"=")
+
+		if [ -n "$SUBARCH" -a "$SUBARCH" != "$arch" ]; then
+			continue
+		fi
+
+		merge_configs $arch $configs
+	fi
+done < $control_file
+
+rm -f config-*