1 files changed, 81 insertions, 0 deletions
diff --git a/kernel/gen_kheaders.sh b/kernel/gen_kheaders.sh
new file mode 100755
index 000000000000..9ff449888d9c
--- /dev/null
+++ b/kernel/gen_kheaders.sh
@@ -0,0 +1,81 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+# This script generates an archive consisting of kernel headers
+# for CONFIG_IKHEADERS.
+set -e
+sfile="$(readlink -f "$0")"
+outdir="$(pwd)"
+tarfile=$1
+cpio_dir=$outdir/$tarfile.tmp
+
+dir_list="
+include/
+arch/$SRCARCH/include/
+"
+
+# Support incremental builds by skipping archive generation
+# if timestamps of files being archived are not changed.
+
+# This block is useful for debugging the incremental builds.
+# Uncomment it for debugging.
+# if [ ! -f /tmp/iter ]; then iter=1; echo 1 > /tmp/iter;
+# else iter=$(($(cat /tmp/iter) + 1)); echo $iter > /tmp/iter; fi
+# find $src_file_list -name "*.h" | xargs ls -l > /tmp/src-ls-$iter
+# find $obj_file_list -name "*.h" | xargs ls -l > /tmp/obj-ls-$iter
+
+# include/generated/compile.h is ignored because it is touched even when none
+# of the source files changed. This causes pointless regeneration, so let us
+# ignore them for md5 calculation.
+pushd $srctree > /dev/null
+src_files_md5="$(find $dir_list -name "*.h"			   |
+		grep -v "include/generated/compile.h"		   |
+		grep -v "include/generated/autoconf.h"		   |
+		xargs ls -l | md5sum | cut -d ' ' -f1)"
+popd > /dev/null
+obj_files_md5="$(find $dir_list -name "*.h"			   |
+		grep -v "include/generated/compile.h"		   |
+		grep -v "include/generated/autoconf.h"		   |
+		xargs ls -l | md5sum | cut -d ' ' -f1)"
+# Any changes to this script will also cause a rebuild of the archive.
+this_file_md5="$(ls -l $sfile | md5sum | cut -d ' ' -f1)"
+if [ -f $tarfile ]; then tarfile_md5="$(md5sum $tarfile | cut -d ' ' -f1)"; fi
+if [ -f kernel/kheaders.md5 ] &&
+	[ "$(cat kernel/kheaders.md5|head -1)" == "$src_files_md5" ] &&
+	[ "$(cat kernel/kheaders.md5|head -2|tail -1)" == "$obj_files_md5" ] &&
+	[ "$(cat kernel/kheaders.md5|head -3|tail -1)" == "$this_file_md5" ] &&
+	[ "$(cat kernel/kheaders.md5|tail -1)" == "$tarfile_md5" ]; then
+		exit
+fi
+
+if [ "${quiet}" != "silent_" ]; then
+       echo "  GEN     $tarfile"
+fi
+
+rm -rf $cpio_dir
+mkdir $cpio_dir
+
+pushd $srctree > /dev/null
+for f in $dir_list;
+	do find "$f" -name "*.h";
+done | cpio --quiet -pd $cpio_dir
+popd > /dev/null
+
+# The second CPIO can complain if files already exist which can
+# happen with out of tree builds. Just silence CPIO for now.
+for f in $dir_list;
+	do find "$f" -name "*.h";
+done | cpio --quiet -pd $cpio_dir >/dev/null 2>&1
+
+# Remove comments except SDPX lines
+find $cpio_dir -type f -print0 |
+	xargs -0 -P8 -n1 perl -pi -e 'BEGIN {undef $/;}; s/\/\*((?!SPDX).)*?\*\///smg;'
+
+tar -Jcf $tarfile -C $cpio_dir/ . > /dev/null
+
+echo "$src_files_md5" >  kernel/kheaders.md5
+echo "$obj_files_md5" >> kernel/kheaders.md5
+echo "$this_file_md5" >> kernel/kheaders.md5
+echo "$(md5sum $tarfile | cut -d ' ' -f1)" >> kernel/kheaders.md5
+
+rm -rf $cpio_dir