1#!/bin/sh
2# SPDX-License-Identifier: GPL-2.0
3
4# This script generates an archive consisting of kernel headers
5# for CONFIG_IKHEADERS.
6set -e
7sfile="$(readlink -f "$0")"
8outdir="$(pwd)"
9tarfile=$1
10cpio_dir=$outdir/${tarfile%/*}/.tmp_cpio_dir
11
12dir_list="
13include/
14arch/$SRCARCH/include/
15"
16
17type cpio > /dev/null
18
19# Support incremental builds by skipping archive generation
20# if timestamps of files being archived are not changed.
21
22# This block is useful for debugging the incremental builds.
23# Uncomment it for debugging.
24# if [ ! -f /tmp/iter ]; then iter=1; echo 1 > /tmp/iter;
25# else iter=$(($(cat /tmp/iter) + 1)); echo $iter > /tmp/iter; fi
26# find $all_dirs -name "*.h" | xargs ls -l > /tmp/ls-$iter
27
28all_dirs=
29if [ "$building_out_of_srctree" ]; then
30	for d in $dir_list; do
31		all_dirs="$all_dirs $srctree/$d"
32	done
33fi
34all_dirs="$all_dirs $dir_list"
35
36# include/generated/utsversion.h is ignored because it is generated after this
37# script is executed. (utsversion.h is unneeded for kheaders)
38#
39# When Kconfig regenerates include/generated/autoconf.h, its timestamp is
40# updated, but the contents might be still the same. When any CONFIG option is
41# changed, Kconfig touches the corresponding timestamp file include/config/*.
42# Hence, the md5sum detects the configuration change anyway. We do not need to
43# check include/generated/autoconf.h explicitly.
44#
45# Ignore them for md5 calculation to avoid pointless regeneration.
46headers_md5="$(find $all_dirs -name "*.h"			|
47		grep -v "include/generated/utsversion.h"	|
48		grep -v "include/generated/autoconf.h"	|
49		xargs ls -l | md5sum | cut -d ' ' -f1)"
50
51# Any changes to this script will also cause a rebuild of the archive.
52this_file_md5="$(ls -l $sfile | md5sum | cut -d ' ' -f1)"
53if [ -f $tarfile ]; then tarfile_md5="$(md5sum $tarfile | cut -d ' ' -f1)"; fi
54if [ -f kernel/kheaders.md5 ] &&
55	[ "$(head -n 1 kernel/kheaders.md5)" = "$headers_md5" ] &&
56	[ "$(head -n 2 kernel/kheaders.md5 | tail -n 1)" = "$this_file_md5" ] &&
57	[ "$(tail -n 1 kernel/kheaders.md5)" = "$tarfile_md5" ]; then
58		exit
59fi
60
61echo "  GEN     $tarfile"
62
63rm -rf $cpio_dir
64mkdir $cpio_dir
65
66if [ "$building_out_of_srctree" ]; then
67	(
68		cd $srctree
69		for f in $dir_list
70			do find "$f" -name "*.h";
71		done | cpio --quiet -pd $cpio_dir
72	)
73fi
74
75# The second CPIO can complain if files already exist which can happen with out
76# of tree builds having stale headers in srctree. Just silence CPIO for now.
77for f in $dir_list;
78	do find "$f" -name "*.h";
79done | cpio --quiet -pdu $cpio_dir >/dev/null 2>&1
80
81# Remove comments except SDPX lines
82find $cpio_dir -type f -print0 |
83	xargs -0 -P8 -n1 perl -pi -e 'BEGIN {undef $/;}; s/\/\*((?!SPDX).)*?\*\///smg;'
84
85# Create archive and try to normalize metadata for reproducibility.
86tar "${KBUILD_BUILD_TIMESTAMP:+--mtime=$KBUILD_BUILD_TIMESTAMP}" \
87    --owner=0 --group=0 --sort=name --numeric-owner \
88    -I $XZ -cf $tarfile -C $cpio_dir/ . > /dev/null
89
90echo $headers_md5 > kernel/kheaders.md5
91echo "$this_file_md5" >> kernel/kheaders.md5
92echo "$(md5sum $tarfile | cut -d ' ' -f1)" >> kernel/kheaders.md5
93
94rm -rf $cpio_dir
95