xref: /openbmc/linux/kernel/gen_kheaders.sh (revision 2022ca0a)
1#!/bin/bash
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/$tarfile.tmp
11
12dir_list="
13include/
14arch/$SRCARCH/include/
15"
16
17# Support incremental builds by skipping archive generation
18# if timestamps of files being archived are not changed.
19
20# This block is useful for debugging the incremental builds.
21# Uncomment it for debugging.
22# if [ ! -f /tmp/iter ]; then iter=1; echo 1 > /tmp/iter;
23# else iter=$(($(cat /tmp/iter) + 1)); echo $iter > /tmp/iter; fi
24# find $src_file_list -name "*.h" | xargs ls -l > /tmp/src-ls-$iter
25# find $obj_file_list -name "*.h" | xargs ls -l > /tmp/obj-ls-$iter
26
27# include/generated/compile.h is ignored because it is touched even when none
28# of the source files changed. This causes pointless regeneration, so let us
29# ignore them for md5 calculation.
30pushd $srctree > /dev/null
31src_files_md5="$(find $dir_list -name "*.h"			   |
32		grep -v "include/generated/compile.h"		   |
33		grep -v "include/generated/autoconf.h"		   |
34		xargs ls -l | md5sum | cut -d ' ' -f1)"
35popd > /dev/null
36obj_files_md5="$(find $dir_list -name "*.h"			   |
37		grep -v "include/generated/compile.h"		   |
38		grep -v "include/generated/autoconf.h"		   |
39		xargs ls -l | md5sum | cut -d ' ' -f1)"
40# Any changes to this script will also cause a rebuild of the archive.
41this_file_md5="$(ls -l $sfile | md5sum | cut -d ' ' -f1)"
42if [ -f $tarfile ]; then tarfile_md5="$(md5sum $tarfile | cut -d ' ' -f1)"; fi
43if [ -f kernel/kheaders.md5 ] &&
44	[ "$(cat kernel/kheaders.md5|head -1)" == "$src_files_md5" ] &&
45	[ "$(cat kernel/kheaders.md5|head -2|tail -1)" == "$obj_files_md5" ] &&
46	[ "$(cat kernel/kheaders.md5|head -3|tail -1)" == "$this_file_md5" ] &&
47	[ "$(cat kernel/kheaders.md5|tail -1)" == "$tarfile_md5" ]; then
48		exit
49fi
50
51if [ "${quiet}" != "silent_" ]; then
52       echo "  GEN     $tarfile"
53fi
54
55rm -rf $cpio_dir
56mkdir $cpio_dir
57
58pushd $srctree > /dev/null
59for f in $dir_list;
60	do find "$f" -name "*.h";
61done | cpio --quiet -pd $cpio_dir
62popd > /dev/null
63
64# The second CPIO can complain if files already exist which can
65# happen with out of tree builds. Just silence CPIO for now.
66for f in $dir_list;
67	do find "$f" -name "*.h";
68done | cpio --quiet -pd $cpio_dir >/dev/null 2>&1
69
70# Remove comments except SDPX lines
71find $cpio_dir -type f -print0 |
72	xargs -0 -P8 -n1 perl -pi -e 'BEGIN {undef $/;}; s/\/\*((?!SPDX).)*?\*\///smg;'
73
74# Create archive and try to normalize metadata for reproducibility
75tar "${KBUILD_BUILD_TIMESTAMP:+--mtime=$KBUILD_BUILD_TIMESTAMP}" \
76    --owner=0 --group=0 --sort=name --numeric-owner \
77    -Jcf $tarfile -C $cpio_dir/ . > /dev/null
78
79echo "$src_files_md5" >  kernel/kheaders.md5
80echo "$obj_files_md5" >> kernel/kheaders.md5
81echo "$this_file_md5" >> kernel/kheaders.md5
82echo "$(md5sum $tarfile | cut -d ' ' -f1)" >> kernel/kheaders.md5
83
84rm -rf $cpio_dir
85